Red mud concentration sedimentation method

Abstract

The invention relates to a red mud concentration sedimentation method. The method comprises the following steps: firstly stirring and mixing evenly concentrated sulfuric acid and concentrated phosphoric acid to obtain a sulfur-phosphorus mixed acid, then mixing a magnetite powder and the sulfur-phosphorus mixed acid and performing aging and cooling, performing solid-liquid separation to obtain anaged powder, mixing and stirring the aged powder with EDTA, and performing solid-liquid separation to obtain a magnetic flocculant; mixing the magnetic flocculant with a red mud slurry and performingstirring for 5-15 minutes, performing standing sedimentation for 5-10 minutes after the stirring is finished, discharging an upper layer clear liquid, performing filtering and drying on a lower layerslurry to obtain a mixture, performing grinding on the mixture and then performing dry magnetic separation, obtaining a red mud dry ore and magnetic substances after the magnetic separation is finished, and using the red mud dry ore to prepare building materials and adsorbing materials and extract valuable metals; and performing recycling and reusing on the magnetic substances after being subjected to activation treatment. The method has the characteristics of comprehensive utilization that the flocculant consumption is low, the flocculant can be recycled and reused, the sodium hydroxide activity is high in the clear liquid after flocculation, the red mud after flocculation can be used for preparing building materials and adsorbing materials and for extracting valuable metals, and the like.

Description

technical field [0001] The invention belongs to the technical field of red mud comprehensive treatment, and in particular relates to a red mud thickening and settling method. Background technique [0002] Red mud is the alkaline tailings produced after alumina smelting in alumina plants. In recent years, as my country's high-quality bauxite resources continue to decrease, domestic alumina plants use more and more imported bauxite, but imported bauxite contains more goethite. After applying the low-temperature Bayer method or adding During the ore concentration and dissolution process, red mud is difficult to separate and the settling tank is easy to run muddy, which will lead to problems such as difficult clarification of the solution during the preparation of alumina products, difficulty in crystallization of aluminum hydroxide, and low utilization efficiency of the settling tank. Therefore, improving the settling performance and rate of red mud has important economic value...

AI Technical Summary

Problems solved by technology

However, during the use of this kind of flocculant, a part will remain in the clarified liquid, which reduces the activity of sodium hydroxide in the clarified liquid, inhibits its return to dissolve a new batch of bauxite, and at the same time settles and separates the red mud It contains a large amount of organic flocculants that cannot be removed, which will lead to the presence of organic pollutants in red mud, which limits its use in the preparation of building materials, extraction of valuable metals, and preparation of environmental materials. At the same time, the amount of flocculants is also large and cannot be recycled. use

[0004] Therefore, although the current red mud sedimentation process has a fast sedimentation rate, there are problems that the amount of flocculant is large, the flocculant cannot be recycled, the activity of sodium hydroxide in the liquid after flocculation and sedimentation is low, and the red mud after flocculation has organic pollution and is difficult to comprehensively utilize. defect

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