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Preparation method of high-purity silicon dioxide

A silicon dioxide, high-purity technology, applied in the direction of silicon dioxide, silicon oxide, etc., can solve the problems of high impurities, unable to reach high-purity standards, etc., and achieve the effect of high purity and simple operation

Inactive Publication Date: 2015-06-24
TIANJIN KERMEL CHEM REAGENT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the preparation of silica generally adopts industrial sodium silicate to be dissolved in water, and then industrial nitric acid is added to precipitate silica. Purity standards, in which the content of sodium reaches 0.005%, boron 0.003%, and the impurities are very high. Therefore, it is of great practical value to seek a preparation method of high-purity silica

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] A preparation method of high-purity silicon dioxide, the specific preparation steps are as follows:

[0016] (1) Add 2000ml of pure water to a 3000ml beaker and heat to 80°C, add 1kg of analytically pure sodium silicate, stir and heat until dissolved, then filter, and the filtrate remains clear to obtain a sodium silicate solution for later use;

[0017] (2) Prepare high-purity nitric acid into a 50% nitric acid solution and slowly add it to the sodium silicate solution in step (1), while stirring continuously to form fine crystals, that is, silicon dioxide crystals;

[0018] (3) After the crystal precipitation is complete, stop adding nitric acid, let it stand for crystallization for 10 hours, add 2000ml of 80°C hot water to wash until the chloride in the crystal is qualified (chloride ≤ 1×10 -3 %), dry the crystals by centrifugation, put them on a tray and dry them at 100°C for 10 hours, then put them into a high-temperature furnace and burn them at 900°C-1000°C for 1...

Embodiment 2

[0030] A preparation method of high-purity silicon dioxide, the specific preparation steps are as follows:

[0031] (1) Add 1500ml of pure water to a 3000ml beaker and heat to 75°C, add 1kg of analytically pure sodium silicate, stir and heat until dissolved, then filter, the filtrate remains clear, and obtain a sodium silicate solution for later use;

[0032] (2) Prepare high-purity nitric acid into a 50% nitric acid solution and slowly add it to the sodium silicate solution in step (1), while stirring continuously to form fine crystals, that is, silicon dioxide crystals;

[0033] (3) Stop adding nitric acid after the crystal precipitation is complete, let it stand for 15 hours to crystallize, add 1500ml of hot water at 75°C to wash until the chloride in the crystal is qualified, spin the crystal to dry, put it on a plate and dry it at 100°C for 12 hours, and then enter the high temperature The furnace was burned at 900°C for 8 hours to obtain high-purity silica. After cooling...

Embodiment 3

[0036] A preparation method of high-purity silicon dioxide, the specific preparation steps are as follows:

[0037] (1) Add 3000ml of pure water to a 5000ml beaker and heat to 90°C, add 1kg of analytically pure sodium silicate, stir and heat until dissolved, then filter, the filtrate remains clear, and obtain a sodium silicate solution for later use;

[0038] (2) Prepare high-purity nitric acid into a 50% nitric acid solution and slowly add it to the sodium silicate solution in step (1), while stirring continuously to form fine crystals, that is, silicon dioxide crystals;

[0039] (3) Stop adding nitric acid after the crystal precipitation is complete, let it stand for 8 hours to crystallize, add 3000ml of 90°C hot water to wash until the chloride in the crystal is qualified, spin the crystal to dry, put it on a plate and dry it at 100°C for 8 hours, and then enter the high temperature The furnace was fired at 1000°C for 12 hours to obtain high-purity silica. After cooling, it...

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PUM

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Abstract

The invention provides a preparation method of high-purity silicon dioxide, which comprises the following steps: (1) heating pure water to 75-90 DEG C, adding analytically pure sodium silicate, dissolving by stirring and heating, filtering, and keeping the filtrate clear to obtain a sodium silicate solution for later use, wherein the volume / mass ratio (ml / g) of the pure water to the analytically pure sodium silicate is (1.5-3):1; (2) preparing high-purity nitric acid into a 50% nitric acid solution, slowly adding the 50% nitric acid solution into the sodium silicate solution, and continuously stirring to generate a fine-grain crystal which is the silicon dioxide crystal; and (3) after the crystal completely precipitates, stopping adding the nitric acid, standing to crystallize for 8-15 hours, adding 75-90-DEG C hot water for washing until the chloride in the crystal is qualified by detection, carrying out centrifugal drying on the crystal, drying on a plate at 100 DEG C for 8-12 hours, and igniting in a high-temperature furnace at 900-1000 DEG C for 8-12 hours. The preparation method satisfies the production demands of the optical field for the high purity of silicon dioxide.

Description

technical field [0001] The invention relates to a method for preparing chemical reagents, in particular to a method for preparing high-purity silicon dioxide. Background technique [0002] The chemical formula of silicon dioxide is SiO 2 , insoluble in water, insoluble in acid, but soluble in hydrofluoric acid and hot concentrated phosphoric acid, and can work with molten alkalis. There are two kinds of crystalline silica and amorphous silica in nature. Silica has a wide range of uses, mainly used in glass, water glass, pottery, enamel, refractory materials, airgel felt, ferrosilicon, molding sand, elemental silicon, cement, etc. [0003] At this stage, the preparation of silica generally adopts industrial sodium silicate to dissolve in water and then add industrial nitric acid to precipitate silica. However, the purity of silica produced by this method can only reach the standard of analytical purity, far from high Purity standards, wherein the content of sodium reaches ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/18
Inventor 李刚刘庆山
Owner TIANJIN KERMEL CHEM REAGENT