Kyanite: Extraction
One formula, three minerals: how rock pressure decides which
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.Kyanite, andalusite and sillimanite share one formula, Al2SiO5, but form under different pressures and temperatures in metamorphic rocks. Heated to high temperature, they convert to mullite, a stable high-alumina phase prized in refractories. Kyanite expands sharply on firing, so it is usually calcined first. Andalusite can be used raw in bricks. US kyanite comes from two hard-rock open pits in Virginia, where one integrated firm also calcines it to mullite. Kyanite and sillimanite are also recovered from mineral sands in the southeast US and in India.
Three minerals with the same formula serve the same furnaces. Kyanite comes from hard-rock pits in Virginia and is mostly calcined to mullite before use. Andalusite, mined in South Africa, France, Peru and China, is used raw in firebrick. Sillimanite comes mainly from India, partly from beach sands. When these are short, refractory makers switch to synthetic mullite made from bauxite or kaolin. Supply is small, concentrated and exposed to disruption, so country totals cannot be added up.
Methods compared
| Method | Share of supply | Typical scale | Recovery / efficiency | By-products | Unit cost |
|---|---|---|---|---|---|
| Hard-rock kyanite mining, flotation and calcining (Virginia) | US 80,000 t in 2025, the main kyanite source (USGS) | KMC capacity about 130,000 t/yr concentrate and 39,000 t/yr calcined; 86,000 t kyanite plus mullite in 2022 | n/a | n/a | US export unit value $510/t (2025e, USGS); 2022 kyanite $383/t, mullite $509/t (Census via Virginia Energy) |
| Andalusite mining and concentration (South Africa, France, Peru, China) | South Africa 120,000 t, France 60,000 t, Peru 40,000 t, China 50,000 t crude ore (2025, USGS) | Andalucita S.A. (Peru) capacity about 50,000 t (2018) | n/a | n/a | India's andalusite imports averaged about Rs 33,100/t in 2021-22 (indicative, basis: IBM import value / quantity) |
| Sillimanite and kyanite from beach sands and small hard-rock mines (India) | India 2,500 t kyanite and sillimanite in 2025 (USGS) | India kyanite 9,432 t and sillimanite 3,432 t in 2021-22 (IBM) | n/a | co-product of ilmenite, rutile, zircon and garnet in beach sands | India mine-head value about Rs 1,860/t kyanite and Rs 2,320/t sillimanite in 2021-22 (indicative, basis: IBM value / quantity) |
| Synthetic mullite (sintered or fused) | not published (US output withheld) | not published | n/a | n/a | not published |
How each method works
Hard-rock kyanite mining, flotation and calcining (Virginia)Kyanite-quartzite is mined in open pits, crushed and floated to a concentrate, then sold raw or calcined in kilns to mullite with more than 55% Al2O3.
Large, stable deposit; a single producer dominates.
USGS MCS 2026; Virginia Energy / SME Mining Engineering 2023 Andalusite mining and concentration (South Africa, France, Peru, China)Andalusite-bearing rock is mined, crushed and concentrated to a refractory-grade grain. It converts to mullite inside the brick during first firing, so it needs no pre-calcining.
No calcining step; South African supply hit by power cuts, floods, labour disputes and shipping problems (USGS).
USGS MCS 2026; Virginia Energy 2023; IBM Indian Minerals Yearbook 2022 Sillimanite and kyanite from beach sands and small hard-rock mines (India)Sillimanite is recovered with ilmenite, rutile, zircon and garnet from heavy-mineral sands, or with kyanite from small mines in Maharashtra, Karnataka and Jharkhand.
Large resources but output curbed by beach-sand mining bans (Tamil Nadu 2013, private sector nationally 2019).
IBM Indian Minerals Yearbook 2022; USGS MCS 2026 Synthetic mullite (sintered or fused)Bauxite, kaolin or bauxitic kaolin is sintered or fused to make mullite grain. Two US companies in Alabama and Georgia make it from four mine sites.
Consistent quality and wide feedstock; more energy-intensive than natural minerals.
USGS MCS 2026 Unit economics are indicative ranges from the sources named; costs vary widely by deposit, region and year.By-product supply
Part of India's sillimanite comes from heavy-mineral beach sands mined mainly for ilmenite, rutile, zircon and garnet, so its supply follows titanium and zircon mining policy rather than refractory demand. India banned private-sector beach-sand mining in 2019 and Tamil Nadu banned it in 2013; some former sillimanite mines were reclassified as beach-sand mines (USGS 2026). Indian sillimanite output fell from 13,221 t (2019-20) to 3,432 t (2021-22) (IBM).
Who does it: global
| Company | Country | Activity | Volume | Year | Source |
|---|---|---|---|---|---|
| Kyanite Mining Corp Described as the world's largest producer of industrial-grade kyanite and mullite; US output 80,000 t in 2025 (USGS). | US | kyanite mining and mullite calcining (Virginia) | 86 kt kyanite plus mullite product | 2022 | Virginia Energy / SME Mining Engineering, 2023 |
| Imerys Leading andalusite producer; volume not published. France produced 60,000 t in 2025 (USGS). | France | andalusite mining (Glomel, France; Rhino mine, South Africa) | not published | n/a | Virginia Energy / SME Mining Engineering, 2023 |
| Andalusite Resources (Pty) Ltd No production status reported since 2019. | South Africa | andalusite mining (Maroelasfontein, Thabazimbi) | not published | n/a | Virginia Energy / SME Mining Engineering, 2023 |
| Andalucita S.A. | Peru | andalusite mining (northern Peru) | 50 kt/yr capacity (estimate) | 2018 | Virginia Energy / SME Mining Engineering, 2023 |
| Resco Products (Piedmont Minerals) Volume not published. | US | andalusite-pyrophyllite mining (Hillsborough, North Carolina) | not published | n/a | Virginia Energy / SME Mining Engineering, 2023 |
Who does it: India
| Company | Country | Activity | Volume | Year | Source |
|---|---|---|---|---|---|
| Mohammad Akram Rasheed (Mysuru, Karnataka) | India | kyanite mining | 5.1 kt kyanite (Karnataka output) | FY2022 | IBM Indian Minerals Yearbook 2022 |
| Jharkhand State Mineral Development Corporation (JSMDC) | India | kyanite mining (East Singhbhum) | 2.9 kt kyanite (Jharkhand output) | FY2022 | IBM Indian Minerals Yearbook 2022 |
| Maharashtra State Mining Corporation | India | kyanite mining (Bhandara) | 1.5 kt kyanite (Maharashtra output) | FY2022 | IBM Indian Minerals Yearbook 2022 |
| Dighori Kyanite Mine and Pavri Kyanite Mines (Bhandara) | India | sillimanite with kyanite | 3.4 kt sillimanite (all Indian output) | FY2022 | IBM Indian Minerals Yearbook 2022 |
India has large resources (kyanite 105.7 Mt and sillimanite 72.3 Mt, IBM, 1 April 2020; USGS puts reserves at 9.1 Mt) but small output: 9,432 t of kyanite and 3,432 t of sillimanite in 2021-22 (IBM), and 2,500 t combined in 2025 (USGS). Indian refractory makers rely on imports, including 10,419 t of andalusite in 2021-22, 79% from South Africa (IBM).