The possibility of extraction of metals from ores of different genesis, containing low-dimensional structures of rare and noble metals, increases their commodity value and, in a deficit for some types of metals, leads to the need to search and develop new nature-like technologies, which can be used to extract from ores of different genesis almost all valuable noble, rare earth and nonferrous metals regardless of their concentration. This article presents the results of studying the processes of comminution and flotation to extract low-dimensional structures of noble and rare metals from carbonaceous ores using low-temperature and energy impacts at successive stages of the ores’ transformation. With the use of modern mineralogical, physical and chemical methods of research of composition, structure and properties of ores, the initial samples, concentrates and tailings after enrichment were studied. During the study, it was established that the difficulty of extraction of strategic metals from carbonaceous hard-enriched ores consists in fine dissemination of valuable components in concentrator minerals, mutual penetration of ore mineralization into each other and into rock-forming minerals, and in proximity of physical, chemical and technological properties of minerals, which complicates selective extraction of valuable components in concentrates. Also, difficulties in enrichment are associated with high flotation activity of waste rock, which significantly reduces the quality of concentrates.

This article presents the results of research aimed at optimizing the process of recovery of valuable components from ash and slag waste from thermal power plants. In this work, both experimental and theoretical studies were carried out to substantiate the use of magnetic separation methods for ash and slag waste processing. Ash and slag wastes were chosen as an object of research due to the presence of valuable components such as iron, aluminum, etc., in them. The research results showed that the method of magnetic separation, including high-gradient magnetic separation, can be effectively used in ash and slag waste processing. As a result, the topology of a magnetic beneficiation technological scheme has been proposed to obtain high-value-added products such as high-magnetic iron minerals, low-magnetic iron minerals, and aluminosilicate microspheres. By using magnetic separation in a weak magnetic field, magnetic microspheres containing high-magnetic iron minerals associated with intermetallics, ranging in size from 20 to 80 µm, were recovered. In the second stage of magnetic separation (high-gradient magnetic separation), an iron ore product with an iron content of 50% with a recovery of 92.07% could be obtained. By using scanning electron microscopy, it was found that the main part of microspheres, which contain low-magnetic iron minerals and aluminosilicates, with sizes from 2 to 15 microns, was recovered in the magnetic fraction. This paper proposes a new approach to the enrichment of ash and slag materials using magnetic separation, which will increase the efficiency of their processing and make the process environmentally sustainable.

This work presents a comprehensive approach for the justification of the reagent regime of coal flotation by investigating the interfacial characteristics of flotation phases with various techniques. For the energy characterization of the surface processes in flotation systems, a method of establishing the components of the specific surface Gibbs energy on the basis of a numerical estimation of surface free energy change during the adsorption of flotation reagents using the Owens–Wendt–Rabel–Kaelble technique was proposed. Using the developed approach, the features of the kinetics of n-hexane sorption on the surface of coal samples were established. The substantiation of differences in the potential mechanisms of the fixation of strictly apolar and aromatic reagents is based on the results of the quantum–chemical modeling of the states of the coal–adsorbate system using the software packages Avogadro and Orca. The simulation shows the possibility of aliphatic and aromatic reagents’ synergetic effects on coal surface hydrophobization. Based on the results of quantum–chemical modeling, it was found that for the physical adsorption of an oxyethylated nonyl-phenol molecule on a molecular fragment of the coal surface, according to the Weiser model, the decrease in the energy of the system was 0.05562 eV, which indicates the high thermodynamic probability of the physical sorption of this compound. The parameters of the Langmuir monomolecular model for the sorption of oxyethylated nonyl-phenol on the surface of the studied coal samples were established. The criterion characterizing the interphase phenomena in the flotation system based on the results of potentiometric studies of the interfacial characteristics, E_f, was proposed. It was found that for the studied values of the flow rate of oxyethylated nonyl-phenol, the highest value of E_f was achieved when the value of the sorption of the reagent equaled 63.99% of the limiting sorption capacity. The performance of the proposed reagents for coal flotation was confirmed by flotation tests.

The increased consumption of strategic metals has led to the necessity to search for new and non-traditional sources of mineral raw materials. All this has resulted in the necessity to develop and justify new technological solutions for the integrated recovery of strategic metals and the associated production of high-purity carbon materials. The purpose of this work was to substantiate the possibility of obtaining high-purity shungite carbon materials and metal-bearing concentrate containing valuable metals from shungite rocks using high-gradient magnetic separation and flotation with the use of an apolar collector emulsion in a frother solution. The conducted investigations using a complex of analysis methods allowed us to justify the obtaining of a metal-bearing concentrate containing iron, titanium, copper and zirconium and carbon material of high purity. By using high-gradient magnetic separation, we obtained a metal-bearing concentrate with a yield of 17.35% and a total metal content of 63.61% broken down as follows: Fe₂O₃ recovery of 87.66%, TiO₂ recovery of 56.03%, CuO recovery of 72.52% and ZrO₂ recovery of 54.42%. By using flotation, we obtained a shungite carbon concentrate with a yield of 31.41%, made of 88.15% carbon with a content and recovery of 88.09% and a sulphur content of 0.084%. The conducted studies showed the possibility of using classical beneficiation operations in the processing of non-traditional mineral raw materials to obtain commercial products.