Know "quartz"

Quartz, inorganic minerals, the main component is silica, often contains a small amount of impurities such as Al2O3, CaO, MgO, etc., is translucent or opaque crystals, generally milky white, hard texture. Quartz is a mineral resource with very stable physical properties and chemical properties. The crystal is a trigonal oxide mineral, ie, low-temperature quartz (a-quartz), and is the most widely distributed mineral species among quartz minerals. The generalized quartz also includes high-temperature quartz (b-quartz). The quartz block, also known as silica, is mainly used for the production of quartz sand (also known as silica sand) as well as raw material for quartz refractories and firing of ferrosilicon. In addition, "quartz" is also a common name.

The chemical formula of quartz is SiO2. The main component of quartz stone in nature is quartz, which often contains a small amount of impurity components, such as Al2O3, CaO, MgO, etc. It has many types. Daily ceramic raw materials used vein quartz, quartz sand, quartzite, sandstone, silica, opal, diatomaceous earth, rice husk ash is also rich in SiO2. Quartz appearance is often colorless, white, milky white, gray and translucent state, Mohs hardness of 7, cut off the mask glass luster or fat luster, the proportion varies depending on the crystal type, change between 2.22 ~ 2.65. With ordinary sand and crystal, it is a kind of substance that “same birth mother”. When the silicon dioxide crystal is perfect, it is crystal; silica gel dehydration is agate; silica hydrous colloid becomes an opal; when the silica crystal grain is less than a few microns, it is composed of chalcedony, vermiculite, secondary Quartzite. Quartz is a non-plastic raw material, and the mullite crystals produced with clay at high temperatures give porcelain higher mechanical strength and chemical stability, and can increase the translucency of the green body. It is a good raw material for preparing white glaze.

During the period of **, more quartz was used in the lower Sanbao Peng Village of Jingdezhen. After the founding of New China, most of the quartz used in Xingzi, Duchang, Xiushui and other places were used. Especially after 2000, the use of quartz increased sharply. The amount of glaze used is 10%~30%. It should be washed and sorted before use to remove impurities and put on the kiln for high-temperature calcination to facilitate crushing.

A variant of colorless, transparent quartz, known by the Greeks as "Krystallos," meaning "white ice," they believe that quartz is a durable and strong ice. Ancient Chinese believed that cold crystals in their mouths could quench thirst.

Quartz is one of the most widely distributed minerals on the earth's surface, and its use is also quite extensive. Far from the Stone Age, people used it to make simple tools such as stone axes and stone arrows to hunt for food and fight against enemies. Quartz clocks and piezoelectric quartz chips are used as standard frequencies in electronic equipment; glass made by melting can be used to make optical instruments, glasses, glass tubes and other products; also can be used as bearings, abrasive materials, glass ceramics, etc. of precision instruments. Industrial raw materials.

When quartz crystals contain tiny bubbles or liquids filling cracks, they create rainbows through interference light and can be made into exquisite jewelry. Napoleon’s wife, Empress Josephine, had a dazzling collection of gemstones, made of rainbow quartz.

Quartz contains a variety of impurities, different colors, there are the following heterogeneous:

Crystal (rock crystal): colorless and transparent

Amethyst (Amethyst): Purple transparent or translucent, heating can be bleached.

Rose quartz: light rose, dense translucent.

Smoky quartz: color or brown transparent xenograft. The reason for coloring is that under the action of radiation, Si is replaced by Al, which is caused by the tetrahedral loss caused by the paramagnetic center. Deeper color becomes black quartz

Citrine: Yellow gold or lemon yellow

Nature structure

Quartz sand is a hard, wear-resistant, chemically stable silicate mineral whose main mineral composition is SiO2. The color of quartz sand is often milky, colorless, and gray. Hardness of 7, brittle, no cleavage, conchoidal fracture. Grease gloss, relative density of 2.65, its chemical, thermal and mechanical properties is obviously anisotropic, insoluble in acid, slightly soluble in KOH solution, melting point 1750°C. Piezoelectricity. The main types of quartz can be classified into ordinary quartz sand, refined quartz sand, high-purity quartz sand, and fused silica sand.

1, ordinary quartz sand:

SiO2 ≥ 90 ~ 99%, FeO ≤ 0.06 ~ 0.02%, refractoriness 1750 ~ 1800 °C, the appearance of some large particles, the surface of yellow skin cysts. Particle size range of 5 ~ 220 mesh, according to user requirements granularity production. Main applications: metallurgy, ink silicon carbide, glass and glass products, enamel, cast steel, water filtration, silicate, chemical, sandblasting and other industries.

2, refined quartz sand:

SiO2 ≥ 99 ~ 99.5%, Fe2O3 ≤ 0.02 ~ 0.015%, selected high-quality ore made of complex processing. The size range is from 5 to 480 meshes, which can be produced according to user requirements. The appearance is white or crystalline. Main uses: Advanced glass, glass products, refractories, smelting stones, precision casting, grinding wheels, etc.

3, high purity quartz sand:

SiO2 ≥ 99.5 ~ 99.9%, FeO ≤ 0.005%, is the use of 1 ~ 3 natural crystal stone and high-quality natural stone, after careful selection, fine processing. The particle size ranges from 1 to 0.5 mm, 0.5 to 0.1 mm, 0.1 to 0.01 mm, and 0.01 to 0.005 mm.

4, fused silica sand

Chemical composition: SiO2: 99.9~99.99%; Fe2O3: 10PPM~25PPM; Max Li2O content: 1~2PPM; Max Al2O3 content: 20~30PPM; Max K2O content: 20~25PPM; Max Na2O content: 10~20PPM. Physical properties: Appearance is colorless, transparent, blocky, granular or white powder. True specific gravity: 2.21; Mohs hardness: 7.0; PH value: 6.0

5, silicon powder

Silicon micropowder: Appearance is grey or off-white powder. Refractoriness >1600°C. Weight: 200 to 250 kg/m3.

Use effect

Quartz sand is an important industrial mineral raw material, widely used in glass, foundry, ceramic and refractory materials, metallurgy, construction, chemicals, plastics, rubber, abrasives and other industries.

Application areas and uses

1, glass

Main raw materials for 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 glass for anti-radiation

2, ceramics and refractories

Raw materials and glazes for porcelain, raw materials for high-silica bricks for furnaces, ordinary silicon bricks, and silicon carbide.

3, metallurgy

Raw materials or additives, fluxes for silicon metal, ferrosilicon, silicon aluminum alloy, etc.

4, Construction

Concrete, cementitious materials, road building materials, artificial marble, cement physical properties inspection materials (ie cement standard sand), etc.

5, chemical industry

Raw materials such as silicon compounds and water glass, fillers of ** tower, amorphous silica fine powder, etc.

6, machinery

The main raw material for casting sand, abrasive materials (blasting, hard abrasive paper, sandpaper, emery cloth, etc.)

7, Electronics

High-purity metal silicon, communication fiber, etc.

8, rubber, plastic

Filler (increases abrasion resistance)

9, coating

Filler (can improve the weather resistance of the paint)

10, Aviation, Aerospace

Its intrinsic molecular chain structure, crystal shape, and crystal lattice variation pattern make it have high temperature resistance, small thermal expansion coefficient, high insulation, corrosion resistance, piezoelectric effect, resonance, and its unique optical characteristics.

Quartz is also a general term for crystals, because the minerals that can be used as crystals are all produced by quartz cutting. All of them have the same characteristics of composition identification. The difference is that crystals can be used as gem grade materials, and quartz is dyed. Most of them can only be used as imitations for jades, such as: Xiuyan jade, Dushan jade, etc.