Manufacturing method of bayer process red mud flocculating agent

Abstract

The invention relates to a manufacturing method of flocculating agents for the sedimentation of Bayer process red mud, which belongs to the environmental protection technical scope. The invention is characterized in that: polyacrylamide obtains cation and cationic polyacrylamide is prepared by the adoption of nonionic polyacrylamide as the raw material, through basic hydrolysis, modification of ester of hydroxamic acid and Mannich reaction, with the formation of Mannich base as the intermediate step; olyacrylamide is made to consist of anion group and cation group and zwitterionic polyacrylamide is prepared by the adoption of nonionic polyacrylamide as the raw material, through basic hydrolysis, modification of ester of hydroxamic acid and Mannich reaction, with the formation of Mannich base as the intermediate step. The invention has the advantages that the preparation method is simple; the flocculation efficiency of ferriferous and siliceous slag during the manufacturing process of prior Bayer process aluminum oxide reaches to more than 20m/h; the seston in the solution after flocculation is less than or equal to 1g/L; the manufacturing method is superior to the international standards; the cost is only 70-80 percent of the international similar products; the manufacturing method is in accordance with the national conditions, easy to go into production of an industrial scale, without the generation of secondary pollution and the three wastes during the production process, and eco-friendly.

Description

technical field [0001] The invention belongs to the category of environmental protection technology, and in particular relates to a manufacturing method of a Bayer process red mud sedimentation flocculant. Background technique [0002] In recent years, with the continuous expansion of the application scope of metal aluminum in the fields of industry, construction, chemical industry, light industry and so on, the aluminum mining industry has developed rapidly. Old enterprises continue to expand and transform, and the scale of new installations is getting larger and larger. [0003] In the current technologically advanced Bayer process of aluminum smelting, in addition to aluminum and its series of products, solid waste is formed--waste red mud (Redmud). The by-products formed in the process have extremely complex physical and chemical properties. When producing one ton of alumina, about 1.0 to 1.3 tons of red mud are produced by-product. At present, the annual output of alu...

AI Technical Summary

Problems solved by technology

The stockpiling of red mud occupies land, pollutes groundwater and surface water, affects the landscape and produces dust, endangers crops and farmland, and affects the environment

[0005] However, the current addition of flocculant - polyacrylamide (hereinafter referred to as PAM) to accelerate the separation process is not satisfactory, and the settling speed is still not fast enough, resulting in the waste residue in aluminum production - red mud processing, becoming the "bottleneck" that restricts the entire aluminum production process