Vol 54 Iss. 3

Hydroxamic acids were recommended to be widely used as reagents for quantitative and qualitative analysis of metals, their extraction isolation, as well as as collectors in the processes of flotation enrichment of ores of rare and non-ferrous metals. Due to the simple technology of synthesis of alkylhydroxamic acids using aqueous solutions of hydroxylamine sulfate, the IM-50 reagent consisting of hydroxamic acids of the C₇—C₉ fraction or their sodium salts was used in processing plants of the USSR. The study of the effect of hydroxamic acids during flotation has shown that their interaction with iron ions located in the pulp volume and on the surface of minerals has a significant and sometimes decisive effect on the results of enrichment.

Carboxymethylcellulose (CMC) is a highly effective high molecular weight flotation suppressor. The features of the depressing and coagulating effect on flotation silicates ensured the use of CMC in all copper-nickel processing plants in the North-West of the USSR.

Zinc technology attracts the attention of researchers of polymetallic ore processing. With the use of zinc, positive results have been obtained for the enrichment of lead-zinc ores. However, sometimes experimenters fail to synthesize the reagent correctly, with all the consequences that follow. In order to avoid such cases, additional information on the synthesis and use of zinc is advisable.

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.

Despite significant advances achieved in the development of methods for selective chlorination and chloride distillation of materials containing nickel, cobalt and copper, iron chlorides remain an indispensable component of both the gas phase and condensate. This indicates the possibility of interaction of chlorine iron gas with oxides of non-ferrous metals in the chlorination zone and with oxygen in the condensation system. As a result of the latter process, iron is converted from gaseous chloride to solid oxide, which improves the selectivity of the condensate, and the released chlorine can be returned to the chloride distillation process.. The present work is devoted to the study of some patterns of these processes.

Laboratory and large-scale laboratory studies of the process of chloride distillation of pyrite concentrate cinder have shown the effectiveness of this method for processing this type of raw material. One of the unresolved problems related to the industrial implementation of this process is the issue of furnace heating.

The continuous conversion process being developed by the Leningrad Mining Institute together with the Gipronickel Institute is based on the upper purge of matte melts in a stationary unit.

The process of continuous conversion of matte with an upper blast supply provides for the presence of a depletion slag chamber in the unit, in which the primary slag formed in the purge part of the continuous converter is processed for depletion.

Heat exchange in a converter bath is a complex and still insufficiently studied process. A ball sensor can be used to study the issues of heat exchange in the converter bath. A method for investigating the heat exchange process between a ball sensor and a melt in a converter bath using an analog computer (AVM) is proposed below.

The upper purging of a liquid or melt by various gaseous agents is associated in most cases with both the physical and chemical interaction of the phases. In recent years, a number of papers have appeared dealing with the physical interaction of phases. There is relatively little work on the chemical interaction of phases in the upper purge conditions. However, they are of interest for a number of non-ferrous metallurgy processes (conversion, refining of melts, etc.).

Melts containing titanium and zirconium chlorides are used in the production of refractory metals and their alloys. In particular, the electrolytic process of obtaining titanium zirconium powders was investigated. An equimolecular melt of NaCl and KS1 salts containing titanium di- and trichloride and zirconium tetrachloride was used as the electrolyte. The content of dissolved zirconium in the electrolyte did not exceed 0.8%.

The article presents the results of laboratory studies of the process of obtaining unalloyed titanium powders by natriethermal reduction of lower titanium chlorides from melts.

Melts containing chlorides of some metals are widely used in chemistry and metallurgy. The production and refining of titanium, zirconium, vanadium and other metals is based on the use of the properties of such melts. In many cases, melts are used in conditions of dynamic interaction with the structural materials of technological equipment.

Sulfide-alkaline electrolytes were studied for the cathodic isolation of tin, antimony, mercury, indium, and tellurium. Electrolysis of sulfide-alkaline solutions of antimony has found industrial application, which has been studied in a large number of works. There is insufficient information in the literature on changes in the ionic composition of the electrolyte during the electrolysis of thiosol solutions and its relationship to the current output. An attempt to study this issue in relation to tellurium solutions is described in this report. For the first time, the electrolysis of such solutions was considered earlier.

One of the links in the tellurium production scheme at the Pyshminsky Copper Electrolyte Plant is the electrolytic separation of tellurium concentrate from solutions from aqueous leaching of soda-tellurium slag. Stainless steel grade 1X18N9T is used as anodes, which has proven itself in alkaline environments. However, during the industrial operation of the electrolytic plant, corrosion of the anodes was revealed, which led to a violation of the electrolysis regime.

Electrolytic separation of tin from alkaline solutions is widely used in industry when using secondary raw materials. However, the cathode reactions occurring in this process have not been sufficiently studied, which excludes clear recommendations for the parameters of electrolysis (electrolyte composition, current density, and the relationship between these parameters). The present work aims to fill this gap.

Heterogeneous equilibria involving metal carboxylates have been studied in sufficient detail. Based on the results of these studies, an extraction series of elements has been compiled, which makes it possible to predict the direction of possible ion exchange reactions. At the same time, the kinetics of heterogeneous processes of this kind has not been studied, which prevents the elucidation of the mechanism of the reactions and the correct choice of equipment for the process.

The presence of large amounts of iron in the ores of non-ferrous metals, and consequently in the solutions obtained during their processing, complicates the technological process of extraction of these metals with naphthenic acids. Thus, the presence of divalent iron naphthenate in the extract makes it difficult to re-extract nickel and cobalt from the organic phase. In this regard, it is of interest to study the composition and properties of this salt.

Ion exchange is widely used in hydrometallurgy, especially in the extraction of rare earth or dispersed elements from solutions. The field of application of ionites in non-ferrous metallurgy can be significantly expanded, firstly, if sufficiently cheap and high-capacity domestic ionites are available, and secondly, if the mechanism of the ion exchange process is known, which makes it possible to obtain, analyze and use appropriate kinetic equations. For a number of cations (copper, zinc, etc.), the domestic KU-2 cationite can be confidently attributed to the number of ionites meeting the first requirement. Not having selectivity with respect to ions of a certain grade in the combined presence of several ions, KU-2 cationite turns out to be quite capacious with respect to each of the cations individually.

When selenium is extracted from copper electrolyte slurries, soda-alkaline selenium-containing solutions are usually obtained. In addition to the main component, selenium, they contain impurities: tellurium, various heavy metals, silver, iron, arsenic, mercury, etc. The main impurity is tellurium, which is isolated from the solution as hydrated dioxide by neutralization to pH = 5--6. At the same time, it is very important to remove other impurities, the ingress of which into selenium reduces its quality.

The distribution of the extracted substance between the aqueous and organic phases, among other factors, depends on the diluent chosen. It has already been noted in many works that dilution with alkanes usually increases the extraction capacity of TBP.

For hydrometallurgical processes occurring in alkaline media, solubility, determined by the instability constants of the corresponding hydroxocomplexes, is essential.

Tellurium in the tetravalent state in hydrochloric acid solutions forms moderately strong complexes that absorb in the ultraviolet region. The spectrum consists of a number of bands characterizing various tellurium-containing particles. Solutions with high HCl content (5-10 mol/l) and low tellurium content (10^-6-10^-3 mol/l) have buffering properties. The proportion of different forms of tellurium-containing particles depends little on the total concentration of tellurium and is determined by the concentration of hydrochloric acid.

The OP-4 reagent is an oxyethylated alkylphenol with an average degree of oxyethylation equal to 4, and is used in ore flotation. Various methods have been proposed for the quantitative determination of such surfactants. However, almost all of them were used for the analysis of either pure surfactants or relatively concentrated solutions. In this case, surfactants such as OP-7 and OP-Yu, which are highly soluble in water, and have a high degree of oxyethylation, were usually determined, unlike OP-4.

The widespread use of various substances in the flotation of minerals clogs wastewater, which, poisoning reservoirs, endangers the normal existence of wildlife.

In theoretical studies of various processes in the metallurgical and processing industries (sintering, leaching, grinding, flotation, etc.), in some cases, important information about the patterns of occurring phenomena is provided by the specific surface area of the corresponding solid phases (sinters, slurries, charges, pure minerals, etc.).