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PotassiumCarbonateHandbookK2C03

Handbook K2CO3 1

In 1986, two strong manufacturersin the chemical industry combinedin a joint venture to form theArmand Products Company… theleading producer and marketer ofpotassium carbonate and potassiumbicarbonate in the world.

From the Occidental ChemicalCorporation came the manufactur-ing capability for the production ofthe highest quality chemicals, withmarketing and technical serviceexpertise for product support.

From the Church & Dwight Co.,Inc. came the sales and R&D func-tions to maintain the high level ofcustomer service that our customersrequire.

As a market leader, the ArmandProducts Company provides thefacilities and manpower needed tomeet the requirements of our cus-tomers. Our two plants and fourreactors run in the continuousmode, assuring an uninterruptedsupply of potassium carbonate. Anadditional reactor is dedicated tothe production of potassium bicar-bonate. This manufacturing facilityis located in Muscle Shoals, AL.

Armand Products Company hasfull integration with a dedicatedproduction source of potassiumhydroxide, the key raw material formaking potassium carbonate.Potassium bicarbonate is producedby further carbonation of potassiumcarbonate. The Tennessee ValleyAuthority (TVA), one of the largest

electricity generators in the UnitedStates, supplies power to the MuscleShoals facility at a reasonably stablecost.

Current capacity is 108,000 shorttons/year for potassium carbonateand 5,000 short tons/year for potas-sium bicarbonate. This placesArmand Products as the largestdomestic and international sourceof potassium carbonate, as well asthe only producer of potassiumbicarbonate in the U.S.

In order to meet the require-ments of the many diverse applica-tions, each product is available inseveral different grades. Variouspackage forms are also available,ranging from bags to railcars.Smaller packages are availabledirectly from the plant or at manywarehouse and distribution pointsacross the country.

Armand Products’ commitmentto quality and consistent perfor-mance is shown in its continuedgood standing as an ISO 9002 certi-fied and OSHA Star facility.

Potassium Carbonate Handbook

Background

Armand Products Company

2 K2CO3 Handbook

PageBackground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1l. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3ll. Markets and Uses of Potassium Carbonate . . . . . . . . . . . . . . . . . . . 4lll. Manufacturing Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6lV. Grades of Potassium Carbonate . . . . . . . . . . . . . . . . . . . . . . . . . . . 8V. Materials of Construction

A. Anhydrous Potassium Carbonate . . . . . . . . . . . . . . . . . . . . . 9B. Liquid Potassium Carbonate . . . . . . . . . . . . . . . . . . . . . . . . 10

Vl. Shipping Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Vll. Precautions in Handling Potassium Carbonate . . . . . . . . . . . . . . 13Vlll.Handling of Anhydrous Potassium Carbonate

A. Bag, Drum and Bulk Handling . . . . . . . . . . . . . . . . . . . . . . 15B. Mechanical Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16C. Pneumatic Conveying . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18D. Bulk Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

lX. Handling of Liquid Potassium CarbonateA. Shipping Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22B. Unloading Tank Cars

Placement, Precautions and Cold Weather . . . . . . . . . . 22Unloading Through Bottom Valve . . . . . . . . . . . . . . . . . 24Top Unloading with Air Pressure . . . . . . . . . . . . . . . . . 26Preparing Car for Return . . . . . . . . . . . . . . . . . . . . . . . . 26

C. Unloading from Tank TrucksMethods and Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . 27Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

D. Dilution of Potassium Carbonate Solution . . . . . . . . . . . . . 30E. Dissolving Anhydrous Material . . . . . . . . . . . . . . . . . . . . . 31F. Solution Storage with Dry Bulk Delivery . . . . . . . . . . . . . . . 31

X. Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33XI. Methods of Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

All recommendations and suggestions appearing in this booklet concerningthe use of our products are based upon tests and data believed to be reliable.However, as the actual use of our products by others is beyond our control,no guarantee, expressed or implied, is made as to the effects of such use, orthe results to be obtained, whether or not any use of our products is made inaccordance with recommendations or suggestions contained in this hand-book or otherwise. Furthermore, information on the use of our products isnot to be construed as recommendation to use such products in the infringe-ment of any patent. These suggestions should not be confused either withstate, municipal, or insurance requirements, or with national safety codes.

Table of Contents


Handbook K2CO3 3

Potassium carbonate is one of themost important inorganic com-pounds used in industry eventhough it is as old as recorded histo-ry. Potassium carbonate was leachedfrom ashes in Pompeii and mixedwith slaked lime for soapmaking.The increase in the use of this alkaliparalleled the growth of westerncivilization. So much wood wasconsumed in the production ofpotassium carbonate that the forestsof Europe were threatened. At thetime of the French Revolution,LeBlanc’s invention allowed sodiumcarbonate to be substituted on ageneral basis.

The potassium carbonate thatwas recovered from ashes becamethe prime potassium compoundbefore 1870. During these earlytimes, potassium hydroxide (KOH,caustic potash) was made frompotassium carbonate by reactionwith calcium hydroxide. However,the recovery of potassium chloridein 1860 from “rubbish salt” in theStrassfurt, Germany salt mineschanged this methodology. Todaypotassium hydroxide is producedthrough the electrolysis of potassi-um chloride brine. Subsequently,the KOH is carbonated with carbondioxide to form potassium carbon-ate.

K2CO3 is the chemists’ short-wayof representing potassium carbonateor PotCarb as it is commonly calledtoday. Although it is known by sev-eral other names, the chemical for-mula is the most definitive way toconfirm this compound. Some ofalternate nomenclature that may beused includes: PC, carbonate ofpotash, pearl ash and carbonic acid,dipotassium salt.

In everyday chemical technolo-gy, the choice between potassiumand sodium carbonate is decided on

the economics or some desiredphysical / chemical property. Theprincipal reasons to utilize potassi-um carbonate are:

t source of potassium iont buffered alkalinityt greater solubility for potassi-

um vs. sodium carbonatet potassium ion is more reactive

than sodium iont replacement for sodium sensi-

tive applicationst enhances fluxing properties of

glasst depresses freeze point of

water, allowing cold tempera-ture applications

In the past, the use of a hydratedpotassium carbonate (16% water)was preferred to the more deliques-cent anhydrous form. Technologyhas since spurred improvements inseveral areas, thereby fostering theacceptance of the anhydrous granu-lar form of potassium carbonate.These improvements include thedevelopment of other PotCarbprocesses and enhancements in theareas of packaging, dry bulk han-dling and storage facilities.

One commonly used methodproduces a calcined PotCarb thatrequires several additional process-ing steps after its liquid phase reac-tion between caustic potash andcarbon dioxide. The final step beinga heat treatment where the temper-ature is raised sufficiently to driveoff the water of crystallization. Twodifferent ion exchange methodseach employ a multi-step processthat requires several raw materialsand also yields several by-products.A more practical approach for sup-porting the use of anhydrous potas-sium carbonate is the developmentof the fluidized bed reactor. This

l. Introduction


4 K2CO3 Handbook

process allows the direct, one-stepmanufacturing of an anhydrousmaterial that needs no furtherrefinement. Typically there is muchgreater customer demand for drymaterial, however, since PotCarb itis readily soluble, aqueous solutionsdo not present a challenge. ArmandProducts is well positioned to meetthe demands of today’s customerswith its four state-of-the-art flu-idized bed reactors and its liquidPotCarb capabilities.

The potassium carbonate market isdivided between the glass industryand other numerous applications.Product is shipped throughout theUnited States and into internationalregions.

Video glass accounts for 44% ofpotassium carbonate usage, whilespecialty glass and ceramics use10%. The main reason that relative-ly expensive potassium carbonate isused in place of soda ash in glassapplications is that it is more com-patible with the required lead, bari-um and strontium oxides. Thesespecialty glasses possess theimproved properties of greater elec-trical resistivity, higher index ofrefraction, greater brilliance or lus-ter, lower softening point and awide temperature working range. Inaddition, potassium carbonateallows improved behavior of manycolorants in glass.

Potassium carbonate has a widevariety of uses outside of the glassindustry. Major applications thataccount for 46% of the PotCarbproduced include but are not limit-ed to: potassium silicate, pharma-ceuticals, food, detergents andcleaners, photographic chemicals,agricultural, gas purification, rubberadditives, polymer catalysts, potassi-um bicarbonate, cement and tex-tiles.

A more complete summary ofthe various uses of potassium car-bonate is given in the followingtable:

Markets and Uses ofPotassium Carbonatell.

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Handbook K2CO3 5

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S


6 K2CO3 Handbook

Armand Products’ PotassiumCarbonate is manufactured in a flu-idized bed reactor at its productionfacility in Muscle Shoals, AL. Thisresults in a product that is anhy-drous, making it unnecessary toperform any further processing toeliminate hydrated water (calcin-ing). Armand Products’ PotassiumCarbonate (PotCarb) is a white,dense, free-flowing granular materi-al which is easy to handle andstore.

The process starts with potassiumchloride, obtained from theCanadian province ofSaskatchewan. Through an elec-trolytic conversion of the KCl salt,potassium hydroxide (causticpotash, KOH), chlorine (Cl2) andhydrogen (H2) are produced. Thehydrogen is a fuel source while thechlorine has numerous importantand varied applications. Liquidcaustic potash and carbon dioxideare the only raw materials requiredfor producing PotCarb.

The dry potassium carbonate caneasily be dissolved in water to forma liquid solution. Typically a 47%solution is recommended as thiscapitalizes on the highest concen-tration with the lowest freezingpoint (3°F). This minimizes han-dling problems during colderweather.

The chemical equation for thisprocess is simply:

2 KCl + 2 H2O →→ 2 KOH + H2 + Cl2

2 KOH + CO2 →→ K2CO3 + H2O

The favorable logistics of this pro-duction facility cover a wide spec-trum of advantages:

t Largest domestic facility, uti-lizing four reactors in twoplants;

t Dry and liquid forms availablein various packaging units;

t Vertically integrated with on-site production of liquid caus-tic potash (KOH), the key rawmaterial;

t Geographical location in prox-imity to Gulf and Easterncoast ports, allowing for time-ly export shipments;

t Electric power for raw materialconversion and plant opera-tions is readily available froma nearby TVA plant.

As a side note, potassium carbon-ate cannot be made by the Solvayprocess used for sodium carbonate(Na2CO3).

The flow diagram for the manu-facturing process is shown on thenext page:

lll. Manufacturing Process


Handbook K2CO3 7

Flow Chart of Manufacturing Process


8 K2CO3 Handbook

Armand Products produces potassi-um carbonate in granular and liq-uid form to satisfy the requirementsof its customers. Each material con-forms to the high standards ofchemical purity and physical prop-erties essential for our extensive andvaried customer base. ArmandProducts’ anhydrous potassium car-bonate is white, dustless, dense,free-flowing granular product.Several grades of dry PotCarb thatdiffer in their typical granulationranges are available. In addition, awater solution in the form of a 47%solution is typically provided.

Requests can be made through theArmand Products’ Technical Servicestaff for the following literature:

Sales Specificationproduct grade sheets listing para-meters and their limits

Technical Informationdata sheets covering chemicaland physical properties

TThhee cchheemmiiccaall ppaarraammeetteerrss iinncclluudd--eedd iinn tthhee ssttaannddaarrdd ssaalleess ssppeecciiffii--ccaattiioonnss ffoorr AAnnhhyyddrroouuss PPoottaassssiiuummCCaarrbboonnaattee aarree::

K2CO3 KOHKCl H2ONa K2SO4As FeHg NiHeavy Metals (as Pb)

PPhhyyssiiccaall PPrrooppeerrttiieess::(not specification items)

Particle SizeTypically material is between 18and 80 mesh for granular andthrough 325 mesh for groundmaterial.

Bulk Density75 - 84 lb/ft3 (granular, varies bygrade); 37 lb/ft3 (extra fine)

Melting Point891°C

Solubility in Water112 grams in 100 grams water at20°C

AppearanceWhite, granular, free-flowing

Grades of Potassium CarbonateIV.


Handbook K2CO3 9

Iron, steel, stainless steel, rubberlined steel or phenolic lined steel isrecommended. If heated to 120°F, the potential foriron contamination exists.Polyethylene drums can be used forliquid storage and handling atambient temperatures.Aluminum, zinc, brass, bronze, andcopper are NOT recommended dueto the potential for a reaction.

Experience with the various poly-meric materials of construction islimited. Additional data based oncustomers’ own experiences shouldbe considered. The weight of thePotCarb must be factored into thestructural constraints of polymericmaterials. The following informa-tion is therefore offered as a startingpoint:

t Polyethylene and propylenecan be used if not exposed totemperatures beyond that rec-ommended for each polymer.Possible deformation of poly-mer surface may occur.Caution is advised duringprocesses that generate heat,e.g., solubilization of drypotassium carbonate.

t Polyester is NOT recommend-ed.

t Polyvinyl chloride (PVC) hasbeen reported to be acceptablebut caution is advised for pos-sible embrittlement. Regularinspection and proper usageprocedures may allow goodservice from this material.

A. ANHYDROUS POTASSI-UM CARBONATE

PPiippiinnggPneumatic systems require 4 inchminimum piping with four footradius curves. Gravity feed systemsshould be 6 inch diameter or larger.

VVaallvveessButterfly or slide gate valves are typ-ical, however, the butterfly type arepreferred for humid conditions.

BBlloowweerrssPneumatic unloading requires blow-ers that are generally 500 - 600 CFMand operate at 10 lbs. of pressure. Inhumid conditions, the transfer airshould be pulled through a desic-cant bed to provide dry transfer air.The dryer should be checked peri-odically and replaced as needed.

SSttoorraaggee SSiilloossCapacity should hold at least 1.5times the size of a normal ship-ment. A dry air purge in wet humidconditions will ease the handling ofproduct. A 45° slope to the silo bot-tom is recommended. A bag houseis recommended for filtering outdust from the transfer air during thepneumatic unloading of product.Storage silos should be steel, linedsteel or stainless. A more thoroughdiscussion of the recommendationsfor bulk storage can be found insection VIII.D.

Materials of ConstructionV.


10 K2CO3 Handbook

B. LIQUID POTASSIUMCARBONATE

PPiippeelliinneessA two inch minimum pipeline

with a 3 inch minimum on the suc-tion side of the pump is recom-mended. Long sections of outdoorpiping should be heat traced andinsulated. Experience has demon-strated that flanged connectionswith alkali-resistant gaskets willminimized the potential for leaks.All piping should be installed witha slight slope to ensure completedrainage. Loops and pockets are tobe avoided.

PPuummppssCentrifugal and rotary types with

all iron construction may be used. Adeep packing gland is desired toprevent leakage at the pump shaft.Graphite/asbestos packing materialis recommended for potassium car-bonate solution service.

VVaallvveessGlobe, angle, gate, and plug

valves may be employed to controlflow rates and for line shutoffs.Valve construction of cast iron,steel, and stainless steel (Type 316and 304) is recommended.

SSttoorraaggee TTaannkkssFabrication specifications require

at least 3/8 inch wall thickness forunits larger than 10,000 galloncapacity and a 1/4 inch wall forsmaller capacities. The withdrawalpipe connection should be a fewinches above the bottom of thetank. To facilitate tank cleaning, adrain connection should beinstalled at the lowest point in thetank.Rubber or phenolic based epoxiescan be used for lining steel storagetanks where prevention of iron con-

tamination is critical. However, rub-ber does not withstand high tem-peratures.

Storage tanks in cold climatesshould be insulated with 2 inchesof polyurethane insulation to main-tain pumpable conditions andshould have an internal or externalheat source to make temperatureadjustments.

Some plastics are also acceptablefor small tank construction (gener-ally less than 10,000 gallons). Poly-propylene, polyethylene, PVC,CPVC and FRP can be used. Poly-propylene is the most commonlyused plastic for storage tanks.

Further discussion with ourTechnical Service staff on the appro-priate materials of construction andequipment for handling potassiumcarbonate is encouraged.


Handbook K2CO3 11

SHIPMENT OF POTASSIUM CARBONATEPotassium carbonate can be shippedin various types and sizes of packag-ing. Armand Products’ TechnicalService is available to discuss allpossible options and can assist thecustomer in determining the mostadvantageous method to receivethis product. Examples of the typi-cal containers available are:

t 50 and 100 pound multiwallpaper bags

t 400 pound fiber drumst 2000 pound bulk bagst hopper and pneumatic truckst hopper and pneumatic railcars

Factors that determine the typeof package include the quantity tobe used, as well as the customer’slocation, unloading system andstorage facilities. Since bulk ship-ments can be made in trucks andrailcars, it is better to determine themost advantageous delivery methodthrough an economic survey foreach individual case.

BAG AND DRUMSHIPMENTThe multiwall kraft bags used byArmand Products are constructedwith a polyethylene moisture barri-er to better protect product qualityduring storage. Fiber drums can befurnished with a polyethylene linerupon request. Bag and drum specifi-cations are available from ArmandProducts’ Technical Service depart-ment.

Although receipt of the materialin bags or drums may not offer theeconomic advantage of bulk, thereare other factors which may promptthe choice of this type of packaging.

The use of bags or drums simplifiesdistribution when potassium car-bonate is used in small quantities atseveral locations. Individual pack-ages also eliminate the necessity ofbatch weighing potassium carbon-ate for various requirements. Noexpensive or elaborate equipment isneeded to unload or handle baggedor drummed potassium carbonateshipments. The use of drums andbags makes potassium carbonateavailable to even the smallest indus-trial consumer.

Trucks and rail cars for this serviceare checked internally for the pres-ence of moisture, previously loadedmaterial, and general surface deterio-ration.

BULK BAG SHIPMENTThis larger form of individual packag-ing offers a unique advantage forthose that meet the space require-ments but do not have the capabilityto unload and store truck or rail carshipments. Typically each bag isfilled with 2,000 pounds of potassi-um carbonate. For truckload quanti-ties however, different weights can befilled to meet the customer’s batchrequirements. These bulk bags aremade of a woven polypropylene fab-ric with a polyethylene liner as amoisture barrier. This is considered aone trip package to ensure the safehandling integrity of the bag and tomaintain product quality. Bulk bagsfilled with a metric ton (2205pounds) of product have become thepreferred package for export ship-ments.

Shipping PackagesVl.


12 K2CO3 Handbook

BULK SHIPMENTBulk quantities of potassium car-bonate may be shipped in coveredhopper cars, pneumatic unloadingcars, hopper trucks, or self-unload-ing pneumatic trucks. The choicedepends on the quantity used, aswell as the customer’s location,unloading system and storage facili-ties. Details of the various optionscan be discussed with TechnicalService personnel.

Covered hopper cars are speciallydesigned to handle products such aspotassium carbonate and providethe most satisfactory method ofbulk shipment. These self-discharg-ing cars are equipped with weather-proof hatches and three or four bot-tom outlet gates which provide pro-tection from outside contamina-tion. The bottom outlets are nor-mally of the Enterprise or slidinggate type, measuring 13 x 24 or 13x 42 inches, with a clearance of 6 to9 inches over the rail that will varywith car design. Hopper cars, nor-mally available in 70 and 95 toncapacities, can be readily adapted tomechanical unloading systems.

Pressure differential (PD) railroadcars are available to customers whohave an appropriate pneumatic sys-

tem in place to handle unloading.Those who have a potential interestin receiving PD bulk railcar ship-ments are invited to discuss thisoption with Armand Products’Technical Service.

Motor truck shipments havebeen found practical for bulk potas-sium carbonate, particularly wherethe distance is not excessive andthe customer’s consumption orlocation will not allow rail deliver-ies. The amount of material thatcan be carried is usually restrictedby the road limitations of the statesthrough which the haul is made,with a typical maximum weight of45,000 pounds. Truck designs canvary but hopper bottom dischargeor self-unloading pneumatic trucksare typical.

The development of self-unload-ing trailers now enables consumers ofas little as 100 tons per year toreceive potassium carbonate in bulkwithout the necessity of providingcostly unloading equipment. Thetank-type trailer available for this ser-vice carries a self-contained unload-ing system which blows the materialinto the customer’s bin. (Figure 1,Page 15) It is operated by the dri-ver, who makes the complete deliv-ery. The receiving equipmentrequired by the customer is relativelysimple in structure and is easy toinstall. It consists of a vertical trans-mission line made with a four inchstandard pipe and four foot radiusbends with a tank vent through a fil-ter system to remove dust.

Since shipments of potassiumcarbonate will be 20-23 tons by thisservice, a minimum storage capacityof 30-35 tons will usually be ade-quate for most plants. Conven-tional silos, tanks or existing storagefacilities can easily be adapted forthis system. The facility must bemoisture-tight and requires a stor-age tank vent dryer.Anhydrous and liquid forms of


Handbook K2CO3 13

potassium carbonate are recognizedas OSHA hazardous substances. Thischemical material is alkaline andmay cause severe irritation by allroutes of exposure.

Before starting to work withPotCarb, the user should be awareof its properties, understand whatsafety precautions to follow, andknow how to act in case of contact.Some general guidelines are listedbelow.

t Read and understand the cur-rent MSDS for complete andupdated information.

t Locate and periodically checkeyewash fountains and safetyshowers in all areas wherepotassium carbonate is han-dled.

t Seek medical attention imme-diately after first-aid measuresare applied.

ROUTES OF EXPOSUREPotCarb can be irritating to theskin and to a severe degree if incontact with the eyes. Tissuedestruction may follow if not prop-erly treated. Inhalation of air-borne concentrations of dust, mistor spray may cause damage to theupper respiratory tract and even tothe lung tissue which could resultin chemical pneumonia, dependingupon the severity of exposure.Ingestion may cause irritation tothe mucous membranes of themouth, throat, esophagus andstomach, with severity dependanton the quantity involved.

There are no known chroniceffects associated with potassium car-bonate. However, acute conse-quences may occur, depending on the

length of exposure and whether prop-er treatment is rendered in a timelyfashion.

OVERVIEW OF FIRST AIDMEASURESImmediately administer the first aidmeasure described below, then seekprofessional medical attention.

Eyes - Flush eyes with largeamounts of water for at least 15minutes, holding lids apart toensure flushing of the entire sur-face. Washing eyes within severalseconds is essential to achievemaximum effectiveness.

Skin - Wash contaminated areaswith plenty of water. Removecontaminated clothing andfootwear. Do not remove gogglesif the eyes are not affected. Washclothing before reuse. Discardfootwear which is contaminatedon the inner surface.

Inhalation - Remove to fresh air. Ifbreathing is difficult have atrained person administer oxy-gen. If respiration stops givemouth-to-mouth resuscitation.

Digestion - Never give anythingby mouth to an unconscious per-son. If swallowed, do not inducevomiting. Give large quantitiesof water or several glasses of milkif available. If vomiting occursspontaneously, keep airway clear.

Vll. Precautions in Handling Potassium Carbonate


14 K2CO3 Handbook

PROTECTIVE EQUIPMENTOSHA requires employers to supplyprotective equipment for employ-ees. When handling potassium car-bonate, the following protectiveequipment is recommended:

t Wear suitable goggles for eyeprotection during the han-dling of potassium carbonatein any form. The gogglesshould be close-fitting to pre-vent the entry of liquids, yetprovide adequate ventilationto prevent fogging.

t Wear gloves coated with rub-ber, synthetic elastomers, PVCor other plastics to protect thehands while handling potassi-um carbonate. Gloves shouldbe long enough to cover wellabove the wrist.

t Potassium carbonate causesleather to disintegrate. For thisreason, wear rubber boots.Wear the bottoms of trouserlegs outside the boots. DoNOT tuck in.

t Wear cotton clothing for someprotection of the body. Wearrubber aprons or a rain suitfor additional protection.

t Wear shirts or jackets withlong sleeves and with the col-lar tightly fastened.

t Wear hard hats to aid in theprotection of the head, faceand neck.

t Wear NIOSH-approved respira-tors for protection from dustsand mists.

Additionally, care should be takento avoid the simultaneous presenceof potassium carbonate and limedust. This chemical combinationwhen in contact with moisture inthe form of water or perspirationwill cause the formation of a veryirritating and corrosive material,namely caustic potash (KOH).Workmen must carefully wash andremove dust from one of thesechemicals before working in an areawhere the other chemical is beinghandled.


Handbook K2CO3 15

A. BAG AND DRUM HANDLING

An efficient system for unloadingbagged or drummed potassium car-bonate depends on the volume tobe handled and the distance it mustbe carried. Lightweight two-wheelhand trucks, with a wide lip onwhich bags are laid horizontally, arecommonly used where a small vol-ume is involved. Larger tonnagemay justify roller conveyors, eitherfreeturning or powered, or portablebelt conveyors. Power lift trucks andpallets may be used to store bags ordrums and distribute them to pointsof usage.

Bags should be piled flat to avoidpackage distortion and load insecuri-ty. Since potassium carbonate ishygroscopic, the best possible stor-age conditions should be provided.Damp floors, leaky roofs, and moiststorage conditions in general mustbe avoided. Moisture absorption willcause lumping of potassium carbon-ate and consequently a reduction in

the alkalinity. To minimize this con-dition, the quantity of materialstored should be limited and the old-est material should be used first. Fordrum users, a good in-plant practiceis to keep the cover secured exceptwhen withdrawing material. Thisminimizes moisture pick-up by thehygroscopic potassium carbonate.

BULK MATERIAL HANDLINGGranular anhydrous potassium car-bonate can readily be transferred ina conventional conveying system ora pneumatic conveying system. In aconventional system, atmosphericconditions have only a negligibleeffect on moisture pickup duringproduct handling. However, theanhydrous material must be shield-ed from rain and snow. It is recom-mended that the product be trans-ferred in one continuous operationand used before caking occurs.

In pneumatic conveying (seeFigure 1), potassium carbonate

Vlll.

Figure 1: Air Unloadingof Bulk Product

Handling of Anhydrous Potassium Carbonate


16 K2CO3 Handbook

may be transferred from truck or railcar with ambient air in dry climates(low dew points). In humid (highdew point) areas like the MississippiValley and coastal regions, dry airfor pneumatic transfer is suggested.For in-plant pneumatic transfer ofanhydrous potassium carbonate, it isalways advisable to use clean, dryair.

In preparing for receipt of anhy-drous potassium carbonate by bulkhopper car, provisions should alsobe made to receive emergency ship-ments by bulk truck. In addition, itis strongly recommended that aroof be provided over the bulktransfer area to provide protectionfrom the weather.

Armand Products’ TechnicalService is available to assist the cus-tomer in selecting the most advan-tageous method to receive potassi-um carbonate and to supply infor-mation on equipment in the mater-ial handling field.

B. MECHANICAL SYSTEMSThis type of transfer equipmentconsists of a belt or screw conveyorin combination with a bucket eleva-tor or a drag flight chain conveyor.A schematic diagram of thisequipment is given inFigure 2. A permanentundertrack unloading sys-tem is recommendedwhen bulk rail receipts areat least 800-1,000 tons peryear. A portableabove track con-veying unit is rec-ommended wherebulk materialreceipt is only400-500 tons peryear.

The screw

conveyor is versatile, relativelyinexpensive, simple to maintainand readily made dust-tight. It canconvey horizontally, vertically, oron an incline and can be fitted withmultiple inlet and discharge open-ings. Screw conveyors are not usual-ly used for long-distance movementand are limited in length to 50-100feet. The grinding action of a screwconveyor on friable materials

Figure 2: MechanicalUploadingSystem


Handbook K2CO3 17

increases particle degradation. Inmany cases where particle size isimportant for granular potassiumcarbonate, the use of a screw con-veyor should be avoided if possible.

Lubricants would contaminatethe potassium carbonate due to thelocation of bearings in the screwconveyor. Therefore, either whiteiron or Stellite bearings is recom-mended. The outboard bearingdrive end of the conveyor should belocated outside the trough todecrease maintenance and increasebearing and drive life. Discussionwith an equipment manufacturerregarding the capacity, size andr.p.m. of screw conveyors wouldfacilitate better potassium carbonateservice.

The belt conveyor is recom-mended primarily where large ton-nages are to be conveyed long dis-tances. The initial expense andhorsepower requirements of beltconveyors are quite low. Particledegradation is kept to a minimumwhere belt conveyors are used. Theycan be used to convey up, down oron an incline at a maximum operat-ing angle of 10° for potassium car-bonate. All bearings and idlers on abelt conveyor for potassium carbon-ate should be antifriction and dust-proof. Discussion with an equip-ment manufacturer regarding thecapacity, size and r.p.m. of screwconveyors would facilitate betterpotassium carbonate service.

Although dusting and contami-nation may become excessive atloading and discharge points, theuse of special housings will over-come this problem. Where wind ormoisture presents a serious problem,the increased cost of weather-tighthousing may increase the totalinvestment above that required forother types of conveyors.

A bucket elevator consists ofan endless rubber belt or chain towhich are attached buckets for ele-vating material vertically or alongsteep inclines. It has a receivinghopper or boot and provisions fordischarging the load. For potassiumcarbonate service, the rubber belttype is preferred to the chain typethereby avoiding metallic contami-nation. Loading should be on thevertical leg rather than forcing thebucket to scoop the material fromthe boot. The added cost of a deep-er elevator pit required for verticalloading will be offset by a muchsmoother and continuous opera-tion.

There are three general types ofbucket elevator discharges: centrifu-gal, continuous and positive. Thecentrifugal elevator dischargesmaterial by centrifugal force, oper-ating at high speeds to assure thatthe buckets empty completely andto prevent the “backlogging” orrecycling of material. Some particledegradation of granular potassiumcarbonate occurrs due to the cen-trifugal force used to fling the mate-rial into the discharge chute.

The continuous elevator isdesigned for slow speed operationand ordinarily should not exceed125 feet per minute. Its buckets aremounted continuously so thatmaterial is discharged from onebucket over the front of the preced-ing one which acts as a movingchute or guide to the fixed dis-charge spout. The continuous eleva-tor has a higher initial cost whencompared to a centrifugal elevator.However, its slower speed causesless wear on buckets, belts andwheels, translating into a lowermaintenance cost.

Although the continuous eleva-tor operates at slower speed than


18 K2CO3 Handbook

the centrifugal, it has about thesame capacity because of the greaternumber of buckets. The continuouselevators are especially well adaptedwhere degradation of material is tobe minimized and where extremedust conditions are to be avoided.

The positive discharge buck-et elevator is also designed forslow speeds of approximately 120feet per minute. The interval spacedbuckets are completely inverted bysnubbing the chains after they havepassed over the head pulley, givingthem an opportunity for completedischarge. Since the positive dis-charge elevator is a low-capacity unitfor the cost involved, it does notreplace the centrifugal or continuouselevators in normal granular potassi-um carbonate service.

The continuous flow convey-or is a unit which carries materials enmasse through a dustproof andweathertight duct, completely fillingits cross section. In general, the con-veyor medium is an endless chainupon which are mounted flights atsuitable intervals or a chain with theflight cast as an integral part of thelink. The flights can be either solid oropen finger type. The conveyor canoperate on a horizontal, vertical orincline plane and in any combinationthereof. Speed is usually limited toabout 80 feet per minute, althoughslower speeds are preferred. Becausethe conveyor is completely enclosedand lubrication points can be locatedoutside the unit, the material con-veyed is not subject to external conta-minations. The conveyor is not com-pletely self-cleaning, so where morethan one material is handled, conta-mination could become a problem.When handling deliquescent materi-als like potassium carbonate, specialcare is required to remove any resid-ual material between product trans-

fers.Another type of en masse con-

veyor is known as the “zipper”. Itconsists of a flat, endless rubber beltwith two attached side beltsdesigned to fold into a semi-circularenclosure. The outer edges of theside belts are made with rubberteeth which interlock when theconveyor is closed. It is dust-tightand will handle granular potassiumcarbonate without degradation.

C. PNEUMATIC CONVEYINGThe pneumatic conveyor differsaltogether from other machines inthat it depends on a high velocityair stream to transport materials. Ifthe velocity is too low, the materialwill drag and build up, particularlyon long horizontal runs and inelbows. The pneumatic conveyor ishigher in capital investment andpower cost than a mechanical con-veying system. Some product degra-dation can be expected, however,the extent of particle breakage isnominal for Armand Products’dense granular potassium carbonatewhen the system is properly operat-ed. Advantages that help offset itshigh cost include dust suppression,flexibility, low handling losses andself-cleaning. Dry air must be usedin the pneumatic transfer of potas-sium carbonate when moisturepickup is detrimental and alsowhere the humidity factor is high.

There are three types of pneu-matic conveying systems: vacuum,pressure and combinationvacuum-pressure.

With a proven record of efficientperformance for low cost unloadingof bulk cars, the vacuum systemis especially effective in picking upmaterial from many points anddelivering to one remotely located


Handbook K2CO3 19

process or storage area. Hook-up ofa bulk rail car and startup of thesystem is quickly and easily done.

The vacuum type pneumaticunloading system requires littleaccessory equipment. The systemconsists of a transport pipe attachedto an adapter mounted on theEnterprise gate of the hopper car.Approximately 20 feet of flexiblepipe should be available to makethe proper connection to the car.

The transport pipe delivers potas-sium carbonate to a receiver abovethe storage bin where the air andpotassium carbonate are separated.The air is exhausted to the atmos-phere through a dust filter or prefer-ably a bag house while the potassi-um carbonate is discharged throughan airlock into storage. A blower onthe exhaust side of the separator ordust collector provides vacuum inthe system. The suction system iscapable of transporting potassiumcarbonate economically for dis-tances up to 500 feet.

The pressure system (Figure3) is an economical, compact sys-tem, for transferring product fromone area to several points, frequent-ly at considerable distances. Thissystem is extremely flexible and canbe adapted to many specific needsincluding unloading, in-plant trans-fer and recirculation.

Pressure type pneumatic systemsusually require additional equip-ment at the inlet end of the trans-port pipe. Generally, a blower or fanis used to furnish compressed airwhich is forced into the linethrough an injection nozzle. In amodified version of the system,potassium carbonate is fed by screwconveyor into an air stream whichcarries the potassium carbonate tostorage. Another pressure systemutilizes a fluidization chamber,

where a predetermined volume ofpotassium carbonate is droppedinto the vessel, fluidized under pres-sure and blown through the line.This unloading method is an inter-mittent and cyclic operation.

The combination vacuum-pressure (Figure 4) is consider-ably more sophisticated. Combiningfeatures of both types describedabove, this system expands therange of usage and is capable ofmeeting multiple needs. Stationaryor portable systems can be operatedunder push-button control. Railcarscan be unloaded simultaneouslyfrom various sidings with simulta-neous delivery to many points,without contamination and at ahigh volume throughput.

Potassium carbonate can betransported a considerable distanceby this combination system. Thisalso eliminates the inlet equipmentnecessary for a straight pressure sys-tem. Although the unloading dis-tance can be extended over that ofa suction system, the power require-ments are likely to be excessivelylarge for the longer application.


20 K2CO3 Handbook

Figure 3: Pressure System

Figure 4: CombinationVacuum-Pressure System


Handbook K2CO3 21

D. BULK STORAGEStorage facilities for potassium car-bonate can be constructed of con-crete or steel. A moisture seal isrequired to eliminate penetration ofwater which both contaminates theproduct and causes it to lump.Storage capacity should be at least1.5 to 2 times the amount of potas-sium carbonate received in a singleshipment. This safety factor insuresan adequate supply of potassiumcarbonate at all times and allows forunforeseen transportation delays.Storage bin capacity should be cal-culated on a basis of 82 lbs./cu. ft.for Armand Products’ granularpotassium carbonate. Bins may becylindrical with cone bottom or rec-tangular with V-slanted bottoms.The slopes of the bin bottomsshould be approximately 45degrees.

Prefabricated storage bins offer themost economical and versatilechoice for bulk storage of potassiumcarbonate. These bins are readilyavailable in a variety of sizes andshapes with galvanized, black orstainless steels as the commonmaterials of construction. The stan-dard vertical types are cylindricalwith the bottom designed for eithercenter or side draw-off. They areeasily assembled in the field ontheir own supports with the assis-tance of the vendor or may beassembled directly by the customer.They must be made weatherproof toprotect the potassium carbonatefrom moisture.

Concrete silos are of three types:stave, monolithic or poured, andblock or tile. The stave type is low-est in cost and is formed of precastconcrete staves, set up in stepped

tiers and bonded with outside turn-buckle rods. The interior walls areplastered for a smooth surface, andthe exterior is brush-coated withwaterproof cement. Cone bottomsare easily adapted to this type ofsilo. Monolithic silos are of pouredconcrete with circumferential rein-forcing steel. Concrete block andhollow tile silos are more expensivethan either the stave or monolithic.Block silos are formed with cham-bered precast concrete blocks, andhollow tile silos are of precastchambered tile with reinforcingrods grouted into recesses betweenthe tiers. Care should be exercisedwhen choosing a silo of this lastdesign.

A vent dryer is recommended for alldry bulk potassium carbonate stor-age facilities. A typical dryer for thisapplication can be fabricated by thecustomer or purchased from a ven-dor.


22 K2CO3 Handbook

A. SHIPMENTS OF 47%POTASSIUM CARBONATE

Liquid 47% potassium carbonate istypically shipped in drums, tanktruck or rail car. It is also availableby consignment as a barge load,shipped from the Armand Products’plant in Muscle Shoals, AL. Eachform of transportation has its ownadvantages. The type of service youselect will depend upon such factorsas size and location of storage, rateof consumption, plant location andfreight rates. Armand Products’Technical Service staff is well quali-fied to survey your present facilitiesand recommend the economicalform of transportation best suitedto your particular requirements.

The unloading and handling of47% liquid potassium carbonate issimple. The freight for transportingthis solution is higher than for thegranular, anhydrous form. It is nec-essary to have enough tank capacityto accommodate a 16,000 gallonrail shipment or a 4,000 gallon tanktruck shipment in addition to what-ever level of inventory the customermaintains.

B. UNLOADING LIQUIDPOTASSIUM CARBON-ATE FROM TANK CARS

PPllaacceemmeenntt ooff RRaaiillccaarr ffoorrUUnnllooaaddiinngg

1 DOT requires setting thehandbrake and blocking thewheels after the car is properlyspotted.

2 DOT regulations also state thatcaution signs must be placedon the track or car to givewarning to persons and switch-ing crews approaching the carfrom the open end(s) of the

siding. Caution signs must beleft up until the car is emptyand disconnected from theunloading line. Signs must bemade of metal or other suitablematerial, at least 12 x 15 inch-es in size, and bear the words,“Stop - Tank Car Connected”or “Stop - Men At Work”.

3 Place derail attachments at theopen end(s) of the siding,approximately one car length(50 ft.) away.

UUnnllooaaddiinngg PPrreeccaauuttiioonnss1 Entrust only responsible and

well-supervised employeeswith the unloading of liquidpotassium carbonate. It is rec-ommended that a worker bepresent during the entire timethat a car is being unloaded.

2 Provide workers with chemicalsplash goggles, hard hats, andrubber or rubber coated glovesto protect against eye and skinexposure. A safety shower andeyewash fountain must belocated in the unloading area.

3 Unload only in daytime orwhen adequate lighting isavailable. Caution workers toexercise care.

4 Before starting to unload,make certain that the tank carand storage tank are ventedand verify that the storagetank has sufficient capacity forthe delivery.

5 Do not allow entry into thecar under any circumstances.

6 If the tank car needs to bemoved when partiallyunloaded, DOT regulationsrequire disconnecting allunloading lines and replacingall car closures.

Handling of Liquid Potassium CarbonateIX.


Handbook K2CO3 23

7 A suggested method for sam-pling is to withdraw intermit-tent samples from a 1/2 inchsample line fitted with a valveand 1/4 inch nipple which isconnected to a vertical por-tion of the unloading line.

8 Armand Products’ liquidpotassium carbonate isshipped in well insulated andspecially lined tank cars.Linings in these liquid tankcars will withstand tempera-tures up to 225°F. To preventdamage to the linings, steamshould not be added directlyinto the tank cars under anycircumstances.

9 If compressed air (20 psigmax.) is used in the unloadingoperations, inspect all fittingsfor leaks or other defectsbefore unloading. Dome fit-

tings should be inspected care-fully. If leaks are found, sus-pend unloading operationsuntil they are fixed.

HHaannddlliinngg iinn CCoolldd WWeeaatthheerrUnder normal weather conditions,47% liquid potassium carbonatewill remain fluid. Since ArmandProducts’ liquid PotCarb is loadedhot into well insulated tank cars,this product should arrive at thedestination in a liquid state. Undersevere winter conditions, 47%potassium carbonate will begin tocrystallize below 8°F. Althoughfrozen material has not presented aproblem in the past, the TechnicalService staff is available for assis-tance should such a situation occur.

Figure 5: Details of TankCar


24 K2CO3 Handbook

Figure 6: BottomUnloading

UUnnllooaaddiinngg tthhrroouugghh BBoottttoommOOuuttlleett VVaallvvee ((Figures 5 and 6))Liquid potassium carbonate is usu-ally unloaded through the bottomoutlet valve. Most cars are alsoequipped with eduction pipes thatallow for unloading through thedome if desired. Both methods aredescribed in this handbook.

1 Open the dome cover andascertain whether the con-tents of the car are liquid.Keep the dome cover at leastpartially open during theentire unloading operation tovent the tank car. This pre-vents a vacuum from beingcreated in the car.

2 Ensure that the bottom outletvalve (10) Figure 5 is closed

tightly. The valve rod (16)which operates the bottom out-let valve has a wheel on itwhich is located either underthe dome or just outside thedome of the car. When locatedoutside of the dome, the wheelis reversed and serves as a capduring transit.

3 Remove the pipe plug (14) andthen carefully open supple-mentary valve (13) in order todrain out any liquid into abucket that may have seepedby the bottom outlet valve(10) during transit. If the sup-plementary valve cannot beopened, apply steam from asteam lance on the valve’sexterior to free it for opening.


Handbook K2CO3 25

4 Attach the unloading line tothe outlet side of supplemen-tary valve.

5 Check the unloading line tosee that all valves are in theproper position for unloading.

6 Open the bottom outlet valveby turning valve rod (16) toallow contents to flow bygravity to pump or tank.

7 Compressed air can be used tospeed up the flow or to transferthe liquid to the storage tankwithout the use of a pump.Check that the rupture disk isintact. The pipe plug on the airconnection valve (7) must beremoved and a flexible air lineconnected for this purpose.This line should be equippedwith a release valve, oil trap,pressure relief valve set at 20

psig, pressure reducing valve setat 18 psig and a shutoff valve.When using compressed air toassist in the transfer of product,the dome cover should besecurely closed before the appli-cation of air pressure.

8 When the car and unloadingline are empty, shut off the airsupply and open the releasevalve if air pressure has beenused in unloading.

9 Detach the unloading line atthe car after the following con-ditions are met: tank car isempty and at atmospheric pres-sure; discharge pipe has com-pletely drained; and if used, airline is disconnected. Prepare carfor returning according to pro-cedure under “Preparing EmptyCars For Return.”

Figure 7: TopUnloading


26 K2CO3 Handbook

TToopp UUnnllooaaddiinngg wwiitthh AAiirr PPrreessssuurree((FFiigguurreess 55 aanndd 77))

1 Open the dome cover andascertain that the contents ofthe car are liquid. Check thatthe rupture disk is intact.

2 Close the dome cover and fas-ten securely, making certainthat it is airtight.

3 Check storage tank to see thatit has sufficient capacity andis well vented. Removal ofcover on top of storage tank isadvisable for venting.

4 Connect the unloading line toa 2-inch unloading connec-tion (5) on the eduction pipe,after removing cover (5). Aflexible steel hose connectionfor unloading is recommend-ed since the car may rise of asmuch as two inches duringunloading.

5 Connect the flexible air sup-ply line to the 1-inch air inletvalve (7, Figure 6). This lineshould be equipped with arelease valve, oil trap, pressurerelief valve set at 20 psig, pres-sure reducing valve set at 18psig and a shutoff valve.

6 Apply air pressure slowly untilthere is a normal flow of liquidto the storage tank, after whichthe pressure should be adjustedand maintained until the tankcar is completely empty. Thesound of air rushing throughthe unloading line and a dropin air pressure indicates thatthe tank car is empty.

7 When the unloading line isempty, shut off air supply,open the release valve andallow the discharge pipe todrain well.

8 After proper draining andwith the tank car at atmos-pheric pressure, disconnectthe air supply line at the rail-car.

9 Open the manway cover anddetermine whether the car isempty, however, do not enterthe railcar to make an inspec-tion. If the car is empty, onlythen should the unloadingline be disconnected. Replacemanway and valve coverstightly.

10 Take care not to spill anyproduct on the car as it willendanger trainmen handlingthe empty car on its returnand may cause damage to thecar.

11 Prepare car for return as high-lighted in the following sec-tion.

PPrreeppaarriinngg EEmmppttyy TTaannkk CCaarr ffoorrRReettuurrnn

1 Close bottom outlet valve andsupplementary valve.

2 Disconnect the unloading lineand replace the bottom outletplug. Do not replace closureson steam openings.

3 Close the dome cover and fas-ten securely.

4 Return the empty tank carpromptly in accordance withthe shipper’s instructions.Follow the shipper’s routingdirections in all instances.


Handbook K2CO3 27

C. UNLOADING LIQUIDPOTASSIUM CARBON-ATE IN TANK TRUCKS

The transportation of 47% liquidpotassium carbonate is accom-plished in 4,000-gallon tank trucksmeeting DOT regulations. The con-signee should determine if suffi-cient tank capacity is available toaccept the shipment. Any specialinstructions concerning the deliverymust be conveyed by the consigneeto the truck driver before permis-sion is given to unload. Each truckdriver is completely familiar withthe equipment used and under nor-mal unloading conditions does notrequire manpower assistance fromthe consignee. However, it is alwaysa good idea to have a consigneeoperator near the unloading area.Customers are asked to report anyproblems that result from the carri-er failing to follow proper unload-ing procedures as well as any per-sonal protective gear or specifiedsafety requirements.

Tank trucks containing liquidpotassium carbonate are commonlyunloaded by one of three methods:

GravityFlow of material direct to storage orto an unloading pump furnished bythe consignee.

Truck Mounted PumpTank truck equipment is availablewhich has an all iron or nickelpump mounted on the tank truck.The pump is driven by a tractorpowered take-off or an auxiliarygasoline engine. At least a 2-inchpump line should be used. If thistype of unloading is desired,arrangements should be made with

your Armand Products Companysales representative at the time ofyour original order.

Compressed AirUnloading by air pressure is anotheroption where the consignee canprovide the air supply system.Equipment on the air supply line tothe truck includes: pressure reduc-ing valve (PRV), pressure gauge,pressure relief valve (set 2-3 psiabove PRV setting) and a pressurerelease valve. All associated equip-ment should be properly main-tained and periodically tested. Anair hose of appropriate length toreach the truck dome is required ifthe customer’s air supply is used.

Another option is to request thatthe carrier come equipped with aself-contained air compressor sys-tem mounted on the truck. If this isthe desired unloading mechanism,arrangements should be madethrough your Armand Products’salesperson at the time of your orig-inal order.

Tank Truck UnloadingFacilities

1 An eye wash and safety show-er should be located nearbyand periodically tested. Ifthese are not available thenclean, potable water flowingthrough a hose must be readi-ly accessible.

2 A storage tank of 6,000 gal-lons capacity is suggested toprovide adequate capacity fortypical tank truck shipmentsand a sufficient reserve supplybetween shipments. Figure 8provides general informationon both horizontal and verti-cal tanks for storage of truck


28 K2CO3 Handbook

shipments. Steam coils are notrequired for these tanks exceptin those areas where the tem-perature will drop below 10°Ffor extended periods of time.In fringe areas, insulation ofthe tank should suffice.

3 A permanent 2-inch unloadingline from a convenient truckunloading area to the top of thestorage tank should be installed.Connection between the truckand the permanent unloadingline is furnished through theuse of an alkali-resistant heavyduty rubber hose carried on thetruck. The distance should bemeasured to determine theappropriate length required onthe truck.

4 The permanent unloading lineshould be equipped with a 2-inch male pipe fitting (kam-lock type) to facilitate con-necting the rubber hose fromthe tank truck. Cap the end ofthe permanent unloading linewhen not in use.

5 A ¾ inch valve connection isrecommended on the unload-ing line at the truck end foruse in flushing out the linewith air, water or steam. It canalso be used as a drain.

Unloading Procedure

1 Purge out the eye wash andshower to remove rust thatmay have accumulated.

2 Connect one end of the unload-ing hose to the customer’s stor-age tank fill pipeline.

3 Depending on the severity ofthe cold weather, the fill line,the unloading hose or truckoutlet may need to be pre-heated with steam.

4 Check the unloading line tobe sure that it is open.

5 Connect the unloading hoseto the discharge outlet on thetank truck.

6 Start the pump or start pres-surizing the truck tankdepending on the type ofequipment used.

7 Open the valves on the truckdischarge line.

8 Monitor in person the entireunloading process until thetruck is empty.

9 If compressed air is used,allow the air to flush out thelines to the storage tank andthen cut off the air supply.

10 When a pump is used, it isadvisable to flush out theunloading line before discon-necting the hose. If water isavailable, a small quantity canbe added to the truck while thepump is running to flush outthe line. Air or water can beused to flush out the line intothe storage tank. If no water isavailable or incomplete flush-ing is suspected, great cautionshould be exercised when dis-connecting lines.

11 Close the valve on the storagetank fill line.

12 Close all valves on the tanktruck.

13 If the customer’s fill line is fit-ted with a drain, this shouldbe disconnected and anyresidue discharged into aproper container.

14 Unload potassium carbonatewith adequate safeguards forspill control. Proper contain-ment and disposal of releasedproduct should be handled inaccordance with federal, stateand local regulations.


Handbook K2CO3 29

Figure 8: Installation ofTanks forLiquid Product


30 K2CO3 Handbook

A x (B - C) / C = DA = Specific Gravity of Strong

SolutionB = % K2CO3 in Strong SolutionC = % K2CO3 in Weak SolutionD = Volume of water to add to

each volume of strongsolution.

Example 1Dilution of 47% liquid potassiumcarbonate to 15% potassium car-bonate solution:

Specific Gravity of 47% liquid at60°F = 1.496 (from Table 4)

Thus, [1.496 x (0.47 - 0.15)] / 0.15 =3.19 volumes of water to add toeach volume of 47% liquid potassi-um carbonate.

It should be noted that volumes ofpotassium carbonate solutions andwater are not additive. When onegallon of water and one gallon ofpotassium carbonate solution aremixed, the resultant yield is some-what less than two gallons. Thisfact is quite significant when deal-ing with large volumes. Figure 9:

AlternativeMixingMethods

D. DILUTION OF POTASSIUMCARBONATE SOLUTION

The references to various tables andfigures will provide important datafor the dilution of an aqueous solu-tion of potassium carbonate:

Table 4, page 36 - weight of potas-sium carbonate solutions at 60°F;used in calculating and estimatingcapacities of process equipment. Table 5, page 37 - density of apotassium carbonate solution as afunction of temperature and con-centration. Graph 1, page 40 - dilution chartfor 47% potassium carbonate withwater at 60°F. Graph 2, page 41 - dilution chartfor various concentrations of potas-sium carbonate with water at 60°F. Graph 3, page 42 - gross weight inpounds per gallon of potassium car-bonate solution including its densi-ty at 60°F.

Dilution CalculationsThe matter of diluting liquid potas-sium carbonate to a given concen-tration is frequently confusing.Dilutions can be simplified to thefollowing formula:


Handbook K2CO3 31

Example 2(using Graph 2)

To make a 100 gallon solution con-taining 2.5 pounds K2CO3 per gal-lon, two solutions containing 1.5and 6.0 pounds of K2CO3 per gallonare used. The volume of each solu-tion is determined by drawing theline “AB” connecting 1.5 lbs./gal.with the 6.0 lbs./gal. This intersects2.5 lbs./gal. at point “C”. Readingdown to the “Volume of Water orWeak Liquor” we find 77 gallons(1.5 lbs./gal.). Next, reading up tothe “Volume of Strong Liquor Used”we find 23 gallons (6.0 lbs./gal.).

DISSOLVING ANHYDROUSPOTASSIUM CARBONATEAnhydrous potassium carbonate isreadily soluble in water. When largequantities of granular potassiumcarbonate are placed in quiescentsolutions, the granular material fallsto the bottom and forms a layer ofhydrate. This layer dissolves quite

slowly, forming an area of heavyconcentration. There also is localoverheating which may cause anattack on the tank lining or coating.

Good practice calls for slowlyadding the granular material to awell agitated solution of water (seeFigure 9). Agitation is best sup-plied by a propeller type agitator, orunder some conditions, by using acirculating pump.

SOLUTION STORAGE WITHDRY BULK DELIVERYA user of potassium carbonate insolution form may want to exploreanother possibility. Bulk trucks ofanhydrous material can allow thedissolution of the PotCarb in wateras it is transferred to the storagetank (see Figure 10). With pneu-matic truck delivery, anhydrouspotassium carbonate is dischargedinto a slurrifier located on top ofthe storage tank. The slurrifier is apipe held in vertical position withdry material added at the top and

Figure 10: Bulk Dilution


32 K2CO3 Handbook

solution added tangentially to thepipe with the resultant slurry dis-charged from the bottom of thepipe into the top of the storagetank. Dissolving of the potassiumcarbonate is completed in the stor-age tank. A vent on the storage tankis required to let the anhydrousPotCarb transport air escape.Armand Products’ Technical Serviceis available for discussion shouldthe customer consider such a sys-tem.

The slurrifier system works bestwith a hot solution (140-190°F).This helps to insure that the potas-sium carbonate dissolves rapidlyand minimizes any problem ofsolids build-up in the tank bottom.The dissolving rate is approximatelydoubled when the temperature ofsolution is raised from 60°F to 150°FA considerable amount of heat isevolved in the charging process dueto the heat of solution. For a 30%solution, a temperature rise of 35°Fwill take place.


Handbook K2CO3 33

Technical DataPROPERTIES OF POTASSIUM CARBONATE

Boiling Point of K2CO3 Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 16

Chemical & Physical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 1

Dissociation Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 2

Electrical Conductivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 6

Equivalent Conductance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 6

Freezing Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 5, Graph 4

Heat Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 7

Hydrogen Ion Concentration (pH) . . . . . . . . . . . . . . . . . . . . . . . . . . Table 8

Index of Refraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 9

Solubility in Water Curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Graph 4

Solubility in Organic Solvents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 3

Specific Gravity as Function of Temperature . . . . . . . . . . . . Table 5, Graph 5

— at 60°F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 4

Surface Tension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 10

Vapor Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 12

Viscosity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Table 11

X.


34 K2CO3 Handbook

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TATABLE 1:

CCHHEEMMIICCAALL AANNDD PPHHYYSSIICCAALLPPRROOPPEERRTTIIEESS OOFF PPOOTTAASSSSIIUUMM CCAARRBBOONNAATTEE

Chemical Name: Potassium Carbonate Chemical Formula: K2CO3Molecular Weight: 138.20 Acid Equivalent: 1 lb. K2CO3 = 0.528 lb. HCIAlkali Equivalent: 100% K2CO3 = 68.16% K2OElectrical Conductivityof Molten K2CO3

1.95 ohm1 cm1 at 1652°F (900°C)2.12 ohm1 cm1 at 1742°F (950°C)2.26 ohm1 cm1 at 1832°F (1000°C)

Dielectric Constant: 4.96 at 18° and 166.6 Kcs/sec.Heat of Fusion: 56.4 cal./g. or 101.5 BTU/lb.Heat of Formation: K2CO3 1982 cal./g. at 25°C

3568 BTU/lb. at 77°FK2CO3 • 0.5 H2O

1429 cal./g. at 25°C 2572 BTU/lb. at 77°C

K2CO3 • 1.5 H2O1715 cal./g. at 25°C3087 BTU/lb. at 77°F

Heat of Solution: K2CO3 47.6 cal./g. (Evolved) 85.7 BTU/lb. (Evolved)

K2CO3 • 0.5 H2O28.9 cal./g. (Evolved)52.0 BTU/lb. (Evolved)

K2CO3 • 1.5 H2O2.6 cal./g. (Absorbed)4.7 BTU/lb. (Absorbed)

Infrared Absorption Band: 6.9 µ and 11.4 µMelting Point: 1636°F (891°C) pH of 47% K2CO3: 12.63Specific Gravity: 2.428 at 66°F (19°C)Specific Heat: 0.216 BTU/lb.-°F over range 73-210°F

0.216 cal./g.-°C over range 2-99°CSolubility in Water:

— at 68°F 112 grams per 100 grams— at 212°F 156 grams per 100 grams

Transitions: Second order at 410°C and 465°C

TABLE 2:

DDIISSSSOOCCIIAATTIIOONN PPRREESSSSUURREE OOFF PPOOTTAASSSSIIUUMM CCAARRBBOONNAATTEE IINNMMIILLLLIIMMEETTEERRSS MMEERRCCUURRYY

Reaction: K2CO3 → K2O + CO2

Temperature (°C) D.P. (mm Hg)900 . . . . . . . . . . . . . . . . 0950 . . . . . . . . . . . . . . . . 1.2970 . . . . . . . . . . . . . . . . 1.68

1000 . . . . . . . . . . . . . . . . 2.11100 . . . . . . . . . . . . . . . . 7.41200 . . . . . . . . . . . . . . . . 10.31300 . . . . . . . . . . . . . . . . 15.11400 . . . . . . . . . . . . . . . . 35.6


Handbook K2CO3 35

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TABLE 3:

SSOOLLUUBBIILLIITTYY OOFF PPOOTTAASSSSIIUUMM CCAARRBBOONNAATTEEIINN SSEELLEECCTTEEDD OORRGGAANNIICC SSOOLLVVEENNTTSS

Solvent Category Solubility (ppm)Anhydrous Solution**

K2CO3

Kerosene Hydrocarbons ND* ND*Carbon Tetrachloride Chlorinated Hydrocarbons ND* ND*O-Dichlorobenzene Chlorinated Hydrocarbons 0.2 0.2Trichloroethylene Chlorinated Hydrocarbons 0.1 < 0.1Perchloroethylene Chlorinated Hydrocarbons ND* < 0.1Acetone Ketones 1.3 17Methyl Ethyl Ketone Ketones 3.7 7.2Ethyl Acetate Esters 1.2 0.6Butyl Acetate Esters 25 5.4Methyl Cellosolve Acetate Esters 45 6.7Diethanolamine Amine 29 27Methanol Alcohols 16,500 16,440Ethanol Alcohols 904 234Isopropanol Alcohols 4.0 21Ethylene Glycol Glycols 15,300 46,100

* ND = None Detected ** Solution: 25% H2O + 75% K2CO2 Dry Basis


36 K2CO3 Handbook

K2CO2 K2CO2 Total Weight K2CO2 Total Weight

Specific Degrees Grams Pounds of Solution Pounds of Solution

% % Gravity Baume Degrees per per in Pounds per in Pounds

K2CO3 K2O 60/60°F Am. Std. Twaddell Liter Gallon per Gallon Cu. Ft. per Cu. Ft.

0 0.0 0.999 — — 0.0 0.0 8.328 0.0 62.301 0.68 1.001 0.15 0.2 10.0 0.084 8.353 0.62 62.492 1.36 1.011 1.58 2.2 20.6 0.167 8.437 1.26 63.123 2.04 1.021 2.99 4.2 30.6 0.256 8.520 1.91 63.744 2.73 1.031 4.36 6.2 41.2 0.344 8.604 2.57 64.375 3.41 1.041 5.72 8.2 52.0 0.434 8.687 3.25 64.996 4.09 1.051 7.04 10.2 63.0 0.526 8.771 3.94 65.617 4.77 1.060 8.21 12.0 74.2 0.619 8.846 4.63 66.188 5.45 1.070 9.49 14.0 85.6 0.714 8.929 5.34 66.809 6.13 1.080 10.74 16.0 97.2 0.811 9.013 6.07 67.4210 6.82 1.090 11.97 18.0 109.0 0.910 9.096 6.81 68.0511 7.50 1.100 13.18 20.0 121.0 1.010 9.180 7.55 68.6712 8.18 1.110 14.37 22.0 133.5 1.112 9.263 8.32 69.3013 8.86 1.120 15.54 24.0 145.6 1.215 9.346 9.09 69.6214 9.54 1.129 16.57 25.8 158.1 1.319 9.422 9.87 70.4815 10.22 1.138 17.59 27.8 170.8 1.425 9.497 10.66 71.0516 10.91 1.148 18.70 29.6 183.7 1.533 9.580 11.47 71.6717 11.59 1.158 19.79 31.6 196.9 1.643 9.664 12.29 72.2918 12.27 1.168 20.86 33.6 210.2 1.754 9.747 13.13 72.9219 12.95 1.178 21.92 35.6 223.8 1.868 9.830 13.97 73.5420 13.63 1.188 22.95 37.6 237.6 1.983 9.914 14.83 74.1721 14.31 1.199 24.07 39.8 251.8 2.101 10.006 15.72 74.8522 15.00 1.209 25.07 41.8 266.0 2.220 10.089 16.61 75.4823 15.68 1.219 26.06 43.8 280.4 2.340 10.173 17.50 76.1024 16.36 1.230 27.11 46.0 295.1 2.463 10.264 18.43 76.7925 17.04 1.240 28.06 48.0 310.0 2.587 10.348 19.35 77.4126 17.72 1.251 29.10 50.2 325.2 2.714 10.440 20.31 78.1027 18.40 1.262 30.11 52.4 340.7 2.843 10.531 21.27 78.7928 19.08 1.273 31.10 54.6 356.4 2.974 10.623 22.25 79.4729 19.77 1.284 32.08 56.8 372.3 3.107 10.715 23.25 80.1630 20.45 1.295 33.04 59.0 388.5 3.242 10.807 24.26 80.8531 21.13 1.306 33.98 61.2 404.9 3.379 10.899 25.27 81.5332 21.81 1.317 34.91 63.4 421.4 3.517 10.990 26.31 82.2233 22.49 1.328 35.82 65.6 438.2 3.657 11.082 27.36 82.9134 23.17 1.340 36.79 68.0 455.6 3.802 11.182 28.44 83.6635 23.86 1.351 37.68 70.2 472.8 3.946 11.274 29.52 84.3436 24.54 1.362 38.54 72.4 490.3 4.092 11.366 30.61 85.0337 25.22 1.374 39.47 74.8 508.3 4.242 11.466 31.74 85.7838 25.90 1.386 40.39 77.2 526.6 4.395 11.566 32.88 86.5339 26.58 1.398 41.29 79.6 545.2 4.550 11.666 34.04 87.2840 27.26 1.410 42.16 82.0 563.9 4.706 11.766 35.21 88.0341 27.95 1.422 43.04 84.4 583.0 4.865 11.867 36.40 88.7842 28.63 1.434 43.89 86.8 602.2 5.026 11.967 37.60 89.5243 29.31 1.446 44.73 89.2 621.8 5.189 12.067 38.82 90.2744 29.99 1.459 45.62 91.8 641.9 5.357 12.175 40.08 91.0945 30.67 1.471 46.43 94.2 661.9 5.524 12.275 41.32 91.8346 31.35 1.483 47.23 96.6 682.2 5.693 12.376 42.59 92.5847 32.04 1.496 48.08 99.2 703.0 5.867 12.484 43.90 93.4048 32.72 1.509 48.91 101.8 724.3 6.045 12.593 45.22 94.2149 33.40 1.522 49.74 104.4 745.7 6.223 12.701 46.56 95.0250 34.08 1.535 50.54 107.0 767.5 6.405 12.810 47.92 95.8351 34.76 1.549 51.40 109.8 790.0 6.592 12.926 49.32 96.7052 35.44 1.562 52.18 112.4 812.2 6.778 13.035 50.71 97.52

TABLE 4:

DDEENNSSIITTYY OOFF PPOOTTAASSSSIIUUMM CCAARRBBOONNAATTEE SSOOLLUUTTIIOONNSS AATT 6600°°FF ((1155..66°°CC))

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Handbook K2CO3 37

TABLE 5:

SSPPEECCIIFFIICC GGRRAAVVIITTYY OOFF PPOOTTAASSSSIIUUMM CCAARRBBOONNAATTEESSOOLLUUTTIIOONNSS AASS AA FFUUNNCCTTIIOONN OOFF TTEEMMPPEERRAATTUURREE

TEMPERATURE (°F)

Conc.* F.P.** 10 20 30 40 50 60 70 80 90 100

0 32 — — — 0.9999 0.9997 0.9990 0.9980 0.9966 0.9950 0.99315 29 — — 1.057 1.046 1.044 1.042 1.040 1.038 1.035 1.03310 25 — — 1.096 1.094 1.092 1.090 1.088 1.086 1.083 1.08115 21 — 1.146 1.145 1.143 1.141 1.139 1.137 1.135 1.132 1.13020 12 — 1.199 1.197 1.194 1.192 1.190 1.188 1.185 1.182 1.17925 3 1.252 1.251 1.248 1.245 1.244 1.242 1.240 1.237 1.234 1.231

30 -3 1.308 1.306 1.303 1.301 1.298 1.296 1.293 1.290 1.287 1.28435 -16 1.366 1.363 1.360 1.358 1.355 1.352 1.350 1.347 1.344 1.34140 -34.6 1.423 1.422 1.419 1.416 1.414 1.411 1.408 1.405 1.402 1.39945 -1 1.486 1.484 1.481 1.479 1.476 1.473 1.470 1.467 1.463 1.46047 8 1.511 1.509 1.506 1.503 1.500 1.498 1.495 1.492 1.489 1.48650 18 — 1.547 1.545 1.542 1.540 1.537 1.534 1.531 1.528 1.525

Conc.* 110 120 130 140 150 160 170 180 190 200 210

0 0.9910 0.9986 0.9860 0.9832 0.9803 0.9771 0.9739 0.9704 0.9669 0.9631 0.95915 1.031 1.028 1.025 1.022 1.019 1.016 1.013 1.010 1.006 1.002 0.99810 1.079 1.076 1.073 1.070 1.067 1.064 1.061 1.058 1.054 1.050 1.04615 1.127 1.124 1.121 1.118 1.115 1.112 1.109 1.105 1.101 1.097 1.09320 1.176 1.173 1.170 1.167 1.163 1.160 1.157 1.153 1.149 1.145 1.14325 1.228 1.225 1.222 1.219 1.215 1.212 1.209 1.205 1.201 1.197 1.195

30 1.281 1.278 1.276 1.273 1.270 1.267 1.264 1.260 1.256 1.252 1.24835 1.338 1.335 1.332 1.329 1.325 1.322 1.319 1.316 1.312 1.308 1.30440 1.396 1.393 1.390 1.387 1.384 1.381 1.378 1.375 1.371 1.367 1.36345 1.457 1.454 1.451 1.448 1.445 1.442 1.439 1.435 1.431 1.427 1.42347 1.482 1.478 1.476 1.473 1.470 1.467 1.464 1.460 1.456 1.452 1.44850 1.522 1.518 1.515 1.511 1.507 1.504 1.501 1.497 1.493 1.487 1.48355 — 1.583 1.580 1.577 1.573 1.570 1.567 1.563 1.559 1.555 1.550

* Conc. = Concentration (% K2CO3) ** F.P. = Freezing point (°F)

TABLE 6:

EELLEECCTTRRIICCAALL CCOONNDDUUCCTTIIVVIITTYY OOFF AAQQUUEEOOUUSS KK22CCOO33 SSOOLLUUTTIIOONNSS AATT 1155°°CC

K2CO3 (wt. %) Conductance Equivalent

(mho/cm x 104) Conductance

5 . . . . . . . . . . . . . . 561 . . . . . . . . . . . . . . . . . 74.210 . . . . . . . . . . . . . 1038 . . . . . . . . . . . . . . . . . 65.720 . . . . . . . . . . . . . 1806 . . . . . . . . . . . . . . . . . 52.430 . . . . . . . . . . . . . 2222 . . . . . . . . . . . . . . . . . 39.440 . . . . . . . . . . . . . 2168 . . . . . . . . . . . . . . . . . 26.550 . . . . . . . . . . . . . 1469 . . . . . . . . . . . . . . . . . 13.2

TABLE 7:

HHEEAATT CCAAPPAACCIITTYY OOFF PPOOTTAASSSSIIUUMMCCAARRBBOONNAATTEE SSOOLLUUTTIIOONNSS

K2CO3 (wt. %) Cp*(cal./g.-°C)

5 . . . . . . . . . . . 0.94 10 . . . . . . . . . . . 0.89 15 . . . . . . . . . . . 0.84 20 . . . . . . . . . . . 0.80 25 . . . . . . . . . . . 0.75 30 . . . . . . . . . . . 0.72 35 . . . . . . . . . . . 0.68 40 . . . . . . . . . . . 0.66 45 . . . . . . . . . . . 0.63

* Good over range from 21-52°C

TABLE 8:

ppHH OOFF DDIILLUUTTEE PPOOTTAASSSSIIUUMMCCAARRBBOONNAATTEE SSOOLLUUTTIIOONNSS

Commercial pH at 22°CK2CO3 (wt. %)

0.01 . . . . . . . . . . . . 10.480.05 . . . . . . . . . . . . 10.910.10 . . . . . . . . . . . . 11.080.25 . . . . . . . . . . . . 11.250.50 . . . . . . . . . . . . 11.370.75 . . . . . . . . . . . . 11.431.00 . . . . . . . . . . . . 11.492.00 . . . . . . . . . . . . 11.583.00 . . . . . . . . . . . . 11.635.00 . . . . . . . . . . . . 11.68

10.00 . . . . . . . . . . . . 11.75


38 K2CO3 Handbook

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TATABLE 9:

RREEFFRRAACCTTIIVVEE IINNDDEEXX AANNDD MMOOLLAARR RREEFFRRAACCTTIIOONN OOFF PPOOTTAASSSSIIUUMM CCAARRBBOONNAATTEE SSOOLLUUTTIIOONNSS

K2CO3 ND25 RD*(wt. %)

0 . . . . . . . 1.3325 . . . . . . . . 8.3495 . . . . . . . 1.3415 . . . . . . . . 8.357

10 . . . . . . . 1.3514 . . . . . . . . 8.36215 . . . . . . . 1.3624 . . . . . . . . 8.37020 . . . . . . . 1.3751 . . . . . . . . 8.381

* Measured at Sodium D Wavelength (5893A°)

TABLE 10:

SSUURRFFAACCEE TTEENNSSIIOONN OOFF PPOOTTAASSSSIIUUMMCCAARRBBOONNAATTEE SSOOLLUUTTIIOONNSS AATT 2200°°CC

K2CO3 (wt. %) Dynes/cm

0 . . . . . . . . . . . . . . 72.010 . . . . . . . . . . . . . . 75.120 . . . . . . . . . . . . . . 78.630 . . . . . . . . . . . . . . 83.835 . . . . . . . . . . . . . . 87.340 . . . . . . . . . . . . . . 91.445 . . . . . . . . . . . . . . 96.650 . . . . . . . . . . . . . . 103.8

TABLE 11:

VVIISSCCOOSSIITTYY OOFF PPOOTTAASSSSIIUUMM CCAARRBBOONNAATTEE SSOOLLUUTTIIOONNSS AATT 2200°°CC

K2CO3 (wt. %) Viscosity (centipoise)*

5 . . . . . . . . . . . . . . . 3.010 . . . . . . . . . . . . . . . 3.315 . . . . . . . . . . . . . . . 3.720 . . . . . . . . . . . . . . . 4.325 . . . . . . . . . . . . . . . 4.930 . . . . . . . . . . . . . . . 5.635 . . . . . . . . . . . . . . . 6.340 . . . . . . . . . . . . . . . 7.545 . . . . . . . . . . . . . . . 9.647 . . . . . . . . . . . . 10.450 . . . . . . . . . . . . . . 11.5

* Viscosities determined byBrookfield Method.

TABLE 12:

VVAAPPOORR PPRREESSSSUURREE,, WWAATTEERR AATT 2200..55°°CC

K2CO3 (wt. %) Water Vapor Pressure*

0 . . . . . . . . . . . . . . 18.119.6 . . . . . . . . . . . . . . 16.846.2 . . . . . . . . . . . . . . 11.854.7 . . . . . . . . . . . . . . 8.6

* Pressure measured in millimetersof mercury, water at 20.5°C.


Handbook K2CO3 39

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DILUTE SOLUTION (lb./gal. K CO )2 3

Example: To make 1 gallon of solution containing 2.0lbs. of K CO2 3 per gallon, add 0.34 gallon of47% solution to 0.68 gallon of water

0 00 1 2 3 4 5 6

0.2 0.2

0.4 0.4

0.6 0.6

0.680.34

0.8 0.8

1.0 1.0

1.2 1.2

Gallons of water addedper gallon of final solution

Gallons of 47% PotassiumCarbonate per gallon offinal solution

Volu

me

ofW

ater

(ga

l.at

60

F)

°

Volu

me

of 4

7% K

CO

(gal

.at 6

02

3°

F)


40 K2CO3 Handbook

TECHNICAL DATAGraph 1. Dilution of 47% Aqueous PotCarb at 60°F

ST

RO

NG

LIQ

UO

R (

lb.K

CO

per

gal.)

23

VOLUME OF STRONG LIQUOR USED (gal.)

VOLUME (gal.) OF WATER OR WEAK LIQUOR ADDED TOMAKE 100 GALLONS OF DILUTED SOLUTION

7.0 7.0

6.0 6.0

5.0 5.0

4.0 4.0

3.0 3.0

2.0 2.0

1.0 1.0

0 0

0 20 40 60 80 100

100 80 60 40 20 0

A

C

B

WE

AK

LIQ

UO

R (

lb.K

CO

per

gal.)

23


Handbook K2CO3 41

TECHNICAL DATAGraph 2. Detemining Dilution Volumes

GROSS WEIGHT (lb/gal. at 60°F)

5

10

15

20

25

30

35

40

45

50

55

1.00 0

1.05 10

1.10 20

1.15 30

1.20 40

1.25 50

1.30 60

1.35 70

1.40 80

1.45 90

1.50 100

1.55 110

1.60 120

SP

EC

IFIC

GR

AV

ITY

DE

GR

EE

ST

WA

DD

ELL

DE

GR

EE

S B

AU

ME

7 8 9 10 11 12 13 140


42 K2CO3 Handbook

TECHNICAL DATAGraph 3. Gross Weight of Aqueous Solutions at 60°F

TE

MP

ER

AT

UR

E (

°F)

-40

-20

0

20

40

60

80

100

120

140

160

0 10 20 30 40 50 60 70

UNSATURATEDSOLUTION

ICE + SOLUTION

K CO 1.5H 0+

SOLUTION

2 3 2

K CO 5H 0+

SOLUTION

2 3 2

ICE + K CO 5H 02 3 2

%K CO (Aqueous Solution)2 3


Handbook K2CO3 43

TECHNICAL DATAGraph 4. Solubility and Temperature Correlations

TEMPERATURE, °F

-20

1.70

1.60 55%

50%

47%

45%

40%

35%

30%

25%

20%

15%

10%

5%

0%

1.50

1.40

1.30

1.20

1.10

1.00

0.9010 30 50 70 90 110

DE

GR

EE

S B

AU

ME

DE

GR

EE

ST

WA

DD

ELL

SP

EC

IFIC

GR

AVIT

Y

130 150 170 190 210

0

20

40

60

80

100

120

140

55

50

45

40

35

30

25

20

15

10

5

0


44 K2CO3 Handbook

TECHNICAL DATAGraph 5. Solution Density at Various Temperatures

0 10 20 30 40 50 60 70200

210

220

230

240

250

260

270

280

TE

MP

ER

AT

UR

E (

°F)

%K CO (Aqueous Solution)2 3


Handbook K2CO3 45

TECHNICAL DATAGraph 6. Boiling Points at 760 mm Hg


46 K2CO3 Handbook

1. A comprehensive Treatise onInorganic and TheoreticalChemistry, Mellor, J.W., Vol. II(New Impression 1961), JohnWiley & Sons, Inc., New York,NY.

2. Mellor’s Comprehensive Treatiseon Inorganic and TheoreticalChemistry, Briscoe, H.V.A.,Eldridge, A.A., Dyson, G.M. andWelsh, H.J.E., Vol. II,Supplement III, 1963, JohnWiley & Sons, Inc., New York,NY.

3. International Critical Tables,West C.J. - National ResearchCouncil (1933), McGraw-HillBook Company, Inc., New York,NY.

4. Kirk-Othmer Encyclopedia ofChemical Technology, Mark,H.F., McKetta, J.J. Jr., andOthmer, D.F., Vol. 16, 1968 -John Wiley & Sons, Inc., NewYork, NY.

5. Contribution to the Study ofBinary and Ternary Systems,Carbonnel, L.; Scientifiques,Algiers Universite. SeriebolgerScience Physiques, Vol. 7 (1-2) -pps. 20-35 (1961).

6. Heats of Fusion of InorganicCompounds, Kelly, K.K., U.S.Bur. Mines Bulletin 393 (1936).

7. Solubilities of Inorganic andMetal Organic Compounds,Seidell, A., 4th Ed., (1965) -American Chemical Society,Washington, D.C.

8. Technical Project Reports,Technical Service, DiamondShamrock Chemicals Company,Painesville, OH.

References


Handbook K2CO3 47

1. Weigh a 4.000 to 6.000 gramsample of anhydrous potassiumcarbonate into a glass weighingbottle. For 47% potassium car-bonate solution, use a 8.000 to10.000 gram sample.

2. Transfer quantitatively theweighing bottle into a 250 milli-liter erlenmeyer flask. Addapproximately 100 ml of dis-tilled water and four drops ofthe modified methyl orangeindicator.

3. Titrate with standardized 1 Nhydrochloric acid using a ClassA 100 milliliter buret until thecolor of the solution changesfrom green to a steel gray.

4. Record the required volume ofacid used to the nearest 0.1 mil-liliter.

CALCULATIONSReport total alkalinity as potassiumcarbonate and/or potassium oxideto the nearest 0.01%.

Let: W = Weight of sample (grams)V = Volume of HCl required

(milliliters)N = Concentration of HCl

(Normality)

% Total Alkalinity as K2CO3 =

% Total Alkalinity as K2O =

REAGENTSHydrochloric Acid, Standardized,

1 N Solution Indicator, Modified Methyl Orange.

Methods are based upon analyticalprocedures as performed at theMuscle Shoals Plant Laboratory.Some variations are included andalternatives are discussed.

DETERMINATION OFPOTASSIUM CARBONATE(Total Alkalinity as PotassiumCarbonate and/or Potassium Oxide)

PPUURRPPOOSSEE AANNDD TTHHEEOORRYYThe alkaline strength of potassi-

um carbonate is determinedthrough titration with hydrochloricacid using modified methyl orangeas the indicator.

Potassium carbonate with eitherpotassium bicarbonate or potassiumhydroxide present reacts with theacid to produce potassium chloride,water, and carbon dioxide.

The alkaline strength of the sam-ple is computed from the volume ofacid required for the titration andmay be reported as either percentpotassium carbonate or potassium

oxide. When required, the exactamount of potassium carbonate canbe determined by subtracting thatportion of the acid required to neu-tralize the potassium hydroxide orpotassium bicarbonate that is pre-sent in the sample.

PROCEDUREThis procedure should be performedas rapidly as possible to preventadsorption/absorption of atmos-pheric CO2.

XI.

K2CO3 + 2HCl → 2KCl + H2O + CO2KHCO3 + HCl → KCl + H2O + CO2KOH + HCl → KCl + H2O

(V)(N)(6.91) W

(V)(N)(4.71)WNOTE:

An automatictitrator may beutilized for easeof analysis, espe-cially if this testis performedoften. ContactTechnical Servicefor further infor-mation concern-ing automatictitration.

Methods of Analysis


48 K2CO3 Handbook

of phenolphthalein indicator.3. Add 10 ml of 0.1 N sodium

hydroxide solution and 100 mlof a 10% barium chloride solu-tion to the flask.

4. Titrate with 0.1 N hydrochloricacid until the pink color is justdischarged. Record milliliters of0.1 N HCl used as Titer “A”.

B. Blank1. To a 500 ml erlenmeyer flask,

add approximately 200 milli-liters of distilled water. Add 4 to6 drops of phenolphthaleinindicator.

2. Add 10 ml of 0.1 N sodiumhydroxide solution and 100 mlof a 10% barium chloride solu-tion to the flask.

3. Titrate with 0.1 N hydrochloricacid until the pink color is justdischarged. Record milliliters of0.1 N HCl used as Titer “B”.

CCAALLCCUULLAATTIIOONNSSKOH is present if “A” is greaterthan “B”.KHCO3 is present if “A” is less than “B”.Only K2CO3 is present if “A” equals “B”.

% KOH =

% KHCO3 =

RREEAAGGEENNTTSSBarium Chloride, 10 % solutionHydrochloric Acid, 0.1 N,

StandardizedSodium Hydroxide, 0.1 N,

StandardizedPhenolphthalein Indicator

DETERMINATION OF POTAS-SIUM BICARBONATE ORPOTASSIUM HYDROXIDE

PPUURRPPOOSSEE AANNDD TTHHEEOORRYYThe bicarbonate (HCO3) andhydroxide (OH) of potassium can-not co-exist in solution. t If hydroxide is present, car-

bonate is precipitated by theaddition of barium chloride.The hydroxide is determinedby titration with standardizedhydrochloric acid.

t If bicarbonate is present, it isconverted to carbonate by theaddition of an excess of stan-dardized caustic soda solution.The carbonate is precipitatedby the addition of bariumchloride solution. The excesscaustic soda is determined bytitration with standardizedhydrochloric acid.

KHCO3 + KOH → K2CO3 + H2OK2CO3 + BaCl2 → 2KCl + BaCO3

PPRROOCCEEDDUURREEThis procedure should be performedas rapidly as possible to preventadsorption/absorption of atmos-pheric CO2.A. Sample1. Weigh a 2.000 to 3.000 gram

sample of anhydrous potassiumcarbonate into a weighing bottleand seal with the cover. For 47%K2CO3 solution use a 4.000 to6.000 gram sample. Record as“W”.

2. Transfer quantitatively the con-tents of the weighing bottle intoa 500 ml erlenmeyer flask. Rinsebottle into the flask using dis-tilled water and cover carefully.Add approximately 200 ml ofdistilled water and 4 to 6 drops

(ml ”A” - ml ”B”)(N)(5.61)W

(ml ”B” - ml “A”)(N)(10.01)W


Handbook K2CO3 49

DETERMINATION OFPOTASSIUM CHLORIDE

PPUURRPPOOSSEE AANNDD TTHHEEOORRYYThis method for determination ofchloride is referred to as either theVolhard or Thiocyanate-Ferric Alummethod. It is applicable to the titra-tion of chloride in acid solutions.When an acidic silver ion solutionand an alkali thiocyanate are mixedin the presence of a ferric salt, thethiocyanate has a selective actiontoward silver, resulting in silverthiocyanate. Any excess of thio-cyanate required by the silver reactswith ferric salt to form reddish-brown ferric thiocyanate, indicatingthe completion of the reaction.

An excess of silver nitrate isadded to a nitric acid solution con-taining chloride and ferric indicator.The excess silver nitrate is titratedwith ammonium thiocyanate.

PPRROOCCEEDDUURREE1. Weigh a 40 gram sample of anhy-

drous potassium carbonate into a250 ml erlenmeyer flask. For 47%solution, use a 50 gram sample.

2. Make up to 100 ml with distilledwater and neutralize sample with1:1 nitric acid using litmus paperas indicator. Caution: Neutralizecarefully - the sample will effer-vesce during neutralization.

3. Add one milliliter of ferricindicator.

4. Add 20 ml of 0.05 N silver nitrate.5. Titrate to reddish-brown end-

point with 0.05 N ammoniumthiocyanate. Endpoint shouldhold for at least 15 seconds.

6. Minimum volumes of AgNO3and NH4CNS should be 10 mland 5 ml, respectively.

CCAALLCCUULLAATTIIOONNSSLet: W = Weight of sample (grams)

N1 = Concentration of AgNO3used (Normality)

T1 = Volume of AgNO3required (milliliters)

N2 = Concentration of NH4CNS used (Normality)

T2 = Volume of NH4CNS required (milliliters)

% KCl =

RREEAAGGEENNTTSSAmmonium Thiocyanate, 0.05 N,

Standardized Silver Nitrate, 0.05 N, StandardizedFerric Indicator Nitric Acid, 1:1 Solution

AgNO + KCl → AgCl + KNO3AgNO3 (excess) + NH4CNS → AgCNS + NH4NO36NH4CNS + Fe2(SO4)3 → 2Fe(CNS)3 + 3(NH4)2SO4

(T1N1 - T2N2)(7.455)W

NOTE: An automatictitrator may beutilized for easeof analysis, espe-cially if this testis performedoften. ContactTechnical Servicefor further infor-mation concern-ing automatictitration.


50 K2CO3 Handbook

DETERMINATION OF SODIUM

PPUURRPPOOSSEE AANNDD TTHHEEOORRYYSodium content in potassium car-bonate is determined with an atom-ic absorption (AA) spectrophotome-ter. The sample is diluted to main-tain total dissolved solids at anacceptable level for proper opera-tion of the burner-aspirator system.An air-acetylene flame is utilized.

Sodium in parts per million (Na,ppm) is determined through a stan-dard additions methodology. Thediluted sample is analyzed alongwith additional sample aliquotswhich are ‘spiked’ with knownamounts of sodium. Most atomicabsorption instrumentation includesbuilt-in programs to calculate stan-dard addition results. If appropriatesoftware is not available, raw sampleresults may be plotted manually andthe content of the original samplemay be extrapolated from the curve.If manual calculation is necessary,curves should be prepared daily. If alarge number of samples is to beanalyzed, it may be sufficient to pre-pare only one or two sets of standardadditions. The slope of the resultingcurve(s) will be suitable for analysisof additional samples providing allsample matrices are similar.

AANNAALLYYSSIISS1. Weigh 10 grams of potassium

carbonate into a 100 ml volu-metric flask. Dilute the flask tovolume with deionized waterand assure that the entire sam-ple is dissolved.

2. Into each of three 100 ml volu-metric flasks, pipet 0.5 ml of thediluted sample.

3. For the first flask, merely diluteto volume with deionized water.

Mark this flask ADD0.4. To the second flask, pipet 1 ml

of a 100 ppm sodium standard.Mark this flask ADD1. To thethird flask, pipet 2 ml of the 100ppm sodium standard. Mark thisflask ADD2. Dilute both of theseflasks to volume with deionizedwater.

5. Set up and optimize your AAaccording to the manufacturer’sspecifications. Analyze all threesamples using the standard addi-tions mode on your AA.a) ADD 0 is obviously the zero

addition.b) ADD1 is an addition of 1

ppm or, if you prefer, anaddition of 2000 ppm if thesample dilution is taken intoaccount.

c) ADD2 is an addition of 2ppm or 4000 ppm if thesample dilution is taken intoaccount.

6. If your instrument does notautomatically calculate resultsfor standard additions, recordthe instrument readout and plotthe results manually. If informa-tion is needed concerning man-ual calculation of standard addi-tions, you may wish to consultan analytical chemistry text-book.

7. If additions were considered as2000 and 4000 ppm, resultsobtained are the ppm sodium inthe original sample. If additionswere considered as 1 and 2 ppm,multiply the result by 2000 toobtain the ppm sodium in theoriginal sample.

RREEAAGGEENNTTSSStandard Sodium Solution, 100 ppm

NOTE: Other techniques,including ICP-AES may be uti-lized. Directanalysis, ratherthan standardadditions, is pos-sible if matrixmatched stan-dards are uti-lized. ContactTechnical Servicefor further infor-mation concern-ing these otheroptions.


Handbook K2CO3 51

DETERMINATION OF IRON

PPUURRPPOOSSEE AANNDD TTHHEEOORRYYThe thiocyanate method is used forthe determination of small amountsof ferric iron. Ferric iron and potas-sium thiocyanate in an acidic solu-tion form a red-colored species. Theintensity is proportional to thequantity of iron present.

Fe+3 + 3CNS → Fe(CNS)3

A visual comparison may bemade between a prepared sampleand a standard. The color intensityof the standard is adjusted to matchthat of the sample by adding a solu-tion containing a known amount ofiron. The volume of standard ironsolution required is used to calculatethe quantity of iron in the sample.

More commonly, especially ifiron is determined routinely, a spec-trophotometer is utilized. A calibra-tion curve is constructed for theinstrument using solutions ofknown iron concentration.

PPRROOCCEEDDUURREE1. Weigh 10 grams of anhydrous

potassium carbonate into a 100 mlvolumetric flask. For 47% K2CO3solution, use a 20 gram sample.

2. Add 25 ml of distilled water andneutralize with 6.5 N HCl usinglitmus paper as indicator andadd 6 ml HCl in excess.Caution: Neutralize carefully -the sample will effervesce duringneutralization.

3. Cool in water bath.4. Add one drop hydrogen perox-

ide (H2O2) and mix well.5. Add 10 ml of 1.5 N potassium

thiocyanate solution and diluteto volume with distilled water.Mix well.

6. Measure absorbance on aBeckman “B” spectrophotometer(or equivalent instrument) usinga wavelength of 480 millimi-crons and a sensitivity setting of“2”. Zero instrument with areagent blank using 50 ml cells.Read within 15 minutes.

7. A calibration curve is preparedby using iron standards in anequivalent potassium chlorideconcentrated solution. Then,starting with Step 4, the sameprocedure is followed.

CCAALLCCUULLAATTIIOONNWeight of Fe (grams) =

% Fe =

RREEAAGGEENNTTSS Hydrogen Peroxide, 30% solutionPotassium Thiocyanate,

1.5N solution (146 g/L) Hydrochloric Acid, 6.5 N

(Weight Fe)(100)Weight of Sample

Microgram Fe from Curve106

NOTE:Other techniques,including ICP-AES may be uti-lized. ContactTechnical Servicefor further infor-mation.


52 K2CO3 Handbook

DETERMINATION OFSULFATE

PPUURRPPOOSSEE AANNDD TTHHEEOORRYYThe addition of a barium chloridesolution to a slightly acidic solutioncontaining sulfate ion results in theprecipitation of barium sulfate.Under specified conditions, the pre-cipitation may be regarded as quan-titative. The barium sulfate is recov-ered and weighed. The sulfate con-tent of the sample is then comput-ed and reported as percent K2SO4.

K2SO4 + BaCl2 → BaSO4 + 2KCl

PPRROOCCEEDDUURREE1. Weigh a 50.0 gram sample in a

600 ml beaker, or 100.0 grams of47% solution. Add 300 ml ofdistilled water and 3-4 drops ofmethyl orange indicator.

2. Add concentrated hydrochloricacid; 1 ml in excess of thatrequired to change the solutioncolor from yellow to red.Caution: Neutralize carefully -the sample will effervesce duringneutralization.

3. Filter through a No. 42Whatman filter paper and washfilter paper with two washes ofhot distilled water, collectingthe filtrate in a 600 ml beaker.

4. Heat the filtrate to boiling, add10 ml of barium chloride solu-tion slowly with constant stir-ring. Continue to boil gently for3-5 minutes. Allow precipitate tostand in a warm place for threehours or at room temperatureovernight.

5. Filter off the precipitate (cold)on a Whatman 42 filter paper,use a rubber policeman to freeany solids sticking to the beaker.

6. Wash the precipitate with suc-

cessive small portions of colddistilled water until a small testportion of the wash water doesnot become cloudy with theaddition of 1-2 drops of silvernitrate.

7. Transfer precipitate and filterpaper to a tared 15 ml crucible(heated 15 minutes at 1000°Fand cooled in a desiccator).Cautiously char filter paper bytilting the crucible on a triangleover a controlled Fisher burner,then heat to about 1000°F forone-half hour.

8. Transfer the crucible to a desic-cator, cool to room temperaturethen weigh. Record weight tonearest 0.0001 gram.

CCAALLCCUULLAATTIIOONNSSReport the results as K2SO4 to thenearest 0.0001%.Let: W1 = Sample Weight (grams)

W2 = Tared Crucible Weight (grams)

W3 = Tared Crucible Weight plus precipitate (grams)

% K2SO4 =

RREEAAGGEENNTTSSBarium Chloride, 10% SolutionHydrochloric Acid, ConcentratedSilver Nitrate Solution, 5%

(W3 - W2)(74.65)W1


Handbook K2CO3 53

DETERMINATION OFHEAVY METALS (as Pb)

PPUURRPPOOSSEE AANNDD TTHHEEOORRYYMetals, such as lead, zinc, tin andcopper, in low concentrations areprecipitated as colloidal sulfides inweakly acidic solution. The turbidi-ty of the precipitated sample iscompared with that of a standardlead solution treated in an identicalmanner.

PPRROOCCEEDDUURREE1. Weigh a 20.0 ± 0.1 gram sample

in a small beaker and transfer toa 100 ml volumetric flask withwater. For a 47% solution,weight 40.0 ± 0.1 grams of solu-tion into a 100 ml volumetricflask.

2. Transfer a 10.0 ml aliquot to a100 ml beaker. Neutralize with1.0 N acetic acid to a pH of 3.0to 4.0. Transfer quantitatively toa 50 ml Nessler tube.

3. To a second 50 ml Nessler tubepipet 2 ml of the standard leadsolution prepared as givenbelow. Dilute to 25 ml withwater and adjust to a pH of 3.0 -4.0 as in Step 2.

4. Dilute both tubes to about 35 mlwith water and add 10 ml offreshly prepared hydrogen sul-fide solution then fill to 50 mlvolume with water. Mix well andallow to stand for five minutes.

5. Compare the sample tube withthe standard by viewing down-ward over a white surface. Thesample should be no darkerthan the standard. The standardsolution contains 10 ppm heavymetals as lead. For other leadlimits, change the size of aliquottaken from lead standard.

RREEAAGGEENNTTSSAcetic Acid, 1 N SolutionHeavy Metals Standard, 10

Microgram of Lead per MilliliterHydrochloric Acid, ConcentratedHydrogen Sulfide, Saturated

Solution

NOTES:Hydrogen sulfideis a poisonous,flammable gas.Commerciallyavailable saturat-ed hydrogen sul-fide solution maybe purchased toavoid the haz-ards of handlinghydrogen sulfidegas.


54 K2CO3 Handbook

DETERMINATION OF MOISTURE

PPUURRPPOOSSEE AANNDD TTHHEEOORRYYTwo methods may be used to deter-mine moisture in potassium carbon-ate. If a relatively complete analysisof the sample is made, then watercan be calculated by difference. Ifthe moisture content is desiredquickly, then the oven loss methodcan be used. In this method, caremust be taken in sample handlingsince potassium carbonate is deli-quescent. When potassium bicar-bonate is present, a correction forits volatile decomposition productsequivalent to 0.3 of the determinedpotassium bicarbonate should besubtracted from the oven loss togive free moisture.

2KHCO3 → K2CO3 + H2O + CO2

PPRROOCCEEDDUURREE1. Weigh a 5.000 gram sample in

an aluminum dish.2 Dry for two hours at 250°C.3. Sample should be placed in a

desiccator for no more than 10minutes. Weigh sample warm,but not at the elevated dryingtemperature. Potassium carbon-ate is deliquescent and will pickup moisture even in a desiccator.

CCAALLCCUULLAATTIIOONNSSLet: W = Sample Weight (grams)

A = Oven Loss Weight (grams)B = Potassium Bicarbonate

Concentration (%)0.3B = Concentration of

Potassium Bicarbonate Volatiles (%);when KHCO3 is small or missing, this term is very small or zero.

% H2O =

PREPARATION OF SPECIAL AND STANDARDSOLUTIONS

Acetic Acid, 1N: Dilute 60 ml ofglacial acetic acid to one liter withwater.

Ammonium Thiocyanate,Standardized, 0.05N: Dissolve3.8062 grams of NH4CNS in waterand dilute to a liter. It is standard-ized against a standard silver nitratesolution, using a ferric alum indica-tor.

Barium Chloride, 10%: Dissolve120 grams of reagent-gradeBaCl2·2H2O in 880 ml of distilledwater.

Ferric Indicator: A saturatedsolution of reagent-gradeFeNH4(SO4) in distilled water.

Hydrochloric Acid,Standardized, 1N: Add 83 ml ofconcentrated HCl to a one liter vol-umetric flask containing distilledwater, dilute to mark and mix well.(This solution is also available com-mercially.) Standardize with 5.0grams of freshly prepared anhy-drous sodium carbonate. Use prima-ry standard analytical reagent gradeNa2CO3. Heat 10 to 20 grams ofsodium carbonate in a weighingbottle at 250°C for one hour.

Hydrochloric Acid,Standardized, 0.1N: Dilute exact-ly 100 ml of 1N standardizedhydrochloric acid solution at 20°C toone liter with distilled water in a vol-umetric flask and mix thoroughly.

(A)(100) - (0.3B)W


Handbook K2CO3 55

Hydrochloric Acid, 6.5N: Add540 ml of concentrated hydrochlo-ric acid to a one liter volumetricflask containing distilled water anddilute to the 1000 ml mark.

Hydrogen Sulfide SaturatedSolution: Prepare fresh solutiondaily. Bubble hydrogen sulfidethrough 250 ml of distilled waterfor 15 minutes in a hood. Hydrogensulfide is very toxic. (A saturatedsolution is available commercially.)

Iron Standard Solution: Dissolve0.7022 grams of reagent-grade ferrousammonium sulfate crystals,FeSO4·(NH4)2SO4·6H2O, in 50 ml of5N nitric acid. Dilute to 500 ml in avolumetric flask with distilled waterand mix well. Dilute 10 ml of thissolution to 1 liter in a volumetricflask and mix thoroughly. One mlequals 20 micrograms of Fe.

Lead Standard Solution:Dissolve 0.1598 grams of leadnitrate, Pb(NO3)2, in 100 ml ofwater containing one ml of concen-trated nitric acid. Solution A: diluteto one liter for 100 micrograms perml. Solution B: dilute 10 ml of solu-tion A to 100 ml for 10 microgramsper ml. Prepare solutions daily.

Modified Methyl OrangeIndicator: Dissolve 0.14 grams ofmethyl orange and 0.12 grams ofxylene cyanolle FF in deionizedwater and dilute to 100 ml.

Phenolphthalein Indicator:Dissolve 1 gram of phenolphthaleinin 100 ml of methanol.

Potassium Chloride, 20%:Dissolve 200 grams of reagent-gradepotassium chloride in 800 ml of dis-tilled water.

Potassium Thiocyanate, (~ 1.5N solution): Dissolve 146grams of reagent-grade potassiumthiocyanate in one liter of distilledwater.

Silver Nitrate, Standardized,0.05N: Weigh out about 8.55grams of silver nitrate and dissolvein a liter of distilled water.Standardize against a standard sodi-um chloride solution by themethod of Mohr, Volhard or Fajous.

Silver Nitrate, 5%: Dissolve 5grams of reagent grade silver nitratein 95 ml of distilled water.

Sodium Hydroxide,Standardized, 0.1N: Dissolveabout 6 grams of caustic soda in ahalf-liter of distilled water and addenough BaCl2 to precipitate anycarbonate that may be present.Allow BaCO3 to settle, then filterinto a liter flask and dilute to markwith CO2-free water. Standardizewith hydrochloric acid using phe-nolphthalein as indicator. To pre-vent CO2 from entering the bottle,the incoming air is filtered througha guard tube containing ascarite.

Sodium Standard Solution:ASTM certified standard atomicabsorption sodium solution.

Armand Products Company469 North Harrison StreetPrinceton, NJ 08540

Customer Service (800) 522-0540NJ only (800) 433-0329Technical Service (716) 278-7071Fax (716) 278-7297

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