Quartz sand is a key industrial mineral. It is widely used in water treatment. It is also used in glass, ceramics, and metallurgy. It is also used in fillers, superhard materials, chemicals, and petroleum. It is used in glass fiber, calcium silicate board, and photovoltaics. It is also used in semiconductors, lighting, fiber optics, aerospace, and optics.
Among these are photovoltaics, semiconductors, lighting, optical fiber cables, aerospace, and optics. These are high-end fields. The raw materials are mainly high-purity and ultra-high-purity quartz sand.
My country has a lot of quartz. But, we primarily use it in traditional fields like glass, plates, and fillers. The supply and demand for ordinary quartz are balanced. The demand is slightly higher. High-quality and even somewhat pure quartz can be self-sufficient. These industries are strategic. They include photovoltaics, semiconductors, and light sources. They still need to import a lot of very pure quartz sand. It is both high-purity and ultra-high-purity.
Traditional application areas of quartz sand
Water treatment industry
Quartz sand is the earliest filter material. It is also the most widely used for wastewater treatment. Quartz sand is mainly used as a filter medium in the water treatment industry. It can filter out inorganic and organic impurities from the water well. It is also great at stopping pollutants.
The size and thickness of quartz sand particles are vital. They greatly affect filtration quality. Ordinary quartz sand is suitable for most water filtration purposes. But, in power plants, the quartz sand used is highly refined and purified. It needs to be pure white, dust-free, and strong. The quartz sand filter has been modified for harder-to-treat wastewater. This improves its filtration.
Glass
Silicon dioxide is the main structure of glass. It makes sure the glass has high strength and good stability. So, quartz sand is the most important industrial mineral. It’s a raw material in the glass industry. This includes flat glass, daily glass, ultra-white glass, photovoltaic glass, and quartz glass.
Quartz sand for silicate glasses makes up over 40% of all quartz sand. Sand for flat glass makes up about 20%. Different glass products have different requirements for the composition of quartz sand.
Mechanical Casting
Silica sand (quartz sand) is the most widely used and the largest amount of foundry sand. Foundry silica sand is a heat-resistant particle. It is made of quartz (SiO2) and is 0.020mm-3.350mm in size. Silica sand comes in two types. There is naturally silica sand, like washed, scrubbed, and selected sand. And there is artificial silica sand.
People mainly use natural silica sand for molding sand and core sand. They use it for non-ferrous alloys, iron, and small to medium steel castings. We mainly use selected natural silica sand. We use it to make various molds and cores. These sands use organic matter as a binder. Artificial silica sand is mainly used for molding sand and core sand of steel castings.
Artificial quartz stone
Artificial quartz stone is made from natural quartz stone. This includes sand, powder, and other inorganic materials. These materials are mostly of silicon dioxide. They are the main raw materials. High molecular polymers or cement, or a mix of the two, are bonding materials. It is called quartz stone or an artificial quartz stone. People usually call it as quartz. It’s a man-made stone used for decoration.
Artificial quartz stone is 90% natural quartz sand. The rest consists of colorants, resins, and other additives. They are for adjusting bonding and curing. There is no unified standard for the requirements of quartz raw materials. As long as it is a quartz ore, it can be used for artificial quartz stones. This includes vein quartz, sand quartz, weathered quartz, and others. At present, vein quartz is the main material in the market.
Metallurgical Industry
In metallurgy, quartz can make refractory materials, called silicon bricks. It can also smelt silicon alloys. These include ferrosilicon, silicon manganese, and silicon chromium. It can also be used as a flux. Quartz has a lot of silicon dioxide. It can be used to make industrial silicon. So, silica (quartz) for metallurgy can be split on purpose. It can be split into silica for refractory materials. Also, silica for ferroalloys and industrial silicon. The SiO2 content of smelting ferrosilicon silica is over 97%. It must be able to withstand high-temperature explosions effectively.
Ceramics
Quartz is one of the main raw material for ceramic production. It is vital in ceramic blanks and glazes. This includes daily-use ceramics and high-silica porcelain. The maximum usage of quartz in ceramic blanks and glazes is 40%. Generally, it is sourced locally, and commercial quartz sand is rarely used. Colored glazes need some basic ingredients. They need these because the formula has strict requirements. One necessary ingredient is quartz sand. It must have a pure composition. So, people generally use quartz sand in ceramic glazes and blanks. These requirements have higher standards. The usage of quartz sand in glazes is 10% to 30%.
The ceramic industry uses common raw materials. They include vein quartz, quartzite, powder quartz, and others. In ceramics, quartz purity, iron, and titanium levels are key. So are the particle size and shape.
Functional fillers
Quartz sand is ground into silicon micropowder. It can fill copper clad laminates. It’s also used in epoxy molding compounds. It’s in insulation, rubber, plastics, coatings, adhesives, cosmetics, and more.
For example, the EMC industry is the main market for silicon microspheres. This is the traditional application market. The filler of EMC mainly uses silicon micropowder, with a filling amount of 60% to 90%. Currently, the highest filling rate of spherical silicon micropowder in an epoxy molding compound (EMC) is over 90%. It’s the highest in the world.
Superhard materials
Now, my country produces silicon carbide industrially. It comes in two types: black and green. Black silicon carbide is made from quartz sand and petroleum coke. It also uses high-quality silica as a main raw material. It is smelted at high temperatures in a resistance furnace. Green silicon carbide is made from petroleum coke and high-quality silica. Salt is added as an additive. It is smelted at high temperatures in a resistance furnace.
Chemical Industry
In chemical product processing, quartz sand is the main raw material. It’s used to make potassium silicate and sodium silicate. It’s also used to make various forms of silicon dioxide. Sodium silicate is also known as water glass. It is a soluble silicate made by mixing sand and alkali in a certain proportion. Then, it melts at a high temperature. At present, sodium silicate is the main product of the silicon series. Its output is more than 90% of all soluble silicates. Sodium silicate is the main inorganic silicate. It is an essential raw chemical for all industries, it melts.
Sodium silicate requires very pure quartz sand. It must at least meet the standards of container glass grade sand. For example, it must have less than 0.03% iron (Fe2O3) and heavy minerals less than 5×10-6. But, it has strict limits for Al2O3 and CaO. They must be less than 0.1%. In some cases, the requirements are higher and their contents are between 0.01% and 0.02%.
Oil Industry
Now, the oil industry mostly uses natural quartz sand. It also uses artificial ceramics and coated proppants. Quartz sand makes up 80%, ceramsite 10%, and coated resin 10%.
Now, PetroChina mainly uses quartz sand proppants. In 2022, the company used 8.34 million tons of proppants. Quartz sand accounted for 7.14 million tons, or 85.6%. Among them, the share of quartz sand in shallow shale gas below 3,500 meters rose from 34% to 75%. Daqing Gulong and Xinjiang shale oil are almost 100% quartz sand.
Glass fiber
Glass fiber is made from inorganic materials. These materials include pyrophyllite, quartz sand, limestone, dolomite, colemanite, boraxite, and other minerals. Chemical raw materials, like boric acid and soda ash, are also used. It is widely used in materials for construction and electronics. Also, in rail, chemicals, cars, planes, and wind power. It is used for filters, environmental and marine engineering, and more.
The cost of making glass fiber is 21.7% raw materials. These materials include pyrophyllite, quartz sand, and limestone. Pyrophyllite is about one-third of this amount. Quartz sand and limestone together are also significant part.
Calcium silicate board
Calcium silicate board is an inorganic building board. It has high strength and is very stable. It is made of silica, calcium, and fibers. They are the main raw materials. They are formed into a slurry, compacted into a slab, and then autoclaved. It can be widely used for wall thermal insulation decoration. This includes both inside and outside houses. It includes ceilings, cabin partitions, billboards, and more. Quartz sand is a key raw material for calcium silicate products. It makes up 40% of the raw material for calcium silicate board.
High-end application fields of quartz sand
Photovoltaic Industry
In the photovoltaic industry, pure quartz sand is mainly used for quartz products. These include diffusion tubes, carriers, and arc crucibles. They are for making polycrystalline and monocrystalline silicon solar cells.
The latest prices for domestic quartz crucibles are: outer sand, 50,000 yuan/ton; middle sand, 100,000-120,000 yuan/ton; and inner sand, 190,000-220,000 yuan/ton. The latest quotation for imported sand is 600,000 yuan/ton.
Single crystal silicon pulling has strict requirements on the content of metal impurities in quartz sand. Quartz crucibles are made of high-purity quartz sand. They have good heat resistance. Both quartz crucibles and crystalline silicon are siliceous materials. In the process of high-temperature refining of silicon crystals, the crucible can avoid contamination of silicon crystals.
Semiconductor field
In semiconductors, they mainly use high-purity quartz sand. They use it to make standard quartz tubes, rods, and crucibles. It is also used to make ultra-high-purity semiconductor-grade quartz tubes and rods.
Sand is used for semiconductors. It is of high purity and mainly imported. The price is about 1 million yuan/ton.
Semiconductor-grade, high-purity quartz sand needs low iron and alkali metal. These are its key features. Quartz sand has a concentrated particle size distribution and a low hydroxyl content. This type of quartz sand makes quartz glass. The glass it makes has very few defects. These include bubbles, gas lines, and color lines.
Lighting Industry
Quartz glass transmits light well. It transmits ultraviolet, visible, and infrared light (160nm~4500nm). It’s a key raw material for industrial lighting. Electric lights usually produce intense gas discharge. So, the bulb’s material surface must withstand high heat and pressure. In order to ensure the quality of the lamp tube, the bulb shell generally uses a quartz tube. Specific products include halogen lamps and HID lamps. They also include automotive lights and other lighting products. They also include infrared heating lamps. They have ultraviolet sterilization lamps and other special lights.
IOTA6, IOTASTD, and IOTACG are series of high-purity quartz sand. They are from Sibelco (formerly Unimin) in the United States. They are the main raw materials for making lighting equipment. This equipment is used to produce automotive xenon lamps. It also makes halogen lamps, high-intensity gas discharge lamps, and ultra-high performance lamps.
Fiber Optic Cable
The sand is very pure. It is mainly used in optical communications. It is used to make preforms and materials for optical fibers. The price of high-purity sand for optical fiber production is between 45,000-55,000 yuan/ton.
Optical fiber preforms are the core raw materials for manufacturing optical fiber cables. They are the “crown jewels” of the optical fiber industry. They are 70% of its value. High-purity quartz sleeves are the essential outer skin material for optical fiber preforms. Quartz target rods, tail rods, etc. are the supporting materials for fiber drawing. The core rods and quartz sleeves have strict requirements. These are for technical parameters like material purity and hydroxyl content.
Aerospace
The China Building Materials Science Research Institute developed quartz glass that resists radiation. They also made high-purity quartz glass. The glass has specific optical properties. It resists cosmic ray radiation and thermal shock. It has become an irreplaceable optical component. It is used in the solar sensor for spacecraft attitude control systems. High-purity quartz sand is now the main raw material. It replaces crystal ore and is used to melt quartz glass.
Quartz fiber is an inorganic fiber. It is made of pure quartz sand through a special process. It is widely used in missiles, airplanes, and satellites. Radar, warship antennas, and electromagnetic windows are also covered. These are for preventing interference and anti-interference. It is also used in stealth technology materials for aircraft, warships, and submarines.
Optical field
Quartz glass is made through electric melting and gas refining. It uses high-purity quartz sand as its raw material.
Quartz glass is a crucial component of optical instruments. Transparent quartz glass has good optical properties and a low refractive index. It can meet any light transmission band in the range of 185-3500mμ. Therefore, it can be used for both ultraviolet and infrared transparent purposes. This is for optical instruments. The main products are the manufacture of spectrographs, infrared cameras, prisms, and lenses. At the same time, quartz glass has strong thermal stability, with a value between 800~1000℃. Quartz glass is also used in high-altitude photography. This is for high-temperature peep windows, rangefinders, and telescopes.
