On possibility of using silicomanganese slag and ladle electric steelmaking slag in manufacture of welding fluxes

Analysis of the existing trends in development of technologies for production of welding and surfacing fluxes showed that one of the actively developing areas is the production of fluxes using man-made waste (including metallurgical one) as components of the initial charge. This is due to the fact that the slag waste of metallurgical production contains a large amount of manganese and silicon, which in turn are the basis in welding fluxes. Within the framework of this direction development, the article describes principal possibility and efficiency of using materials based on ladle electric steelmaking slag from JSC “EVRAZ United West Siberian Metallurgical Combine” and slag produced by silicomanganese from LLC “West Siberian Electrometallurgical Plant” in the charge for production of fluxes used in the surfacing of rolling rolls. All the laboratory tests were made using the equipment of the scientific and production center “Welding Processes and Technologies”. For surfacing steel samples, the authors used a flux additive obtained by mixing ladle electric steelmaking slag of a fraction less than 0.2 mm with liquid sodium glass in a ratio of 62 and 38 %. The resulting flux additive was mixed with slag from the production of silicomanganese of a fraction of 0.45 - 2.50 mm in various ratios. Studies of the chemical composition (by the spectral method) and metallographic studies of the deposited layer revealed a tendency to an increase in sulfur content and in contamination with non-metallic inclusions in it with an increase in content of the flux additive in the charge of more than 20 %. According to the results of visual quality control of the deposited layer macrostructure, the absence of defects was established with a flux additive content of up to 30 %.

The Chemical Technology for Producing Precious Metals from Enrichment Rejects of Copper-Pyrite Ores

The chemical technology for recovery precious metals Au and Ag from mature flotation tailings of copper-pyrite ores by two-stage sintering with chlorine-ammonium reagents and leaching of bakes with water is developed. The chemical extraction of gold and silver is carried out, using NH4Cl and NH4NO3 reagents in the ratios of 1:1 at a temperature of 250 °C, and 2:1 at 200 °C. In accordance with the obtained results, a chemical technology of enrichment rejects of copper-pyrite ores processing and a scheme of primary apparatus chain for implementing this technology are proposed. The economic effect of the technology realization is calculated. This effect is 96.3 million rubles with a payback period of 8 years when processing enrichment rejects of copper-pyrite ores in amount of 109.5 thousand tons per year under the conditions of JSC “Uchaly Mining and Metallurgical Combine”.

Analysis of the microstructure of wear resistant chrome cast irons after heat treatment

At the Navoi Mining and Metallurgical Combine, which uses a large number of machine parts for mining operations, the issue of optimizing the compositions of wear-resistant chromium cast irons while maintaining their operational characteristics has arisen. The paper presents the results of studying the phase composition of the cast alloy, as well as the effect of heat treatment of cast iron with a high chromium content on its structure and properties. As heat treatment operations, quenching in various modes and low tempering were used. The study made it possible to systematize the known literature data on the heat treatment parameters of a group of wear-resistant chromium cast irons, as well as to optimize their heat treatment modes for parts operating in mining and processing industry.

Prerequisites for Processing a Foam Product in the Process of Bacterial Oxidation of Gold-Bearing Concentrates in a Separate Cycle

The recovery of gold from refractory ores and concentrates is a significant problem in the modern gold processing industry. The use of bacterial oxidation technology at the Navoi Mining and Metallurgical Combine (Uzbekistan) made it possible to increase the share of recoverable gold during the processing of refractory ores from the Kokpatas and Daugyztau deposits. However, during the operation of the biological installation, a problem arose of abundant foaming in bacterial oxidation reactors. This article is devoted to the issue of foaming during biooxidation and its negative impact on the oxidation process. Methods of combating foaming and the choice of the optimal solution, providing for the processing of bio-oxidation foam in a separate cycle, have been analyzed.

Development of welded structure of 5-nozzle lance heads in converter shop of PJSC “Dneprovsky metallurgical combine”

For the upper blasting lances of 250-tons oxygen converters at PJSC «DMС» (Kamenskoe, Ukraine) the author has proposed a number of welded structures of 5-nozzle lance heads with increased resistance. A set of industrial studies of their operation made it possible to establish that the devices which provide cooling of the areas back from the nozzle zone of the tip have the highest resistance. Measures to increase the values of the average cooler speeds in welded structures of the lance heads and their rigidity also turned out to be quite effective. The transfer of copper welds holding the nozzle inserts in the copper tip from its outer surface to the inner proved to be ineffective from the point of increasing resistance of the lance head (the average resistance of the heads increased by only 7 heats – from 78 to 85 heats). This allows us to assert the need for complete elimination of copper welds in the head (both external, exposed to high-temperature and mechanical stresses, and internal) that hold nozzle inserts in the holes of the welded tip and lance head collector. Thus, in spite of all the measures taken to transfer the welds from the outer surface of the tip to its inner surface, to improve cooling of the tip and its back from the nozzle zones, which also include sections of copper welds around the nozzles, as well as to increase the rigidity of the blast welded structure heads, this led, although to positive, but still to relatively low results. The data obtained indicate that welds made of copper around the nozzle inserts, which are held by this in the tip (also in the collector) of the head, are the limiting link that does not significantly increase the resistance of welded lance heads, and it is urgently necessary to back off its use.

Investigation of the radiation situation near the tailings dumps of the Stepnogorsk Hydrometallurgical Plant

The article discusses issues related to the production waste of Stepnogorsk Mining and Metallurgical Combine (SМMС). The greatest danger to the environment is represented by radionuclides. Soil types and their resistance and ability to accumulate radionuclides are considered. It is also noted that harmful radioisotopes spread through the soil and atmosphere and the maximum permissible concentration (MPC) of these substances decreases from the source of their storage and this is due to the fact that different soils have different conductivity of these harmful substances. The article also identifies opportunities to reduce the impact of SМMС wastes on soil and vegetation, as well as the atmosphere near a dangerous source of radiation infection.

Influence of cultivation conditions on morphotype and phenotype of different-aged juveniles of Russian sturgeon (Acipenser gueldenstaedti Brandt, 1833)

Investigated the genetic variability of domesticated herds of the Russian sturgeon. This was selected three samples of fingerlings: the offspring of wild spawners and offspring domestizierung producers grown on Bertuliskan sturgeon hatcheries and the offspring domestizierung manufacturers grown at the hatchery Elektrogorsk TPP. Was investigated three polymorphic enzyme systems, the malate dehydrogenase (MDH), lactate dehydrogenase (LDH) and esterase (Ect). Genetic and biochemical studies carried out by electrophoresis. Review such factors as frequency of occurrence and level of heterozygosity. Investigated the relative abundance of Homo — and heterozygous genotypes in each enzyme system. To study morphological variability, we studied data on young Russian sturgeon caught from the Volga, Don and Kuban rivers, fingerling raised in a fish farm outside the range from the larval stage, fingerling raised in the conditions of the pilot fish-breeding workshop of the Novolipetsk metallurgical combine and fingerling raised in a fish farm using warm waste water of the Elektrogorskaya GRES-3 named after R. E. Klasson. We used both literary sources and our own data. The following features were selected for analysis: the number of beetles in the dorsal (Sd), lateral (Sl) and abdominal (Sv) rows. It is shown that the number of beetles in fingerlings grown in warm waters is significantly less than in fish from the natural environment.

Mises and Hayek in “Kremikovtzi” MC

The author makes an attempt to investigate functioning of the largest metallurgical plant in Bulgaria – “Kremikovtzi” MC – through the prism of Misesian and Hayekian arguments concerning the economic organization of the socialist society. The main conclusion is that the arguments with a high degree of abstraction – especially those of Mises - remain invisible at the level of a particular enterprise. The views of Hayek, however, those of the classical political economists, and of Simeon Demostenov find their confirmation in the everyday life of the metallurgical combine even before its official opening in 1963 and until the last day of the Bulgarian socialist regime in 1989. To some extend “Kremikovtzi” is representative for the economic reality in Bulgaria during the era of socialism and is indicative of the results and shortcomings of the state-implemented industrialization of the country. Bulgaria became an industrialized country, but it is not sure whether the industrialization was successful.