Method for recovering iron in low-iron Bayer process red mud

Abstract

The invention discloses a method for recovering iron in low-iron Bayer process red mud. The method comprises the steps that de-alkalization treatment is conducted on the Bayer process red mud by adopting calcium oxide to mix the de-alkalization red mud with activated carbon; the mixture is mixed with a binding agent to be pressed into tablets; the tablets are placed into a graphite crucible, high-temperature treatment is conducted under the condition that argon is introduced all the time in a vacuum electromagnetic sensing furnace, the tablets are cooled down along with the furnace, grinding is conducted, and iron slags are separated through magnetic sorting. The method has the advantages that the recovery rate and grade of iron are higher than 80%, the processed Bayer red mud can be usedfor producing building materials, recovered iron is conformed to demands of industrial steel melting, the problem of excessively high red mud accumulation amount is effectively solved, and an excellent guiding meaning is achieved on the recovery of iron in the low-iron Bayer process red mud.

Description

technical field [0001] The invention belongs to the field of metallurgy and resource recycling, and in particular relates to a method for recycling iron in low-iron Bayer process red mud. technical background [0002] Bayer process red mud is a highly alkaline solid waste produced in the process of producing alumina by Bayer process. The chemical composition is quite complex. For every ton of alumina produced, about 1 to 2 tons of red mud will be produced. Under the existing technical conditions , Stockpiling is still the main way to deal with red mud. The cumulative stockpiling of red mud in the world has reached 4 billion tons, and the annual discharge is about 120 million tons; The speed is constantly increasing, taking up a lot of land. The production of a large amount of red mud has brought a very serious impact on human production and life. With the continuous increase of red mud discharge, the gradual depletion of mineral resources and people's attention to environm...

AI Technical Summary

Problems solved by technology

Therefore, red mud has great economic value. There are many ways to recover iron in red mud. Direct magnetic separation can be used to recover iron in red mud. However, the iron grade and recovery rate recovered by this method are low. And for low-iron red mud, the effect is even worse; reduction roasting and magnetic separation can also be used to recover iron in red mud. At present, this method mainly uses resistance furnace heating for reduction roasting and then magnetic separation. The recovery effect of red mud is better, but for low iron (T Fe <8%) red mud, the recovery effect is not ideal, and the practicability is poor