SU1274999A1 - Method of processing alumina-containing material - Google Patents

Abstract

This invention relates to non-ferrous metallurgy. The purpose of the invention is to improve the quality of the cake and reduce energy consumption. The method involves the preparation of a soda-lime, alumina-containing mixture with additives of the waste of the aluminum refining process by the three-layer method in quantities. 15% and its subsequent sintering. 2 tab.

Description

The invention relates to non-ferrous metallurgy and can be used in the production of alumina by sintering. The purpose of the invention is to improve the quality of the cake and reduce energy costs. Example. The nepheline soda-known mixture is prepared from the races of the JAGO + BaO four molar ratios CaO + MgO 1.1; , The additive is a solid waste from the aluminum refining process using a three-layer method (salt portion of electrolyte crusts, garnish, sludges) and contains, in May,% AE 27, .9; Na 5.1; Ba 26.5; F 8.3; CE 7.3; Mg 1.1; Ca Oh, A; SiO 0.2; K 0.05; 0.01. The waste is introduced into the mixture in the form of a powder with a particle size of 0.05 mm (90%) in an amount of 3%. The mixture is thoroughly mixed for 2 hours and then briquettes are prepared on a hand press at P 100 kg / cm. Sintering is carried out in a laboratory rotary kiln with a temperature rise rate of 8-10 ° C per minute. The cooling of the cake was carried out with the furnace up to 600 ° C, then in a desiccator. The sintering temperature was 1190 ° C, the heating time was 2 h, and the holding time was 30 min. The study of the sintering process by the method of differential thermal analysis shows that the introduction of fluorine and low-melting compounds into the mixture as a part of the waste shifts. Calcium carbonate decomposition to lower temperatures, and the appearance of liquid phases activates the interaction between the components of the charge and, thus, reduces the temperature of completion of speciation. The addition of 3% of waste per shtcht reduces the sintering temperature by 70-80 ° C. The resulting porous specs, good quality, the composition is given in table. one . Table

Claims (2)

chromium, phosphorus, vanadium and especially silicon, iron, as well as organic substances entering the spec from the fuel. Barium aluminate, a component of a fluorine-containing additive in stoichiometric amounts with respect to impurities, makes it possible to remove them from solution to 100% SiOj and Fe2092. The proposed composition of the specs with its properties meets the requirements of further hydrochemical processing. Extraction of alumina and Na-0 from the cake after adding waste in an amount of 3% is 93.0 and 90.6%, respectively. In addition to the presence of fluorine, BaClF (with a melting temperature of 1008 ° C) and KaCl (with a melting temperature of 750 ° C) also affects the rate of the reaction during sintering. Experimental research data are presented in Table. 2. Table 2 As can be seen from table. 2, an increase in the amount of waste additive (higher than 5% by weight of the dry blend) leads to a loss of NajO notices the formation of low-melting sodium-calcium silicate. An increase in temperature leads to a sharp decrease in the recovery of valuable components. The spec obtained is slightly porous, clinker-like. When the amount of fluorine-containing additive is reduced (less than 1%), the extraction of the ACO is reduced and, although the quality of the spec was porous. The presence of barium aluminate in the specters facilitates the removal of harmful impurities of S04, 00, 3 ions up to 94% COj, up to 36% 50 and up to 13% phosphorus from the solutions when the heals are spelled. The sludge obtained by imparting cakes containing BaCO, BaSa4, GaFj, BaFj, etc., it is advisable to use in. cement production. Thus, the use of the proposed method as compared with the known. Will increase the recovery rate of alumina from 91 to 93%, reduce energy consumption by reducing the sintering temperature to 11801190 ° C, as well as the content of impurities in solutions and alumina due to the presence of barium aluminate during hydrochemical processing of the cake, dispose of wastes that are dumped into the dump and contain valuable codes of 99 psi ID., which in turn will improve the state of the environment. Invention Formula). A method of processing alumina-containing material, including preparation of a mixture of alumina-containing material, soda, limestone and fluorine-containing waste from aluminum production by electrolysis and subsequent sintering of the mixture in a rotary kiln, which is used to improve sinter quality and reduce energy costs. waste of the aluminum refining process by the three-layer method in the amount of 1-5%.