Features of technical silicon cleaning in melting in helium with impact on electric field melt on molybdenum and graphite electrode

A. V. Kaibichev, I. A. Kaibichev

ABSTRACT

The features of the purification of technical silicon in helium with molybdenum and graphite cathodes are considered. The formation of silicides and carbides in the melt is substantiated. The effect of melt polarity on the removal of impurities and gases is shown. The evaporation of technical silicon and the interelectrode transfer of elements are quantitatively determined. The efficiency of evaporation and removal of impurities in an electric field is estimated.

KEYWORDS

iron, titanium, silicon, silicides, carbides, melt, electricity

DOI: 10.1134/S023501061903006X

Thermal researches of the process of obtaining magnesium master alloy with ittrium and zinc

S. А. Savchenkov, V. Yu. Bazhin, V. N. Brichkin, V. L. Ugolkov

ABSTRACT

Using thermal analysis (DTA), processes occurring during the interaction of yttrium fluoride melts with sodium fluoride and potassium chloride, used as a flux in the metallothermic synthesis of the Mg–Y master alloy, were investigated. In addition, to identify patterns of magnesium thermal reduction of yttrium from the salt mixture, thermal studies of the interaction of yttrium and sodium fluoride salt systems and potassium and sodium chlorides with magnesium and zinc were carried out.

KEYWORDS

magnesium master alloy, master alloy magnesium–zinc–yttrium, thermal analysis, magnesium thermal reduction, synthesis

DOI: 10.1134/S0235010619030095

A study of slag melting cyclone to select the direction for the future use

I. N. Tanutrov, M. N. Sviridovа, S. O. Potapov

ABSTRACT

At the metallurgical enterprise of the Far East (the district of Novoshakhtinsky village of Primorsky Krai) during the processing of the germanium-containing raw materials of the Pavlovsky brown coal deposit, the waste of the production process is formed–granulated slag sent to storage. In order to dispose of this technogenic education, it is necessary to propose an energy-efficient, environmentally friendly method for processing waste from a metallurgical enterprise in compliance with environmental norms. In accordance with modern requirements, it is necessary to solve the problem with the utilization of cyclone smelting slag before the operation of the facility. The design documentation recommends the use of cyclone smelting slag in construction or production of building materials. To determine the direction of utilization of cyclone slag, information is needed on the chemical, granulometric composition of the slag, as well as on the properties of the material when interacting with water. Using the method of reducing sulfide cyclone melting with flux and sulphidizer additives, an experimental preparation in the laboratory of granulated slag similar in properties to the slag of cyclone smelting obtained at the enterprise was carried out. Slag samples were obtained for further study. With the use of modern methods and approaches applied during the work, the compositions and properties of slags and additives, chemical analysis of slag for macro components, X-ray phase analysis necessary for environmental assessment are determined. The physicochemical and organoleptic parameters of the slag are determined in accordance with existing standards. Thus, the maximum particle size of the slag, no more than 10 mm, the content of particles in the material of particles larger than 5 mm, not more than 9.70%, which corresponds to GOST 5578E94. The density and humidity of the slag are also determined. It was found that when interacting with water, the resulting solution is characterized by a weak alkaline reaction, which does not interfere with the use of the material in the industrial process. It is shown that the resulting slag is suitable for its subsequent utilization.

KEYWORDS:

melted slag, water granulation, germanium-containing raw materials, processing, cyclone melting, properties

DOI: 10.1134/S023501061902004X

Influence of weather conditions on aluminum work indicators of electrolysis of Kazakhstan electrolysis factory

V. A. Lebedev, Zh. Zh. Kamzin

ABSTRACT

According to the average monthly data of OA “KEZ” from January 2010 until March 2011 for two series of electrolysis, working at the plant, a regression analysis of the dependences of the average voltage, current yield, specific consumption of electricity from the water vapor pressure in atmospheric air (P) was performed. Increase in P by 10 mm Hg does not affect the amount of working interference, increases the current efficiency by 0.48– 0.63%, reduces the specific power consumption by 73–78 kW • h/t. The observed regularities are explained by a decrease in the fluorine content in flowing into the cryolite-alumina melt of alumina by the removal of desorbed hydrogen fluoride with water vapor in the presence of fluorinated alumina in the range of APG punching.

KEYWORDS:

fluorinated alumina, fluorine content, water vapor pressure, average voltage, current efficiency, specific power consumption, regression analysis

DOI: 10.1134/S0235010619020026

High-temperature calorimetric research of CaO–MgO–Al2O3–SiO2 slags

A. Korytseva, A. Navrotski

ABSTRACT

The enthalpy of dissolving slag-forming oxides in slag CaO–SiO2–Al2O3–MgO at 1450 C was measured by drop-calorimetry. The enthalpy of dissolution becomes more exothermic in the order of Fe2O3, MgO, Al2O3, CaO, SiO2, which reflects the relatively basic nature of this slag with a low silica content. The observed trends are consistent with the available other melts, while the observed differences in the values reflect differences in the acid-alkaline character of the melts. The obtained results give reliable data for the future modeling of the thermal balance of both steelmaking furnaces and various processes in geological and ceramic systems.

KEYWORDS:

calorimetry, slag, enthalpy, iron oxide, aluminum oxide, silicon oxide

DOI: 10.1134/S0235010619010092

The effect of calcium-containing additives on the extraction of alumina from red muds of alumina production

S. A. Bibanayeva, V. N. Koryukov, V. M. Skachkov, N. A. Sabirzyanov,

V. M. Ufimtsev, E.M. Lebedeva

ABSTRACT

The results of an experimental study of the effect of calcium-containing reagents on the process of high-temperature autoclave extraction of alumina from red muds obtained from Timan deposit bauxites by the parallel BayerEsintering method are presented. The phase composition of products is determined by XRD and EDXR methods. Increased extraction of alumina from red mud when used the surfaceEcarbonized lime in the process is shown.

KEYWORDS

red mud, processing, leaching, calcium oxide

DOI: 10.1134/S0235010618050031

Thermodynamic analysis of joint aluminothermal recovery ZrO2 and Nb2O5

S. N. Agafonov, A. A. Ponomarenko, A. S. Russkikh

ABSTRACT

In this work, we studied the joint aluminothermic reduction of zirconium and niobium oxides. Thermodynamic modeling of metal-thermal reactions, differential thermal (DTA) and X-ray phase (XRF) analyzes were used in the work. The research can serve as a scientific basis for the development of promising metal-thermal technologies for the production of rare-metal alloys.

KEYWORDS

thermodynamic modeling, aluminothermic reduction, alloy, zirconium, aluminum, niobium, oxides

DOI: 10.7868/S023501061901002X

Activity of oxygen in nickel melts containing aluminum, lanthanum and cerium at PAr = 0.1 MPa

V. T. Burtsev.

ABSTRACT:

The deoxidation of nickelEbase superalloys upon vacuum melting was carried out in the presence of Al with strong deoxidizers such as La and Ce. The oxygen activity (a[O]) in the Ni–O–Al (0.001–5%), Ni–O–La/Ce (0.001–0.1%) and Ni–O–Al (5%)–La/Ce (0.001–0.1%) melts at 1560°C and PAr = 0.1 MPa has been studied by the method of instantaneous EMF recording by certified sensors. For the former two melting systems, the a[O] = f[Al/La/Ce%] dependences are described by logarithmic functions. The deoxidizing ability of Ce in the second system is higher by a factor of 4.7 than that of La. For the melts of the third system, the a[O] = f[Al (5%)–La/Ce] dependences constructed in the “spline” regime showed that the introduction of La (0.02–0.05%) decreases a[O] by a factor of 6–8 relative to the data on the second system of melts, and the introduction of Ce (0.02–0.05%) decreases a[O] by a factor of 3–3.4 relative to the data on the second system of melts, and the deoxidizing capacity of Ce remains higher than that of La in the presence of aluminum. Therefore, Ce is preferable as the final oxidizer in the practice of deoxidation.

KEYWORDS:

Nickel-oxygen-aluminum melts, lanthanum, cerium, EMF method, deoxidation

DOI: 10.7868/S0235010618050043

Influence of niobium and tantalum on peculiarities of phase formation at metallothermic interaction between aluminium and titanium dioxide

T. V. Osinkina, S. A. Krasikov, E. M. Zhilina, S. N. Agafonov,

L. B. Vedmid, S. V. Zhidovinova

ABSTRACT

Thermodynamic modeling of joint aluminothermic reduction of titan, niobium and tantalum from oxides have been carried out. The results were coordinated with research of this process by a method of the combined scanning calorimetry and indicators of metal-thermic obtaining alloy Al–Ti–Nb in the laboratory electric furnace.

KEYWORDS

thermodynamic modeling, aluminothermic reduction, alloy, intermetallic compounds, oxides

Processing of Zn–Pb–Ag alloys vacuum distillation

A. A. Korolev, S. A. Krayukhin, G. I. Maltsev,

V. G. Lobanov, E. S. Filatov, V. M. Ivenko.

ABSTRACT:

In the processing of lead is formed of silver foam (SP), which requires complex processing, with commercial production of single products. One of the possible ways of SP recovery is vacuum distillation, which is considered one of the most effective and environmentally friendly methods for the separation and purification, processing and refining of various metals. The aim of this work is to determine quantitative and qualitative composition of the products of vacuum distillation are different in composition of polymetallic alloys Zn–Pb–Ag depending on the temperature, pressure and gas environment and in assessing the possible use of calculated equilibrium phase diagrams “gas–liquid” VLE (vapor liquid equilibrium) for predicting technological parameters of the refining joint ventures. It is established that the zinc in the source content in the alloy is 0.4 to 16.7 wt.% speeds of more than 95% within 3 hours at a temperature of 1473 K and a pressure of 1 · 105 Pa. When sublimation of the zinc in the air and the contact of the condensate with water vapor at elevated temperatures oxidizes ~14% of the metal that recommends carrying out the process in inert gas argon. At a temperature of 1323 K and the duration of the distillation 14 hours reducing the pressure in the system from 133 to 7 Pa increases the content of silver 0.046–of 3.48% in the condensate of lead up 98.61–95.94%. At step heating to 1373 K and P = 13 Pa with an exposure of 0.4 hour at 873 K and 1173 K, and the duration of the sublimation 1 hour lead content of the distillation residue amounted to 3.61%, and silver in the sublimates of lead – 0.046%. Deficiencies identified during use of dust products – mechanical ablation or under vacuum, or in the case of allocating a large volume of vapor of volatile components when heated.

KEY WORDS:

zinc, lead, silver, component, vacuum distillation, temperature, pressure, argon, equilibrium phase diagram.