Method for disposing filter cake of vertical leaf filter

Abstract

The invention relates to a method for disposing a filter cake of a vertical leaf filter, in particular to a method for disposing a sodium alumina solution fine filter cake in the Bayer-process alumina production, and belongs to the technical field of alumina production. The method for disposing the filter cake of the vertical leaf filter comprises the following steps: conveying a filter cake generated after coarse liquid filtration to solid-liquid separation equipment for concentration, so as to reduce the content of filter cake-attached liquid; pulpifying the filter cake and conveying to a target receiving process for recycling. Compared with the prior art, the method provided by the invention has the advantages that the filter cake after solid-liquid separation is conveyed to a red mud separation and washing and subsequent process, so that the circulation quantity of coarse liquid can be reduced, and the alkali loss is reduced; the filter cake after solid-liquid separation is conveyed to a raw material grinding, silicon pre-removal and dissolution process, so that useful components in the filter cake can be recovered, and the adverse effect of the filter cake attached liquid on desilication and dissolution can be reduced; the quantity of the coarse liquid and the content of suspended matters are reduced, so that the workload of the leaf filter is reduced; alumina and calcia in the filter cake can be recovered; the flow rate of the attached coarse liquid in the receiving process is reduced, and the production capacity of original equipment is maintained.

Description

technical field [0001] The invention relates to a method for disposing of a filter cake of a vertical leaf filter, in particular to a method for disposing of a filter cake for fine filtration of sodium aluminate solution in the Bayer alumina production process, and belongs to the technical field of alumina production. Background technique [0002] During the production of alumina by the Bayer method, the overflow of the red mud separation settling tank (ie crude liquid) needs to be filtered under pressure to further reduce the content of floating solids in it, so as to obtain a sodium aluminate solution (ie semen) that meets the requirements of the decomposition process. The process is called fine filtration of sodium aluminate solution. In the process of fine filtration, milk of lime is usually added as a filter aid, and the amount of milk of lime added should be determined according to the content of floating matter in the crude liquid. After the crude liquid is filtered,...

AI Technical Summary

Problems solved by technology

In conventional alumina production, the fine filter cake is mostly directly pumped into the red mud separation and washing process, and is discharged to the red mud stockpile along with the red mud. Due to the large amount of attached liquid and the high concentration of alkali, this not only increases the red mud The workload of the mud separation and washing process will cause the loss of useful components

Chinese patent application number "200810229446.6" invention patent "Utilization method and system of sodium aluminate solution fine filter cake", is to send the fine filter cake to the pre-desilication tank for desiliconization treatment, and then in the pressure cooker Dissolution, although this method can recover the alumina in the filter cake, but when the filter cake slurry enters the pre-desilication tank, since a large amount of crude liquid is brought in with the filter cake, it will cause disadvantages to the desilication and subsequent dissolution process influences

Images