Preparation of copper-nickel concentrates for electric smelting by means of their agglomerative roasting and oxidative roasting of pyrrhotite concentrates - the main operation of segregation technology of their processing - is insufficiently studied and causes great difficulties ...

The mechanism of converter slag depletion includes the process of enlargement and sedimentation of matte droplets, the efficiency of which depends on the extraction of valuable components ...

In metallurgical and chemical industries reactors with circulation of reactants are widely spread. Application of circulation allows to regulate quite precisely the degree of transformation of reacting substances, to carry out the process with an excessive amount of one of the reagents, which is introduced with the recirculant and reduces the yield of reaction by-products ...

The main directions of technical progress in non-ferrous metallurgy, stipulated by the Directives of the XXIV Congress of the CPSU on the ninth five-year plan for the development of the national economy of the USSR, are: increasing the extraction of metals from ores, improving the comprehensiveness of the use of raw materials, widespread introduction of closed technological schemes with full processing of semi-products.

It is advisable to perform a thermodynamic assessment of sulfatizing firing of sulfide materials based on an analysis of the equilibria in the Me—S—O system. The basic firing reactions of simple sulfides can generally be represented by the equations.

Sulfatization of zinc, copper, and cobalt oxides was performed on a fluidized bed setup at a conditional normal gas mixture velocity (air and S02) of 0.15 nm/sec. The process was controlled by residue analysis. In special experiments, before the gas mixture entered the reactor, part of the sulfur dioxide was oxidized to sulfur on a vanadium catalyst. The object of the study is zinc and copper oxides of the HC classification and nitrous oxide-cobalt oxide obtained by calcination of cobalt oxide of the HC classification at 700°C. The material size class is 0.17 + 0.14 mm. The solid products of the process were analyzed by infrared spectroscopy and X-ray.

Double sulfates of non-ferrous metals are formed during sulfatizing firing of sulfide materials in the presence of sodium sulfate. The thermochemical stability of double sulfates has not been studied.

The most effective method of opening pyrite concentrates is known to be sulfatizing roasting. A great contribution to the understanding of sulfatizing roasting processes was made by the Soviet school of metallurgists. However, many issues of sulfatizing roasting remain unexplained and to date.

The dissociation of cobalt sulfate and its interaction with iron sulfide are important for understanding the process of sulfatizing roasting of cobalt-bearing pyrite concentrates. The dissociation of cobalt sulfate in a nitrogen atmosphere in a fixed bed begins at 730° C, in an atmosphere of air and oxygen, respectively, 15 and 30° C higher. According to A. V. Vanyukov, the beginning of thermal decomposition is observed at 692 and at 720-770 ° C, is active. According to other data, the decomposition of cobalt sulfate at 2-3-hour heating in a current of air comes already at 600 ° C. Information on the kinetics of dissociation of cobalt sulfate in the fluidized bed in the literature is absent.

Metal-oxide electrodes are used to determine the pH of solutions in various technological processes, but the mechanism of their action has not been sufficiently studied to date.

Pyrite concentrates are one of the promising types of raw materials for cobalt production. Sulfatizing roasting is the most widespread in processing of such concentrates. It is established that three periods can be distinguished in the sulfatizing roasting of pyrite concentrate: 1) oxidative; 2) intensive sulfatization; 3) slow sulfatization of metals. The present work aims to determine the main factors affecting the processes in these periods of pyrite concentrate roasting.