By the grace of Allah, Pakistan Foundry Association is celebrating its first decade, completed in the month of March, 2014. I would like to congratulate PFA members on ten years of our existence. During this journey we achieved several milestones. I feel satisfied that PFA is recognized and linked with several foundry associations globally and are in constant communication. Construction of Foundry Service Centre, the first of its kind in Pakistan in collaboration with SMEDA and UET. It is already in operation and providing technical services and skill development in foundry industry. An interactive workshop for young engineers was held by Mr. Joop Kikkert - senior foundry expert PUM, Netherlands has helped them to upgrade their skills.

In this period PFA organized four International Foundry Congress and Exhibitions. I am happy international participation is increasing and the last IFCE was successful in display and participation.

One of our objectives is to bridge the gap between academia and the industry. PFA is providing internship to students of all engineering universities in our member foundries from Karachi to Islamabad. On the job training to students play a vital role in their skills development.

PFA organized many delegations to participate in international foundry exhibitions, GIFA, Turkcast, IFEX, MMI, FSC etc to facilitate export – import related activities and to promote trade, commerce and manufacture of foundry products for local and global markets. I recently participated in 62nd IFC, India and feel our members can get technology up gradation by participating in such events.

5th International Foundry Congress and Exhibition will be held on December 02- 03, 2014 in Faletti's Hotel, Lahore. PFA desires to grow its member's technologies to get business in the global market by interacting with international customers. I understand it is important for all members to participate in this mega event and display their products to enhance their business and collaborative association to make this event a success.

Decade of Evolution

Graded Coal

Uses of Foundry Waste

An Overview of Energy Saving

Energy Efficiency leads to competitiveness

Important consideration in Stainless Steels

02

08

12

20

30

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Foundry Service CenterOppt. Gate # 5, U.E.T, G.T. Road Lahore, Pakistan Ph: +92-42-35023525, 36851559 Cell: +92-322-8487873 Email: info@pfa.org.pk pakistanfoundryassociation@gmail.comURL: www.pfa.org.pk

DECADE OF EVOLUTIONPakistan Foundry Association

PFA Objectives

Milestones in the Journey of PFA

lTo develop skill in various foundry trades through training and expert's advise.

lTo promote establishment of training institutes for foundry technology and assist in transfer of technology.

lTo facilitate export/import related activities of the members.

lTo represent the foundry industry at Domestic and International forums.

lTo promote trade, commerce and manufacture of foundry products for the local and global markets.

lTo correlate the foundry industries of Pakistan with the latest international manufacturing practices.

lTo cooperate with other associations and organizations, to collect information for the members.

lTo compile data on foundry inputs and undertake analysis.

International Foundry Congress & Exhibition (IFCE)

Over the last ten years, PFA has organized 4 International Foundry Congress & Exhibitions in 2006, 2008, 2010 and 2012. IFCE provides an opportunity to interact with the international buyers and customers. A number of foreign countries have been participating in IFEC including Turkey, India, China, UK, Italy, Germany, Japan, Vietnam and Czech Republic etc.

Pakistan Foundry Association was established in the early half of year 2003 and was registered on 15th March, 2004 with the vision to provide a platform for the growth of the Foundry Industry by improving skills and upgrading technology with special emphasis on small and medium sized Foundries. When a few foundries started working on the use of computer simulation technology for foundry in Pakistan, it was realized that technology growth issues cannot produce enormous results unless they are taken up on common platform. Responding to this idea some of the leading foundries teamed up for creating the structure of this great idea.

Members of the association are encouraged to develop a relation that will promote and enhance cooperation, exchange of ideas and experience among the members. PFA has decided to accelerate its efforts in developing the local foundry sector for export markets. Pakistan is set to grow as a producer and exporter of castings, expecting high growth in the auto sector, tractor industry, agriculture machinery, truck and bus sectors.

Abdul Rashid e-mail: pakistanfoundryassociation@gmail.com

02

5th IFCE

ELEMENT Magazine

Website

Foundry Service Center (FSC)

Pakistan Foundry Association will organize 5th International Foundry Congress & Exhibition (IFCE - 2014) on Dec 02, 03 -2014 at Faletti's Hotel, Lahore – Pakistan. The 5th IFCE – 2014 will provide an opportunity to Investors, machinery manufacturers, foundry material suppliers and service providers to showcase their products and services to their counterparts and potential customers to make alliances. The forum shall also provide a platform to the participants to get together & discuss advancements and opportunities in foundry business with eminent academicians and technologists from many parts of the world.The participation of International guests and speakers from Europe, China, India, UK, Turkey, representatives from European & Asian Foundry Associations has been ensured. This mega event will also provide a networking opportunity for members of foundry industry as well as its supply & service sectors.

Pakistan Foundry Association is publishing a quarterly magazine “Element” from PFA Secretariat since 2009. The idea behind printing Element is to share knowledge for the technological up gradation through print media. It is distributed to all leading teaching institutes of Pakistan (dealing in metallurgy), all related government officials, foundrymen all over Pakistan, steel mills, (steel alloys and foundry suppliers, sugar mills, cement factories. It is sent online to foundries in India and other Asian countries members of Asia Foundry Forum, foundrymen in Europe, Iran & GIFA participants. Element is your guide to enhance the corporate image of companies and to grow your business to advertise in.

www.pfa.org.pk PFA is in link with 65 international foundry associations and receiving number of international foundry journals also linked on website for our readers. Here you can find profile, members list and lot of activities of PFA since its creation along with useful links.

The basic problem of the Foundry industry was the scarcity of trained manpower. This issue is being addressed with the development of Foundry Service Center at UET Lahore. Mr. Shahid Rashid – C.E.O (SMEDA), Lt. Gen. (Retd) Muhammad Akram Khan – V.C (UET) and Mr. Sikandar Mustafa Khan – President (PFA) laid down on Feb 25, 2010 the foundation stone of Foundry Service Center (FSC) at UET premises.The operation of Foundry Service Center at Lahore will enable the foundry sector to avail the modern

03

facilities like Computer Aided Pattern Designing, Material Testing, Training and R & D. Foundry Simulation Software has been provided to the Department of Metallurgical & Materials Engineering, UET, Lahore on the recommendation of PFA, to their students for a better understanding of mold filling, solidification, mechanical properties, cost control and extensive database, etc.

In continuation to our services since 2009, PFA will provide internship in the year 2014 to the student of B. Sc Metallurgical & Material engineering U.E.T Lahore, Punjab University, Bahau-din Zakarya University- Multan, NED Karachi, NUST - Islamabad & GIKI - Topi Khyber Pakhtun Kha etc. Our prime objective is for the up gradation of technology and skills development by building up bridges between Academia & Manufacturers resulting in Technical & Human Resource development. PFA has special emphasis on the job training and have invited students for internship in the member foundries.

To up-grade knowledge of foundrymen in small medium industry, technical seminars and workshops are regularly organized by Pakistan Foundry Association. I.e. A two days Interactive Workshop was held on 7-8 November, 2013 in Foundry Service Center U.E.T Lahore, conducted by Mr. Joop Kikkert - senior foundry expert PUM, Netherlands. This workshop was intended to coach the foundry engineers who are responsible for the Method Engineering (designing of Gating / Running Systems in molds) / Charge Calculations for Cupola / Induction Furnace, Green Sand Preparation and dealing with Defect Analysis of various castings.

Netherlands is a non-profit organization for the promotion of sustainability, entrepreneurship, self-sufficiency of small and medium-sized enterprise locally. PUM deploys Dutch senior managers and experts to provide assistance to entrepreneurs in developing countries. Mr. Sjaak Vink-Country Coordinator, PUM for Pakistan, Afghanistan, Russia visited PFA office at September 16, 2013.

a German organization offered Energy Management System (EnMS). After proving EnMS cost benefits in 25 textile industries, GIZ and SMEDA aimed to introduce this system in foundry industry of Pakistan. As a pilot project 5 foundries are picked on merit basis and they are getting the services of EnMS free of cost. Addionally GIZ is been requested to offer their EnMS services to 3 more member foundries of PFA.

is an Agency of the Netherlands Ministry of Foreign Affairs, supporting 48 developing countries in 27 sectors, providing them sustainable strengthening of the competitive capacity of SME exporters and producers, focusing primarily on European markets. Export Coaching Program (ECP) has been started by CBI in Pakistan in which PFA has been enrolled as a Business Development Organization.

To facilitate export/import related activities of the members, Pakistan Foundry Association organize delegations to participate in international exhibitions GIFA, IFEX, MMI, Turkcast, and Automechanica.

Internship for Metallurgical Students

Technical Seminars

PUM,

GIZ,

CBI

International Foundry Exhibitions

04

PFA Executive Committee Meeting with Indian High Commissioner

PAKTURK Business Association (PTBA)

His Excellency Dr. T.C.A. Raghavan - Indian High Commissioner had a meeting with of PFA Executive

Committee on March 19, 2014 at Avari Hotel, Lahore.It was a fruitful meeting to understand a n d d i s c u s s m a t t e r s o f

mutual interest and business development between India and Pakistan. India has progressed in the development of technology and machinery which can be beneficial for Pakistan. Our m e m b e r s a r e interested to get advantage of this opportunity due to easy access and economical prices of machinery. Additionally, we feel there is potential to cooperate in HR development with technical institutes in India for technical managers, floor-shop

supervisors and f o r s k i l l development. In PFA's presentation w e d i s c u s s e d suggest ions to facilitate issuance of visa for the members of PFA. I

thank you for your positive response and feel this will promote interaction for trade.

On 9th March, 2014 PFA had a meeting with PTBA at their office. The objective of this meeting was to give a brief introduction of foundry sector of Pakistan and Pakistan Foundry Association to Secretary General PTBA – Mr. Nida Yilmaz. He appreciated the role and efforts of PFA for the development of foundry sector. He offered to introduce 5th IFCE in Turkish and African foundries and will invite them to participate.

08

Graded CoalIts role in Iron Casting production from Greensand Systems

Foundrymen have often regarded Coal and Carbonaceous additives to Greensand systems for the production of Iron Castings as a “necessary evil”. It is perfectly possible to produce castings with little or no carbonaceous products but experience has shown this is limited to the smaller casting weights and such systems are generally characterised by poorer surface finish and lack of casting definition.

Fundamentally a Greensand system is Silica Sand, Bentonite and Water. To improve the surface finish, improve casting dimensional stability and to have less sand carryover and cleaner castings at knockout, carbonaceous additives are used to good effect. Surface defects, gas related problems often associated with a poor choice of carbonaceous additive, normally results in reducing or removing this carbon additive as the “lesser of two evils” and to spend more time at shot blast to clean the castings.

Looking across the Foundry Industry, Coal is still widely used and is the most cost effective carbonaceous additive and even many “so called” Coal Substitutes or replacements contain a large percentage of Coal. Coal has not only stood the test of time but its set of unique properties actually makes it ideal for Iron Casting production in Greensand Systems. It is accepted theory that Coal not only provides a Lustrous Carbon barrier to metal penetration but its ability to produce Coke helps create a filler between sand voids, resulting in good surface finish, with excellent knockout conditions.

With the correct choice of Coal, the combination of low Ash, high Volatile and Swell Index properties coupled with the key element of grading size, ensures castings are produced free from metal penetration and surface related problems.

Coal, like Bentonite has two moistures, which need consideration. Surface moisture and chemically combined moisture (Inherent), which need to be treated with great respect in storage and processing. This particular property has often given Coal a “bad press” and fires caused by spontaneous combustion have in the past led many Foundrymen to seek alternatives.

By careful selection, safe handling and processing Coal continues to offer a good simple cost effective solution. Coal is subject to regulations in storage, processing and transportation and then further subjected to safe handling and use by the Foundry. Despite these handicaps, it is still ecomonical to the end user and modern processing and grading methods ensure it is used in the optimum condition.

Coal processing plants have to be compliant to the UK directive DSEAR (Dangerous Substances and Explosive Atmospheres Regulations) which is in harmonisation with the European ATEX regulations and in particular to zone 21 and 22 for motorised values and controls. Regular temperature monitoring during processing along with CO measurements ensures safety. Nitrogen purging is an additional safety feature and even after processing, the storage of Coal, either in bulk silos or bags, is carefully monitored for temperature before release to the end user.

A further safety consideration is the ADR regulations ECE/TRANS/140 Volume 1 & 2 (for the safe transportation of dangerous goods) under which Coal and Blended Coal/Bentonite/Lustrous Carbon are classed. Coal and products containing Coal are classed as S2 Organic (not otherwise specified) Solid with a

Safety Consideration

Horizontal Greensand moulding line

Alexandar Brown, Product Manager (Coal / Bentonite), James Durrans & Sons Ltd. e-mail: abrown@durrans.co.uk

09

self heating property subject to UN Number 3088 Class 4.2 regulations. The packing groups 2 & 3, Bulk Loads and Bulk Polybags are covered. Currently paper bags, typically 25 kg, are not subject to ADR.

As a general rule, tests show that blended Coal products have to contain 50% Bentonite to be outwith these ADR regulation rules. Coal and Blended products subject to the regulations need to be transported in dedicated ADR road transport and bulk bagged products need accredited UN3088 ADR polybags. Added to this the drivers must be specifically trained and licensed and the transport vehicles must display the approved orange placard.

For Iron Castings in Greensand Systems, Bituminous Coals are the logical choice but these vary widely in composition and properties. It is the correct selection of properties that helps produce the ideal carbon additive. Of utmost importance is a low Ash content (2 to 3%) coupled with a high Volatile (34 to 42%) and a good Swell Index (2 to 8). These properties can be found in a variety of Coking Coals. Inherent Moisture needs to be considered for safe processing and the production of Lustrous Carbon is key to good casting atmosphere. Under no circumstances can two or more Coals be mixed in processing or final products for safety reasons.

Graded Coal is the term given to ground Coals with the fines (particle sizes below 75 microns / 200 #) effectively removed or reduced considerably. If Coals are used with over 60% below 75 microns / 200 # they lose some of the activity, simply because the release of Volatile is quick and at this very fine particle size they are often removed by extraction systems. A well graded Coal is characterised by zero percentage above 1 mm (such particles may cause surface gas blows) and around a maximum of 30% below 75 Microns / 200 #. This is only consistently achieved by considerable investment in cyclone type extraction processing allied to screening technology.

The ideal Coal grading is dependent on the casting weight and configuration, coupled with the type of moulding plant and the metal analysis. As a general rule, the finer the detail required the finer the Coal grading. High pressure moulding plants, either Vertical or Horizontal, tend to use the coarser grades as these will aid Permeability and the slow release of Volatile is a major advantage in these systems. These coarser grades have the ability to re-cycle and therefore have a positive effect, as well as the important Coke forming stage which helps increase the Total Carbon in the system. This Total Carbon build up is maximised in straight Coal systems and is one of the keys to a successful operation.

Coal is used primarily as a Volatile additive coupled with a Lustrous Carbon formation to ensure metal flows over a deposited carbon layer. This non-wetting barrier to metal penetration is aided by Coke formation. Coal at the interface of a moulding sand under goes a liquid phase expansion and this protects

Types of Coal

Grading considerations

Theory and principles of Carbon in Greensand systems

Quality surface finish from Graded Coal

Typical Knockout condition using Graded Coal

10

against metal penetration. A good Foundry Coal has minimal direct contribution to moulding properties other than Permeability and should be regarded as an essential additive to achieve the desired surface finish and casting dimensional stability.

Other Carbon products used in Greensand systems tend to be either expensive or have very fast and excessive volatile release and fundamentally they do not have the all round properties of a quality Coal. Small amounts can be beneficial when used in conjunction with Coal and Blended products, including “one-shot” (combined Coal / Bentonite / Lustrous Carbon) but these are normally not as efficient or economical as straight Coal/Bentonite systems and certainly not as flexible.

Coal in a Greensand System is a proven key to improved surface finish, good casting “peel” at knockout and reduced sand carryover. Coal has a positive effect on casting dimensions and a helps reduce sand related surface defects by producing a reducing atmosphere and with low Ash content this helps maintain balanced system moisture.

System Sand is the term given to re-cycling Greensand Systems. This method was firstly developed as an economical and environmental friendly way to mass produce castings. Sand continually re-cycles, with top ups of Bentonite and Carbon, and new sand as cores or sand addition, to replace losses to waste or sand carryover at knockout.

It was quickly found that newly prepared facing sands from virgin Silica sand simply could not produce good quality castings because they were “too clean”. These sands lack adequate “spent” products, Coke and other fines that make up the whole picture of a suitable Greensand.

System Sand moistures are often the key to better control and poor Carbon selection is firstly manifested in increased moisture demand. This increased moisture has a detrimental on Bentonite development and helps create “oxidising” conditions on casting. This is often characterised by a whitish finish at knockout coupled with poor knockout and excessive sand carryover.

Quality Coal, if correctly balanced with Bentonite addition will produce “reducing” conditions and the blue finish often observed in well run systems. Allied to this will be a clean casting strip and minimal sand carryover. These Coals with low Ash do not put a strain on moisture demand and this allows the Bentonite to have ideal conditions for maximum development, resulting in a balanced system with low levels of sand related casting defects.

No two greensand systems are the same and not even two plants in the same foundry as they each have unique properties. Some basic rules apply to all systems and these should form the plan for any control tests and action plans.

Bentonite : Coal by weight averages around 3 : 1

Loss on Ignition % : Volatile % also averages 3 : 1

Loss of Ignition should operate between 4.5% (smaller castings) and 7% (+ 10 Kg castings) depending on casting size. Systems with less than 4.5% LoI tend to be too clean and lack enough Total Carbon to be

System Sands

Basic Rules for Carbonaceous additions

Dedicated ADR regulated transport

Quality castings from a horizontal Greensand system

11

effective in producing good surface finish free of casting defects. Such low systems are prone to produce oxidising conditions instead of the preferred reducing conditions and this is normally evident in the knockout condition with excessive carryover of sand.

Ash in Coal should not be above 2.5% otherwise the additional demand for moisture will impact over time on green properties and ultimately on casting performance.

Volatile in Coal should be between 30 and 42% and between 1.8 and 2.5% in system sand.

Moisture in Coal should always be 1% above the Inherent Moisture when supplied. System Sand moisture will be ideally around 3 % and anything above 3.8% should be a major cause for concern.

Grading in Coal should match the type of castings and moulding systems and as rule the finer the detail the finer the Coal but be aware that finely ground Coal (+60% passing 75 Microns / 200# with and AFS of 190 +) will be uneconomical and can be extracted out of the system. Modern high pressure moulding lines benefit from Coarse (75 Grade) to Medium (100 Grade) grades of Coal. These grade numbers refer to AFS numbers.

Total Carbon should operate between 3 and 5% again depending on casting size and moulding line but as a general rule heavier castings +10 Kg will operate 4% with +25 Kg castings around 5%.

Sulphur in Coal is typically between 0.7 and 1.3% and in greensand systems Sulphur levels will vary between 0.03 and 0.15% depending on Bentonite and Core sands used in the system. Sulphur in Coal is not normally an issue as long as below 1.5%.

Many alternatives have been tried and great claims have been laid for complete Coal replacements but to date none have successfully replaced Coal for the simple reason that Coal has many properties that make it ideal for greensand systems. Replacements such as Pitch based products are considered dangerous due to health and handling issues and must be used with caution and in very small amounts (<10%). Products such as Gilsonite can only be used in small quantities due to fast release of volatile and others such Pitch and Asphalt based replacements have a string of label warnings that in the long term make them unsuitable. Some replacements are water based slurries of Carbon based compounds and again these are much more expensive in the long run and do not give either the surface quality or definition supplied by a good graded Coal.

Coal has often been regarded as a problem additive to solve and improve the surface finish of Iron Castings, but at the same time causes other issues such as increased Loss on Ignition, Total Fines and Moisture in System sands. With the careful selection of Coal, these issues are minimized and the advantages considerably outweigh the problems.

Coal has been undervalued in its use to the Foundryman, often regarded as dirty with excessive dust, but in reality Coal has been one the keys to quality castings in combination with a quality Bentonite. Responsible suppliers will continue to process and transport Coal safely and continually search for the ideal Coal.

Coal has a massive continuing part to play in the production of quality Iron Castings and although many alternatives have been tried, there is no real substitute for the all round properties of this wonderful natural resource.

Carbonaceous additives other than Coal

Conclusion

Classic “Blue” Finish from a Graded Coal Greensand system

12

USES OF FOUNDRY WASTERub Nawaz Ansari, Dy. Manager, rnansari@yahoo.comBolan Casting Ltd. e-mail:

The scientists and researchers are involved in finding the uses of the wastes. The recycling of materials, energy production and finding other uses of the municipal, as well as industrial, wastes are the outcome of such activities. In Pakistan the awareness level is lesser than that in the European countries where common citizen knows the types of trashes like paper, plastic, glass etc and disposes off in different bins accordingly. There are many materials which are useful for recycling, for example dry batteries used in mobile phones and many other electronics, that are recycled in the modern world but we are worried about their dispose off methods. Very few people know that the water obtained through water vapors (air humidity) condensation by their air conditioner, for which they worry to dispose off in the sewerage line, is zero conductivity distilled water that they buy in bottles for the wet batteries of their cars. As per a rough estimate a 1.5 ton Split Air Conditioner condenses 40 ~ 60 liters of distilled water in 12 hours depending on humidity factor.

The foundry waste has been in use as land fills for a long time. Even sometimes the foundries find it difficult to get rid of its waste. For instance the cast iron foundry uses silica sand with the mesh size in range of 40 to 55. The raw sand is graded before use and tons of fine and coarser sand is disposed off. The coarser sand than requirement can be supplied as raw material to glass manufacturer [1] who need it while the finer sand is used in many engineering purposes e.g., sand blasting, civil works etc.

The municipality and environmental laws also bound them to dispose off their waste in a proper manner. The modern world has gone through the same problems in the past and different uses have been discovered.

The cast iron foundry wastes mainly include:

£Cupola Slag

£Foundry Sand

The scientists have found very efficient properties of the cupola slag that serve much better the mankind than to be a landfill. The best use found

CUPOLA SLAG:

is its blending in the Portland Cement and roadway building.

During the 9th International Multidisciplinary Scientific GeoConference - SGEM2009, S.P. Demeter D. Baricova and A. Pribulova presented paper that states: “In some countries it is used by roadway building but in Slovakia it is waste only. In some European countries it is granulated and granulation product is used in building industry. Cupola slag is after tipping from cupola furnace casted in to slag dip and put in to waste depot. Cupola slag properties are similar with blast furnace properties and it was reason why cupola slag was used as a replacement of blast furnace slag by concrete production.” [2]

In USA the blend of cupola slag in Portland Cement is patent to Willie W. Stroup, Randy D.Stroup and James H. Fallin. According to the inventors “A slag cement mixture and process of making the same is disclosed. The slag cement mixture is composed of cupola slag and Portland cement. The cupola slag is optionally ground granulated. One embodiment of the process includes rapidly quenching the slag by submersion into water or by spraying water onto it, and grinding the resulting product to achieve a fineness of at least 6000 cm2/g. The process also includes the addition of 35 % ground granulated cupola slag to Portland cement to achieve a stronger and harder cement than Portland cement alone.” [3]

In the summary of the same invention the authors declare that: “Accordingly, The present invention is directed to a cupola slag blended cement with an increased compressive strength. The principal advantage of the present invention is a cement mixture that results in a concrete which is both harder and stronger while providing a means of recycling cupola slag that is both environmentally sound and economically practical. The cement compositions of the present invention have a resistance to expansion due to sulfate attack and alkali silica reaction, and can be formulated to have a wide range of curing times." [4]

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There are hundred of cupola furnaces installed in Pakistan that produce thousands of tons of slag which can be used for a better Portland cement manufacturing with higher compressive strength.

Cupola slag has also been used successfully as road base materials for the construction of highways in Wisconsin, USA. [5]

Foundry sand is basically fine aggregate. It can be used in many of the same ways as natural or manufactured sands. This includes many civil engineering applications such as embankments, flowable fill, hot mix asphalt (HMA) and Portland cement concrete (PCC). Foundry sands have also been used extensively agriculturally as topsoil. [6]

FOUNDRY SAND:

Foundry Sand as Embankment Material:

Foundry Sand in Road Bases:

Embankment materials used in construction are generally classified on the basis of soil type, grain size distribution, Atterberg limits, shear strength (friction angle), compactability, specific gravity, permeability and frost susceptibility. The foundry sand has all the properties which make it a very good embankment material. Foundry sand has been used effectively in normal embankment construction with and without permeability and leachate control. Foundry sands have also been used in conjunction with geogrid systems and with reinforced earth retaining walls that use straps or grids as horizontal tiebacks.

A road base is a foundation layer underlying a flexible or rigid pavement and overlying a subgrade of natural soil or embankment fill material. It can be composed of crushed stone, crushed slag, or some other stabilized material. It protects the underlying soil from the detrimental effects of environment and from the stresses and strains induced by traffic loads.

The road base material should be made of a mixture of crushed rock and enough fine material to hold the rock in place and to provide good compaction. Foundry sand can be used as the fine material in a road base. Engineering properties that characterize foundry sand as a subbase material are plasticity, shear strength, compaction (moisture density relationship), drainage and durability. The better shear strength (ability to resist deformation)

Figure 1. Stepped embankment, Ohio turnpike, Made with foundry sand

Table 2. Foundry sand applications by volume in USA [4]

Application Ranking

Embankments/Structural FillsRoad base/SubbaseHot Mix Asphalt (HMA)Flowable FillsSoil/Horticultural Cement and Concrete Products Traction Control Other Applications

12345678

43.878.5

1.9333.33.380.300.100.300.34

<0.011.180.084.34

97.84

Table 1. Composition of Cupola Slag

Composition of Cupola Slag

Component Proportion (wt. %)

SiOA1 OFe OCaOMgOSONa OK OTiOP OMn OSrOL.O.I.Total

(950 C.)

Alkalies as Na O2

o

33

52

2

2

2

3

2 3

2 3

0.30

14

and compactibility (better compaction) of the foundry strength makes it a better material for road base. Foundry sand has sufficient strength to resist excess breakdown when placed in road bases. Foundry sand has good particle strength that makes it more durable.

Asphalt concrete is the most popular paving material used on our highways and roadways in the United States. The most prevalent type of asphalt paving material is hot mixed asphalt (HMA). This consists of a combination of plant-dried coarse and fine aggregates. They are coated with hot asphalt cement, which acts as a binder.

Foundry sand has been used successfully to replace a portion of the fine aggregate used in HMA. Studies have shown that foundry sand can be used to replace between 8 and 25% of the fine aggregate content [6]. When mixes are properly designed, foundry sand can be an effective sand alternative.

Hot mix asphalt production requires that all constituent products:£ Have inherently good quality characteristics,£Come from consistent, reputable supply sources,£Meet all environmental requirements, and£Are economically competitive with similar

materials.Foundry sand has the potential to be a very high

quality material in hot mix applications. In addition to USA, Canada has also used foundry sand as a fine aggregate substitute for the past 10 years in both foundation and surface HMA layers. Use of foundry sands can be cost effective for both the foundries and the HMA industry.

Foundry Sand in Hot Mix Asphalt:

Figure 2. Construction of HMA pavement

Foundry Sand in Flowable Fills:

Foundry Sand in Portland Cement Concrete:

Foundry Sand in Portland Cement Manufacturing:

Flowable mixtures make up a class of engineering materials having characteristics and uses that overlap those of a broad range of traditional materials including compacted soil, soil-cement, and concrete. Flowable mixtures consist of sand, water, cement and sometimes fly ash.

Flowable fills have been used as backfill for bridge structures including abutments, culverts, and trenches. It has been used for embankments, bases, and subbases. It is commonly used as bedding for slabs and pipes. It has also been used to economically fill caissons and piles, abandoned storage tanks, sink holes, shafts and tunnels.

Most foundry sands can be used in flowable fill mixtures. Foundry sand for flowable fill can be used in a dry or moisture conditioned form. Flowable fills typically contain Portland cement, fly ash, sand and water. Foundry sand can be the major ingredient in flowable fills.

Portland cement concrete (PCC) is a mixture of approximately 25% fine aggregate, 45% coarse aggregate, 20% cement and 10% water. Foundry sand can be used beneficially in concrete production as a fine aggregate replacement.

Various characteristics of foundry sand can significantly affect the quality of concrete produced. When foundry sands without fines replaced a portion of the fine aggregate, the concrete produced had compressive strengths, tensile strengths and modulus of elasticity values comparable to mixtures composed of natural sand.

Concrete can be used for cast-in-place or pre-cast products such as pipes, ornamental concrete units, load bearing structural units (i.e., beams, girders, etc.), utility structures and concrete blocks.

Portland cement reacts chemically with water when hydrating, causing it to set and to harden. When mixed with fine and coarse aggregate, concrete is formed.

Portland cement is manufactured using materials with the appropriate proportions of calcium oxide, silica, alumina, and iron oxide. These ingredients are

15

circulate through the material and to stimulate decomposition.

Foundry sand can be used in the manufacture of fiberglass. Fiberglass is produced by melting silica sand and straining it through a platinum sieve with microscopic holes, thereby forming the desired glass fibers.

It is hoped that Pakistan Foundry Industry will consider the re-use of the foundry waste. With the better co-ordination of the construction sector and the foundry sector, the waste of the foundry may get the status of its marketable by-product and the environmental issues can also be resolved in a practical and more economical way.

1. “THE REQUIREMENTS OF SAND AND LIMESTONE FOR GLASS MAKING.” By EKNEST F. BURCIIARD.

2. AUTHOR/S: P. DEMETER, D. BARICOVA, A. PRIBULOVASunday 1 August 2010 by Libadmin2009

3. 9th International Multidisciplinary Scientific G e o C o n f e r e n c e - SGEM2009,www.s_Hlt375516401_Hlt375516402g_Hlt375516401_Hlt375516402em.org, SGEM2009 Conference Proceedings/ ISBN 10: 954-91818-1-2, June 14-19, 2009, Vol. 2, 683-688 pp

4. “Cupola Slag Cement Mixture and Methods of Making and Using the same”, Inventors: Willie W. Stroup {Maceo, KY(US)}, Randy D.Stroup, {Lewisport, KY(US)}, James H. fallin {Lewisport (US)}, United States Patent Application Publication. Pub. No.:US 2002/0038617 A1, Pub. Date: Apr. 4, 2002

5. “Using recovered materials in highway construction”, Wisconsin Transportation Bulletin No. 20

6. “Foundry Sand Facts for Civil Engineers” May 2004, US Environmental Protective Agency and the Department of Transportation,

Foundry Sand in Fiberglass Manufacturing:

Conclusion:

References:

found in natural rock, like shale, dolomite, and limestone. It is the chemistry of the foundry sand as a silica source that is more important in cement production than is its grain size or shape. The requirements that must be met for foundry sand to be used in Portland cement production are:£ Its silica content equals or exceeds 80%,£ It is a low alkali material,£ A large quantity of sand is available, and£ It has uniform particle sizes.

Foundry sand may be one of the highest quality sources of silica available to the cement industry. The major chemical constituents of raw Portland cement available in foundry sand include silica and alumina and iron oxides. By using foundry sands to replace virgin sands, the quantity of mined virgin sands can be reduced.

Blended hydraulic cements are of particular interest in the beneficial use of foundry sand, since these cements are produced by blending together two or more types of fine materials. Historically, blended cements have included portions of blast furnace slag or fly ash.

The American Foundry Society (AFS) in Illinois studied using green sand from a gray iron foundry in Portland cement manufacture. The cement produced with the foundry sand met all the relevant chemical specifications. The properties of the cement, namely set time and compressive strength, were not affected by the presence of foundry sand. There was even a slight increase in compressive strength.

In January 1994, a green sand manufacturer (Frazer & Jones) in up-state New York shipped 15,000 tons of foundry sand to a cement manufacturer in Ontario, Canada. It was used successfully as a replacement for excavated silica materials in the manufacture of low-alkali Portland cement. The finished product was a high quality Portland cement.

Foundry sand can be used as an additive in topsoil and compost materials. It is ideal for topsoil manufacture because of its uniformity, consistency, and dark color. Since a high sand content is required in topsoil, it is an essential ingredient. In composting, foundry sand reduces the formation of clumps and prevents the mix from compacting. This allows air to

Foundry Sand in Agricultural/Soil Amendments:

Dear Sir/Madam,

The 5th International Foundry Congress & Exhibition (IFCE) on Dec 02 & 03-2014

at Faletti's Hotel, Lahore Pakistan

Pakistan Foundry Association is pleased to announce the 5th International Foundry Congress & Exhibition (IFCE–2014) to be held on Dec 02,03 -2014 at Faletti'e Hotel, Lahore – Pakistan.

Pakistan Foundry Association is a registered organization engaged for the development of foundry sector in Pakistan along with its technological up-gradation and skills development. The foundry industry is the base for the growth of engineering and allied industries worldwide, as such, importance of foundry industry cannot be ignored for the economic development of Pakistan.

The 5th IFCE – 2014 will provide an opportunity to Investors, machinery manufacturers, foundrymaterial suppliers and service providers to showcase their products and services to their counterparts and potential customers to make alliances. The forum shall also provide a platform to the participants to get together & discuss advancements and opportunities in foundry business with eminent academicians and technologists from many parts of the world.The participation of International guests and speakers from Europe, China, India, UK, Turkey, representatives from European & Asian Foundry Associations has been ensured. This mega event will also provide a networking opportunity for members of foundry industry as well as its supply & service sectors.

Pakistan Foundry Association has decided to accelerate its efforts in developing the local foundry sector for export markets. Pakistan is set to grow as a producer and exporter of castings, expecting high growth in the auto sector, tractor industry, agriculture machinery, truck and bus sectors. Pakistan is still an economical market although lying between two giants producers of castings, China & India.

Pakistan Foundry Association cordially invites you to register yourself as visitor, exhibitor and paper presenter in 5th IFCE – 2014.

In case of any query, please feel free to contact the undersigned on following numbers: Land line: 0092-42-35753619/ 35023525 Cell#: 0092-322-8487873 Email: pakistanfoundryassociation@gmail.com , info@pfa.org.pk

Best Regards,

Sikandar Mustafa Khan Abdul Rashid Chairman Secretary Pakistan Foundry Association Pakistan Foundry Association

Foundry Service Center, Oppt. Gate # 5, U.E.T, G.T. Road, Lahore, PakistanPh: +92-42-35023525, 36851559 Cell: +92-322-8487873

Email: pakistanfoundryassociation@gmail.com/info@pfa.org.pk. URL: www.pfa.org.pk

20

An Overview of Energy Saving Opportunities in Foundries

V.S. Saravanan -General Manager, Indo Shell Cast Private Limited

It is well-known to all that foundry industry is highly energy-intensive. Foundry processes and the quality

of the castings produced from the foundries are not only requires quantum of energy but also it requires

quality energy. Normally foundries are using electric energy to produce heat, but other sources of energy

such as diesel, coke, LPG, solar wind etc. are also being used. But primarily electric energy is being used in

majority of the foundries. So, the whole of the foundry sector in India, say about 4500 listed foundries and

other non listed foundries are depending upon the electric power primarily to produce about 10 million

metric tonnes of castings (9.3 million metric tonnes in 2012). Indian Foundry Industry i s planning to reach 20

million metric tonnes of castings in the year 2020 which means the power requirement will also go up to the

two-fold level from the current level. But we are all aware that we are struggling for power production and

distribution to cater the existing demand.

In India over 56% of electricity is generated from

coal-based power plants. Other renewable sources of

energy such as wind, geothermal, solar, biogas and

hydroelectricity contributes 30% of the Indian power

production. Nuclear holds a 3 per cent share.

The share of coal and petroleum is expected to be

about 66.8 per cent in total commercial energy

produced and about 56.9 per cent in total commercial

energy supply by 2021-22. Demand for coal is

expected to reach 980 MT during the twelfth planning

period, whereas domestic production is expected to

touch only about 795 MT in the terminal year (2016-17). The gap between demand and production will be

met through imports. Dependence on import is not always good for any country. So we are in a position to

increase our domestic coal production which is growing at an average rate of 8 per cent compared to about

4.6 per cent in the Eleventh Five Year Plan. Though India is having only 7.1% of world coal reserve, in

consumption it ranked 3rd in the world after China and America. At this rate of consumption, India's coal

reserve is estimated to deplete completely in another 114 years. But it will deplete sooner than the estimate

due to increased demand for the energy. Energy requirement is increasing day by day due to increasing

population and improvement in standard of living.

During the Eleventh Five Year Plan, nearly 55,000 MW of new generation capacity was created, yet an

overall energy deficit of 8.7 per cent and peak shortage of 9.0 per cent continues. Currently, allocated

resources to energy production and supply are not sufficient for narrow down the gap between energy

needs and energy availability.

With the above statistics, foundry industry will be in a critical position to face a tough task in near future

on account of energy requirement and utilisation. But in the midst of all the difficulties we need to grow with

other industry to cater the needs to create a balancing industrial growth.

As foundry industry is the mother industry and catering to all the other industries, stagnation in growth of

foundry industry will restrict the growth of other industries. Auto Industry, a major consumer of castings

amounting to about 32% has planned to increase the casting requirement to 10 million metric tonnes in the

year 2020. So shortage or non-availability of power should not stop the growth of the foundry industry as

well as the dependent Auto and other Engineering Industries.

21

It is estimated that by 2030 India will become the third largest energy consumer after China and USA. Now India is the 6th largest energy consumer in the world and the energy consumption per unit of GDP is 3.7 times that of Japan and 1.5 times that of USA. This is an indication of a high wastage of energy but at the same time it shows a very high energy saving potential.

In the above deficit power situation, we are talking about the growth of this energy-intensive industry which is playing an important role in the nation's continued economic development. We need to work aggressively amidst of so many hurdles to sustain the growth of this industry.

There are a number of barriers which are to be overcome to ensure the energy-efficient working of this industry.

£Lack of training and awareness on importance and necessity of energy conservation.

£Lack of standardisation on equipment and devices.

£Lack of financing and incentives on getting energy-efficient machines since they are costlier than normal ones.

£Lack of effective co-ordination among us.

£Complacency – self-satisfaction with our performance.

£A wrong feeling that energy monitoring and energy-efficient equipment are expensive.

£More importance to production equipment than energy monitoring equipment.

It is the time to revisit our foundry process in terms of energy consumption and the effective utilisation of the available energy. There are many areas which need more focus on energy perspective. In this paper, only some vital areas are addressed in the perspective of energy savings.

Melting is one of the significant areas where it consumes about 60-70% of the total power consumption of the industry. When we talk about the theoretical power requirement to melt the metal we are using only 40 -50% of the input energy to melt the metal and 50% -60% % is going as a waste.

Useful heat energy requirement can be calculated as below :

Heat energy requirement = specific heat of iron weight (Final temperature – Initial temperature)

Specific heat of Iron is 0.11 kcal/kg °C

Weight is 1000 kg

Assuming that final temperature of the metal is 1510°C and initial temperature is about 35°C.

Then the actual heat requirement to heat one tonne (1000 kg) metal upto 1510°C from 35°C is 162250 kcal i.e 189 kW (189 units). This is only a theoretical calculation, here time duration, charge material condition, thermal losses etc are not considered. In practice, we are using 650 kW to 700 kW energy to melt one tonne of metal. Then, minimum of 461 units is going in waste theoretically in the form of convection, conduction and radiation losses. The above calculation indicates that the theoretical efficiency of melting furnace is about 29% only.

Some losses are inevitable due to technical factors but we can save upto 20-30% of the energy from the losses easily by following proper melting practices and proper maintenance of equipment.

Energy losses in melting furnace are classified as follows :

So the above losses are accounted for 40% to 60% of the input energy. So, there is huge potential in saving the energy in melting furnace. We have already seen that in the overall energy consumption in the foundry, melting furnace takes nearly about 60% -70%. So saving 20% energy in melting

Energy Savings in Melting

22

will bring down the overall electricity cost by 12- 15%. The total duration of general melting process can be divided as follows :

From the above table except melting, the other processes are non-value added activities. We cannot eliminate those non-value added process but we can reduce the time duration of these processes which bring down the total duration of the melting process.

There are some simple ways to save the energy in melting which are given below :

£Superheating of metal to be avoided which is not only increase the power consumption but also deteriorate the quality of the metal. Superheating of every 100°C increase in metal temperature will consume approximately 20 units of power.

£Holding of metal is to be avoided for want of chemical composition correction or for any other reasons. Every second is accounted. Also it deteriorates the nucleation potential of the metal.

£ Lids must be used for closing the crucibles to avoid radiation and convection heat losses.

£Proper insulation around the coils is to be always ensured. £Charge material with maximum compaction is required.

£ Bundle scrap of about 30 kg per bundle for 500 mm diameter crucible will give better saving of power.

Process DescriptionS No. Duration in % Process Type

Charging

Melting

Chemical composition correction

De-Slaging

Tapping the metal

1

2

3

4

5

25%

40%

15%

10%

10%

Non-Value Added

Value Added

Non-Value Added

Non-Value Added

Non-Value Added

23

£Foundry returns can be broken into small pieces by using hydraulic breakers. Compact charging will prevent arcing and reduce the cap voltage. So continuous poking of charge material is required for better compaction of charge material.

£ Uniform and continuous charging of materials is required. Dumping the charge material in the furnace crucible at a time is to be avoided. Dumping of charge material may sometimes create bridging.

£ Using clean scrap as much as possible is advisable.

£ The furnace operation must be with full power and full capacity.

£Lining thickness is to be monitored. Excess thickness due to slag deposition will reduce the impedance which leads to more power consumption. So, proper de-slagging should be carried out in the furnace.

Apart from the above, simple ways some of the following actions will also enhance the furnace performance,

£ Installation of APFC (Automatic Power Factor Correction) panel helps us to improve the quality of input energy and to improve the power factor.

£Installation of Harmonic filters will safeguard the furnace transformers.

£Installation of OLTC (Online Tap Changer) will always ensure the uniform and constant input- rated voltage to the furnace.

£De-mineralised water used for furnace cooling (through copper tube) should be with good quality, preferably zero resistance to minimise the leakage current.

£Water circulating through the copper tube should not be over cooled due to excess capacity of cooling towers. Overcooled water will extract more heat from the furnace.

£Electrical loose connections between furnace transformer output and furnace input should be completely eliminated to prevent energy loss in the form of heat. This can be easily monitored by using thermal imaging devices online.

Length of the bus bar should be as minimum as possible to avoid eddy current losses and transmission losses. So furnace transformer location should be closer to the furnace with the minimum possible distance.

The next equipment to be focused in foundries in terms of energy utilisation is the air compressor. It has been estimated that only about 30% of the input energy is converted into useful work and nearly about 70% of the input energy is wasted in the form of friction, heat, work done for converting air pressure into mechanical work and leakage. The following things are to be followed in using air compressors.

£Compressed air is a costlier and if not properly monitored it drains significant amount of money without any indication. So, pneumatic applications can be used only where it is essential and functions which cannot be replaced by any other means. But wherever possible to replace by electrical or mechanical we need to replace it. For example air grinder, pneumatic torque wrenches etc can be replaced by electrical appliances.

Energy Saving in Air Compressors

24

£ Blowers can be used wherever possible. For example, for air cleaning of moulds, if possible compressed air can be replaced by blower air.

£Air leakage in the pipeline throughout the company to be monitored and then arrested and there for which periodic air leak audit should be conducted. It has been estimated that a hole diameter of 6 mm could waste about 70 CFM of air at 5.5 bar pressure which means about entire compressed air generation of 20 HP air compressor. A 3mm hole at 7 bar pressure will drain Rs. 2/minute.

£Air pressure can be reduced to the minimum possible level i.e just sufficient to perform the work since reduction of 1 kg/cm2 air pressure saves 7% of input power.

£Location of the compressor should be closer to the working area.

Pipeline design should not have more perpendicular bends and abrupt changes in size.

£Compressor should be kept away from the heat sources. Every 3°C increase in output air will increase the power consumption by 1%.

£Pressure drop after air drier should be less than 0.5 bar. Pressure drop more than 0.5 bar indicates the poor drier efficiency.

£Filters at the intake side should be cleaned periodically. It will increase the free air discharge (FAD) to about 10%.

£Maintain the correct belt tension between the drives. Poor (loose) belt tension will increase the power consumption by about 5%.

£VFD (variable frequency drive) can be installed to operate the compressor according to the demand to balance the load.

£If two or more compressors are under operation, airlines can be designed separately according to the air pressure requirement of the equipment.

£Isothermal efficiency and volumetric efficiency can be calculated periodically to ensure the performance of the compressor.

£ FRL (filter, regulator and lubricator) units to be installed wherever necessary and proper maintenance to be ensured.

£ Air reservoirs can be placed based on the usage to fluctuation in the compressor load.

£Right-sized motor with right rating to be fixed according to the application.

£ Motor should always run with maximum load for better efficiency, at least 80% of the rated load.

£Energy-efficient motors are now available in the market. Though the cost of these motors are little higher it is worth to install these motors which will repay the money spent in a short span of time through energy saving. For example if we replace a 7.5 HP motor by energy-efficient 5 HP motor, monthly savings will be about 400 units.

£Temperature of the motor body, vibration of the motor, abnormal noises are to be monitored through preventive maintenance. These factors are the indicators of poor performance of the motor. Temperature of the motor should not increase beyond 30°C from the ambient temperature.\

£Balanced voltage in all the three phases is to be ensured for better performance of the motor in terms of current usage, speed and torque.

£Proper maintenance of motor such that cleaning of bearings and journals, lubrication, run out check of output shaft etc will reduce the losses on account of friction and heat.

Energy Savings in Electric Motors

£Rewinding of motor should be carried out by authorised personnel. Improper winding will significantly affect the motor performance. Even with proper rewinding 4% to 6% drop in motor efficiency is inevitable.

£Capacitors can be installed across the motor to reduce the distribution losses and to increase the power factor.

£Belt tensions across the pulleys should be checked to reduce transmission losses and also to increase the loading of motor. Temperature of the motor body, vibration of the motor, abnormal noises are to be monitored through preventive maintenance. These factors are the indicators of poor performance of the motor. Temperature of the motor should not increase beyond 30°C from the ambient temperature.

Normally in foundries, less focus is there in post-casting process such as shot blasting, grinding etc. Ensure the maximum load to the motors fixed in the shot blasting machines. Motor loading can be checked through current meter. For example 30HPmotor at least should take 20amps of current. Less than this value indicates that the motor is not loaded to the optimum level.

We need to check the steel shots volume in the shot blasting machine and also the average steel shots size. If steel shots are not properly replenished, the size of the steel shots are reduced to due continuous abrasive action and become powder finally. It reduces the motor efficiency and also shot blasting quality. Also to get good blasting surface finish we need to do the shot blasting for a longer time.

Periodic maintenance of shot blasting is very much essential. Dust bags are to be checked properly through a regular maintenance. Condition of the dust bags and dust collection systems are playing a vital role in the shot blasting machine performance to have effective utilisation of energy.

Grinding motors used for parting line flash removals and riser pad grinding are consuming significant amount of power. These areas are normally less focused. So we need to take care on all the points discussed under the heading of Energy Saving in Electric Motors. Apart from that we need to check the grinding wheel weight and size which should be suitable to the motor. Balancing of grinding wheels is very important which is affected by grinding wheel dimensions and condition of the motor shaft. Poor quality of grinding wheels exhibit uneven wear which lead to imbalance over the period of time. Care should be taken in selection of grinding wheels also for effective utilisation of energy.

£D.G. sets are to be loaded to the maximum level. At least it should be loaded to 80% to get the maximum efficiency.

Energy Saving in Post-Casting Processes such as Shot Blasting and Grinding

Energy Saving Diesel Generator (D.G) Sets

25

£UPL (units per litre of diesel) of the D.G. set should be between 3.8 and 4.0.

£Suction air quality to be maintained as clean as possible to have better combustion efficiency.

£Nowadays, mixing of hydrogen gas with the air at the air fuel mixing chamber is getting popularised to have better combustion efficiency.\

£Lubricating oil temperature is to be monitored on daily basis. Temperature of the lubricating oil should not cross 80°C even at the extreme condition. Increased temperature will change the viscosity level of the oil and results in poor efficiency of the D.G. set. Contamination of the oil will also result the poor efficiency, for which lubrication oil must be changed once in every 300 running hours at least.

£Bearing condition, transmission shaft condition etc. are to be checked to avoid loss due to friction.

£The coupling of engine to alternator is to be fit perfectly without any slack to avoid transmission losses.

£Underground cable from alternator can be put in copper instead of aluminium for better conduction of current and minimise the transmission loss. Though the initial cost is more for copper underground coil but it will repay us in a very short span of time.

£Radiator is to be maintained properly. Quality of coolant is to be checked for better heat extraction. We should not allow scales inside the pipelines and dust accumulation on the radiator fins. These things will affect the heat extraction efficiency of the radiator which will bring down the efficiency of the generator.

By following proper process techniques and by preventive maintenance, we can save nearly 15% of the energy from the current level without any additional investments. Many of the above things discussed here are not a big science but are logics and common sense. So we can save 15% of our energy only by application of common sense.

Now ISO 50001 system came into existence for energy management system. It is not mandatory to go for ISO 50001 for energy savings and this system also not giving any technical inputs for energy savings, but it tells us the way to save energy through a systematic approach in order to have continual improvement in energy utilisation and energy efficiency.

Energy Audit through a third party or by a approved energy auditor will help us to know our current level and the scope for further improvements. We are aware that one unit of energy savings is equal to three units of energy production. So, to safeguard the energy-intensive industry, we need to work on energy conservation right from this moment.

26

Non Systematic Approach Systematic approach

27

Press release by WFOWFO welcomes New President

Mr. Vinod Kapur has been elected as World Foundry Organization (WFO) President for 2014 and 2015.

Vinod has served on the WFO Executive board for the past five years and is a former President of The Institute of Indian Foundrymen. He is the Chairman and Managing Director of Gargi Huttenes Albertus Pvt.Ltd, a well-respected businessman and foundry material supplier based in Mumbai.

Vinod has long been a familiar face in the foundry industry throughout the world, having joined the then Institute of British Foundrymen in 1973 and has travelled around the globe to develop his extensive knowledge of the Cast Metals Industry.

Speaking of his appointment Vinod said: “I am very thankful to the WFO General Council for their confidence in me and having elected me as President of WFO for the years 2014 and 2015. I feel proud to be in this esteemed position, to represent my country and of course The Institute of Indian Foundrymen”.

The GIZ-Renewable Energy & Energy Efficiency team, organized a three day session on “ESCO Market development in Pakistan” held in the P.C. Hotel Lahore during March 11th-13th, 2014. Topics undertaken in this session were . . .

Another meeting was held on 26th March, 2014 at GIZ office, Lahore between Dr. Frank Fecher (Component Manager – GIZ REEE), Mr. Shahid Rashid (Technical Advisor – GIZ REEE) and Mr. Abdul Rashid (Secretary PFA) to discuss about "EnMS Dissemination Workshop.

The status of EnMS implantation in the foundries and acknowledged that industry has successfully completed the first phase of implementation with some minor delays. The reasons for delays are being taken care of by AFTEC and Libra technologies (software specific).

He added a second monitoring exercise will commence this week and last till 15th April, 2014. Thereafter, more savings are expected to be achieved due to the implementation of EnMS.During the meeting it was decided to conduct "EnMS Dissemination Workshop" on April 29, 2014 for about 20-25 foundry members including GIZ, SMEDA and PFA. A brainstorming session will be held for industries during the workshop to discuss on the energy key performance indicators (ENKPI) and the final output of this activity can be an ENKPI's table.

The purpose of EnMS Workshop is to develop a road map for the future of EnMS success in other foundries and the energy managers training and association by an Energy Manager Trainer (EMT) for the sustainability towards the first milestone. PFA has requested its members to nominate one or two persons from their energy management team to present the success story of their organization with the offer to guide other foundries for EnMS success as volunteers.

Progress in Energy Management System (EnMS) by GIZ, PFA and SMEDA

Foundry Service CenterOppt. Gate # 5, U.E.T, G.T. Road, Lahore, Pakistan

Ph: +92-42-35023525, 36851559 Cell: +92-322-8487873Email: info@pfa.org.pk.

pakistanfoundryassociation@gmail.comURL: www.pfa.org.pk

30

Energy Efficiency Leads to Competitiveness at Astrum Foundry

Two regulated-speed compressors from CompAir have helped Astrum, a steel components manufacturer, to cut its compressed air energy costs by more than a half and increase productivity at its foundry in Country Durham.

Astrum was able to benefit from an interest-free loan from the Carbon Trust to fund the installations, than to high energy efficiency of its new compressed air system.

Based in Stanhope, County Durham, Astrum is a specialist steel foundry making components and assemblies for military fighting vehicles, ground engaging tools for the construction industry and wear parts for the mining industry. In 2008, due to rising energy prices, Astrum embarked on a programme of improving the energy efficiency of its processes.

Mike Hutchinson, operations director at Astrum explains, “One of our key areas of spend is our compressed air system, which is critical to the performance of our plant and is fundamental to our processes for moving sand around the foundry and for operating industrial equipment.”

“ As part of our programme of improving the energy efficiency of our processes, we looked to replace existing compressors and approached CompAir distributor, Air Energy Management to assess our air requirements.”

“Air Energy Management was able to demonstrate that by looking at the overall efficiency of the existing system, and making sure it is designed specifically for our needs, we could save a significant amount of money.”

To accelerate its investment plans, Astrum approached the Carbon Trust and was awarded an interest free loan through its Big Business Reft scheme, which aims to provide businesses with zero-cost capital to invest in new high performance, energy efficient equipment

Hutchinson comments, “The Carbon Trust loan enabled us to install a system that will not only cut power consumption, but will also improve the efficiency of our business.”

“The loan will pay for itself within four years through energy savings alone, and has provided a cost effective way for us to upgrade crucial equipment.”

Working alongside Astrum and CompAir, Air Energy Management developed an engineering solution to reduce the demand on compressed air at the foundry, and replaced old, large compressors with two more efficient, smaller CompAir compressors.

Attention To Details Of Energy Management

Gaining Credits from Carbon Trust

Engineered Solution Provided for Astrum's Unique Needs

Benefits at a Glance£50% reduction incompressed air

energycosts – saving over

££80,000 per annumHigh quality, ex t r a d r y a i r I n c r e a s e d productivity

£Backup compressor forincreased productionreliability

£Hot air ducting – saving

££10,000 per year inheating costs

£Number of air receiversreduced from 16 to 3

Two Regulated-Speed Compressors Help to Cut Energy Costs by 50% at A British Foundry

By: Imtiaz A. Rastgar, web: www.rastgar.com

The CompAir L75 RS and L160 RS compressors both feature regulated-speed technology and are protected and monitored by a Delcos 3100 electronic control system.

Both compressors are linked to a flow measuring system, allowing operators to check airflow, allocate costs to different departments and pinpoint any leakage. In addition to compressors, CompAir also supplied energy efficient thermal mass refrigerant and desiccant dryers. The new system will reduce Astrum's compressed air energy demand by 1,255,000 kWh and save it over £80,000 per annum.

A CompAir L75 RS regulated-speed compressor is located in a small compressor house at the foundry and provides air at 7.5 bar to a bore blast machine for optimum surface quality.

The L75 RS's regulated -speed drive technology matches compressor flow to plant demand with great efficiency. This means that the unit produces the correct volume of air required by the application at all times. The unit is suitably sized to serve a second bore blast machine, should it be needed.CompAir overhauled an existing compressor to provide system redundancy. Previously, Astrum did not have any backup, meaning that if a compressor stopped working, production would be brought to a halt.Hot air venting from the small compressor house ensures that 80% of the energy lost in the compression process is reclaimed. The hot air is ducted into the foundry during winter and out into the atmosphere in the summer, allowing Astrum to turn off heaters, saving £10,000 per year in diesel costs.The second CompAir compressor, an L160 RS regulated-speed unit with Delcos 3100 controller, is located in one of the main compressor houses. Working alongside overhauled existing compressors, the unit provides air for the 5,000-litre main foundry receiver.

Hot air from this compressor room, and exhaust air from the receiver is again ducted into the foundry. A control valve ensures that the receiver can be shut off from the compressor house to eliminate leakage.

The number of air receivers at the Astrum site has been reduced from sixteen to just three, thanks to a more efficient use in the new system. In addition to the two compressors, CompAir has also supplied a desiccant dryer, providing the extra dry air required by a molding machine. The new system also includes low-pressure drop piping, and a leak detection programme. A flow measuring system brings information from all meters into one control panel, allowing operators to check airflow, allocate costs to different departments and pinpoint any leakage.

How Speed Regulated Compressors Save Energy

31

Both compressors are linked to a flow measuring system

32

Important Considerations to Select & Procure Stainless Steels Castings for

Cement Plant Applications

Abstract

Introduction

In recent times, the cement sector has shown overall positive trends with respect to production and export volumes which have compelled the progressive cement producers to investmore in procurement of new plants or up-gradation / expansion ofinstalled capacities.

To attain higher production targets, timely replacement of worn-out or damaged critical parts, especially of high-value castings produced from different grades of stainless steels, is verydesirable. Given the lack of knowledge about metallurgical aspects of cast & wrought steels including stainless steels, the technical and procurement staff in cement sector find it difficult to reach a prudent decision while selecting & procuring steel products. This article intends to provide some basic information about stainless steel castings for their better understanding and to outlines some important considerations while procuring such high-value products - this shall results in substantial savingsby cutting down the replacement costs&shut-down time.

At the time of independence in 1947, Pakistan had only 4 cement plants with an installed capacity of approx.500,000 tons per annum.Over last 6 decades, the cement industry had shown an impressive growth with the establishment of new plants and expansion of the existing ones. Currently Pakistan is ranked as 5th largest exporter of cement in the world which implies that the cumulative production of about 30 cement plants not only meet the current needs of the country but produce surplus quantity for export to a number of countries in the Gulf & African regions, India, KSA etc. Petrographic images of the different grades of cements being produce are given below:

Given this environment the plants have to be kept in running condition for most of the times with constant supply / availability of quality spare parts required for important sections of plant such as preheaters, kiln, clinker cooler, cement mill, ball mills and others. Various steps involved in the production of cement are illustrated below:

Table 1 gives a summary of stainless steel products which are used in the “as-cast” plates for installation in different units of a cement plant.

Engr. Mehak Iqbal Qureshi, Engr. M. Awais Ali & Engr. Dr. M. Iqbal Qureshi Steel Castings & Engineering Works, Gujranwala (qureshi1551@yahoo.com)

Manufacturing Process Flow Chart

Mining: Limestone

Primary &

Grinding & Blending

Pre-heating (4-stage)

Clinker Production

Clinker Cooling

Milling & Mixing

Packing & Dispatching

Cr / NiContent (Wt.%)

SS Grades

SN Applications in Cement Plant

Pre-heaters / Dip Tube plates (Cyclone 1 & 2) 18 / 83044

Pre-heaters / Dip Tube plates (Cyclone 5), Nose Ring Plates 26 /203103

Pre-heaters / Dip Tube plates (Cyclone 3& 4), Bridge& protecting Plates, Cooler Plates26 / 123092

Diaphragm & Cooler plates (Stage 3), Pre-heater (Cyclone 1&2), U-profiles, Retainer brackets26 /04A-2791

33

As evident from the above table, the critical parts for above applications are produced by casting methods using different grades of stainless steels – as the prevalent conditions for such applications demand combination of corrosion, thermal, creep and wear resistant characteristics.

A distinction between stainless steels &other types of alloy steels is generally made on the basis of achromium content which shall be above 10.5% to induce corrosion& oxidation resistance. With a few exceptions, stainless steel castings are classified as "corrosion resistant" when used in aqueousenvironments and vapors below 650°C and "heat resistant" when used above thistemperature. It may also mentioned that the carbon content is also important with reference to the categorization the heat and corrosion resistant casting grades a stainless steel casting with low carbon content is expected to performwell in a corrosive environment whereas the castings with higher carbon contents will have higher elevatedtemperature strength.

Given the fact that all the SS grades included in the table are high-value products, therefore careful evaluation of the manufacturers about their expertise in production of these types of castings, should be exercised in the light of information provided below:

Chromium, nickel, and molybdenum are the primary alloying elements that determine the structure, mechanical properties, and corrosion resistance of stainless steel castings. WhileNi and Cr are known to have the greatest influence on heat resistant castings, the additions of less than 1 %carbon, nitrogen, niobium, tantalum, titanium, sulfur, and slightly larger additions of copper, manganese, silicon, and aluminum are used to modify properties; these minor elements can have a positive or negative effect on properties depending on the application.

Minimum of 10.5% Cr can promote the spontaneous formation of a stable, transparent, passive, protective film while increasing the Cr beyond this level shall contribute in enhancing corrosion resistance.In preheaters and kilns, operating temperatures above 850oC are common and there the presence of Cr provides resistance to oxidation, sulfur-attack and corrosive atmospheres; it further contribute to high temperature creep and rupture strength; and, in some alloys, increases resistance to carburization.

Nickel - primarily a austenite stabilizer – promotes formation of austenitic phase which is stronger and morestable at higher temperatures then ferrite. Lessnickel is needed to retain an austeniticstructure as the nitrogen or carbon levelsincrease. Microstructural transformation from ferritic to austenitic occurs with the addition of nickel to achromium stainless steel, with associated improvement in toughness, ductility, andweldability. Nickel – an important alloying addition, also contributes in increasing resistance to oxidation, carburization, nitriding, thermal fatiguewhile discourage the formation of sigma phase.

Molybdenum additions improve not only the resistance topitting and crevice corrosion but also improvethe mechanical properties of austenitic stainless steels at the elevated temperature especially the strength.

Though minor addition of C andN are unavoidable during melting but in some cases, these elements are addedintentionally; for example, increasing the carbon content improveselevated temperature strength and creep resistance,but reduces ductility. On the other hand, carbon have tendency to form chromiumcarbides along grain boundaries thus reducing corrosion resistance adjacent to the grainboundary (sensitization) and can lead tocorrosion of chromium-depleted areas resulting in intergranular corrosion. Titanium,columbium, and tantalumadditionspreferentially combine with carbon andnitrogen to prevent sensitization and eliminate susceptibility inter-granular corrosion& subsequent fracture. Adding sulfur, selenium, and lead improve

Influence of Alloying Elements

Chromium

Nickel

Molybdenum

Other Minor Alloying Elements

34

Cement cooler grate plate(HH) Rotary cement kilnentrance ring:

machinability of stainless steel.Columbium & Copper additions can improvecreep strength&resistance to acidic attack, respectively. Silicon (generallylimited to 1.5%) assists to increasefluidity of melt and hence improvecastability but it adversely affect creep and rupture properties (especially above 8150C) if Silicon content exceeds 1.5% limit. Silicon, in the presence of alloying elements such astungsten or niobium (columbium) improves hightemperature strength& oxidation resistance. Aluminum also improves resistance to oxidation.

From the above, it becomes clear that chemical composition and microstructure differences between the wrought and cast versions of stainless steels can affect performance. Some stainless steel casting grades can be precipitation hardened by heat treatment, but the mechanical properties of most rely on their chemical composition. The yield and tensile strengths of castings are comparable to their wrought equivalents.

Cast stainless steels generally have equivalent corrosion resistance to their wrought equivalents,but they can become less corrosion resistant due to localized contamination, micro-segregation, orlack of homogeneity. For example, mold quality may cause superficial compositional changesthat influence performance, and carbon pick-up from mold release agents can affect corrosionresistance.

Welding

Machining

Considerations for Ordering / Procurement

Welding is used to upgrade the quality of castings as well as during fabrication of assemblies that are too large or complicated to be produced as a one-piece casting. Welding is also used to improve the surface and eliminate shrinkage voids. If the welding is done properly, it will not adversely affect the performance of the casting. Grade, filler metal, surface preparation, welding process, heat treatment, and testing weld quality should be considered whenevaluating welding techniques. Castings have equal or better weldability than their wrought equivalents, butthere are variations in weldability from grade to grade.

Stainless steel castings are generally more difficult to machine than carbon steel and require comparatively slow speeds and moderate feeds. If carbide tooling is used, the speeds should be increased by a factor of two or three

Successful machining is dependent on avoiding work hardening of the metal ahead of the cutting tool. Techniques that minimize work hardening include sharp cutting tool edges, positive rake angles, adequate clearance angles, avoidance of dwelling, and machines and setups with sufficient power and rigidity to keep vibration to a minimum. Feed rate and cutting depth should be set so that subsequent passes are below the previously work hardened layer.

1. Since high-value stainless steel castings are high performance products and are custom-made to meet the requirements of demanding conditions, consistent communication between the producer and buyer/ordering firmwill have significantinfluence on achieving the goals pertaining to quality & timely

delivery. The buyer should share all the information based on their earlier experiences of using the product

07

(s) and problem faced.

2. Casting methods, properties and fabrication and design considerations need to be discussed for evaluation and selection. Technical literature only providesgeneral information and typical applications only for reference purposes. Before making a final decision, the buyer / end-user should obtain specific informationfrom the supplier (s)because service conditions and performance requirements vary.

3. To ensure timely delivery and low costs relating to testing, unusual and unnecessary tests must be avoided. The best quality assurance is affected by working closely with the supplier /firm who possess long experience in the field and have qualified & experienced technical staff.

4. The procurement staff, during the bidding and design process, should provide to supplier / producer (foundry) all the details pertaining to theser v ice environment ( temperature, corrosiveenvironment, loading, thermal variation etc.), installation techniques (welding, machining) in addition to the specifications and standards' requirements of thefinished product(s).

5. If substitution of forgings or welded assemblies by casting is required for the purpose of improving performance and reduce costs, a consultation between the technical staff at both ends is highly desirable at anearly stage and for reaching complete designdetails and dimensions.

1) Davis, J.R., Stainless Steels, ASM International, Metals Park, Ohio, 1994

2) Bradley, Elihu F, High Performance Castings: A Technical Guide, ASM International, Metals Park, Ohio, 1989

3) Steel Founders Society of America, Steel Casting Handbook Supplement 8 High Alloy Data Sheets, Corrosion Series, SFSA, Rocky River, Ohio, 1981

4) ASM International, Metals Handbook, Ninth Edition, Volume 15, Metals Park, Ohio, 1988

5) ASM International, Metals Handbook, Tenth Edition, Volume 1, Metals Park, Ohio, 1990,

6) ASM International, Steel Casting Handbook 5th Edition, ASM, Metals Park, Ohio

7) Sedriks, A. John, Corrosion of Stainless Steels, 2nd Edi., John Wiley & Sons, 1996

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