SU931716A1 - Method for processing high-grade and low-grade bauxites - Google Patents

Description

(54) METHOD FOR PROCESSING HIGH-QUALITY AND LOW-QUALITY BOXITES

I

The invention relates to non-ferrous metallurgy and can be used to obtain alumina from high-quality and low-quality α-bauxites, according to a parallel version of the combined Bayer-sintering scheme.

There is a known method of processing low-quality bauxites, according to which the resulting red mud is fired at ZOO-750C in a reducing atmosphere, cooled, crushed and subjected to magnetic separation. The nonmagnetic fraction is sintered with soda and limestone, and clay is leached from the cake. The magnetic fraction after briquetting is used to produce iron 1. /

The disadvantages of this method include the complexity of the process and its gleam, due to the need for carrying out the restoration roasting.

The closest to the proposed technical souting and the achieved result is. processing method

high quality and low quality bauxite to alumina in parallel. The main variant of the combined Bayer-sintering scheme, which includes high-grade bauxite o6opOTfsbiM alkaline-alkali solution, separation of the aluminate solution from the red mud, its thickening and swelling, decomposition of the aluminate solution with the production of aluminum hydroxide and red octane, decomposition of the aluminate solution with the production of aluminum hydroxide and redimeter, decomposition of the aluminate solution with the production of aluminum hydroxide and red octane, redistication the solution, the calcination of aluminum hydroxide to produce alumina, the sintering of low-grade bauxite with soda and limestone, the leaching of sinter, the grinding of the resulting alkyd solution and the mixing with the aluminate solution obtained by processing high-quality bauxite G2.

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The disadvantages of this method are the low extraction of alumina and the significant consumption of limestone at the redistribution stage.

The chain of the invention is an increase in the degree of extraction of alumina and the reduction of lime consumption. The goal is achieved by the fact that in the method of processing high-quality and low-quality bauxite, which includes targeting high-quality bauxite by recycling aluminum-alkaline solution, separating the aluminous solution from the red sludge, thickening and washing it, the ayour CHA-milo-aluminate solution, the reddening solution of the liquid sludge from the red mud; alkaline-oil solution, sintering of low-quality bauxite with soda and lime, escalation of cake, desiliconization of the obtained alkylate solution and mixture With aluminate solution, obtained by treating high-quality bauxite, red mud after drying and washing is subjected to magnetic separation in a magnetic field with a strength of 15.92-10-31.85-10 A / m, the nonmagnetic product is classified and the resulting fraction with size -.

About 2 +0.063 mm is sent for sintering. Red sludge 100 14., O1 6.84 2.55 Fractions -O, 2 + O, O63mm 15 15.24 5.92 1.45 Fractions -O, Ob3 mm75 14.63 7.72 4.25 Red sludge 1OO 15.14 7.29 4.25 Fractions -0.2 + 0.063 mm S 14.5 5.04 1.25 Fraction -O, O63 mm9O 15.0 8, O 4.85

Data on the effect of magnetic field intensity on the content of the magnetic fraction of the red mud can be used to produce pig iron.

The method is carried out as follows.

Red grains of 10 g each, obtained by processing high-quality and low-quality bauxites in a parallel variant of the Bayer-sintering combined scheme and differing in the content of the constituent components, are subjected to wet magnetic separation in a field with a intensity of 15.921 O / m. In this case, a magnetic fractao is extracted from the sludge, the yield of which is 1-3% by weight of the sample. Then the red mud is classified with a fraction of 0.2 + 0.063 mm, the output of which is 10-15% by weight of the initial sample.

The chemical composition of samples obtained during the processing of red mud with a different content of the constituent components is presented in Table. 1 and 2.

Table

Table 2

Claims (2)

components in the magnet NML product are given in Table. 3. 42.32 13.72 3.9 22.96 27.5 ie, 28 16.32 DA, O6 46.91 11.75 2.81 4 .1.92 13.44 4.5 18.36 30 , 52 17.1 47.0 12.22 3.2.28 As can be seen from the table. 1 and 2, “{Rakshsh with a size of - 0.2 + 0.063 mm can be used as an aluminum-containing raw material. for addition to bauxite in the sintering zone. From the data shown in the table. 3 it follows that an increase in the magnetic field strength leads to a decrease in the content of PEO in the product directed to the production of cast iron, and its contamination with CaO impurities and the proposed method can increase the extraction of alumina by 2-4 by comparing 1C %, reduce lime consumption in redistribution of sintering by 66.5% and by 25% replace bauxite of the sintering branch with a product isolated from red mud. The invention The method of processing high-quality and low-quality bauxite, including the purpose of high-quality bauxite recycling alkaline-aluminate. solution, the separation of the aluminum solution from the red mud, its TableiaZ thickens and washes, decomposes the aluminate solution to produce aluminum hydroxide and an alkaline aluminate circulating solution, sintering low-quality bauxite with soda and lime, sinter leaching, desiliconization of the aluminate solution obtained and mixing with the aluminate solution obtained by treatment. that, in order to increase the degree of extraction of alumina and reduce the consumption of limestone, the red mud after the thickening and washing is subjected to magnetic separation uu in a magnetic field with a field intensity 15.92 85 .IOA / M, nonmagnetic klassifitsiruyutI resulting product with a size frakshpo - 0.2 + 0.063 mm fed to sintering. Sources of information taken into account in the examination 1. S. Kuznetsov, V. Derevkin. Complex processing of low-quality bauxite. M., Metallurgists, 1972, p. 83 2. Liner A.I. and etc. Alumina production. M, Metallurgists, 1978, p. 264.