SU1271907A1 - Method of producing aluminium - Google Patents

Abstract

This invention relates to the field of aluminum production by reducing alumina with carbon. The aim of the invention is to increase the yield of the product and improve its quality. The gas mixture from the reduction chamber enters the column through the gas exhaust hose. The gas mixture is distributed throughout the volume and is irrigated with liquid aluminum supplied in an amount of 38-100% of the initial aluminum content in the mixture. The dosage of aluminum is carried out in a closed loop. 3 W1., 1 tab.

Description

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This invention relates to the metallurgy of light metals and, in particular, relates to the production of aluminum by direct reduction of aluminum oxide with carbon.

The aim of the invention is to increase the yield of the product and improve its quality.

The invention consists in that the condensation of the gaseous aluminum obtained in the process of two-stage heat treatment of an aluminum-carbon-containing charge is carried out in the condensate chamber with liquid aluminum supplied to the volume of gaseous aluminum in the amount of 38,100% of the initial content of aluminum in the charge.

Figures 1-3 show an installation diagram for implementing the method. The installation consists of the first heating chamber 1, lined with graphite blocks, has openings 2 for removing carbon monoxide, is equipped with resistance graphite electrodes 3 for heating the charge, coal for 4 furnaces, made inclined

0-20 angle, high-temperature heating chamber 5, which can be heated either by electrodes 3 or by a plasma torch | mounted vertically (not shown), by a venting sleeve 6, by an automatic valve 7 for cutting off the gas flow and by a condensation chamber 8.

The condensation column 8 can be of two structures (Fig. 2) and is made of a steel casing 9 lined with asbestos and alumina on liquid glass. To supply gas from the reduction chamber, the column is equipped with a sleeve with a valve 10, and for discharge of metal - an exhaust valve 11, for irrigation with a pipeline 12.

 The column is divided inside by three steel gratings 13, which are fastened detachably on the casing with 9 bolts. Balls 14 of inert material with a diameter of 5–8 m are loaded on the gratings. In the upper part, the column is equipped with rapping nozzles 15 for supplying liquid aluminum with a pump 16 from the reservoir 17.

The briquettes of the charge are fed horizontally into the preliminary heating chamber 1, lined with graphite blocks and inclined below 4. The required temperature (14001800 ° C) is maintained with the help of a graphite electrode 3 resistances. As a result of the pre-stage calcination, the bulk of the moisture of the volatile carbon monoxide is removed.

The bulk of the carbon monoxide produced leaves the chamber due to natural thrust through the holes 2 in the furnace vault and due to the difference in gas pressure inside and outside the furnace, because of the formation of gaseous aluminum in the reduction chamber 5 heated either by electrodes 3 or by a plasma torch, CO is insignificant, which excludes any complications in gas condensation.

The process in the condensation column 8 is continuous at a pressure of 1 atm.

The gas mixture from the reduction chamber 5 through the gas discharge hose 6 through the valve 10 enters the column 8 filled with balls 14 of inert material placed on steel gratings 13. The gas is distributed throughout the entire volume of column 8 and irrigated with liquid aluminum supplied in the amount of 38- 100% of the initial content of aluminum in the mixture by means of a pump 16 from the tank 17 through the expansion nozzles 15. The dosage of aluminum is carried out in a closed loop.

Another scheme for implementing the method is shown in FIG. For irrigation of aluminum gas, the chamber is provided with a pipeline 18 for pumping liquid aluminum and irrigation funnels 19.

The dependence of the extraction of aluminum from the gas mixture on the conditions of the condensation process is shown in the table.

As can be seen from the table, with the dosage of Af in the amount of 38-100%, the gas mixture becomes saturated, the vapor reaches the dew point and an intensive separation of liquid aluminum begins.

The application of external pressure to the gas mixture from 2 to 3 atm leads to a change in the thermodynamic equilibrium conditions of the gas mixture and shifts the equilibrium towards the release of liquid aluminum (i.e.

3

the partial pressure of aluminum is reached by the mixture (dew point).

Af dosage over 100% is not economically feasible due to overloading of the aggregate with excess material and due to additional energy costs.

The dosage At is below 38% and the total pressure below 2 atm does not produce an effect due to the fact that the partial pressure AI is not enough in the gas mixture (the concentration of AF is not sufficient to saturate the vapor, the condensation process is insignificant)

The invention will make it possible to produce higher quality aluminum in terms of impurities by eliminating extraneous gases (H and CH) from the system and diluting it with liquid pure aluminum during the condensation of gaseous gas. Output

9074

the pure product is also due to the fact that the condensation of aluminum gas is carried out in bulk, and not on a plane.

Claims (1)

Invention Formula A method for producing aluminum, which includes a two-stage thermal treatment of an aluminum carbon-containing charge apk, followed by condensation of the resulting aluminum gas, characterized in that, in order to improve the product yield and improve its quality, the condensation is carried out with liquid aluminum supplied to the volume of aluminum gas in an amount of 38-100 % of the initial aluminum content in the charge. w ////////// m. .2 gas Fig.Z from lechi