Preparation method of sodium silicate

Abstract

The invention discloses a preparation method of sodium silicate. The preparation method comprises the following steps: (1) cleaning fluorine-containing silicon slag with water until a pH value is 4.5 or above, drying the cleaned silicon slag to enable the moisture content in the silicon slag to be 2 percent or below; (2) mixing sodium carbonate and the fluorine-containing silicon slag according to a certain material ratio, putting an obtained mixture in a high temperature furnace after uniform mixing, starting a negative pressure system with water absorption to enable a reaction system to form trace negative pressure being -0.01MPa, and absorbing fluorine-containing gas escaped in the temperature rising process of the fluorine-containing silicon slag with water; completing escape of fluorine in the fluorine-containing silicon slag when rising the temperature of the high temperature furnace to 900 DEG C; heating the high temperature furnace to 1100-1250 DEG C, and ensuring the reaction temperature of the sodium carbonate and the silicon slag to be from 1050 DEG C to 1200 DEG C; reacting for 30-60min; taking out solid sodium silicate after a reactant is cooled to room temperature, and grinding the solid sodium silicate to obtain a powdery sodium silicate product, wherein a modulus of the sodium silicate is 2-3. The preparation method overcomes the disadvantages that the fluorine-containing silicon slag cannot be recycled, and the sodium silicate which can meet the requirements for phosphate ore processing and has the modulus being 2-3 is prepared.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a preparation method of sodium silicate. Background technique [0002] Sodium silicate, commonly known as sodium silicate, is an important chemical raw material with a wide range of uses, covering almost all sectors of the national economy. Sodium silicate can be used to manufacture various silicate products such as silica gel, white carbon black, zeolite molecular sieve, sodium metasilicate pentahydrate, silica sol, layer silicon, etc. It is the basic raw material of silicon compounds. In the light industry, it is an indispensable raw material for detergents such as washing powder and soap, and it is also a water softener and sedimentation aid; it is used in dyeing, bleaching and sizing in the textile industry; it is widely used in casting and grinding wheels in the machinery industry Manufacturing and metal preservatives, etc.; used in the construction industry to ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the disadvantage that fluorine-containing silicon slag cannot be recycled, and provide a method for preparing sodium silicate from the by-product fluorine-containing silicon slag after the production of anhydrous hydrogen fluoride by the fluosilicic acid method