CZ307417B6 - A method of producing liquid potassium water glass - Google Patents

Abstract

The solution relates to a method of producing liquid potassium water glass from silica sand, potassium hydroxide and water, wherein the mixture of 20 to 40% by weight of the silica sand, 20 to 70% by weight of the potassium hydroxide and 0 to 60% by weight of water is subjected to synthesis in an autoclave pressurized with water vapour to 0,8 to 1.4 MPa for 5 to 9 hours.

Description

Technical field

The invention relates to a method of liquid potassium water glass of silica sand, potassium hydroxide and water.

BACKGROUND OF THE INVENTION

Liquid potassium water glass has hitherto been produced by dissolving the glass batch in potassium hydroxide and water. This procedure is lengthy and therefore expensive. Also known is DE 3500469, which is directed to the production of sodium water glass, the minimum molar ratio being SiO ₂ : Na ₂ O or SiO ₂ : K ₂ O of 2.0. Sodium water glass is then used to produce silica gel. To date, however, there is no suitable method for producing liquid potassium water glass.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a new process for the production of liquid potassium water glass, which speeds up this process.

SUMMARY OF THE INVENTION

This object is solved and the drawbacks of the known processes of this kind are largely eliminated by the process for producing liquid potassium waterglass from silica sand, potassium hydroxide and water according to the invention. % silica sand, 20 to 70% potassium hydroxide, and 0 to 60% wt. of water for 5 to 9 hours was synthesized in an autoclave pressurized with water to 0.8 to 1.4 MPa. In this way, the process can be significantly accelerated and thus the production costs can be reduced.

It is further preferred that the obtained liquid potassium water glass is filtered after adjusting the viscosity and density at 80-85 ° C.

DETAILED DESCRIPTION OF THE INVENTION

In the process according to the invention, liquid potassium water glass is produced by direct synthesis from silica sand, potassium hydroxide and water in an autoclave, which is pressurized with steam to a pressure of 0.8 to 1.4 MPa. The charge consists of 20 to 40 wt. % silica sand, 20 to 70 wt. % potassium hydroxide and 0 to 60 wt. water, depending on the desired final product specification, which is the weight ratio between the content of silica and potassium oxide and the concentration which is the sum of the contents of silica and potassium oxide. Percentages are by weight.

The reaction is carried out in an autoclave

P (MPa)

K ₂ O. mSiO ₂ + nH ₂ O --------------------> K ₂ O. mSiO ₂ . nH ₂ O

Upon completion of the reaction for 5 to 9 hours, depending on the type of waterglass, the potassium waterglass preform is extruded from the autoclave into a container where it is adjusted for filtration, i.e. at a temperature of 80-85 ° C, viscosity and density are adjusted. with regard to the possibilities of filtering equipment. After this treatment, the preform is filtered and ready for further use.

- 1 GB 307417 B6

As described above, potassium water glasses can be produced in a concentration range of K ₂ O of 10 to 28% by weight.

% SiO ₂ 15 to 35 wt.

the remaining component is water at a weight ratio of 1.0 to 3.5.

Claims (2)

Process for the production of liquid potassium water glass from silica sand, potassium hydroxide and water, characterized in that the mixture is 20 to 40 wt. % silica sand, 20 to 70 wt. % potassium hydroxide and 0 to 60 wt. of water for 5 to 9 hours was synthesized in an autoclave pressurized with water to 0.8 to 1.4 MPa. Method according to claim 1, characterized in that the obtained liquid potassium water glass is filtered after adjusting the viscosity and density at a temperature of 80 to 85 ° C.