METHOD FOR ENRICHMENT POLYMETALLIC ORES CONTAINING NICKEL, COPPER AND IRON SULFIDE MINERALS Russian patent published in 2017 - IPC B03B7/00 B03D1/02 

FIELD: mining.

SUBSTANCE: method of enrichment of polymetallic ores comprises grinding ore raw components, collective flotation of sulfide minerals in the presence of sulfhydryl collectors such as xanthate and aeroflot to obtain a collective sulphide concentrate with froth product and rock tailings with flotation tail. The obtained collective sulfide concentrate is desorbed succesively in two stages. At the first stage of desorption sodium sulfide is pumped into the slurry, at the second stage - activated charcoal is pumped in an amount to provide a weight ratio of the said pumped sulfhydryl collector at the step of collective flotation collector, sodium sulfide and carbon in the range of 1:(4-18):(4-18). Then collective sulfide concentrate is regrinded untill there are at least 80% of particle of size grade under 30 microns, processed with alkaline of reagent regulator medium (pH to at least 11.5 units.) and transferred to a selective copper-nickel flotation using fresh and/or cleared water carried out in several stages. Meanwhile the collective sulfide concentrate pulp with the desorbed sulfhydryl collector is pre-aerated at first and then flotation of copper minerals is carried out in the presence of copper mineral collector of the dithiophosphates group and frother, with sulfidization of copper minerals with sodium sulfide, and activation via pumping in the pulp of a sulfidizating agent(s)-aktivator(s) of flotation of copper minerals with acidic properties until the pH value of the pulp level achieves 10÷10.5 units. At the beginning of each subsequent flotation stage pH is reduced by 1÷1.5 units until pH value achieves the level as at the stage of discharge of the finished copper concentrate of 5.5÷8 units. Flotation tail of the selective copper-nickel flotation is a nickel-pyrrhotite product which is regrinded prior flotation separation until there are at least 80% of particle of size grade under 30 microns. Release of nickel iron sulphides with high nickel content is performed in the presence of dimethyldithiocarbamate and a sulfhydryl collector at the weight ratio of (3÷15):1. PH values at the stages of separating nickel iron sulfide from low nickel pyrrhotite are maintained at the range from 9.5 to 11 units. Flotation tail at the first separation stages with low nickel contents is subject to control separation and low nickel pyrrhotite is obtained with the flotation tail. Flotation tail at the subsequent separation stages is transferred to the control flotation to obtain a pyrrhotite concentrate with froth product.

EFFECT: increase in the degree of separation of the collective sulphide concentrate.

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