quartz
quartz
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Quartz is one of the main rock forming minerals, generally referred to as low temperature quartz (α - quartz), which is one of the most widely distributed minerals in the quartz group. Generalized quartz also includes high temperature quartz (β - quartz) and coesite. It is mainly composed of SiO < sub > 2 < / sub >, colorless and transparent, and often contains a small amount of impurities. It becomes translucent or opaque crystal, and has a hard texture.
Quartz is a kind of mineral resource with stable physical and chemical properties, and its crystal belongs to the oxide mineral of cubic system. Quartz block, also known as silica, is mainly the raw material for producing quartz sand (also known as silica sand), as well as quartz refractory and raw material for firing ferrosilicon.
Quartz is a mineral composed of silica with the chemical formula SiO < sub > 2 < / sub >. The pure quartz is colorless and transparent, and has various colors due to the presence of trace pigment ions, dispersed inclusions or color centers. The fracture surface is glassy and greasy. Hardness 7, no cleavage, shell fracture. 65. It is piezoelectric.
Colorless, transparent quartz, called by Greeks
“
Krystallos
”
They are convinced that quartz is durable and strong ice. Ancient Chinese believed that cold crystal in the mouth could quench thirst.
On October 27, 2017, the list of carcinogens published by the international agency for research on cancer of the World Health Organization (who) was preliminarily sorted out. For reference, crystalline silica dust in the form of quartz or cristobalite is included in the list of class I carcinogens.
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brief introduction
Quartz is one of the most widely distributed minerals on the surface of the earth. There are many types of quartz. The raw materials for daily ceramics include vein quartz, quartz sand, quartzite, sandstone, silica, opal, diatomite, etc. With ordinary sand, crystal is "with the birth of a kind of material.". When silica crystallizes perfectly, it is crystal. After silica gels and dehydrates, it is agate. After silica water colloid solidifies, it becomes opal. When the grain size of silica is less than a few microns, it forms chalcedony, chert and secondary quartzite.
It is also widely used. As far back as the stone age, people used it to make stone axes, stone arrows and other simple production tools to hunt for food and fight against the enemy. Piezoelectric quartz is used as standard frequency in quartz clock and electronic equipment. The fused glass can be used to make optical instruments, glasses, glass tubes and other products. It can also be used as bearing, grinding material, glass ceramics and other industrial raw materials for precision instruments.
Quartz is a non plastic raw material. The mullite crystal formed by quartz and clay in high temperature gives porcelain higher mechanical strength and chemical stability, and increases the translucency of green body. It is a good raw material for preparing white glaze.
During the period of the Republic of China, quartz from xiasanbaopeng village of Jingdezhen was mostly used. After the founding of the people's Republic of China, quartz from Xingzi, Duchang, Xiushui and other places was mostly used, especially after 2000. The amount of glaze is 10% ~ 30%. Before use, it should be cleaned and selected to remove the dirt and impurities. It should be calcined in the kiln at high temperature for easy crushing.
Quartz is the main mineral component of silica ore. The silicon content is 46.70%. It can be divided into low temperature quartz (α - quartz) of cubic system and high temperature quartz (β - quartz) of hexagonal system. Generally speaking, quartz refers to low temperature quartz. The crystal is hexagonal columnar and bicrystal is very common. It is usually in the form of crystal cluster, material and massive aggregate. In a variety of colors, colorless and transparent is called crystal, milky white is called milk quartz, purple is called Amethyst, light rose is called Rose Quartz, smoke is called smoke crystal, Brown is called tea crystal, etc. Glass luster. The hardness is 7 and the density is 2.65g/cm3. Insoluble in any acid except hydrofluoric acid. One of the most widely distributed minerals in the earth's crust is the mineral composition of various rocks and deposits. It is used to make silica gel, water glass and various silicides and silicates, as fillers for plastics and rubber. Also widely used in glass, ceramics, petroleum, metallurgy, casting, building materials and other departments
Quartz sand
Property structure
Quartz sand is a hard, wear-resistant and chemically stable silicate mineral, and its main mineral composition is SiO < sub > 2 < / sub >. The colors of quartz sand are various, usually milky white, colorless and gray. Hardness is 7, brittle, no cleavage, shell fracture. The oil is glossy with a density of 2.65g/cm3, and its chemical, thermal and mechanical properties are obviously anisotropic. Insoluble in acid, slightly soluble in KOH solution, melting point 1750 ℃. It is piezoelectric.
Main types
According to the quality, quartz sand can be divided into ordinary quartz sand, refined quartz sand, high purity quartz sand and fused quartz sand.
1. Ordinary quartz sand
SiO < sub > 2 < / sub > ≥ 90 ~ 99%, FeO ≤ 0.06 ~ 0.02%, fire resistance 1750 ~ 1800 ℃. The appearance of some large particles, the surface of the yellow skin capsule. The size range is 5 ~ 220 mesh, which can be produced according to the user's requirements.
Main uses: metallurgy, silicon carbide, glass and glass products, enamel, cast steel, water filtration, foam alkali, chemical industry, sand spraying and other industries.
2. Refined quartz sand
SiO2≥99~99.5%，Fe2O3≤0.02~0.015%。 It is made of high quality ore by complex processing. The particle size range is 5 ~ 480 mesh, which can be produced according to user's requirements, with white or crystalline appearance.
Main uses: advanced glass, glass products, refractories, melting stone, precision casting, grinding wheel, etc.
3. High purity quartz sand
SiO2≥99.5~99.9%，FeO≤0.005%。 Is the use of 1 ~ 3 natural crystal and high-quality natural stone, after careful selection, fine processing. The particle size ranges from 1 to 0.5mm, 0.5 to 0.1mm, 0.1 to 0.01mm and 0.01 to 0.005mm.
4. Fused silica sand
Chemical composition: SiO < sub > 2 < / sub >: 99.9 ~ 99.99%. Fe2O3：10PPM~25PPM。 Maxli < sub > 2 < / sub > o content: 1 ~ 2ppm. Maxal < sub > 2 < / sub > o < sub > 3 < / sub > content: 20 ~ 30ppm. Maxk < sub > 2 < / sub > o content: 20 ~ 25ppm. Maxna < sub > 2 < / sub > o content: 10 ~ 20ppm.
Physical properties: colorless transparent block, particle or white powder.
True specific gravity: 2.21
Mohs hardness: 7.0
PH value: 6.0
5. Silicon powder
Silicon powder: the appearance is gray or gray white powder. Fire resistance > 1600 ℃.
Bulk density: 200-250 kg / m3.
Purpose and function
Quartz sand is an important industrial mineral raw material, which is widely used in glass, casting, ceramics, refractories, metallurgy, construction, chemical industry, plastics, rubber, abrasives and other industries.
1. Glass
It is the main raw materials of flat glass, float glass, glass products (glass cans, glass bottles, glass tubes, etc.), optical glass, glass fiber, glass instruments, conductive glass, glass cloth and special anti ray glass.
2. Ceramics and refractories
It is the raw material of high silicon brick, common silicon brick, silicon carbide and so on.
3. Metallurgy
Raw materials or additives and fluxes for silicon metal, ferrosilicon alloy, aluminum silicon alloy, etc.
4. Architecture
Concrete, cementitious materials, road building materials, artificial marble, cement physical properties testing materials (cement standard sand), etc.
5. Chemical industry
Raw materials of silicon compounds and water glass, fillers of sulfuric acid tower, amorphous silica powder, etc.
6. Machinery
The main raw materials of foundry sand, abrasive materials (sand blasting, hard abrasive paper, sandpaper, sandcloth, etc.).
7. Electronics
High purity metallic silicon, optical fiber for communication, crystal oscillator, piezoelectric crystal, etc.
8. Rubber and plastics
Filler (improves wear resistance)
9. Coatings
Filler (can improve the weatherability of coating)
10. Aerospace
The internal molecular chain structure, crystal shape and crystal lattice change rule are discussed. It has high temperature resistance, low coefficient of thermal expansion, high insulation, corrosion resistance, piezoelectric effect, resonance and unique optical properties.
11. Jewelry
In fact, quartz is also the mineral name of crystal, with the same chemical composition. The difference is that gem grade crystal can be used as a gem material and can be processed into a variety of jewelry. After dyeing, most of polycrystalline quartzite can only be used as imitation of jade, such as jadeite, Xiuyan Jade, Dushan jade, etc. Single crystal quartz can also be first cracked and then dyed to imitate tourmaline and other gemstones.
QUARTZ GEM
When quartz crystal contains tiny bubbles or liquid to fill cracks, it will produce rainbow through interference light, which can be made into exquisite jewelry. Napoleon's wife, Empress Josephine, has a dazzling collection of gems, jewelry made of rainbow quartz.
Quartz contains various impurities and has different colors
1. Rock crystal: colorless
Chinese PinYin : Shi Ying
quartz
