U + Z type seed precipitation tank and working method thereof

Abstract

The invention relates to the technical field of Bayer process production of aluminum oxide, in particular to a U + Z type seed precipitation tank and a working method thereof. Through a U + Z type configuration scheme, the distance between the seed precipitation tanks is shortened as much as possible, and the head tank and the tail tank of a decomposition tank face one direction, so that on one hand, the occupied area is saved, the length of a chute between the seed precipitation tanks is shortened, and the average basic height of the seed precipitation tank is reduced; and on the other hand,the feeding and discharging direction of the seed decomposition process is adjusted to one direction, so that the pipe network length and the slurry conveying energy consumption are reduced.

Description

technical field [0001] The invention relates to the technical field of alumina production by the Bayer method, in particular to a U+Z type seed separation tank and a working method thereof. Background technique [0002] Seed decomposition is one of the important processes in the production process of Bayer process alumina. The purpose of this process is to precipitate the alumina in the supersaturated sodium aluminate solution in the form of aluminum hydroxide crystallization to obtain high output rate and meet the quality requirements. At the same time, the mother liquor with a higher caustic ratio is obtained to return to the next batch of bauxite for dissolution. Due to the longer residence time required for seed decomposition, the number of seed tanks is larger. Taking the annual output of 1 million tons of alumina as an example, The number of sub-slots will be more than 16. The traditional arrangement of seeding troughs is generally a strip configuration, that is, th...

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Problems solved by technology

The traditional arrangement of seeding troughs is generally a strip configuration, that is, the seeding troughs are arranged in a row, and the slurry flows from the previous seeding trough to the next trough. This configuration occupies a large area and the chute connecting the seeding troughs is longer. Sub-process slurry enters from the first tank and exits from the last tank. The direction of the first and last tanks is opposite, and part of the slurry in the last tank needs to be returned to the first tank, which is not conducive to the optimization of investment, land occupation and energy consumption.

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