Question

Question 2 (5 marks) A nickel ore contains the following valuable and gangue minerals: Valuable minerals: minor millerite (NiS), major pentlandite (Fe,Ni)Ss) Gangue minerals: minor pyrite (FeS2), major Lizardite (MgsSi2Os(OH)) Xanthate, polypropylene glycol, copper sulphate, carboxy methyl cellulose (CMC) and lime are used in the flotation of this nickel ore to separate valuable minerals from gangue minerals. Explain the role of each of the reagents used in this process.

Answer 1

Mostly gravity-separation and flotation methods are used for separation of valuable minirals from Nickel ore.

(a) Xanthate is mainly used as a collector which is a chemical that attaches to the mineral surface and produces a hydrophobic (water-fearing) surface. While certain minerals are naturally hydrophobic and do not require a collector, recovery is often improved when a collector is used. This water-repellent film facilitates the attachment of the mineral particle to the air bubble

(b) Polyprolylene glycol is a low moleculer weight alcohal based solvent commonly used as "frothers" that produce the froth or foam on which the flotation process depends.

(c) Copper sulphate is useful in in solvent extraction unit as a hydrometallurgical process

(d) Carboxyl methyl cellulose (CMC) is well know emulsifier which creates an emlsions and thus inenhances the separation.

(e) Lime is used as flocculant for ore separation. Lime is also often used to raise the pH of the mixture and reduce the flotation of valueless minirals.