In Russia and some other countries proposed various ways to the chemical enrichment of bauxite, which usually does not affect the question of regeneration of an alkaline solution of silica, or reduce it to the release of silica in the form of calcium silicate. While the technological circuits of the chemical enrichment of the return should include an alkaline solution, after regeneration, the following parties desiliconization bauxite. It is known that the chemical enrichment is accompanied by a secondary process – the formation of hydroaluminosilicates sodium, the rate of which depends on the concentration in the alkaline solution as aluminum oxide and silicon dioxide. This paper presents data a two-stage osazhdniya silica from an alkaline solution. In the first stage in the form of sodium hydro-aluminosilicates and second in the form of calcium silicate.
Sharp selectivity of hydrocarboaluminates of caustic-earth metals and magnesium oxide in relation to the most dangerous classes of the organic substances playing defining role in decrease in extent of decomposition level and deterioration of produced alumina properties– humic, carboxylic acids and high-molecular organic compounds are defined. Soda is good for humic acids sorption (about 40 %) also is inefficient for removal of carboxylic acids and high-molecular compounds. Harmful groups of organic substances generally provide chromaticity of aluminate liquors. The photometric analysis states an objective assessment of the content of the painted organic substances in relation to their initial quantity in aluminates liquors.
The behavior of impurities – colored organic compounds (COC) in aluminate liquors of Bayer process during electrolysis treatment was investigated. Experimental data for the impact of various technological parameters and conditions are found to reduce the content of COC to 50-80 %.
In the article the basic principles of energy conservation and efficiency of the enterprises of metallurgy. The analysis of the energy saving potential in the metallurgical complex. We describe the stages of implementation of energy management, energy analysis of the structure of the enterprise.
The theoretical basis of the synthesis of calcium hydrocarboaluminates 4CaO×Al2O3×mCO2×11H2O based on the CaCO3 in the aluminate-base system. We construct the isotherm of metastable equilibria in the system CaCO3 – 4CaO×Al2O3×mCO2×11H2O – 3CaO×Al2O3×6H2O – NaAl(OH)4 – NaOH – H2O at 50, 70 and 90°C.
The results of laboratory studies on super deep desilication of alumina liquors based on hidrocarboalyuminat calcium supplements 4CaO×Al2O3×0,5CO2×11H2O in advance of entering into the process of working hydrogranat sludge. Obtained qualitatively new alumina liquors with a silicon module (weight ratio Al2O3 / SiO2) of 50000 units. Impact of type-ahead hydrogranat sludge to a desilication depth given from the viewpoint of heterogeneous catalysis. The results obtained can be used to solve the problem of diversification of production in the complex processing of phosphogypsum in the synthesis calcium hydrocarboaluminates on the basis of fosfomel.
Calcium hydrosulfasaluminates (GSAK) is a component of cement. They are slowly formed together with the forming of the structure of cement in water solution at measurable temperatures (0-25 °C) during about 4-6 months. Slow rate of crystallization of GSAK wasn`t allowed to treat them as self-autonomy objects for use in various technological applications. The possibility of formation of GSAK (4CaO×Al 2 O 3 ×mSO 3 ×nH 2 O) is proved in an environment of saturated electrolytes – aluminates solutions of alumina production. They crystallize in a short time about 1-2 hours and retain their stability in long time about 24-36 hours. This allowed for us to identify ways of their industrial use.
Описана математическая модель процесса сверхглубокого обескремнивания алюминатных растворов с предварительным вводом оборотного гидрогранатового шлама, которая может быть использована для создания АСУТП процесса в технологической схеме комплексной переработки нефелинового концентрата на глинозем и попутные продукты.
The paper describes the theory and practice of low-temperature decomposition of alumina solutions. Scientific substantiation of the use of activated nepheline solution as an inoculum for HASN crystallization is given. Materials of experimental study of chemical equilibrium and kinetics of the decomposition process in the system activated nepheline alcohol - aluminate solution are presented. The possibility of achieving technological low-temperature factors of the process sufficient for the subsequent complete deposition of silica is shown.
The data allowing to reveal the most effective solutions for the production of new by-products in the complex processing of nepheline have been obtained. It is shown that calcium hydrocarbon aluminates synthesized under conditions of alumina production play the main role in the technology of new materials: carbon sulfoaluminate-type mineralizers, rapid hardening cements of the "Rapid" type, high alumina cements, foundry cements. The main technical characteristics of new pro-ducts are given.
The study was carried out in order to find technological conditions that allow anodic dissolution of metal concentrate of radio-electronic scrap without difficulties caused by anode passivation. The thermodynamic probability of sufficiently complete oxidation of impurities included in the metal concentrate was established. The composition of refining slag allowing to bind oxidized impurities in slag is selected. Time dependence of oxidation of impurities by air due to application of radial-axial tuyere is shown. It is indicated that for 15min of blowing it is possible to prepare the metal-concentrate alloy for successful anodic dissolution in sulfuric acid electrolyte.