Preparation method of aluminum-chromium alloy

Abstract

The invention provides a preparation method of aluminum-chromium alloy, in particular to a method for preparing aluminum-chromium alloy by electrolysis of chromium oxides which serve as the main raw material in an aluminium electrolysis cell. By the conventional aluminum electrolysis cell with pre-baked anode, industrially continuous production of aluminum-chromium alloy in batch is realized without adding of any other devices through the preparation method. The preparation method has the advantages that fluctuation in electrolysis production caused by strong reaction after adding of the raw material can be controlled within a reasonable range, content of chromium of the aluminum-chromium alloy can be controlled precisely and the utilization rate of the raw material of chromium oxides is high; the prepared aluminum-chromium alloy has the advantages of high content, low segregation and uniform component.

Description

Technical field: [0001] The invention relates to a method for preparing an aluminum-chromium alloy, in particular to a method for preparing an aluminum-chromium alloy by using an aluminum electrolytic cell. Background technique: [0002] At present, there are two main methods for the industrial production of Al-Cr alloys, namely the self-propagating thermite reduction method and the counter-mixing method. The self-propagating aluminothermic reduction method is produced by using the principle that chromium oxide and aluminum automatically react at a certain temperature. The disadvantage of this method is: the combustion is violent during the production process, and the smoke generated has a certain poisonous effect on the human body; at the same time , the aluminothermic reduction method is to use chromium oxide as a raw material, use metal aluminum as a reducing agent, and produce aluminum-chromium alloy by reduction reaction at high temperature, but the alumina replaced by ...

AI Technical Summary

Problems solved by technology

The self-propagating aluminothermic reduction method is produced by using the principle that chromium oxide and aluminum automatically react at a certain temperature. The disadvantage of this method is: the combustion is violent during the production process, and the smoke generated has a certain poisonous effect on the human body; at the same time , the aluminothermic reduction method is to use chromium oxide as a raw material, use metal aluminum as a reducing agent, and produce aluminum-chromium alloy by reduction reaction at high temperature, but the alumina replaced by this method is slag, resulting in serious aluminum loss. Difficulty in removing slag, resulting in poor melt quality and serious defects in the produced Al-Cr alloy

There are two methods of mixing: one is to mix chromium additives containing chromium with pure aluminum. The chromium additives are composed of pure chromium and a combustion aid. The disadvantage of this method is that a large amount of smoke will be generated during the addition of chromium additives. Serious pollution is caused, while the chromium yield is low and the cost is high; the second is to use pure chromium and pure aluminum to mix, the disadvantage of this method is that the chromium yield is low, the composition segregation is serious, and the composition content is not easy to control

[0005] The existing problems are as follows: First, in the alloy elements with stronger oxidizing properties than aluminum, such as chromium and aluminum react violently, excessive feeding amount will easily cause changes in the technical conditions of the electrolysis process and affect normal electrolysis production; It is necessary to extract a certain amount of raw aluminum liquid from the stock aluminum in the electrolytic cell for casting every day. It is a dynamic equilibrium process that requires comprehensive consideration in order to achieve a stable increase in the content of metal elements in the stock aluminum.

A stable and continuous corrosion-resistant and high-temperature resistant device that can pass through the electrolyte layer and join the aluminum liquid layer has not been reported so far, and the content mentioned in this patent is not easy to realize

[0007] The third is the time point of feeding, because it is necessary to extract a certain amount of raw aluminum liquid from the stock aluminum in the electrolytic cell for casting every day, which is a process of dynamic balance. When the reaction is complete, it is extracted along with the daily primary aluminum, resulting in unnecessary consumption of raw materials, pollution of primary aluminum liquid and increase in cost

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