Method for separating iron and aluminum in red mud

Abstract

The invention relates to a method for separating iron and aluminum from red mud, which comprises the following steps: (1) sequentially carrying out pretreatment, acid leaching and solid-liquid separation on the red mud to obtain a leaching solution; (2) carrying out coprecipitation treatment on the leachate obtained in the step (1), and then carrying out solid-liquid separation to obtain a precipitate; and (3) carrying out alkaline leaching treatment on the precipitate obtained in the step (2), and then carrying out solid-liquid separation to obtain a solution containing NaAlO2 and filter residues containing Fe (OH) 3. The method for separating the iron and the aluminum in the red mud can be connected in series with the aluminum oxide industry and the iron and steel industry, effective separation and recovery of the iron and the aluminum are achieved, the treatment cost is low, and secondary pollution is avoided.

Description

technical field [0001] The invention relates to the field of solid waste recycling, in particular to a method for separating iron and aluminum in red mud. Background technique [0002] Red mud is a solid waste produced in the production of alumina. It is difficult to be effectively utilized because of its complex components and strong alkalinity. As alumina production continues to increase, the resulting red mud is also rapidly increasing. The output of red mud is large, but the comprehensive utilization rate is very low. At present, the disposal of red mud is mainly based on stockpiling. The existence of red mud piles not only occupies a lot of land resources, but also requires huge capital investment in the construction and maintenance of red mud piles. The radioactive substances contained in the red mud will radiate the environment near the yard and cause harm to the health of people, animals and plants; the alkaline solution produced by the red mud stacking will cause ...

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Problems solved by technology

[0004] CN111589572A discloses a process for recovering iron concentrate and ore from alumina red mud, which uses cyclone gravity separation, strong magnetic magnetic separation, reverse flotation, weak magnetic magnetic separation, cyclone classification and vibrating screen classification Although the combined process realizes the recovery of iron in red mud, the comprehensive recovery rate of this method is low

[0005] CN107385197A discloses a resource utilization method of red mud, which can effectively recycle iron, aluminum and sodium in red mud through reduction roasting, magnetic separation to extract iron, separation and alkali extraction, aluminosilicate mineral utilization and other steps and other main components, but there are disadvantages of high energy consumption and complicated operation

[0006] CN113857209A discloses a red mud recycling method and its application. In this method, the red mud is made into red mud slurry, and the amount of iron dissolution is controlled to be less than 5% by acid hydrolysis, and then the red mud-based iron ore is obtained through flotation desiliconization , but this method is complicated to operate, the processing cost is relatively high, and the added value is relatively low

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