There are two kinds of quartz glass, transparent and opaque quartz glass. Transparent and unshuming quartz glass are the most economically valuable materials used in industry and scientific research. The raw materials used for its manufacture (by melting method) are crystal or high purity, ultra high purity quartz sand (transparent quartz glass) and white quartz sand (opaque quartz glass). These two kinds of raw materials exist in nature, its composition is the most pure SiO₂composed.

Quartz glass and crystal have the same chemical composition, but are very different in structure. One is glassy and the other is crystalline. Crystal can not withstand high temperature thermal shock, it will crack at high temperature and transform into other crystal metamorphosis, and quartz glass withstand the impact of extremely high temperature. The manufacture of transparent quartz glass and opaque quartz glass requires high temperature, because the crystallization of SiO₂It can be melted above 1713 ℃.

　Quartz Glass Overview

Quartz glass has a history of more than 160 years abroad. In 1839, the French first melted quartz with hydrogen-oxygen combustion flame to make quartz glass. In 1902, the British used graphite rods to obtain high temperature (called single rod electric melting furnace) to make quartz glass. In the 1940 s, the electric melting furnace was invented. In the 1950 s, with the development of semiconductor technology and new electric light sources (a large amount of quartz glass was urgently needed), quartz glass developed rapidly. Because the production technology of quartz glass is difficult, until now, there are only a few countries that can produce quartz glass in large quantities, such as the United States, Germany, France, Japan, Britain, China and so on. The study of quartz glass in China began in 1957 and was blank before the establishment of the the People's Republic of China. In 1956, the state formulated a 12-year scientific and technological development plan, requiring the development of 57 key research tasks urgently needed by national defense, solving new high-performance materials for two bombs and one satellite, and making material preparations for the study of atomic bombs, missiles, and artificial satellites. Quartz glass is the content to be studied in the 26th and 40th task books, and the task is to be assigned to the then National Institute of Building Materials. The development of Shi Ying glass in China can be roughly divided into five stages: 1957-1961 was the initial stage, with research on technological manufacturing methods as the main part; 1962-1966 was the stage of forming an industry, during which many military tasks were completed, and the output and quality of civilian products were greatly improved, thus initially forming an industry. 1978-1988 was a period of reform and innovation. Shi Ying glass was used for high and new technology, such: high purity and high temperature resistant quartz glass tubes for large-scale integrated circuits, high purity coated crucibles, arc method crucibles, quartz glass for optical communications, quartz glass for laser, etc. were all studied and mass produced during this period. 1989-2000 is a period of great development such as the introduction of foreign advanced technology, technological innovation, and the increase of varieties and output. Donghai County has developed into a production base of quartz glass for electric light sources, with an annual output of 6000 tons of quartz glass (including more than 2000 tons of high-quality products), the quality has been greatly improved, the cost has been reduced several times, and the technical equipment has been significantly improved.

For more than 40 years, the development speed of Shi Ying glass is relatively fast. Take the production of transparent Shi Ying glass tubes as an example: in 1975, the output was 172 tons. 31 factories needed to use more than 60 resistance furnaces to produce. The quality of the tubes was very poor (equivalent to the current waste tubes). Now, two continuous furnaces can produce nearly 200 tons per year. By 2000, the annual output of transparent Shi Ying glass tubes will reach 7000 tons (including 3500 tons of high-quality products), it has increased nearly 40 times in 25 years.

　　Properties of quartz glass

Quartz glass is known as "glass king" because it has a series of special physical and chemical properties.

　　Chemical composition of quartz glass

The chemical composition of quartz glass is SiO₂A single component, also commonly referred to as purity.

　　High temperature discoloration of quartz glass

The above-mentioned quartz glass performance is transparent quartz glass, and other varieties of quartz glass (opal quartz glass, quartz ceramics, opaque quartz glass, quartz cotton, quartz fiber, etc.) have their own special properties.

　　Main varieties and uses of quartz glass

The variety and use of quartz glass are closely related. According to the characteristics of quartz glass, the user requires the manufacture of the quartz glass he needs, and the variety of quartz glass is produced. The new variety improves the performance and quality of quartz glass and promotes The development of the quartz glass industry. Quartz glass is used in almost all walks of life, but because of the complex process of quartz glass products and the high price of raw materials, the price of quartz glass is also expensive, which limits the extensive use of quartz glass. Here is a brief introduction to the main varieties and uses of quartz glass.

　　Quartz glass for discharge tube

Transparent quartz glass is widely used in electric light sources such as mercury lamps, ultra-high pressure mercury lamps, xenon lamps, ultraviolet lamps, iodine tungsten lamps, halogen lamps, gas laser lamps, metal halide lamps, etc. due to its excellent light transmittance and heat resistance from ultraviolet to infrared regions. It is the largest user of quartz glass in China and the second largest user of foreign countries (the largest user is semiconductor technology). The first task is to improve quality and strive for more exports.

　　Quartz glass for semiconductor industry (electronics industry)

　　Quartz glass for infrared heaters

With opaque quartz glass (opal quartz glass) manufacturing infrared heater, heater, crystal heater, etc., the annual consumption of opal quartz glass tube nearly a thousand tons. Mainly used for electroplating solution heating, acid heating, home heating, tempered glass heating, industrial (bicycles, cars, etc.) paint baking drying channel, food, paper, textile industry drying channel, etc.

　　Various kinds of acid-resistant container quartz glass

Due to its excellent acid resistance and heat resistance, it is widely used in the field of chemical industry. Such as synthetic hydrochloric acid device; high temperature acid gas combustion, cooling and guiding device; acid solution evaporation, cooling, absorption and storage device, distilled water, hydrochloric acid, sulfuric acid, nitric acid manufacturing device; chlorination reaction vessel; distillation column filling, steam heating and stirring device; acid valve; filter plate, etc.

　quartz glass for electrical insulation

Because of its excellent electrical insulation and heat resistance, quartz glass is used for Coplier electrostatic collector, high frequency and various electric meter insulation materials, power plant boiler liquid level tube, high voltage insulation tube, etc.

　　Various quartz glass containers for firing

Since the quartz glass is a pure fired material without contamination, it can be used as a vessel for firing a phosphor substance, various cups, trays, and the like.

　Protection tube type quartz glass

Quartz glass is widely used in the protection tube of general thermometer; in addition, it can also be used as an indispensable material for the temperature measurement of immersion pyrometer protection tube and steel making.

　　Quartz glass for metallurgical industry

Due to its excellent heat resistance, quartz glass can be used as samples for analysis of oxygen and carbon in flat hearth furnace and blast furnace. Quartz glass for steel-making continuous injection rolling outlet; Quartz glass for precious metal, gold and platinum smelting; Quartz glass for non-ferrous metal smelting (aluminum and alloy, fusible metal evaporation tank) and other quartz glass.

　　Furnace core tube type quartz glass

Due to its excellent electrical properties, heat resistance and air tightness, quartz glass can be used as the core tube and outer tube of electric furnace, gas furnace, high frequency furnace, etc., and can also be used for air, various gases and vacuum furnace.

　Quartz glass for various physical and chemical instruments

Because Shi Ying glass has many excellent characteristics, it can be used for expansion instrument, thermal balance, electrical meter, spring balance, seismograph and other parts, flask, beaker, evaporating dish, crucible, boat, sulfur quantitative device, condenser and other analysis tools, spectrophotometer with absorption capacity walk dragon set and other physical and chemical experimental supplies.

　　Optical quartz glass

Because quartz glass has high ultraviolet transmittance, heat resistance and low expansion, it can be used for window glass for schlieren photography, heat-resistant lens and window glass, reflector for reflecting telescope, prism, window glass for gas laser, optical standard, etc. In addition, because the quartz glass does not contain SiO₂It can be used as a crucible and tube for melting optical glass.

　　Quartz Glass for Optical Communication and High-tech

80% of the world's information business is transmitted by optical fiber. The development of optical fiber industry is of more strategic significance. The development of optical fiber cannot be separated from Shi Ying glass, because optical fiber is Shi Ying glass fiber. The production of Shi Ying glass fiber requires Shi Ying glass preform and Shi Ying glass foreskin tube. Due to the extremely high purity requirement of such Shi Ying glass, German Heraeus Company produces a special product Heralux-WG Shi Ying glass tube, which amounts to 3500 yuan per kilogram. The production of optical fiber in China uses a large number of foreign imported tubes. In addition, quartz glass is needed in high-tech fields such as biological engineering, optical communication technology, atomic energy technology, laser technology, aviation technology, and aerospace technology. Quartz glass is like cooking monosodium glutamate, the amount is not large, but very wide, all industries can not lack it. Quartz glass is a very important new material with great social and economic benefits.