Process for rapidly separating sodium aluminate solution and washing red mud in aluminum oxide production

Abstract

The invention relates to a process for rapidly separating sodium aluminate solution and washing red mud in an aluminum oxide production. According to the process, stable operation of rapid separation of a large-scale industrialized sodium aluminate solution and red mud washing is realized through the steps of mixing dilution, rapid separation, repulping, rapid washing, circulating water balance and the like; a flocculating agent does not need to be added or the addition amount can be reduced; the consumption of the flocculating agent and the investment in a settling tank are avoided or reduced; secondary loss of the aluminum oxide caused by overlong separation and settlement time is avoided; the dissolution rate and the total recovery rate of the aluminum oxide are improved, so that bauxite resources are saved and the production cost is reduced; meanwhile, due to the circulating water balance, a lot of washing water is available for a filtering medium (filter cloth), so as to ensure the filtering property when large filtering and washing equipment continuously runs; through reduction of wastewater in the red mud, and rapid separation and washing, the washing water is greatly reduced; the target of high recovery rate is finished; and the production cost of the aluminum oxide is reduced.

Description

【Technical field】 [0001] The invention belongs to the technical field of alumina production from hydrometallurgical bauxite, fly ash and nepheline, and specifically relates to rapid separation of sodium aluminate solution and red mud washing process in the alumina production process. 【Background technique】 [0002] my country's bauxite resources are naturally scarce, and the current domestic bauxite reserves only account for 2.4% of the world's total reserves. In recent years, foreign countries have imposed restrictions on the export of bauxite resources, making the actual requirements of increasing the dissolution rate of bauxite and reducing production costs more urgent. [0003] According to relevant statistics, in the alumina production process, whether it is sintering method, Bayer method or Bayer sintering combined method, the existing alumina dissolution slurry sedimentation separation technology, the net dissolution rate of alumina is 3% to 5% lower than the actual d...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to solve the technical problems existing in the existing alumina production process, and to provide a rapid separation of sodium aluminate solution and red mud washing process in the alumina production process. The difference between the dissolution rate and the actual dissolution rate is large, the secondary reaction is serious, the consumption of alkali, washing water, and flocculant is large, the sedimentation and running mixing and the cleaning of the settling tank are difficult, and a single separation equipment cannot complete rapid separation and full washing of red mud. Technical problems such as high liquid content of discharged red mud and inability to dry stack

Images