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Preparation method of low-hydroxyl ultrahigh-purity quartz sand

A quartz sand, low hydroxyl technology, applied in the direction of silica, silicon oxide, etc., can solve the problems of low price, high cost and poor dehydroxylation effect of primary vein quartz ore

Active Publication Date: 2017-12-08
江苏凯达石英股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The traditional quartz sand purification process uses a vacuum high-temperature furnace to remove hydroxyl groups, and the dehydroxylation effect is not good, resulting in a great dependence of low-hydroxyl quartz sand on raw material ores. However, the available primary vein quartz ores are rare and expensive, resulting in production high cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] (1) Material selection: choose SiO 2 Content ≤99.000%, refined quartz sand with particle size ranging from 280 to 300 mesh;

[0022] (2) Calcination - water quenching: from room temperature to 6°C per minute to 500°C, from 500°C to 3°C per minute, the calcination temperature is maintained at 750°C for 30 minutes, at 900°C for 30 minutes, and at 1300°C 30 minutes, then rinse the quartz sand with 0°C water for 60 seconds, then place the quartz sand in 20°C water for 10 minutes while applying ultrasound;

[0023] (3) pickling-drying: soak the quartz sand in 80wt% acetic acid solution containing 5wt% ethylenediaminetetraacetic acid for pickling, the pH value of the solution is 4, the temperature is 60°C, apply ultrasound and stir the solution for 5 hours, Filter and separate the quartz sand, rinse the quartz sand three times with deionized water, dry the quartz sand at 300°C for 3 hours and cool to room temperature;

[0024] (4) Esterification: Soak the quartz sand in anh...

Embodiment 2

[0027] (1) Material selection: choose SiO 2 Content ≤99.000%, refined quartz sand with particle size ranging from 280 to 300 mesh;

[0028] (2) Calcination - water quenching: from room temperature to 6°C per minute to 500°C, from 500°C to 3°C per minute, the calcination temperature is maintained at 750°C for 30 minutes, at 900°C for 30 minutes, and at 1300°C 30 minutes, then rinse the quartz sand with 0°C water for 60 seconds, then place the quartz sand in 20°C water for 10 minutes while applying ultrasound;

[0029] (3) Pickling-drying: Soak the quartz sand in a 60wt% acetic acid solution containing 4wt% ethylenediaminetetraacetic acid for pickling, the pH of the solution is 4, the temperature is 50°C, apply ultrasound and stir the solution for 4 hours, Filter and separate the quartz sand, rinse the quartz sand three times with deionized water, dry the quartz sand at 300°C for 2 hours and cool to room temperature;

[0030] (4) Esterification: Soak the quartz sand in anhydro...

Embodiment 3

[0033] Propionic anhydride is replaced with hexanoic anhydride in the step (4) of embodiment 2, and all the other processing steps and parameters are identical with embodiment 2.

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Abstract

The invention discloses a preparation method of low-hydroxyl ultrahigh-purity quartz sand. The preparation method mainly comprises the following processes: selecting materials, calcinating, performing water quenching, performing acid pickling, drying, esterifying, calcinating and the like, wherein in the acid pickling step, ethylenediamine tetraacetic acid and acetic acid are prepared into an acid pickling solution for removing metal impurities from quartz sand; in the esterifying process, the quartz sand is soaked in anhydride-containing anhydrous ether and a surface hydroxyl esterification reaction is performed, and then ester groups are removed through high-temperature calcination to finally obtain the ultrahigh-purity quartz sand with the silicon dioxide content being 99.990% or higher and the hydroxyl content being 10ppm or lower.

Description

technical field [0001] The invention relates to the field of inorganic material processing, in particular to a preparation method of low-hydroxyl ultra-high-purity quartz sand. Background technique [0002] Ultra-high purity quartz sand usually refers to SiO 2 The content is higher than 99.990% quartz sand, which has excellent chemical stability, high insulation and voltage resistance and extremely low volume expansion coefficient. Quartz glass prepared from ultra-high-purity quartz sand through high-temperature softening and molding processes is a basic material for cutting-edge technologies and emerging industries such as optical fiber communications, large-scale integrated circuits, and aerospace. The quality requirements of the quartz glass industry for its raw material quartz sand mainly include three aspects: bubble gas lines, purity and impurity points, among which the bubble gas lines mainly caused by hydroxyl groups and water molecules existing in gas-liquid inclus...

Claims

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Application Information

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IPC IPC(8): C01B33/18
CPCC01B33/18C01P2006/80
Inventor 张勋张凤凯李玉军赵云良刘祥友
Owner 江苏凯达石英股份有限公司