What is High Purity Quartz

What is High Purity Quartz?

High-purity quartz is a rare high-tech strategic mineral resource in the world. It is an irreplaceable mineral raw material for the manufacture of high-tech quartz glass and a rare generic high-value-added mineral resource required by strategic emerging industries. Based on the opinions of researchers and the current international technical level, we can call quartz with a purity of ω(SiO2)≥3 N~5 N and ω(Fe2O3)<10×10-6 as high-purity quartz. 6 N to 7 N is called ultra-high-purity quartz.

High-purity quartz products are widely used in electric light sources, optical fiber communications, solar cells, semiconductor integrated circuits, precision optical instruments, medical utensils, aerospace and other high-tech industries. It plays an important role in a country’s scientific and technological development and is a resource of strategic significance.

High-purity quartz has different application fields according to its content. Among them, the content of 99.5% to 99.99% is used in the light source industry, the content of higher than 99.99% is used for high-end optical devices and laser devices, and the content of 99.995% to 99.9999% is used in semiconductors, photovoltaic and other industries.

1 Semiconductor Industry

The semiconductor industry is the foundation of the global information industry, and the wide application of semiconductor products has promoted the advent of the era of informationization and intelligence.

Chip manufacturing is mainly composed of four parts: single crystal growth, wafer processing and manufacturing, production of integrated circuit wafers and post-package. Single crystal growth requires the use of quartz crucibles and quartz devices.

A large number of auxiliary materials such as quartz glass are used in the etching, diffusion, oxidation, annealing and other steps of wafer processing, such as high-purity quartz products such as quartz sheets, quartz rings, and quartz boats. The diffusion step is to diffuse elements such as boron and phosphorus into the silicon wafer in a quartz furnace tube at about 1000°C.

2 Optical fiber industry

The communication industry is an “information industry highway”, and the high-speed intelligent “pipe” of information made of high-purity quartz optical fiber will provide a basic guarantee for Industry 4.0 and Internet+.

Silica optical fiber is a very thin filament with a diameter of less than 8 mm. Digital data is transmitted through the optical fiber in the form of light. It is widely used in the field of communication, microelectronics and optoelectronic devices. Compared with other transmission media (cable or copper wire), silica fiber has the characteristics of stronger anti-electromagnetic interference ability, anti-corrosion ability, better frequency bandwidth and capacity, and less resource loss.

According to different materials, silica glass fiber can be divided into pure silica glass fiber and doped silica fiber. Doped silica fibers mainly include rare earth doped silica fibers, fluorine doped silica fibers and nitrogen doped silica fibers. Rare earth doped silica fibers have good laser performance, and fluorine doped silica fibers and nitrogen doped silica fibers have radiation resistance. The structure design, refractive index distribution, doping process, pre-irradiation treatment, post-irradiation treatment, etc. can improve its anti-space radiation performance.

Therefore, optical fibers are not only used in traditional communication fields, but also in special high-energy radiation environments, such as the internal detection of fusion reactors, amplifiers for highly distributed data networks in aerospace, broadband superluminescence sources for fiber optic gyroscopes, fiber lasers that provide signals for fission reactors, etc.

In addition, high-purity quartz also has certain optical properties. It can form a polarized laser beam. Using high-purity quartz as a window, a fiber laser is fabricated with prisms, filters and timing devices. High-quality quartz crystals are also used in prisms and lenses for optical instruments. It can be seen that optical fibers made from high-purity quartz have very high added value.

3 Photovoltaic industry

Photovoltaic is the abbreviation of solar power generation system. As a sustainable green industry, photovoltaic is receiving more and more attention. The application cost has been greatly reduced in recent years, and it is rapidly popularizing in the civilian field. High-purity quartz is one of the key raw materials in the photovoltaic industry, and its main application forms include quartz crucibles, quartz tubes and various quartz equipment.

Solar quartz crucibles are consumables used in the photovoltaic industry, and are consumable containers for large-diameter single crystal and polycrystalline silicon products.

4 Fields of optics and light sources

Optical quartz glass has the characteristics of high temperature resistance, corrosion resistance and low expansion rate, and is widely used in the optical field. High-purity quartz glass is used in the production of telescope lenses and laboratory optical equipment, communication equipment, diffractive lenses, projection displays, optics for scanning equipment and printers, lasers, as well as cameras and ultra-flat TV screens, flame control equipment, etc.

Electric light source glass can be divided into potassium calcium glass, lead-containing silica glass, borosilicate glass, alumino-silicate glass and quartz glass according to chemical composition. High-purity quartz glass is used as raw material to produce electric light source products including high-pressure mercury lamp, metal halide lamp, halogen dock lamp, xenon-based lamp, automobile lamp, etc., which can withstand high temperature and provide high transmission characteristics.