SU481543A1 - The method of cleaning aluminate solutions - Google Patents

Description

(54) METHOD FOR CLEANING ALUMINATE SOLUTIONS

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The image refers to non-ferrous metallurgy, in particular to the production of alumina.,

A known method of purification of demineralized aluminate solutions from iron with potassium permanganate with subsequent filtration through a layer of aluminum hydroxide or tricalcium aluminate.

In this method, the manganese compound is introduced for the purpose of adding bivalent, ferric to ferric iron.

However, the known method requires the use of expensive and scarce pure manganese salts, the preparation and use of adsorbents, the process is carried out in two stages, it has a low productivity of the solution filtration stage through the adsorbent layer, the aluminate solution is contaminated with potassium, em no more than 7%.

If the aluminate solution is contaminated with sulfide sulfur, the consumption of oxidants increases dramatically and the cleaning process becomes much more expensive.

The purpose of the invention is to increase the degree of purification of the solution, to simplify and cheapen the process of removing impurities.

This is achieved by using a compound of manganese mixed with silica. In this case, the ability of oxides of manganese makes low-soluble compounds with oxides of iron and silicon, as well as with sulfide sulfur. Oxidizing ability, manganese oxides do not play a significant role here. As a cleaning material, cheap manganese pyrolysite ore and manganese metallurgical slags can be used.

.Prime p. 20 g of crushed bauxite is leached with an alkaline solution containing 315 g / l 134 g / l

A1 „O and 4 g / l of sulfide sulfur at 230 ° С i. about,

for 2 hours at L: T equal to 4.: Manganese ore at the rate of 2.5 g per 100 ml of solution is introduced into the pulp before leaching. After leaching, the pulp is diluted with water, cooled to 96 ° C, kept for thickening of the sludge DZ min and the clarified solution is filtered, (TO e. Simulate the process of obtaining an alumina solution in the Bayer process). l feed sulfur. According to the analysis, the iron content in the solution is reduced by 93.2% „of sulfide sulfur - by 8158%. This reduces the silicon content by 42.5%. The concentration of alkali and, agiomini oxide solution remained the same as the iF solution, without the addition of manganese ore manganese content in solution g / The advantages of the method are. that there is no need to use expensive pure manganese salts, filtering the solution through the adsorbent layer is eliminated, the degree of purification of the solution from iron increases. In addition, the solution is shed from the impurities of sulfide, sulfur and silicon; This means that the cost of solution cleaning is reduced. The cleaning of the aluminate solution is combined with the leaching process of bauxite e and does not require additional technological equipment. The proposed method can be implemented at aluminum plants in the Urals. Subject matter The method of cleaning aluminate solutions from impurities by treating with oxygen-containing manganese compounds so that, in order to increase the degree of purification and simplify process, manganese compounds use B mixtures with silicon dioxide