Sintering process sodium aluminate solution desilicification method

Abstract

The invention relates to a method for desiliconizing sodium aluminate solution by sintering, relating to a method for updating desiliconized residues and desiliconizing during two-stage desiliconization normal pressure desiliconizing-lime milk adding depth desiliconizing in the alumina producing course, characterized in firstly mixing silicon residues with sorting evaporation mother solution, polishing to complete the surface updating of the silicon residues, then adopting the silicon residues with updated surfaces as crystal seeds, and making normal pressure desiliconization on the conditions of temperature 98 deg.C-105 deg.C, activated crystal seeds of silicon residues 80-100 g / l, desiliconizing original liquor alpha K 1.45-1.52 and desiliconizing time 4-5 hours. After separated from the normal pressure desiliconizing pulp, the solid acts as desiliconizing crystal seeds and the residual solution is separated into two flows: one flow is processed by sorting resolution and the other flow is deeply desiliconized by addition of lime milk, and the solid liquid separation is made on the serum: the PaCO2 estimation is made on the obtained solution and the silicon residues are distributed by sintering. The method has simple flow and low processing energy consumption.

Description

technical field [0001] The invention relates to a method for desiliconization of a sodium aluminate solution by a sintering method, and relates to an alumina production method. Background technique [0002] In the production of sintered alumina, the existing three-stage desiliconization process is usually pre-desilication at atmospheric pressure - desilication by medium pressure cooking - deep desilication with milk of lime. β-2CaO·SiO in the process of clinker dissolution 2 Decomposed by lye, making SiO 2 into the solution so that the crude solution contains SiO 2 5~6g / l, silicon content index 20~30, these SiO 2 It is unstable, and most of it precipitates into aluminum hydroxide during the decomposition process, which affects product quality. It is necessary to set up a separate desiliconization process to desilicate the crude liquid to obtain a refined sodium aluminate solution that meets the requirements of the decomposition process. The essence of the desiliconizatio...

AI Technical Summary

Problems solved by technology

This process has the following disadvantages: first, the production process is complicated, and second, the implementation of the medium pressure desiliconization process greatly increases the energy consumption and steam consumption in the alumina production process