Method and system for recycling iron from red mud

Abstract

The invention discloses a method and a system for recycling iron from red mud. The method for recycling iron from red mud comprises the steps of carrying out fine grinding treatment on red mud powder and carbon-based material powder; then, carrying out wet grinding treatment, so as to obtain uniform mixed material fine powder, wherein the mass fraction of the mixed material fine powder, of which the particle size is not larger than 0.02 mm, is not lower than 90%; carrying out reduction treatment on the mixed material fine powder under the reduction atmosphere, so as to obtain alkali-containing furnace gas and a dealkalized material; carrying out cooling treatment on the dealkalized material, so as to obtain a cooled material; and carrying out ore grinding and magnetic separation treatment on the cooled material, so as to obtain iron powder and tailings. According to the method for recycling iron from red mud, the technological process is simple, the cost is low, the iron recovery rate is high, the iron level of the recycled iron powder is high, the content of sulfur is low, the alkali content of the tailings is low, and the recycled iron powder can be used for producing cement.

Description

technical field [0001] The present invention relates to a method for recovering iron from red mud, and a system for recovering iron from red mud. Background technique [0002] Red mud is the most important solid waste generated in the production process of alumina industry. At present, the annual discharge of red mud in China exceeds 30 million tons. Except for a small part used in cement production, brick making and other purposes, most of them are wet open-air dams Stockpiling, the cumulative stockpiling of red mud has exceeded 350 million tons. In the field of cement building materials, my country's cement consumption in 2015 was about 2.2 billion tons, and the market is very huge. However, the main limiting factor restricting the application of red mud in cement is the high alkali content in red mud. The existing red mud dealkalization methods mainly include lime method, atmospheric suspension carbonization method, water washing method, and pickling method. Lime hydrot...

AI Technical Summary

Problems solved by technology

For this reason, an object of the present invention is to propose a method for recovering iron from red mud. This method makes the powder fully mixed and finely ground by controlling the particle size of the powder, and realizes red mud recovery under reducing atmosphere and low temperature conditions. Reduction of iron oxides and alkali metal reduction in powder materials, thus effectively solving the problems of low dealkalization rate and high energy consumption of red mud fire method

And in view of the high sulfur content in coal-based direct reduced iron, the dealkalized material is cooled and then subjected to grinding and magnetic separation to produce metal iron powder with low sulfur content, which solves the problem of excessive sulfur content in red mud iron powder in the existing process. high technical difficulty

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