Method for processing diaspore ore to produce alumina

Abstract

The invention relates to a method for processing diaspore ore to produce alumina. Size generated by resolving seeds enters aluminium hydroxide separating equipment to be separated so as to obtain mother liquor, the obtained mother liquor is sent into a depth decomposition slot to be decomposed and is added with seed crystal in the depth decomposition slot, part of aluminium hydroxide obtained by depth decomposition is adopted as the depth decomposition seed crystal to be recycled, the rest aluminium hydroxide is sent to the tail end of a dissolving-out system to be dissolved again, and the mother liquor which is subjected to depth decomposition returns to the front end of the dissolving-out system for dosing. According to the depth decomposition, the causticity molecule ratio of the mother liquor can be enhanced from 2.8-3.2 to 3.0-3.4; as the mother liquor returns for dosing after being subjected to evaporation concentration, the production capacity of dissolving out is enhanced; andas the aluminium hydroxide is dissolved again by a flash tank at the tail end of the dissolving-out system, the molecule ratio of liquor dissolved out is reduced to be 1.28-1.32 from 1.4-1.6, so thatthe enhancing of the quality of products is facilitated, and the time for resolving the seeds is shortened. Compared with traditional technological process, the production capacity of a whole system can be enhanced by about 15%.

Description

technical field [0001] The present invention relates to a method for producing alumina, in particular to a method for processing diaspore ore to produce alumina. Background technique [0002] In the alumina production process for processing diaspore, high-concentration circulating lye is generally used to dissolve the useful component in the ore—alumina under high temperature and pressure. After the dissolution, the serous liquid is called semen after dilution, separation, and purification. . The semen needs to be decomposed under the condition of adding a certain amount of seed crystals, and the aluminum hydroxide obtained from the decomposition is separated, washed, roasted and other processes to obtain the product alumina, and the decomposed mother liquor is evaporated and concentrated and then returned to the batching system. cycle. [0003] Due to the mineral properties of diaspore, the caustic molecular ratio ([Na2O] / [AL2O3]) of the eluate is about 1.4 to 1.6 under a...

AI Technical Summary

Problems solved by technology

This solution is used in the decomposition process. In order to ensure the quality of the aluminum hydroxide obtained from the decomposition, the caustic molecular ratio of the decomposition mother liquor is generally controlled in the range of 2.8 to 3.2, so the lye circulation efficiency in the entire production process is not high

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