Currently, methods of precipitation of dissolved substances by various precipitators are most widely used for wastewater treatment of mining and metallurgical enterprises, with the associated extraction of metals contained in them. However, bulky equipment for settling, filtration, or centrifugation limits the use of these time-consuming methods. The use of ion-exchange resins, taking into account the solid phase in wastewater, is also not always economically justified. The method of liquid extraction from very dilute solutions is associated with significant losses of extractant per unit of extracted metal caused by the solubility of the extractant in the aqueous phase...

The harmful effect of fine powders on the flotation of mineral grains is due to the absorption of some reagents, slurry coatings on the surfaces of minerals and air bubbles, changes in the viscosity of the pulp, increased foam stability, etc.

In copper-nickel ores, some of the nickel isomorphically bound to some silicates floats very poorly. At the same time, the easy acid decomposition of nickel silicates indicates the possibility of using the Mostovich method for certain difficult-to-enrich intermediate enrichment products or substandard concentrates with a high content of nickel silicate. In order to judge the possibility of practical and economically advantageous application of the proposed combined method of processing nickel industrial products, it was necessary to establish the conditions for flotation of cement nickel, ensuring high results in this operation...

The presence of nickel in sulfide copper-nickel ores, isomorphically bound to some silicate minerals, sometimes predetermines the possible enrichment results of such ores. The recovery of silicate nickel during flotation is low, and a significant part of it is lost in the tailings. According to M.N. Godlevsky, silicates of copper-nickel ores containing nickel are easily decomposed by acids. In this connection, a combined method was tested for processing products with relatively high silicate nickel content.

Technical efficiency of enrichment E of the processed material determines the degree of approximation of the obtained separation results to the theoretically possible. This indicator, allowing a single number to characterize the achieved results of separation, clarifies the analysis of experimental data, facilitates the selection of optimal separation conditions (by the maximum values of E), makes the results of separation of ores of different composition easily comparable, etc. Evaluation of separation efficiency is especially useful for polymetallic ores, where when analyzing the test results have to compare a very large number of different indicators. In order to select the most convenient method for assessing the separation efficiency of polymetallic ores, the existing methods are considered and new calculation formulas are derived, based on the use of the methodology for determining the separation efficiency of monometallic ores.

The results of flotation of oxidized copper ores at a given mineralogical composition are mainly determined by the selected conditions of preliminary sulfidization of the ore. Conscious management of this operation at the factory requires clear ideas about the kinetics of the process of interaction between soluble sulfides and copper carbonates, about the influence of the sulfide layer on minerals on the subsequent process of their interaction with xanthates, etc. Detailed studies of the sulfidization process, carried out in the laboratory of general and physical chemistry of the Leningrad Mining Institute, on the example of malachite characterized: 1) kinetics of interaction between soluble sulfides and malachite; 2) influence of electrolytes on the sulfidization process; 3) kinetics of interaction between xanthates and malachite - natural and sulfidized; 4) flotation of malachite using different sulfidizers, etc. The results of the study are of interest for industrial flotation of ores containing oxidized minerals, since the processes of interaction between such minerals and flotation reagents have not yet received sufficient coverage in the literature.

The choice of the scheme and recipe for flotation of ores is usually made only by comparing the final separation indices with variations in processing conditions, which often does not provide sufficient material for confident judgments about the defects of the adopted technological process mode. Theoretically, the most justified method for analyzing the results of flotation is the method based on the data of studying the kinetics of the process in its individual stages. This method, proposed by K. F. Beloglazov, allows for a quantitative assessment of the results obtained, a pre-calculation of possible separation results, and is a tool for a strictly justified resolution of many controversial issues in practice. Below is an account of the experience of applying this method to the assessment of industrial flotation schemes.

As indicator electrode at the potential titration of diluted solution of the xantate Ag—Ag₂S and mercurial electrode were tested. The most convenient for analysis of xantate solutions not including the sulphide sulphur is a mercurial electrode. The presence of a caustic alkali soluble carbonates, sulphates, sulphites and thiosulphates does not effect the result of titration. The method was worked out as to the potential metrical titration of xantates and soluble sulphides in diluted solutions at their compatible presence. The method consists in determination of the sum of sulphide and xantate by means of potential metrical titration by sublimation with mercurial electrode and determination of sulphide by means of potential metrical titration by the double cyanide of Ag at the Ag—Ag₂S electrodes. On account of the simplicity and dependability the recommended method of analysis could be applied not only in the laboratory conditions but at works for to control the process of sulphidisation of oxidized ores.

The extraction of cassiterite from ores by flotation, despite numerous attempts, remains an unresolved problem in practice. The presented results convincingly show the following. Activation of cassiterite with hydrosulfites significantly increases the flotation activity of the mineral. High tin recovery into the concentrate is achieved at collector dosages lower than usual in flotation. The flotation rate of activated cassiterite does not differ from the flotation rate of sulfides under optimal reagent schemes. One of the tasks for subsequent research should be the selection of a collector more effective for activated cassiterite. The extraction of cassiterite from ores by flotation remains an unresolved problem in practice. Numerous proposals for the flotation of tin stone described in the literature (1936) have not found industrial application due to technological and economic difficulties. Tests of the method of preliminary activation of cassiterite proposed by Prof. K. F. Beloglazov have shown that the use of activation significantly increases the floatability of cassiterite. Flotation of the activated mineral from synthetic mixtures with quartz proceeds even at collector dosages lower than usual, with a flotation rate normal for sulfides.

This work was to clarify the necessity of controlling pulp alkalinity at the Khibinogorsk processing plant. The main focus of the work was on studying the properties of the minerals and the flotation of apatite at various pulp alkalinity levels. Experiments showed that the dissolution process of apatite in the pulp proceeds very slowly and does not reach equilibrium within 60 minutes (for the coarse fraction—20 mesh). The article presents potentiometric measurements and test results. During apatite flotation, the alkalinity of the pulp significantly affects the the results of the process. High alkalinity reduces the rate of concentrate recovery, and for a given flotation duration, the recovery of apatite decreases. Increasing the consumption of oleic acid accelerates the process.