Integrated calcination method for dealkalization and magnetization of Bayer process red mud

Abstract

The invention discloses a method for calcination dealkalization and magnetization of Bayer process red mud, and relates to a treatment and utilization technology for waste-red mud produced in the aluminum oxide industry. The method aims at conducting reduction on sponge iron and magnetite or dealkalization on the red mud; based on the principle that the temperature spot of red mud magnetization calcination and the temperature spot of red mud dealkalization calcination are similar, 5%-20% of a dealkalization agent and 5%-25% of a reducing agent are added into the Bayer process red mud and calcinated at a temperature ranging from 1,100 DEG C to 1,240 DEG C at the same time, and calcinated materials are ground to separate out the sponge iron and magnetite with the iron content larger than 55% and dealkalized red mud with the alkali content smaller than 2%. The extracted sponge iron or magnetite can be used as raw materials in the ferrous metallurgy industry, the dealkalized red mud can be widely applied to the field of building materials, and extremely high actual application value is achieved. Tailing-free utilization of the red mud is really achieved, and a new technical route is provided for comprehensive utilization of the red mud.

Description

technical field [0001] The invention relates to the treatment and utilization technology of red mud, a waste material produced in the alumina industry. Specifically, it uses Bayer process red mud as the main raw material, adopts a roasting process, and performs magnetization in the process of dealkalization of red mud, which belongs to solid waste The field of comprehensive utilization. Background technique [0002] The red mud produced by the alumina industry has caused great harm to the environment due to its strong alkalinity and large output. In 2012, my country produced 37.696 million tons of alumina, accounting for about 37-40% of the world's total output, and produced more than 40 million tons of red mud, with a cumulative stockpile of nearly 300 million tons; international red mud is mainly disposed of by stockpiling and covering soil At present, the effective utilization of red mud is mainly based on: adopting the red mud dealkalization technology with simple operat...

AI Technical Summary

Problems solved by technology

[0004] At present, although the methods of magnetizing or dealkalizing red mud separately are mature, they are difficult to popularize due to the high cost.

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