This paper discusses the results of flotation tests on finely dispersed Cu–Pb–Zn–Fe–sulphide ore of the in which microbubbles finer than 50 µm were used as carriers. It was found that volume dosage of microbubbles in the amount of 0.1 liter per kilogram of solids increased the flotation rate of various sulphide ore components by factors of 2–4 and recovery by 0.5–3%. An analysis of the recovery kinetics was performed using previously developed theory of combined microflotation. It was found that the major effect of using microbubble carriers, which has led to the gain in flotation rate efficiency, can be attributed to the fact that the effectiveness of particles and microbubbles hetero-aggregation exceeds the capture efficiency of particles by coarse bubbles by factors of more than 50–70 and the flotation rate of mineralised microbubbles by coarse bubbles by several times compared to the flotation rate of separate particles.

The article presents the results of laboratory research on the possibility of flotation processing of copper-containing technogenic raw materials. Studies were performed using a sample of copper-containing tailings obtained after the processing of copper ore from the Kazakhstan deposit and a composite flotation reagent. The application of a combination of various collectors allows for raising technological indicators of flotation. The purpose of the research is the increase extraction of copper at flotation of copper-containing technogenic raw materials with the application of a composite reagent. The studied sample of tailings contains 0.23% of copper. A mixture of sodium butyl xanthate and thionocarbamate in the ratio of 1:1 was used as a composite flotation reagent. Parameters of flotation of copper-containing tailings were worked out: degree of regrinding, charges of sodium butyl xanthate, blowing agent T-92, and a composite reagent. Composite flotation reagent was fed into the flotation process of copper-containing tailings in the form of emulsion produced in a T 18 digital ULTRA-TURRAX dispersant. The optimal emulsification time of the composite flotation reagent was 1 min. Without emulsification in the composite reagent the percentage of particles smaller than 1.192 µm is 55.047%. After emulsification of the composite reagent for 1 minute, the percentage of particles smaller than 1.192 μm is 91.134%. In optimum basic mode the rough copper concentrate with a copper content of 4.2% was obtained with the extraction of 61.56%. With the use of a composite reagent, a blister copper concentrate with a copper content of 4.5% and a recovery of 66.54% was obtained. Extraction of copper increases by 4,98%.

The article presents the results of laboratory studies on the effect of the liquid-gas ratio and the foaming agent type on the average water-air micro dispersion size obtained from the foaming agent solution. The size of microbubbles significantly effects the efficiency of flotation and depends on the type and concentration of foaming agent used for their production. A generator was used to obtain water-air micro dispersion. The works were performed to work out the water-air micro dispersion parameters of at different liquid-gas ratio and different performance of the generator. The following foaming agents were used as objects of research: sodium butyl aero flot (BTF), flotanol C-7, butyl triethylenetetramine (B-TETA) at a concentration of 0.5 g/dm3. It has been established, that the optimal phase liquid-gas ratio was 1:1, the optimal capacity of the generator was 6-7.2 dm3/h with an average particle size of air-water micro dispersion- 33-41 mm for BTF solution, 103-107 mm for C-7 solution, 90-93 mm for B-TETA solution. The type of foaming agent used in flotation effects the size and stability of microbubbles. It is established that the flotation agents can be arranged in the following line with respect to their ability to create micro dispersion: IIBK→Senfroth 580→B-TETA→OPSB→Flotanol C-7→T-92→BTF. The best results are shown by BTF that creates micro dispersion of 43-58 μm (t 20-40 °С) and stability of 80 sec with concentration of 0.5 g/dm3.

The Shalkiya deposit lead-zinc ore flotation processing regimes were developed with application of regrinding and apolar reagent based on oil and diesel fuel. An optimal ore grinding flow sheet was proposed, including feed grinding prior to flotation to 80 % of –0.074 mm size fraction, regrinding of the first lead cleaning cycle froth product to 97 % of –0.074 mm size fraction and scavenging lead flotation cycle tail — to 99 % of –0.074 mm size fraction. The Kumkolskoye deposit oil and diesel fuel mixed in the ratio of 1 : 1 was used as apolar reagent. It is shown that application of regrinding and apolar reagent, if compared with the plant established regime, permits to increase zinc content in zinc concentrate by 3.83 %, and zinc recovery — by 9.42 %; lead content in lead concentrate is increased by 5.18 %, and its recovery — by 12.36 %. With that, lead content in flotation tail decreases from 0.87 to 0.5 %, that of zinc — from 1.42 to 1.0 %, i.e., losses of lead and zinc in flotation tail are decreased by 20.07 and 10.29 %, respectively.

Producing of heterogeneous concentrates with good recovery in the processing of polymetallic ores is a challenge. Many factors must be taken into account including ore grinding, reagent mode, water composition, pulp density and the volume of supplied bubbles when producing high-quality selective concentrates. Microbubbles smaller than 50 μm in size were produced based on the frother oxal T-92 at different concentrations using a generator. The most optimal number of microbubbles smaller than 50 µm was produced at a T-92 concentration of 0.5 g/dm³. Polymetallic ore of Kazakhstan deposit was used for flotation studies. The studies were conducted in the copper-lead rough concentrate producing cycle. Flotation active minerals chalcopyrite and galena pass into the foam product, while sphalerite and pyrite remain in the chamber product in this cycle. In this paper, the density of pulp (20, 30 and 50%) as one of the main factors that effects the selectivity of flotation is studied. The kinetics of ore flotation in the base mode and with the use of a microbubble generator has been studied at these densities. Test experiments have been performed at the optimum density. The use of a water–air microemulsion generator makes it possible to maintain the quality of the copper-lead concentrate and increase the extraction of copper into the rough concentrate by 7.41%, lead by 5.98%.