Preparation method of casting water glass

Abstract

The invention relates to a preparation method of casting water glass; the preparation method is characterized in that: the material is heated to 158-169 DEG C, and the temperature is kept for 1-4 hours, and then the temperature is raised to 179-212 DEG C for 4-10 hours, and the pressure is released to 0.3MPa, and then the material is driven to a cooling tank by excess pressure, 50-70 DEG C is cooled, and non-reactive material is separated out and removed by solid-liquid separation equipment, and the non-reactive material can be used continuously in the follow-up production, supernatant liquidis sucked in a water glass raw material storage tank, plain sedimentation is carried out for 48-72 hours to obtain transparent liquid water glass, and a bottom port is used for draining turbid water glass; the mass percentage of SiO2, Na2O and K2O is adjusted by one or all of industrial solid sodium hydroxide and industrial solid potassium hydroxide, and 0.5-21 percent of modifiers is added by mass percentage, wherein the modifiers are one or a plurality of sorbitol, xylitol, mannite and maltitol; the raw material is added in a stirring tank to obtain the casting water glass including 23-31 percent of SiO2, 0.5-28 percent of K2O, 9-21 percent of Na2O, 0.5-21 percent of modifiers and remaining water by mass percentage.

Description

technical field [0001] The invention relates to molding materials for casting technology, and in particular provides a method for preparing water glass for casting. Background technique [0002] Water glass, commonly known as sodium silicate, is a system in which a true solution and a colloidal solution of a monovalent metal silicate coexist in water, and can generally be expressed as: M 2 O mSiO 2 ·nH 2 O, where M is Na + 、K + , Li + , Rb + . Foundry water glass is mainly Na + Water glass, or Na + 、K + A modified product of water glass mixed with the two, with a modulus of 1.7 to 2.6. CO in 1952 2 Sodium silicate water glass sand was introduced into the foundry industry and widely used. According to statistics at the end of 2007, my country's annual output of castings is 31.269 million tons, including 4.047 million tons of steel castings, and the annual consumption of ordinary sodium silicate glass is 300,000 to 400,000 tons, and the consumption is increasing at ...

AI Technical Summary

Problems solved by technology

[0011] 1. Long reaction time and low production efficiency;

[0012] 2. The modulus of water glass production is low, modulus ≤ 2.2, and the market demand is limited;

[0013] 3. There are many solid residues, accounting for about 5-15% of the total, and the solid waste is discharged, which endangers the ecological environment

[0014] Due to the above reasons, the wet process has not been widely applied.

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