Comprehensive utilization method for low-grade aluminum-containing raw material

Abstract

A comprehensive utilization method for a low-grade aluminum-containing raw material is carried out according to the steps of: 1) mixing sodium ferrite, the low-grade aluminum-containing raw material and lime and leaching the mixture with a caustic alkali solution, adding lime milk or lime to the leachate to perform a retention reaction, and filtering produced tricalcium aluminate slurry to preparea high-molecular solution; 2) heating and evaporating the high-molecular solution to prepare a caustic alkali solution; 3) performing mixing and secondary dissolution to the tricalcium aluminate filter cake and evaporation mother liquid to prepare calcium carbonate slurry; 4) filtering the calcium carbonate slurry to prepare a secondary solid phase and a secondary filtrate, feeding CO2 to the calcium carbonate filtrate for carbonation decomposition, thus producing carbonation decomposition slurry; 5) respectively processing the carbonation decomposition slurry to obtain aluminum hydroxide andlime; 6) processing leaching residue to prepare andradite. The method forms a closed loop of novel technology for comprehensive utilization of the low-grade aluminum-containing raw material, whereinthe ultra-white aluminum hydroxide and andradite are produced, while other materials are circulated internally in the process.

Description

technical field [0001] The invention belongs to the technical field of mineral processing, in particular to a comprehensive utilization method of low-grade aluminum-containing raw materials. Background technique [0002] my country's bauxite resources are relatively rich, but it is mainly a diaspore type, and its main characteristics are high aluminum, high silicon, and low aluminum-silicon ratio; among the world's major bauxite smelting countries, my country mainly uses the Bayer process to process diaspore. Bauxite produces alumina. Due to the low aluminum-silicon ratio of the ore, the energy consumption and alkali consumption of alumina production are higher than those of foreign alumina factories that use gibbsite as raw material; with the development of my country's aluminum industry, the production of bauxite The aluminum-silicon ratio of ore is gradually decreasing. Bauxite with low aluminum-silicon ratio increases the production cost of enterprises, and the stockpiling...

AI Technical Summary

Problems solved by technology

[0003] The intensified Bayer method is improved on the basis of the Bayer method to adapt to the processing of low-grade bauxite. Simple, but there are problems such as difficult physical dressing, large consumption of raw ore, low recovery rate of alumina, flotation reagents affecting the Bayer process, etc. At the same time, a large amount of tailings with an aluminum-silicon ratio lower than 2 cannot be used during the dressing process, resulting in resources. Great waste; the lime Bayer method is based on the Bayer method by adding excess lime to reduce alkali consumption, but the large amount of lime added leads to a significant decrease in the dissolution rate of alumina, increased red mud discharge, and increased red mud sedimentation load and other issues; the sintering method mainly includes soda lime sintering method and lime sintering method, but high energy consumption and high production cost are the main shortcomings of its development; soda lime sintering method belongs to wet batching and wet sintering, and raw material The evaporation of about 40% of the water in the slurry greatly increases the total energy consumption of production; the lime sintering method has problems such as high lime ratio, large amount of spoil, and low clinker alumina leaching rate; Bayer-sintering combined method includes series method, Parallel method and hybrid method can process low-grade bauxite, but there are problems such as complex process and high energy consumption, which have been basically replaced by Bayer method; other processes such as acid method and acid-base combined method are currently mainly in the experimental stage In the stage of laboratory research or semi-industrialization, there are many problems such as poor quality of alumina products and serious corrosion of equipment

[0004] Looking at the above methods of processing low-grade bauxite, the sintering method and the Bayer-sintering combined method have problems such as large investment and high production costs. The lime Bayer method was developed to solve the problem of alkali consumption in a specific historical period. Currently, only the Bayer method for mineral processing It was applied in Zhongzhou Branch of Aluminum Corporation of China; however, after the industrial practice in recent years, the increasingly exposed problems of ore dressing Bayer process have seriously hindered the normal operation of the production process and become the bottleneck of its continued promotion and development; therefore, for a large number of our country It is imperative to develop new methods for efficient and economical treatment of low-grade diaspore bauxite

Images