METHOD OF PREPARING CONCENTRATED HYDROSOL OF SILICON OXIDE Russian patent published in 2010 - IPC C01B33/141 C01B33/148 

FIELD: chemistry.

SUBSTANCE: invention can be used in production of different types of paper, film-forming compositions on metal and ceramics, as binding material in production of thermal protective material, shell moulds for precision casting and in production of construction materials. A sodium silicate solution is subjected to ion-exchange conversion to polysilicic acid, stabilisation with sodium hydroxide solution, thermal treatment at temperature not above 130° C for 2-3 hours with intense stirring without changing volume of the solution. The thermally treated hydrosol of silicon oxide is passed through a pre-filtration unit with subsequent concentration of the solution through ultra-filtration using a membrane unit with tangential distribution of the flow of liquid.

EFFECT: invention allows for increasing concentration of hydrosol of silicon oxide, its degree of purity, reducing deposits on reactor walls, increasing efficiency of the process.

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