Process and apparatus for preparing high-purity silicon dioxide by utilizing rice hull

A technology of high-purity silica and process method, which is applied in the field of devices for extracting high-purity amorphous silica, which can solve the problems of large acid treatment capacity, lack of research, and large pollution, and achieve reduced carbon content and shorter burn-out time Short, pure effect

Inactive Publication Date: 2006-07-19
SECTION OF SCI & TECH DEV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0026] The above relevant patented technologies and researches have all illustrated a problem. Through appropriate processes (mainly thermal cracking and pickling) from rice husks, high value-added activated carbon, silicon dioxide and silicon-based ceramic materials can be produced, but the existing technology There is no systematic optimization research on the process flow in the literature, especially the lack of research on how to adopt green chemical pretreatment process, and most of the acid treatment processes are acid treatment first and then roasted. Washing and then roasting, the amount of acid is large, and strong acid has a corrosive effect on organic matter such as cellulose, hemicellulose and lignin. If two-stage combustion is used during roasting (that is, carbonization with oxygen deficiency first, and then oxygen-enriched combustion), chemical Both energy recovery and energy recovery rate are very small, so the pollution is also large, which is not conducive to industrial application

Method used

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  • Process and apparatus for preparing high-purity silicon dioxide by utilizing rice hull
  • Process and apparatus for preparing high-purity silicon dioxide by utilizing rice hull
  • Process and apparatus for preparing high-purity silicon dioxide by utilizing rice hull

Examples

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Effect test

Embodiment 1

[0041] A process method for producing high-purity silica by using rice husks, the process steps are:

[0042] 1. Sieve the rice husk to remove sand and dust;

[0043] 2. Place the sieved rice husks in a drying oven to dry;

[0044] 3. Send the dried rice husks into a temperature-controlled carbonization device for carbonization by temperature-controlled carbonization to obtain carbonized rice husks, and recover chemicals and rice husk gas. The temperature-controlled carbonized rice husks are placed at a temperature-controlled temperature of 400 ℃, to keep the active state of silica in the rice husk unchanged, and at the same time, the hot water generated by temperature-controlled dry distillation and carbonization is used as heat source for pickling and water washing;

[0045] 4. Put the carbonized rice husk in the pickling device to remove the alkali metal impurity elements in the carbonized rice husk. The acid used for pickling the carbonized rice husk is 5% hydrochloric ac...

Embodiment 2

[0049] A process method for producing high-purity silicon dioxide from rice husks, the process steps are the same as in Example 1, except that the temperature-controlled carbonized rice husks are placed at a temperature of 450°C, and the temperature-controlled temperature of the temperature-controlled combustion is At 550°C, the acid used for pickling carbonized rice husk is 15% citric acid.

Embodiment 3

[0051] A process method for producing high-purity silicon dioxide by using rice husks. The process steps are the same as in Example 1, except that the temperature-controlled carbonized rice husks are placed at a temperature of 490°C, and the temperature of the temperature-controlled combustion is 600°C. ℃, the acid used for pickling carbonized rice husks is 15% acetic acid, and after implementing step 5 of Example 1, carry out temperature-controlled combustion and wash with pure water to obtain a high-purity ultrafine white carbon black product.

[0052] The device for implementing the process of the present invention includes units such as rice husk screening, drying, temperature-controlled dry distillation carbonization, carbonized rice husk pickling and water washing, temperature-controlled combustion, flue gas condensation, membrane water production, ion exchange + membrane waste acid recovery, etc. The operating device, wherein the temperature-controlled dry distillation c...

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Abstract

The disclosed method to prepare high-pure silicon dioxide with rice hull comprises: sieving the rice hull to remove sand and dust, drying hull and distillating to char the hull at 400-500Deg, and recovering chemical compound and gas; acid washing the hull to remove the alkali metal impurity, and drying the hull to obtain the silicon nitride, silicon carbide and carbon-containing crystal whisker material; controlling temperature 500-600Deg to burn and obtain the amorphous silicon dioxide as material for silicon nitride and silicon carbide; or acid washing to remove the alkali metal impurity, cleaning with pure water directly to obtain hihg-pure ultrathin white carbon black product.

Description

technical field [0001] The invention relates to a method for extracting biomass, in particular to a method for extracting high-purity amorphous silicon dioxide from rice husks, and at the same time relates to a device for extracting high-purity amorphous silicon dioxide from rice husks. In the chemical pretreatment process of making silicon-based ceramic materials from rice husks. Background technique [0002] Silica is abundant in many natural resources and hardly exists in the highly pure amorphous form. Silica found in inorganic substances of natural resources is a typical crystalline form and contains inorganic impurities, and the effect of this crystalline silica is not great. On the contrary, the silica contained in the biomass is in the form of an amorphous structure, and the role of this amorphous silica is great, especially in cutting-edge technologies such as the production of special ceramic blades. High-purity amorphous silica is used as the precursor of silico...

Claims

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Application Information

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IPC IPC(8): C01B33/113C01B33/18
Inventor 刘建文
Owner SECTION OF SCI & TECH DEV
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