Method for defoaming spent mother liquor in production of aluminum oxide

Abstract

The invention discloses a method for defoaming spent mother liquor in production of aluminum oxide. The method comprises the steps of arranging a branch at a pipeline spent mother liquor pipeline for sending concentrate solution to be subjected to cooling treatment, continuously returning a part of the spent mother liquor to a spray device arranged in a gas-liquid separator through the branch pipeline, wherein the returned spent mother liquor produces impulsion force to defoam filter liquor due to a high pump lift. The method for defoaming spent mother liquor in production of aluminum oxide has the advantages that the technological progress is continuous, and basically no manual operation is needed; pressure in an outlet of the spray device and flow in the branch pipeline can be adjusted according to different foaming conditions, the method can be applicable to a wide range of spent mother liquor under different technological conditions, and only a small amount of investment in pipe materials and sprayers are needed. In spite of adding of mother liquor circulation volume and water volume, defoaming effects are obvious, thus a production and operation environment of an enterprise is improved, and an effect of decreasing cost and increasing benefits is achieved.

Description

technical field [0001] The invention discloses a simple method for eliminating foaming of the filtrate produced by filtering aluminum hydroxide seed crystals by using a filter machine in alumina production, that is, decomposing mother liquor. Background technique [0002] At present, the Bayer process is the leading process for producing alumina in the world. The Bayer process eluate is diluted and separated from the red mud to obtain semen. Aluminum hydroxide is obtained by adding aluminum hydroxide seeds to the semen, that is, the seed decomposition process. The decomposed semen is called the decomposed mother liquor. The aluminum hydroxide seeds precipitated in the mother liquor need to be filtered to reduce the sodium aluminate solution attached to its surface, otherwise the decomposition rate and aluminum hydroxide particle size will be affected. In actual production, due to the specific chemical and physical properties of the decomposed mother liquor, the filtrate obta...

AI Technical Summary

Problems solved by technology

In the production, mechanical defoaming, adding defoaming agent to defoam and heightening the filtrate tank have been used to solve this problem. Mechanical defoaming needs to add a defoaming device in the decomposition mother liquor tank, and there is a liquid seal tank in the filtrate tank, so Mechanical design is difficult, and if the design is unreasonable, more foam will be generated; the defoamer is a chemical, which enters the alumina production system after being added, and is not conducive to normal production after long-term accumulation; and the heightened decomposition mother liquor tank can only Appropriately improving the working conditions cannot fundamentally solve the foaming problem, and after the filtrate tank is raised, the floor where the filter is located needs to be raised, resulting in an increase in capital investment in this process

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