Silica content of quartz sand and micro-silica powder

2021-07-20

Quartz has high fire resistance. In the industry, quartz sand is often divided into: ordinary quartz sand, refined quartz sand, high-purity quartz sand, fused quartz sand and silica powder.Quartz sand production line, quartz sand washing equipment, and complete screening equipment models.

1. Ordinary quartz sand: SiO2≥90-99%, Fe2O3≤0.06-0.02%, refractoriness 1750℃, some large particles in appearance, and yellow skin cysts on the surface. The particle size range is 5-220 mesh, and can be produced according to user requirements. Main applications: metallurgy, silicon carbide, glass and glass products, enamel, cast steel, water filtration, soda, chemical, spray and other industries.

2. Refined quartz sand: also known as pickled quartz sand, SiO2≥99-99.5％, Fe2O3≤0.02—0.015％, made of carefully selected high-quality ore for complex processing. The particle size range is 5-480 mesh, which can be produced according to user requirements, and the appearance is white or crystalline. Main applications: high-grade glass, glass products, refractory materials, smelting stones, precision casting, grinding wheel grinding materials, etc.

3. High-purity quartz sand: SiO2≥99.5-99.9%, Fe2O3≤0.005%. It is made of 1-3 natural crystal stones and high-quality natural stones, carefully selected and finely processed. The particle size range is 1—0.5mm, 0.5—0.1mm, 0.1—0.01mm, 0.01—0.005mm, and can be produced according to user requirements.
4. Fused silica sand: chemical composition:
SiO2 99.9-99.95%
Fe2O3 5PPM-25PPM max
Li2O 1-2PPM max
Al2O3 20-30PPM max
K2O+20-25PPM max
Na2O 10-20PPM max (PPM is one part per million)

5. silicon powder
The appearance of the silicon powder is gray or off-white powder with a refractoriness of 1600°C. Bulk density: 200～250 kg/m3. The chemical composition of silicon powder is shown in the following table:

Item	SiO2	Al2O3	Fe2O3	MgO	CaO	NaO
Average value	75～96%	1.0±0.2%	0.9±0.3%	0.7±0.1%	0.3±0.1%	1.3±0.2%

Features of raw materials Quartz is a stable mineral at room temperature and is insoluble in water, sulfuric acid, hydrochloric acid, and nitric acid. The hardness is 7, the specific gravity is about 2.65, and the melting point is 1713°C. The gloss is glassy and sometimes fatty. Those with pure texture are colorless and those with impurities are red, yellow, blue, black, brown, purple, and green; transparent to opaque, and brittle. Quartz has the ability to transmit ultra-ultraviolet rays and does not conduct electricity. Quartz crystal has the optical properties of birefringence and rotating polarization plane, and has piezoelectric effect. The oscillation frequency of the quartz plate has a high degree of stability, and the oscillation energy of the quartz plate is used to radiate ultrasonic waves. Quartz is a non-plastic raw material, and the mullite crystals formed by the high temperature of the clay and the clay give the porcelain higher mechanical strength and chemical stability, and can increase the translucency of the body. It is a good raw material for the preparation of white glaze.

Quartz is one of the most widely distributed minerals on the earth’s surface, and it has a wide range of uses. The piezoelectric quartz plate is used as the standard frequency in electronic equipment; the glass made after melting can be used to make optical instruments, glasses, glass tubes and other products; it can also be used as industrial materials such as bearings for precision instruments, abrasive materials, glass ceramics, etc.