The article presents the results of flotation beneficiation experiments for polymetallic ore of complex mineralogical composition with the use of alkylbenzenesulfonic acid (ABSA) as a frothing reagent. Additional experiments showed the highest efficiency of ABSA application for samples of mixed-type ores, showing a significant increase in the recovery of gold, copper, zinc, and lead in the collective concentrates of flotation beneficiation. The use of an ABSA activator promotes the additional cleaning of fragments containing valuable metals from oxide films and coatings, as well as the transfer of microparticles of valuable metals due to the adsorption properties of organics and the formation of metal–carbon bonds. Another effect of this reagent use is an increase in the mass yield of concentrate while maintaining the quality parameters. Gold recovery in the main collective flotation concentrate more than doubled from 46.81 to 97.06%; copper recovery increased from 67.5 to 90.8%, zinc from 22.04 to 58.81%; and lead from 51.13 to 81.1% during the beneficiation process of polymetallic ore with the use of ABSA. A similar effect was observed for beneficiation of copper ore with complex composition; copper recovery in the main concentrate increased from 33.57 to 87.61%. Selective flotation with the development of gold concentrate from difficult-to-beneficiate polymetallic ore also showed a significant increase in gold recovery from 60.41 to 90.24% with ABSA pretreatment.

The depletion of high-grade copper ore reserves in Kazakhstan, coupled with the increasing proportion of refractory ores and the high costs of extraction and processing, necessitates the development of efficient and economically viable technological solutions. In this context, biogeotechnology has gained considerable attention. Recently, alternative approaches based on the use of natural organic compounds—so-called bioreagents—have been introduced into the field of bioleaching. The present study aimed to investigate the effect of amino acids, aliphatic alcohols, and alcohol-based industrial by-products, used as bioadditives, on the bioleaching of copper. The results demonstrated that the influence of amino acids on copper bioleaching decreased in the following order: glycine > leucine > cysteine > histidine > asparagine. Furthermore, the addition of fusel oils, a mixture of aliphatic alcohols, to the bioleaching pulp enhanced copper recovery, achieving extraction efficiencies exceeding 90%.

The article presents the results of an environmental experiment conducted under the green utilisation project for mining waste from hydrometallurgical copper production. The primary objective of this project was to investigate the feasibility of safely conserving spent copper ore through the creation of soil and vegetation layers. The ore, after sulfuric acid leaching using iron-oxidising bacteria, which contributed to increased copper recovery and reduced sulfuric acid consumption, was used as the object of research. When more than 80% of copper was extracted from the ore, and the pH of the wastewater was subsequently increased from 2.0 to 4.0, a soil layer was applied to the surface of the mineral raw materials, and seeds of acidophilic herbs were planted. Subsequent observations of the plants over several months revealed their stable growth, the formation of a root system in the soil layer, and the capture of part of the ore dump layer. Additionally, there was a gradual decrease in wastewater acidity to a pH range of 6.0-6.5.

The article presents the results of experiments on the extraction of uranium from black shale rock by the combined method of reverse flotation followed by leaching with sulfuric acid. The shape of the uranium in the test sample is typical for such types of black shale rock. The distribution of uranium in silicate and carbon-containing fragments makes it difficult to isolate it by the standard flotation method and reduces extraction by sulfuric acid leaching. Based on the characteristics of the composition of black shale rock, studies were conducted on the extraction of uranium by reverse coal flotation, using various grinding modes and the addition of an oxidizing reagent - trichloroisocyanuric acid (TCCA). The effect of the grinding regime on the transfer of uranium-containing carbon fragments and coal to the reverse flotation concentrate has been revealed. The most representative results of the processing of black shale rock with coarse and fine grinding options are presented. As a result, it was found that when crushed to a fineness class of 60% minus 0.071 mm in the presence of the oxidizer TCCA, the maximum extraction of 98.2% uranium into the tailings during reverse flotation was achieved. Subsequent leaching of the tailings of the reverse flotation made it possible to obtain the maximum concentration of uranium in the productive solution at 94.5% extraction.

This paper presents the results of testing a copper bioleaching technology applied to two types of ore sampled from different sections of deposits within one of the deposits in the Balkhash region. Preliminary microbiological studies of microorganisms present in mineral raw material samples from the deposit revealed that, under conditions favorable for the growth of iron- and sulfur-oxidizing bacteria, active proliferation of yeast-like fungi was also observed, along with a bacterial culture identified as Skermanella aerolata. Preliminary experiments demonstrated that the effect of the identified bacterial culture, in association with Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, positively influences oxidative processes involved in the decomposition of sulfur- and iron-containing minerals. The complete consortium of endemic microorganisms used in bioleaching experiments exhibited the highest efficiency compared to both individual cultures and the conventional sulfuric acid leaching method. The effect of biological oxidation on a simple-composition ore sample resulted in a 5.4% increase in copper recovery, while the efficiency of sulfuric acid consumption improved by nearly 40%. The use of bacterial oxidation for a low-grade, high-acid-consuming ore sample showed comparable copper recovery; however, sulfuric acid consumption was reduced by a factor of 2.5.