Method for directly preparing metallic iron and aluminum concentrate by using aluminum high-iron red mud as raw materials

Abstract

The invention discloses a method for directly preparing metallic iron and aluminum concentrate by using aluminum high-iron red mud as raw materials, belonging to the field of recycling technology of solid wastes. The method is characterized by comprising the steps of: de-alkalizing wet aluminum high-iron red mud by adopting a CO2 de-alkalization technology, separating to obtain de-alkalized red mud and NaHCO3 solution and distilling the NaHCO3 solution to obtain NaHCO3 solid; treating the de-alkalized red mud by adopting an ultrafine grinding technology to obtain dry ultrafine powder; reducing the dry ultrafine powder by using a CO fine reduction technology so as to obtain a reduction product; and conducting magnetic separation to the reduction product by using a non-molten state separation technology so as to obtain the metallic iron and the aluminum concentrate with alumina as major component. The method of the invention has the advantages that the high-iron red mud is de-alkalized by CO2 at a temperature below 100DEG C and recycled to obtain NaHCO3; the oxide of the iron is reduced at a temperature below 900DEG C; and magnetic separation is carried out to obtain high-purity metallic iron and aluminum concentrate so that the full recycling of the aluminum high-iron red mud is realized.

Description

technical field [0001] The invention belongs to the technical field of solid waste recycling and utilization, and in particular provides a process for separately preparing metallic iron and aluminum concentrate by using aluminum industry high-iron red mud as raw materials. Background technique [0002] The content of iron oxide, aluminum oxide and sodium oxide in the red mud produced during the production of alumina by Bayer method is high, which has the value of resource reuse. There are dozens of technologies for reusing red mud as a resource, but most of them are in the stage of laboratory research and cannot be widely used. At present, the resource utilization of high-speed iron red mud in the aluminum industry mainly adopts the method of combining reduction roasting and magnetic separation to extract iron elements in red mud. This method has the disadvantages of low iron recycling efficiency, complex operation process, high temperature, long reduction time and the like...

AI Technical Summary

Problems solved by technology

A large amount of red mud is piled up, which not only occupies land, wastes resources, but also easily causes environmental pollution and safety hazards

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