Method and system for treating red mud

Abstract

The invention discloses a method and a system for treating red mud. The method for treating the red mud comprises the following steps: drying water-containing red mud to obtain dry red mud; finely grinding the dry red mud to obtain superfine red mud powder; carrying out pre-reduction de-alkalization treatment on the superfine red mud powder in a fluidized bed under the reducing atmosphere to obtain de-alkalized red mud and high-alkali smoke dust; mixing and briquetting the de-alkalized red mud with the a reducing agent to obtain red mud briquette; and melting and separating the red mud briquette in a melting and separating furnace to obtain melted iron and tailings. Through application of the method, the alkali metals in the red mud can be effectively removed; the reducibility of the subsequent red mud iron is improved; the technical problems that the red mud is low in de-alkalization rate, the iron reducing effect is poor and the iron is difficult to recycle are solved; meanwhile, the melting and separating furnace is used for deeply reducing and separating slag iron; the products with higher recycling rate and metalizing rate can be further obtained; the method has important economic benefits.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and energy, and in particular relates to a method and system for processing 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 and brick making, most of them are used in wet open-air dam construction 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 pick...

AI Technical Summary

Problems solved by technology

When no limestone is added or the amount added is small, the pellets cannot be fully reduced, and the metallization rate is very low, which is not conducive to the subsequent separation of slag and iron.

When more limestone is added, CaO in limestone reacts with FeO and SiO at high temperature 2 、Al 2 o 3 The formation of low melting point compounds such as calcium ferrite olivine leads to severe bonding between the pellets and refractory materials, so it is difficult to obtain metallized pellets with high metallization rate. The existing rotary kiln adopts red mud powder sintering method. Although the dealkalization rate can reach more than 60%, the metallization rate is only 50%-70%, and the iron recovery rate is 30%. The equipment is easy to loop and the production is not smooth.

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