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Introduction. Electrochemical treatment of mineral suspensions is used in electrochemical conditioning of flotation pulp and electrochemical dissolution of minerals and metals in the processes of gold-bearing products electrochemical chlorination. Research objective is to develop and implement the procedures for determining the values of the liquid phase resistance, contact resistance under contact polarization, and ion discharge energy loss resistance under contactless polarization of the electrically conductive part. Methods of research. Equivalent circuits of electrochemical processes have been built for various electrochemical cells. Circuits for various polarizations of electrically conductive particles are established. A formula is proposed for calculating the electrically conductive particle resistance through the electrical resistivity of a unit of volume. A procedure has been developed for calculating the liquid phase resistance through the resistance increment under changing distance between the electrodes. The contact area and pressure influence on the value of the contact resistance is studied through the contact of pyrite and chalcopyrite with an iron electrode. Results. When studying the electrical resistivity of the liquid phase, it was found that increased distance between the current-carrying electrodes leads to an equivalent increase in the liquid phase resistance. It has been established that increased pressure and contact area between the contacting particles and the current-carrying electrode results in decreased contact resistance. The contact resistance between the particle and the electrode in the electrolyte solution is much less than the contact resistance under dry surfaces contact. This phenomenon is explained by electrons tunneling through the electrolyte film. The obtained experimental data on the determination of the liquid phase resistance, contact resistance and ion discharge energy loss resistance make it possible to mathematically describe the processes of electrochemical chlorination under a large number of particles in the pulp. Conclusions and scope of results. Procedures have been developed and specific data have been obtained on the liquid phase resistance, contact resistance, and ion discharge resistance. They can be used for practical application when implementing electrochemical technologies for mineral suspensions treatment.

The article discusses a brief history of development of the flotation classification, reflects current trends in the development of flotation ore dressing, in foreign and domestic enrichment practice. Variants of implementation of the flotation classification, due to behavioral patterns, the degree of interaction are discussed. The relationship of flotation and gravitational processes in the flotation classification was identified and confirmed by theoretical and experimental studies. The directions of application of the flotation classification in a closed grinding cycle were considered. Variants of practical application of the flotation classification in a closed grinding cycle for sulfide ores and on tailings for various products of the grinding cycle, in the modes of froth flotation and separation were analyzed, the main advantages were identified. Ways to achieve optimal conditions for flotation classification were described. A new direction for the flotation classification using tapering chutes was identified. It is possible to obtain a conditional concentrate of flotation classification in a closed grinding cycle with the enrichment of the froth product in the tapering chutes. The flotation classification of tailings ensures the maximum extraction of flotation minerals into the froth with the tailings flotation classification being drained. A schematic diagram of flotation classification enrichment in a closed grinding cycle is presented, and the results of calculating final flotation classification parameters for sulphide copper ore dressing are presented. Flotation classifiers in a closed grinding cycle reduce energy costs and increase technological indicators of the enrichment of mineral and industrial raw materials.

The paper briefly considers the specifics of the material composition of sulfide ores and reflects the causes of losses in dressing. The basic dressing principles are given. The main ways to reduce ore overgrinding are briefly specified and described. The concept of flotoclassification and its relevance in closed-circuit grinding is described. The flowsheets of grinding and flotoclassification of sulfide ores are substantiated. Possible options of flotoclassification flow sheets in closed-circuit grinding are described. The use of flotoclassification in closed-circuit grinding of the hydrocyclone overflow allows obtaining an on-spec concentrate in the overflow of the tapered launder. Flotoclassification in closed-circuit grinding under laboratory conditions has been simulated. The experiment is described in detail. The simulation scheme, the finished product balance, and the qualitative and quantitative diagram of flotoclassification in closed-circuit grinding are given. The experimental results show the efficiency of the proposed way of reducing mineral overgrinding in the sulfide ore dressing technology.

Achievements and current state of technology for processing of technogenic materials have been assessed. The goals and objectives of the research have been defined. New laboratory apparatuses for processing mineral raw materials have been developed and manufactured. Laboratory and experimental industrial research of methods of circulation concentration, flotation classification, electrochemical chlorination, turbulization centrifugal separation have been carried out. The methods efficiency was assessed. The results of study of physical and chemical properties and distribution of metals by size classes of tungsten containing tailings are given. Studies of tailings enrichment by gravity, flotation and electrochemical enrichment methods are carried out. It is shown that for preliminary processing it is rational to use the method of circulation concentration. The methods of flotation classification, molybdenum flotation of a collective concentrate, electrochemical leaching of copper from a concentrate from flotation classification, turbulization centrifugal separation of products of tin flotation have been investigated. The innovative technology has been developed for processing complex tungsten containing tailings, based on research on a sample of tungsten containing tailings in the Zhambyl enrichment plant of the Kara-Oba deposit. This technology opens wide opportunities for processing of technogenic products and is offered for industrial implementation.