Method for high-value comprehensive utilization of red mud

Abstract

The invention discloses a method for extracting aluminum, ferrum, rare earth and scandium from red mud, and belongs to the field of high-value comprehensive utilization of red mud. The method comprises the steps that after the red mud and a proper amount of concentrated sulfuric acid are evenly mixed and cured, rapid reduction roasting is conducted on the mixture with a reducing agent at a certain temperature for desulfuration, and regeneration and recycling of sulfuric acid is achieved through acid making with smoke containing SO2; water leaching is conducted on reduced roasted sand for extracting rare earth and scandium, and a water extract is concentrated, separated and purified through wet metallurgy, so that an Sc2O3 product and a rare earth-enriched product are obtained; and magnetic separation is conducted on water leaching residues, so that iron ore concentrate and magnetic separation tailings are obtained, and alkaline leaching is conducted on the magnetic separation tailings, so that aluminum oxide is prepared. According to the method, based on the principle that each component in the red mud is separated out in each step, effective separation can be achieved, the technique for each step is an existing industrial production technique, and industrial production can be achieved easily.

Description

technical field [0001] The invention belongs to the field of high-value comprehensive utilization of red mud, and in particular relates to a method for extracting aluminum, iron, rare earth and scandium from red mud. Background technique [0002] Red mud is the residue produced when bauxite is leached by strong alkali during the production of alumina. For every ton of alumina produced, 1 to 1.6 tons of red mud are produced. According to incomplete statistics, the world produces about 70 million tons of red mud every year, and only five alumina plants in my country produce 6 million tons of red mud every year. The discharge of red mud in the world is large, but the utilization rate is low. A large amount of red mud is still treated by stockpiling or sea discharge. The huge amount of red mud has not been effectively utilized, causing many social, ecological, environmental and economic problems. [0003] A large amount of land is required to store waste red mud, and dam breaks...

AI Technical Summary

Problems solved by technology

Using direct acid leaching method, because a large amount of iron, aluminum, calcium, magnesium and other impurities not only consume a large amount of acid, but also a large amount of impurities entering the solution will also cause problems such as difficulty in metal extraction and low purity of scandium oxide.

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