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

Research of the effect of phase composition and structure on the micro-hardness of casted alloys of the Cu–Ce–La system

O. V. Samoilova, E. A. Trofimov

ABSTRACT

The Cu–Ce–La system is of interest both for the production of bronzes with the addition of rare earth metals, and for the production of amorphous alloys. In the course of this work, we studied the phase composition, structure, and microhardness of 13 cast samples of alloys of the Cu–Ce–La system belonging to the copper angle of the phase diagram of this system. Experimental samples were investigated by the methods of optical microscopy, scanning electron microscopy and X-ray microanalysis analysis, by the method of atomic emission analysis with inductively coupled plasma, by the methods of X-ray phase analysis and thermal analysis. Also on the samples was measured microhardness Vickers HV. The structure of the samples along the grain boundaries of the solid solution based on copper revealed the presence of eutectic, which, according to X-ray microanalysis data, includes copper, lanthanum and cerium. X-ray diffraction data indicate the presence of Cu6Ce and Cu6La compounds in addition to the solid solution based on copper in the samples. The volume fraction of the eutectic component in the sample structure (which is equal to the fraction of the area occupied by the eutectic in the area of thin sections of the samples) was determined. With increasing concentrations of cerium and lanthanum in the composition of the samples, the proportion of the eutectic component also increases. Thermal analysis data indicate the presence of triple eutectic equilibrium in addition to double eutectics. The presence of a strong correlation dependence between the share of the eutectic component in the structure and the microhardness of the experimental samples is shown. With an increase in the share of eutectic in the sample structure, the microhardness index HV also increases. The results obtained may be of interest to practicing materials scientists when analyzing the effect of additives of rare earth metals on the phase composition, structure and mechanical characteristics of copper alloys.

KEYWORDS:

Cu–Ce–La system, phase composition of alloys, structure, microhardness of copper alloys

DOI: 10.1134/S0235010619020038

A new multipurpose thermodynamic database for oxide systems

E. Yazhenskikh, T. Jantzen, K. Hack, and M. Müller

ABSTRACT

A new thermodynamic database for oxides has been developed in order to perform calculations and predictions of equilibria for various scientific and industrial applications (slags, ashes, glasses, minerals, ceramics, refractories, etc.). The database containing all known phases (gas, stoichiometric compounds, solid and liquid solutions) for combinations of 27 different components provides proper descriptions for many different processes under varying conditions (temperature, pressure, overall composition) including interactions between materials and environments, and thus supports the development of new materials.

KEYWORDS:

thermodynamic assessment, CALPHAD modelling, database development, phase equilibria, oxide systems, associate model, calculations of thermodynamic properties.

DOI: 10.1134/S0235010619010237

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

Mesoscopic model for a metal vapor condensation

A. E. Korenchenko, A. G. Vorontsov, B. R. Gelchinski

ABSTRACT

We consider a way to transfer data from molecular dynamic simulation of metal vapor condensation to partial differential equations of continuous medium. To simulate condensation in mesoscale model we suppose that the chemical mixture changes with time according to series of reactions Me + Men = Men + 1 and reaction rates are depended on the internal energies of Men clusters. The dependences were obtained from statistical data of molecular dynamics simulations. The results of molecular dynamics method and developed numerical model show a good agreement.

KEYWORDS:

multiscale simulation, condensation, metal clusters

DOI: 10.1134/S0235010619010080

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

Computer simulation of multicomponent melts of metallurgical slags

E. V. Dyul’dina, B. R. Gelchinski, V. N. Selivanov

ABSTRACT

Based on the experimental data on the density, the molecular dynamics simulation of multicomponent oxide-fluoride metallurgical slag-forming systems: SiO2–CaO–Al2O3–MgO–CaF2–Na2O–K2O–FeO was carried out for the first time in the approximation of the ionic bond model. The results were discussed and compared with literary experimental and calculated data. The obtained model indicates a weak temperature dependence of the structure of the melt. An increased diffusion mobility of fluorine ions as well as ions of alkali metals in comparison with other elements has been revealed.

KEYWORDS

melt, metallurgical slag, computer simulation, structure, properties

DOI: 10.1134/S0235010618050055

Model investigation of liquid interaction metal and dispersed steel inclusions in castingon gasificable models

B. S. Vorontsov, N. V. Nesterov

ABSTRACT

A mathematical model for the interaction of liquid metal with metallic inclusions embedded in the foam polystyrene, reflecting the filling of molds, the effect of thermal decomposition of expanded polystyrene and heat exchange of the base alloy and filler material, is developed. The resulted results of the experiment on obtaining prototypes by casting on gasified models, confirming the predictions of mathematical modeling.

KEYWORDS

mathematical model, interaction of metal particles with melt, local alloying, casting for gasified models, composite materials

DOI: 10.1134/S0235010618050158

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