Горные науки и технологии (Dec 2020)
Collector for copper-arsenic ore flotation
Abstract
Copper and scheelite concentrates are produced from scheelite-sulfide ores of the Vostok-2 deposit at the Primorsky processing plant. Chalcopyrite, gold, silver, and harmful impurities (arsenopyrite, pyrrhotite) are extracted into the copper concentrate. As a collector, dialkyldithiophosphate-type IMA-I413p reagent is used. Bulk sulfide concentrate is produced using activated carbon and trisodium phosphate; copper cleaner flotation is carried out in the medium of ferrous sulfate. The commercial copper concentrate contains 16 % copper, 33 g/t gold, and 280 g/t silver. The recovery of the metals is 67.6, 44.7, and 50.1 %, respectively. The weight fraction of arsenic in the ore fluctuates in the range of 0.04–0.25%, and that in the concentrate, 0.7–2.3 %. The enterprise looks for ways to increase recovery of the valuable metals and decrease content of arsenic in the copper concentrate to below 1% at the expense of increasing contrast in the separation of chalcopyrite from iron sulfides/arsenopyrite/pyrrhotite. For solving this problem, we performed a study of flotation properties of sulfide collectors based on dialkyldithiophosphates: BTF-15221, BTF -271, non-ionic collector Reaflot-277, and combinations of Reaflot-277 and IMA-I413p. Applying BTF-15221 collector allowed, as compared to the standard IMA-I413p reagent, to increase recovery of copper, gold, and silver and reduce arsenic content in the copper concentrate. The higher selectivity of BTF-15221 as compared to IMA-I413p was confirmed by the fact that the bulk of the increase in copper recovery and decrease in the weight fraction of arsenic in the copper concentrate was achieved in the selective cycle. Besides, during the study, surface activity and hydrophobizing ability of the water-soluble collectors were assessed. Using the example of BTF-15221, it was shown that improvement of the reagent collecting properties can be achieved not only due to increasing the surface activity of the reagent, but also at its decrease – in case of sufficient hydrophobizing ability of the reagent, close to that of the standard reagent. By adjusting these parameters through the use of low-molecular weight homologues of the main components, it is feasible to increase or decrease the selectivity and collecting ability of the reagent. Collector BTF-15221 is of practical interest for further testing in flotation of copper-arsenic and other ore types.
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