Silicon: Extraction
How quartz rock is turned into metal by electricity
What this tab covers How it is mined, drilled or grown, and processed into a tradeable form: the main methods compared, their unit economics, by-products, and the companies that do this work globally and in India.Silicon is never mined as metal. Producers quarry high-purity quartzite and reduce it with coal, coke or wood chips in electric submerged-arc furnaces. Adding iron gives ferrosilicon for steel and foundries. Without iron the furnace yields metallurgical-grade silicon at about 98 to 99% purity (Conway, pdf p. 80). That metal feeds aluminium alloys and silicone chemistry, or goes on to the Siemens process, where it is turned into a chlorosilane, distilled and redeposited as polysilicon. The energy cost is extreme: Smil, cited by Conway, puts ultra-pure silicon at over 3,000 times the energy of cement (pdf p. 81).
All silicon starts as quartz, one of the most common minerals. Quartz is reduced with carbon in electric arc furnaces, a process that needs very large amounts of electricity, so smelters sit near cheap hydro or coal power. The furnace makes metallurgical-grade silicon metal or, with iron added, ferrosilicon. Silicon metal is sold to aluminium and silicone makers or refined chemically into polysilicon of eight to eleven nines purity for solar cells and chips. China dominates every stage, and its coal-based power makes Chinese silicon more carbon-intensive than European hydro-based output (Conway).
Methods compared
| Method | Share of supply | Typical scale | Recovery / efficiency | By-products | Unit cost |
|---|---|---|---|---|---|
| Submerged-arc furnace smelting to metallurgical-grade silicon metal | China about 4,000 kt of 4,600 kt world silicon metal in 2025 (USGS) | Ferroglobe shipped 147,112 t of silicon metal in 2025 from plants in Spain, France, the US and elsewhere (Ferroglobe FY2025) | n/a | microsilica (silica fume) for concrete | Indicative price: Ferroglobe's average silicon metal price was $2,924/t in 2025, down 10.4% from $3,262/t; US silicon metal averaged 130 cents/lb in Jan-Oct 2025 (USGS) |
| Ferrosilicon smelting | China 3,500 kt of 5,000 kt world ferrosilicon (Si content) in 2025; Russia 420 kt (USGS) | Ferroglobe shipped 190,159 t of silicon-based alloys in 2025 (Ferroglobe) | n/a | microsilica | Indicative price: Ferroglobe silicon alloys $2,095/t in 2025; US 75% ferrosilicon about 140 cents/lb (USGS) |
| Siemens and fluidised-bed processes to polysilicon | China makes nearly all solar polysilicon; Wacker is the largest maker outside China (Conway 2023) | n/a | n/a | silicon tetrachloride, recycled in the process | n/a |
| Crystal growth and wafering (Czochralski) | A handful of firms in Japan, Germany, Singapore and Korea supply chip wafers (Conway 2023) | n/a | n/a | n/a | n/a |
How each method works
Submerged-arc furnace smelting to metallurgical-grade silicon metalLumpy quartz is mixed with low-ash coal, charcoal and wood chips and fed into three-electrode submerged-arc furnaces. Carbon reduces silica to liquid silicon, which is tapped, refined with oxygen or slag, cast and crushed. Fume is collected as microsilica.
Simple, scalable process; power is the main cost and coal-based plants have high emissions.
USGS MCS 2026; Ferroglobe FY2025 results (17 Feb 2026); Conway (2023) Ferrosilicon smeltingQuartz, coke and iron ore or steel scrap are smelted together in submerged-arc furnaces to produce 75% or 50% silicon alloys, plus magnesium-ferrosilicon for ductile iron.
Lower purity needs than silicon metal; heavily traded and subject to anti-dumping duties.
USGS MCS 2026; Ferroglobe FY2025 results Siemens and fluidised-bed processes to polysiliconSilicon metal is ground and reacted with hydrogen chloride to trichlorosilane, which is distilled to extreme purity and decomposed onto heated silicon rods at about 1,150 C. Grades are named by nines: solar multicrystalline up to eight nines, monocrystalline up to nine, semiconductor up to ten or more (Conway).
Gives the purity needed for cells and chips; very energy-intensive and capital-heavy, with chronic overcapacity in China.
Conway (2023); USGS MCS 2026 Crystal growth and wafering (Czochralski)Polysilicon is melted in a quartz crucible and a seed crystal is slowly pulled and rotated to grow a single-crystal ingot, which is sliced, polished and cleaned into wafers. Speeds, temperatures and defect control are closely guarded trade secrets (Conway).
Highest value step; very concentrated know-how.
Conway (2023) Unit economics are indicative ranges from the sources named; costs vary widely by deposit, region and year.Who does it: global
| Company | Country | Activity | Volume | Year | Source |
|---|---|---|---|---|---|
| Ferroglobe Also 190,159 t of silicon-based alloys and 305,747 t of manganese alloys. | UK / Spain / US | silicon metal and silicon-based alloys | 147,112 t silicon metal shipped | 2025 | Ferroglobe Q4 and FY2025 results (17 Feb 2026) |
| Hoshine Silicon Industry Volume not found in sources consulted. | China | industrial silicon and silicones (Xinjiang, Yunnan) | not published | 2025 | |
| Elkem Volume not found in sources consulted; Norway produced 130 kt silicon metal and 150 kt ferrosilicon (Si content) in 2025 (USGS). | Norway | silicon metal, ferrosilicon, silicones | not published | 2025 | |
| Wacker Chemie Volume not found in sources consulted; largest polysilicon maker outside China (Conway). | Germany | polysilicon (Burghausen) and silicones | not published | 2025 | Conway (2023) |
| Shin-Etsu Chemical Volume not published in sources consulted; a leading wafer supplier (Conway). | Japan | semiconductor silicon wafers | not published | 2025 | Conway (2023) |
Who does it: India
India produced about 59 kt of ferrosilicon (Si content) and no silicon metal in 2025 (USGS). It imported 5.2% of world silicon metal and 8.5% of world ferrosilicon by value in 2024 (UN Comtrade). Silicon is on India's 2023 critical minerals list. No Indian producer volumes were found.