1. Application status of high-purity quartz
High-purity quartz has excellent physical and chemical properties. The properties include: high temperature resistance, corrosion resistance, high strength, high light transmittance and low coefficient of thermal expansion. It is widely used in fields of semiconductor, fiber-optic communication, photovoltaic, optic and electro-light source. It is an important support and irreplaceable material for strategic merging industries.
There are two main technologies for the production of high-purity quartz. They are technologies of physical and chemical processing and purification and chemical synthesis. At present, because the natural crystals, which are raw materials of high-purity quartz, are becoming increasingly depleted, and the existing vein quartz raw ore are mainly small and medium in scale, difficult to process and purify, China’s high-purity raw material of quartz is in short supply, it is highly dependent on imports. Under such circumstance, in recent years, many enterprises have begun to focus on the production of high-purity quartz through chemical synthesis.
2. Methods of synthesizing high-purity quartz
◈ Gas phase synthesis method
The gas phase synthesis method refers to flame hydrolysis. Specifically, it uses silicon or organosilicon chloride as raw material. First, gasify raw material, then mix it with hydrogen and oxygen, and hydrolyze it at high temperature to form mist-like SiO2. Finally, through gas-solid separation of cooling, separation and deacidification, high-quality quartz is obtained. Quartz obtained by this method is gas phase SiO2, with particle size of less than 100nm. It has fluffy and porous appearance, large specific surface area, high chemical purity, and good dispersibility.
◈ Chemical precipitation method
Chemical precipitation method is one of the most widely used methods for synthesizing quartz powder. This method uses sodium silicate with carbon dioxide or acid solution as raw material, then they react under the action of surfactant and certain synthesis temperature, to obtain metasilicic acid precipitate. Next, through filtering, washing, drying and calcining, SiO2 is finally obtained.
◈ Sol-gel Method
The sol-gel method uses inorganic salt or metal alkoxide (generally ethyl silicate) as raw material. By adding alcohol as co-solvent, and acid or alkaline solution as catalyst to hydrolyze, then after polycondensation to form SiO2 gel. Next, filter SiO2 gel, and through washing, drying and calcining of organic solvent in gel, to obtain SiO2 powder.
◈ Silicon tetrachloride liquid phase hydrolysis method
This method means that SiCl4 undergoes hydrolysis and polycondensation when in contact with pure water, and then through washing, filtering, drying, calcining and screening of the reaction product , to obtain SiO2 powder.
3. Summary
The above are the main methods of producing high-purity synthetic quartz. These methods can meet the needs of high-purity quartz in different fields and ensure its performance and stability in various applications. To some extent, they solve the problem of short supply of high-purity quartz.
High-purity quartz is mainly used in fields of semiconductor, photovoltaic, optical fiber and precision optic etc. These fields have strict requirements on purity and fineness of quartz. Therefore, it’s very important to grind and classify quartz before practical application. Ball mill and air classifier produced by Qingdao Epic can grind and classify quartz with good performance.
Qingdao Epic Powder Machinery Co., Ltd. is a manufacturer specializing in the production of powder processing equipment.
Its products include:
– Mill: ball mill, roller mill, jet mill, air classifier mill, vibration mill and impact mill etc.
– Air classifier: four series of air classifiers: HTS, ITC, MBS and CTC.
– Modifier: pin-mill modifier, turbo-mill modifier and three-roller modifier etc.
– Auxiliary equipment: control cabinet, dust collector and bucket elevator etc.
– Customers can also customize according to their needs, one customer one design.
If you are interested in ball mill or air classifier or other equipment from Qingdao Epic, please contact staff directly, they are always at your service.
Below are photos from Qingdao Epic for your reference.
