Method and device for online cleaning filtering cloth for filtering sodium aluminate slurry

Abstract

The invention discloses a method and a device for online cleaning filtering cloth for filtering sodium aluminate slurry, which is characterized in that a dissolving and washing groove filled with 5-30wt% sodium hydroxide solution and a washing groove filled with 1-5wt% diluted sodium hydroxide solution are additionally arranged on a returning path of filtering cloth of a horizontal belt type vacuum filter, firstly the filtering cloth enters the dissolving and washing grooves to rapidly dissolve aluminum hydroxide crystal on the surface of the filtering cloth and in a capillary passage, generated sodium aluminate enters the solution, and then the sodium aluminate carried by the filtering cloth is diluted by the diluted sodium hydroxide solution, thereby achieving the purpose of avoiding the hardening of the filtering cloth and recycling the filtering cloth after the regeneration. The invention has simple theory and easy application, and is especially suitable for rapidly dissolving outclinker aggregate by a sintering method and separating solid and liquid, thereby providing a new and important technical support for restraining the secondary reaction, improving the recycling rate of alumina and sodium oxide, reducing the content of red-mud sodium oxide and improving the utilization of the red-mud. The invention can produce great economical and environment benefits which generalized and applied to the alumina industry.

Description

technical field [0001] The invention belongs to the technical field of alumina production, and relates to the liquid-solid separation technology of sodium aluminate slurry after dissolving alumina from clinker of bauxite or soda lime sintering method, in particular to the liquid-solid separation of sodium aluminate slurry Cleaning method and cleaning device with filter cloth. Background technique [0002] Extracting alumina from bauxite mainly adopts Bayer method and soda lime sintering method. In these two methods, the separation of aluminum and non-aluminum minerals is nothing more than making most of the aluminum enter the solution in the form of sodium aluminate, while most of the non-aluminum minerals still exist in the solid state. After liquid-solid separation, sodium aluminate solution and red mud are obtained. [0003] There are two main methods of liquid-solid separation in industry: filter cloth filtration and sedimentation separation. When using filter cloth t...

AI Technical Summary

Problems solved by technology

However, due to the long liquid-solid contact time of the sedimentation separation technology, the secondary reaction opportunity is increased, which not only causes the loss of alumina and sodium oxide, but also leads to high alkali content in the red mud, which not only pollutes the environment, but also damages the red mud. use

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