flotation-studies.docx

8/16/2019 flotation-studies.docx

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FLOTATION

Flotation is a process of separating fine particles of different minerals from each other bylifting creation minerals at or on a water surface. The mineral particles which are heavier

than water are usually maintained in suspension by surface tension forces. The separation is

then effected by the adhesion of some solid particles to gas bubbles which are introduced inthe pulp. The most commonly employed technique for metallic minerals is called froth

flotation. As the name implies, this involves the production of fine bubbles either from

appropriate chemicals used or from the introduction of air in the system. The valuableminerals then adhere to the air bubbles and float while the gangue minerals remain in the

pulp.

This is usually applied for the concentration of metallic sulfide minerals such as copper sulfides, lead sulfides, etc. At present, however, it has become highly effective in the

treatment of a great variety of oxide ores, native ores, and even non-metallic minerals.

FROTH FLOTATION (!

This process is based on the differences in the physico-chemical properties of variousminerals. The difference can be enhanced by the treatment of the minerals with various

reagents. "# this operation, the valuable minerals adhere to the air bubbles and can be

collected by scraping off the bubbles. $n the other hand, the gangue minerals tend to remainsuspended in the pulp and can be collected after the process has been scooped.

Objectives: This experiment aims to familiari%e with the concentration of minerals using

froth flotation. The student will also be able to learn the effect of flotation time, feed si%e, p&, pulp density, conditioning time and reagent dosages on the wettability of minerals, thus

its ability to float.

Materials and Equipment: 'enver flotation cell, low grade copper or chromite ore, p&

meter or p& paper, )* +mesh sieve, rod or ball mill, vacuum filter, drying oven, balance,

graduated cylinder, graduated syringe, collectors, frothers, lime, conditioners, aluminum pansand trays.

Prcedure:

. repare and clean all materials for the flotation test.

). From a bul of ore, crush and grind samples, and obtain six (/! samples each weighing000 grams by using the appropriate sampling techniques. 1rind your samples using the

rod mill for )0 to 0 minutes.

. 'etermine the amount of slimes by screening through )* mesh. The -)* mesh portion

should be considered as slimes. The 2)* mesh portion will be used as feed in the

flotation test. 3alculate the pulp density based on the 2)* product.


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4. 5un a flotation test maintaining the following parameters6

ercent solids6 07

3onditioning time6 0 minutesFlotation time6 * minutes

article si%e6 -)* mesh (after grinding for 0 minutes!

p&6 acidic or neutral

*. Ad8ust the pulp density to around /9 to 90 percent solids with around 400 ml water and

turn on the flotation cell. :eep the air coc closed.

/. Add the predetermined amt. of collector per gram of feed, and ad8ust the p& to the

desired level using lime at least minutes before the required conditioning time expires.

;. Add water to the desired pulp level of the flotation cell. The pulp level is usually

maintained at around half an inch from the rim of the flotation cell. This should be done

before the frother is added, usually one (! minute before the conditioning time expires.

3hec and ad8ust the p&.

9. $pen the air coc and start collecting the froth using a froth paddle. 3ontinue collectingthe froth or concentrate for * minutes. "f no bubbles are formed, stop the air source and

add very small amount of frother and condition the pulp for 0 seconds, then open the air

coc.

ample and analy%e your products. "f the ore sample is pre-mixed, analysis can be done by the microscopic method. Apply the proper sampling procedure to reduce the amount

of sample and can be analy%ed easily by microscopic method. The analyses of the head,

concentrate and tail products should be conducted in the same way.

. 5epeat the test for the different conditions stated above.

!OR" #A$TIO$%L& TO A'OI( $NNE#E%%AR& REPETITION OF TE%T


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)$I(E FOR (I%#$%%ION%:

. ?hat are the advantages@ disadvantages of flotation over other mineral dressing or concentrating processes

). Bxplain the basic principle of flotation.

. 'ifferentiate sulfide and oxide flotation.

4. Flotation is a very complex process and it requires the investigation of many parameters

that might have an effect on the recovery and separation of valuable minerals.

3onventional flotation test requires many trials and tests in order to determine the

individual effects of each of the flotation parameters. &ow do you decrease the number of trials or test and minimi%e the error in analy%ing the interactions among the flotation

parameters

*. ?hat are the most recent developments of flotation process6 in terms of flotationequipment, reagent application, particle si%e, and grade of ore

flotation-studies.docx

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