Core conclusion: Quartz sand (SiO₂ ≥ 95%) is one of the most widely used non-metallic minerals in industry. From glass to chips, from construction to chemicals, it is everywhere. Its value lies not in being "sand" but in being "high-purity SiO₂".
This is the core and highest-volume destination for quartz sand.
Flat Glass: Quartz sand provides the SiO₂ backbone, accounting for 70%–73% of the glass formula. Sand purity directly determines light transmittance and strength.
Photovoltaic (PV) Glass: Ultra-clear glass demands extremely low iron content (Fe₂O₃ ≤ 0.015%), requiring high-purity quartz sand (SiO₂ ≥ 99.9%). This is currently the highest value-added segment.
Bottle Glass, Optical Glass, Electronic Glass: Impurity control (Al, Fe, Ti, Cr) tightens progressively, corresponding to different purity grades of quartz sand.
Key specs: Flat glass uses sand with SiO₂ ≥ 99%, Fe₂O₃ ≤ 0.03%. PV ultra-clear glass requires SiO₂ ≥ 99.9%, Fe₂O₃ ≤ 0.008%.
Quartz sand is the absolute主力 for foundry molding.
Molding Sand: Quartz sand has a refractoriness of 1713°C, far exceeding cast iron pouring temperatures (1400–1500°C), making it the core material for making sand molds and sand cores.
Key specs: SiO₂ ≥ 97%, particle size 0.15–0.6mm, acid consumption value ≤ 5ml.
Quartz sand is the most classic and reliable filtration medium in water treatment.
Single-layer filter: Quartz sand directly filters suspended solids, colloids, and algae, reducing effluent turbidity to below 1 NTU.
Dual/multi-layer filter: Anthracite (top) + quartz sand (bottom), layered dirt capture with better backwash performance.
Drinking water pretreatment: Quartz sand as coarse filter before activated carbon, protecting the carbon bed from clogging and extending carbon life by 30%+.
Wastewater treatment: Quartz sand filter for tertiary treatment of secondary effluent, removing residual SS and partial phosphorus.
Key specs: SiO₂ ≥ 98%, uniformity coefficient K ≤ 1.5, HCl solubility ≤ 3.5%, breakage rate ≤ 1%.
Ceramic bodies: Quartz sand is the main aggregate in daily-use ceramics, architectural tiles, and sanitary ware, providing hardness and dimensional stability. In tile glazes, it also reduces thermal expansion.
Refractory materials: Silica bricks (SiO₂ ≥ 93%) made from quartz sand are used in blast furnace and hot blast stove linings, withstanding temperatures up to 1650°C.
Silica micro-powder: Quartz sand ground to 1–10μm, used in high-performance concrete (improving strength and durability) and electronic packaging materials.
Sodium silicate (water glass) production: Quartz sand + caustic soda, reacted at high temperature to produce Na₂SiO₃, used in detergents, papermaking, and foundry binders.
Silica gel and precipitated silica raw material: High-purity quartz sand is chemically processed into silica gel desiccants and precipitated white carbon black (used in tires, rubber, and paint thickeners).
Silicone sealants: Quartz sand → metallurgical silicon → silicone monomers → sealants, lubricants, and release agents.
Paint filler: High-purity quartz sand as functional filler in epoxy floor paints and anti-corrosion coatings, improving hardness and abrasion resistance.
PV silicon wafers: High-purity quartz sand (SiO₂ ≥ 99.9999%, i.e., 6N grade) → metallurgical silicon → polysilicon/monocrystalline silicon → wafers. This is the "pyramid tip" of quartz sand applications. 1 ton of 6N quartz sand can cost 100,000–300,000 RMB — over 100× the price of ordinary sand.
Semiconductor quartz crucibles: Crucibles for pulling monocrystalline silicon require equally high purity (Fe ≤ 1ppm, Al ≤ 1ppm).
Quartz glass components: Semiconductor diffusion furnace tubes, lithography machine parts, etc., made from high-purity synthetic quartz sand (not natural sand).
Concrete fine aggregate: Quartz sand is the fine aggregate in ordinary concrete, massive volume but low value-add. SiO₂ ≥ 85% is typically sufficient.
Dry-mix mortar: Quartz sand accounts for 60%–70% of the formula, used for wall plastering, tile adhesion, and floor leveling.
Engineered stone countertops: Quartz sand + resin, pressed into slabs — hard, scratch-resistant, stain-resistant, the mainstream material for kitchen countertops.
Epoxy flooring: Quartz sand + epoxy resin, used in factory floors and parking garages for wear and compression resistance.
Sandblasting: Quartz sand (Mohs 7 hardness) for surface preparation of steel structures, ships, and pipelines — cheaper than steel shot with less dust.
Sports venues: Used in artificial turf infill, golf course bunkers, and children's sandpits.
Oil well fracking: High-strength quartz sand as proppant injected into shale gas wells to hold fractures open and allow oil/gas to flow. This is an emerging market driven by the North American shale revolution.
Abrasives: Used in sandpaper, grinding wheels, and polishing compounds for metal and glass processing.
Ordinary Grade — SiO₂ ≥ 95%, Fe₂O₃ ≤ 0.1%: concrete, construction mortar, sandblasting.
Industrial Grade — SiO₂ ≥ 98%, Fe₂O₃ ≤ 0.03%: foundry, water treatment filter media, ceramics.
Refined Grade — SiO₂ ≥ 99%, Fe₂O₃ ≤ 0.01%: flat glass, chemicals, paint fillers.
High Purity Grade — SiO₂ ≥ 99.9%, Fe₂O₃ ≤ 0.005%: PV glass, optical glass.
Electronic Grade — SiO₂ ≥ 99.99%, Fe ≤ 1ppm: semiconductor, quartz crucibles.
Ultra-High Purity Grade — SiO₂ ≥ 99.9999% (6N), Fe ≤ 0.1ppm: PV silicon wafer pulling.
Quartz sand is essentially the "universal industrial sand" — low purity for concrete and castings, medium purity for glass and water treatment, ultra-high purity for chips and photovoltaics. Same mineral, one extra 9 in purity, one hundred times the price. It is one of the few non-metallic minerals that spans both infrastructure and semiconductors.