The effects of mixtures of potassium amyl xanthate (PAX) and isopropyl ethyl thionocarbamate (IPETC) collectors on grade and recovery in the froth flotation of a nickel sulfide ore

Potassium amyl xanthate (PAX) and sodium isobutyl xanthate (SIBX) are commonly used collectors in both the bulk and selective froth flotation of sulfide ores. These thiol xanthate collectors are conventionally mixed together as well as with more selective thiol collectors such as dithiophosphates (DTP) and dithiocarbamates (DTC), in order to improve selectivity. With deteriorating nickel sulfide ores, more selective collectors and collector mixtures are desired for the efficient extraction of nickel. Thionocarbamates (TC) are another group of thiol collectors used for selective froth flotation of sulfide minerals. Thionocarbamates are especially used in the selective froth flotation of chalcopyrite over pyrite and galena, but little is known about its selectivity with regards to nickel. Thionocarbamates are also more stable over larger pH ranges in comparison to xanthates and they possess beneficial frothing properties. This study compared the effects of using potassium amyl xanthate (PAX), isopropyl ethyl thionocarbamate (IPETC), sodium isobutyl xanthate (SIBX) and their mixtures in the froth flotation of a pentlandite ore. In the mixtures of PAX or SIBX with IPETC, the xanthate accounted for 95.5 mol% and for the PAX and SIBX mixture a 50:50 mixture was used. This study showed that the highest cumulative nickel grades were obtained with PAX, SIBX and there mixture. The highest cumulative nickel recoveries were obtained with IPETC and its mixtures with PAX and SIBX (50-62%).