The authors experimentally compared collecting properties of diisobutyl dithiophosphinate (DDP), butyl and isobutyl xanthate, and diisobutyl and dibutyl dithiophosphate relative to pyrite, chalcopyrite and other sulfides. It was found that pyrite adsorption grew in nonfrothing flotation with all the listed collecting agents. The nonfrothing pyrite flotation by DDP showed higher rates of adsorption and flotation as against butyl xanthate. The ratio of DDP and butyl xanthate flotation rate constants was 1.19, which agreed with the ratio of the adsorption rate constants of 1.18 in nonfrothing flotation. The low selectivity of dithiophosphinates toward sulfide ores is explained.

A computational method for selecting collectors to investigate the flotation separation of minerals using the principle of hard and soft acids and bases (the Pearson principle) is presented with the e

The results of experimental investigations into the zeta potential of ultrafine sulfides (chalcopyrite, tennantite, galenite, sphalerite, pyrite, and pyrrhotine), the floatability of monomineral fractions of sulfides of the floatation coarseness (–0.1 + 0.05 mm) in a mechanical flotation machine, and the floatability fine particles of sulfide (–0.044 + 0.010 mm) in the Hallimond tube are presented. The preparation procedure of ultrafine powders and sulfhydril collectors to measure the zeta potential is presented. Zeta potentials of the surface of mineral particles and insoluble forms of sulfhydril collectors are investigated in the pH range from 2.0 to 12.5 (an acidic medium was formed by using H₂SO₄ and basic one by using NaOH or Ca(OH)₂), and various values of zeta potentials are found for sulfides in the sodium hydroxide and lime medium. Zeta potentials for all sulfides are negative in the NaOH medium at pH > 9.5, they are positive (1–18 mV) in the Ca(OH)₂ medium at pH > 11, and zeta potentials for chalcopyrite are positive in the studied range \(p{H_{Ca{{\left( {OH} \right)}_2}}}\) 9.0–12.5. The values of the isoelectric point in the medium of sulfuric acid and sodium hydroxide are as follows: for chalcopyrite—pH 6.5 and 8.8, for tennantite—pH 3.0, for sphalerite—pH 5.1 and 6.4, for pyrite—pH 3.1 and 8.9, and for pyrrhotine—pH 7.0. In the lime medium, the value for tennantite and sphalerite pH 12.0, for galenite—pH 11.2, for pyrite—pH 9.5 and 11.2, and for pyrrhotine—pH 9.5 and 12.1. Measurements of zeta potentials of ultrafine sulfide particles give the opportunity to refine the interaction mechanism of sulfhydril collectors with sulfides and associate the nonselective recovery of final tailings of sulfides in the highly alkaline lime medium with the contribution of the electrostatic component during the adhesion of ultrafine sulfide particles on bubbles and their mechanical carryout into the froth product.

The results of investigations into increasing the contrast of process properties of calcite and scheelite due to the combined application of water glass wi

The results of the studies on butyl xanthate ionized sulfhydric collector fraction or isobutyl dithiophosphate fraction in combination with thionocarbamates (ITK), as well as butyl xanthate fraction in combination with sulfhydric collector M-TF, which itself is a combination of thionocarbamate and dithiophosphate, affecting chalcopyrite, sphalerite, pyrite and pyrrhotine monominerals flotation rates, are analyzed. Special techniques, used for sulfides preparation for flotation studies, are described. It is shown, that combination of ITK with isobutyl dithiophosphate is characterized by a lowest flotation activity with respect to pyrite, and combination of M-TF and butyl xanthate demonstrates an extremely low flotation activity with respect to pyrrhotine. It was established, that increasing butyl xanthate fraction in any combinations leads to increase in flotation rates of all monominerals. Recovery into concentrate with application of butyl xanthate is higher for pyrite, than for pyrrhotine. Sulfhydric collectors films are visualized on chalcopyrite surface for the first time. Application of M-TF reagent in combination with butyl xanthate on copper-pyrites ore sample provided for selective separation of copper sulfides into primary fractions in contrast to conventional reagent regime with butyl xanthate. The highest rate constant of flotation corresponds to M-TF combination with butyl xanthate in a 4 : 1 and 3 : 1 ratio, depending on ore material composition. The studies were performed with the aid of the Russian Science Foundation Grant (Project No. 14-17-00393). The equipment of the SUC «Metal Science and Metallurgy» of the National Research Technological University «Moscow Institute of Steel and Alloys» was used in the studies performed.