Using Vein Quartz to Produce High Purity Quartz Powder

High-purity quartz powder has excellent optical, thermal, chemical stability and radiation resistance, so it has a wide range of applications in electronic industry, optical communications, military and other fields. With the development of electronic industry, optical communication, laser, optics and other fields, the demand for high-purity quartz powder is increasing. Smelted crystal and high-quality natural crystal have been the main raw materials of high-purity quartz materials, and the supply of these raw materials is increasingly short. Due to the multiple impurity minerals associated with vein quartz mineralization, and the variety varies with the ore-forming environment, the main impurity minerals generally include feldspar, mica, clay, hematite, etc. At present, quartz micro powder is prepared with quartz vein as raw material. The process includes raw material, coarse crushing, fine crushing, acid washing, water washing, drying, grading and product. The content of SiO2 in the quartz powder obtained by this process is 99.0-99.6%, while the content of SiO2 in the refined high-purity quartz should reach 99.99%, and the total content of impurity elements is less than 100pm.

Sinonine provides you with a solution of preparing high purity quartz powder with common quartz vein as raw material. The specific steps of this method are as follows.

1) Calcination

Use quartz vein as raw material, crush to 200~400 mesh, add proper amount of NaC1 solid to mix evenly, the amount of NaC1 solid added is 2~4% of the mass of quartz vein, and calcine at 800~850 ℃ for 2~4 hours.

2) Quenching and flotation

Pour the calcined material into the flotation solution for quenching while it is hot. The flotation solution used is a mixture of 0.2~0.5g/kg dodecylamine and 0.2~0.5g/kg sodium dodecylbenzene sulfonate. Adjust the pl value to 2~3 with dilute sulfuric acid. The mass ratio of flotation solution to quartz powder is 3~10:1. The flotation time of quartz powder in the flotation solution is 3~10 minutes, and the temperature is maintained at 10~70 ℃.

3) Acid leaching

Transfer the quartz powder at the bottom of the above flotation solution to the mixed acid solution and soak it at 10~60 ℃ for 6~12 hours. The mixed acid used is a mixed solution of 10~20% hydrochloric acid and 1~5% hydrofluoric acid. The mass ratio of the mixed acid to the quartz powder is 2~6:1.

4) Complexation

Transfer the above acid leached quartz powder into the complexing solution and soak it at 10~60 ℃ for 3~8 hours. The complexing solution used is a mixture of 0.2~1% citric acid and 0.2~1% lauric acid. The mass ratio of the complexing solution to the quartz powder is 1~5.

5) Washing and drying

Take out the quartz powder soaked in the above complex solution, wash it with deionized water, and dry it to obtain high-purity quartz powder product. The content of SiO2 in the product is more than 99.99%, and the total content of impurities is less than 100ppm.

The high-purity quartz powder of electronic grade and microelectronic grade can be produced through the treatment of quartz powder. The preparation process uses the addition of NaCl solid high-temperature calcination, quenching, flotation, acid leaching and complexation to remove impurities, so that the content of SiO2 reaches 99.99%, the total impurity content is less than 100ppm, and the product performance is excellent, which can be applied to microelectronics and optical communication industries.