The development and implementation of new TTC flotation chemicals

Abstract

Batch floats were done on Merensky ore from Section 10 at Impala Platinum. The ultimate objective of this project was a pilot plant trial and certain questions had to be answered before the trial could be conducted. To circumvent decomposition of trithiocarbonates (TIC's) in water, tablets, solvents and emulsions were prepared and tested as carriers of TIC's in the flotation system. The emulsion gave the best result. The decomposition rate of short chain ionic and covalent collectors in water were measured. In water iC3-TIC was less stable and decomposed faster than the corresponding xanthates. Long and short chain ionic TTC's, covalent TTC and long chain mercaptans were evaluated and compared to the standard collector. iC3-TTC dosed in an emulsion showed significant improvement on the standard at Impala Platinum. Combinations of the collectors also showed good results. Mineral potential data for the TTC's differed from xanthates. The TIC dosed as a powder or in emulsion showed a two step drop in potential. At this stage the only conclusion from this is that xanthates and TTC have a different mechanism of adsorption. Three collectors were chosen for testing on a continuous 60 litre cell at Impala Platinum. iC3-TTC dosed in water and the emulsion were compared to the standard collector. A 2.8% and 5% improvement on PGM and nickel recovery was observed with the emulsion.