Quartz sand is a hard, wear-resistant, and chemically stable silicate mineral with a main mineral component of SiO2.
The color of quartz sand is milky white, or colorless and translucent, with a hardness of 7. It is brittle without cleavage, has a shell-like fracture, and has a greasy luster. Its density is 2.65, and its bulk density (1-20 mesh, 1.6 to 1.8), and 20-200 mesh, 1.5. Its chemical, thermal, and mechanical properties have significant anisotropy, are insoluble in acids, and slightly soluble in KOH solution, The melting point is 1750 ℃.
Common specifications include: 0.5-1mm, 1-2mm, 2-4mm, 4-8mm, 8-16mm, 16-32mm, 10-20 mesh, 20-40 mesh, 40-80 mesh, 100-120 mesh. Quartz sand is a variant of colorless and transparent quartz, known in Greece as "Krystallos", which means "pure white ice".
They are convinced that quartz is durable and strong ice. In ancient China, people believed that holding cold crystals in their mouths could quench thirst. Quartz sandstone is a consolidated clastic rock with a quartz debris content of over 95%, derived from various magmatic, sedimentary, and metamorphic rocks, with fewer heavy minerals, and associated minerals of feldspar, mica, and clay. Quartzite can be divided into two types: sedimentary genesis and metamorphic genesis.
The former has an indistinct boundary between clastic particles and cements, while the latter refers to deeply metamorphic and pure quartzite ore. Vein quartz is formed by hydrothermal action, almost entirely composed of quartz, with a dense massive structure. The mineral content in quartz sand varies greatly, mainly quartz, followed by feldspar, mica, rock debris, heavy minerals, and clay minerals.
Quartz has high fire resistance. In industry, quartz sand is often divided into ordinary quartz sand, refined quartz sand, high-purity quartz sand, fused quartz sand, and silica powder.
Ordinary quartz sand, i.e. SiO2 ≥ 90-99%, Fe2O3 ≤ 0.06-0.02%, fire resistance 1750 ℃, appearance: some large particles have yellow skin cysts on the surface. Ordinary quartz sand is generally a water treatment filter material made of natural quartz ore, which is crushed, washed, dried, and screened twice; This filter material has the characteristics of no impurities, no edges and corners, high density, high mechanical strength, strong pollutant carrying capacity, and long service life. It is an ideal material for chemical water treatment. The particle size range is 5 to 220 mesh, which can be produced according to user requirements. Main Applications: Metallurgy, inky silicon carbide, glass and glass products, enamel, cast steel, water filtration, caustic soda, chemicals, spray noise, and other industries.
Also known as acid washed quartz sand, SiO2 ≥ 99-99.5%, Fe2O3 ≤ 0.005%, using high-quality natural quartz sand and mortar.
SiO2 ≥ 99.5-99.9%, Fe2O3 ≤ 0.001%, using high-quality natural quartz stone and mortar. (mm is millimeter)
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 in parts per million units).
Physical properties: The appearance is colorless, transparent, blocky, granular, or white powder.
Relative specific gravity: 2.21.
Mohs hardness: 7.0.
PH value: 6.0.
Silica powder: The appearance is gray or gray white powder, with a fire resistance of>1600 ℃. Volume weight: 200~250 kg/m3. The chemical composition of silica fume is shown in the following table:
| composition | average value | |
|---|---|---|
| 1 | SiO2 | 75～96% |
| 2 | Al2O3 | 1.0±0.2% |
| 3 | Fe2O3 | 0.9±0.3% |
| 4 | MgO | 0.7±0.1% |
| 5 | CaO | 0.3±0.1% |
| 6 | NaO | 1.3±0.2% |
| 7 | pH | Neutral |
Quartz is widely distributed in nature and has various origins. Currently, there are seven types of quartz mineral resources that can be used as industrial applications: natural crystal, quartz sandstone, quartzite, vein quartz, silty quartz, natural quartz sand, and granite quartz.
A colorless transparent crystalline mineral of quartz, mainly composed of SiO2. The natural growth environment of crystals is mostly in caves, rock fractures, or joints, and faults. The growth conditions are relatively harsh, and four conditions must be met at the same time: sufficient growth space, the ability to provide silica rich hydrothermal solution, a certain temperature and pressure, and sufficient growth time.
A consolidated sandy rock with a content of quartz and siliceous clasts generally above 95%. The accessory minerals are mostly clay minerals such as feldspar and kaolinite, illite, and montmorillonite, while the content of heavy minerals is small, including pyrite, magnetite, ilmenite, tourmaline, and rutile. The cement is generally siliceous, mainly including opal, chalcedony, etc. The siliceous cemented quartz sandstone is also known as siliceous quartz sandstone. In addition, there are calcareous, ferritic, and glaucous quartz sandstones, while dolomite cemented quartz sandstones are rare.
A metamorphic rock formed by regional metamorphism or thermal contact metamorphism of quartz sandstone or other siliceous rocks. In addition to feldspar, mica, and clay minerals, quartz associated minerals often contain trace amounts of tourmaline, hematite, and zircon. Compared with quartz sandstone, its ore is dense and hard, with higher hardness.
Its formation is mainly related to magmatic hydrothermal processes related to granite, with dense massive structures, a single mineral composition, almost all of which are quartz, and a SiO2 content generally above 99%. Vein quartz deposits generally have a small scale, steep bed shape, and irregular vein shape, with a thickness of several meters to tens of meters, and a length of tens of meters to hundreds of meters. A mining area can be composed of one ore vein or multiple ore veins.
Due to the widespread application of quartz in strategic emerging industries such as electronic information, new materials, and new energy, the industrial type of quartz vein deposits characterized by high natural purity of SiO2 is attracting great attention.
A natural powdery quartz with extremely fine particles and a high content of silicon dioxide. The term "silty quartz" used to be used in many ways, including "weathered silica", and was also known commercially as "amorphous silica". Powder quartz ore is mainly a sedimentary weathering type deposit formed by weathering and disintegration of siliceous parent rock. Siliceous rock has a good weathering resistance, making it almost impossible to change its material composition under epigenetic action. However, under special geological and structural conditions, under the influence of factors such as warm and humid paleoclimate, gentle topography, and paleogeography, siliceous rocks are constantly disintegrated, and impurities are carried away under hydraulic action, resulting in the formation of fine grained, high-purity silty quartz deposits.
A sandy quartz mineral material formed by long-term weathering of parent rocks such as granite, quartzite, quartz sandstone, and quartz vein, with quartz as the main mineral component. Its associated minerals include feldspar, rock debris, mica, clay minerals, and heavy minerals such as zircon, tourmaline, ilmenite, and amphibole. They are mainly marine sedimentary sand deposits and river lake sedimentary sand deposits.
The fundamental reason why the IOTA high-purity quartz series products of Unimin Corporation of the United States have obtained an international monopoly position is that they possess the unique high-quality raw material of high-purity quartz - granite quartz, which has been discovered so far in the world. The raw material is pegmatite granite (formerly known as white granite) produced in Spruce Pine, North Carolina, USA.
The discovery of this particular type of quartz deposit is legendary: in the early 20th century, the main mineral resource targets in the region were pegmatitic feldspar and mica minerals, which can be beneficiated directly by manual processing due to their coarse grains. At first, quartz in granite was not well utilized, and as a tailings for feldspar flotation and kaolin recovery, thousands of tons of crystalline quartz sand were produced every month. Some quartz sand is processed and sold to nearby ceramic factories as common ceramic raw materials, while most of it is discarded along with garnet, biotite, and other impurities in feldspar and kaolinite.
In the 1970s, due to the gradual depletion of natural quartz, the raw material for quartz glass, the search for natural quartz to replace crystals became an urgent goal for many countries at that time. In this context, improved flotation techniques have been used to replace natural crystals with quartz from pegmatite granite in the Spruce Pine area, producing high-purity quartz sand.
The unique physical and chemical properties of quartz sand make it occupy a pivotal position in the aviation, aerospace, electronics, machinery, and today's rapidly developing IT industry. In particular, its inherent molecular chain structure, crystal shape, and lattice change laws make it possess high temperature resistance, small coefficient of thermal expansion, high insulation, corrosion resistance, piezoelectric effect, resonance effect, and unique optical properties, It plays an increasingly important role in many high-tech products.
It can be used as an important building cornerstone, batch material, and building material, as well as a correction material for Portland cement. The construction industry has low requirements for the quality of quartz ore, and there are a large number of resources that can be met locally.
It is mainly used for manufacturing refractory materials - silicon bricks, smelting siliceous alloys (ferrosilicon, silicon manganese, silicon chromium), and as a flux. The general metallurgical industry also has low requirements for the quality of quartz ore.
Quartz stone is the main raw material for manufacturing glass, which can be used as ordinary and optical glass. Pure quartz can be melted into high-quality technical glass. The glass industry, especially the optical and technical glass industry, has high requirements for the quality of quartz ore.
Ceramic and refractory materials: Raw materials such as raw materials and glazes for porcelain, high silicon bricks for kilns, ordinary silicon bricks, and silicon carbide; Raw materials or additives for metallurgical silicon metal, ferrosilicon alloy, silicon aluminum alloy, etc. Flux concrete, cementing materials, road building materials, artificial marble, cement physical performance testing materials (i.e. cement standard sand), etc.
It can be used to produce various silicides, silicates, and nitrates. The best quality can be used as a filler in acid resistant sulfuric acid towers. The chemical industry also has high requirements for the quality of quartz ore.
Quartz rock and quartz sandstone can be used to produce abrasive materials such as grinding stone, oilstone, sandpaper, and silicon carbonate; Quartz sand is also commonly used for sawing stones, polishing glass, grinding the surfaces of metal and stone products, and quartz is also used for polishing jewelry.
Due to the smaller particle size of quartz sand in the three-layer filter bed than in the double-layer filter bed, and the presence of a finer layer of heavy anthracite filter material beneath the quartz sand layer, the water quality of the filtered water in the three-layer filter bed is better than that in the double-layer filter bed under the same other conditions, even with a higher filtration rate. When using quartz sand, try to use it together.
The tail water of the sewage plant enters the bottom of the filter through the inlet pipe, and passes through the filter material layer from top to bottom after evenly distributing water through the water distributor. During this process, the tail water is filtered to remove contaminants from the water. At the same time, the content of pollutants in the quartz sand filter material increases, and the pollution level of the lower filter material layer is higher than that of the upper filter material. At this time, open the air lift pump located in the center of the filter, and lift the quartz sand filter material from the lower layer to the sand washer on the top of the filter for cleaning. After cleaning, the filter sand is returned to the filter bed, and the pollutants generated by cleaning are discharged outward.
