Kaolin & clays: Extraction
How weathered granite and volcanic ash become clay
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.Clays form where rocks weather or alter. Kaolin comes from deeply weathered granites and kaolinitic sediments, as in Georgia and Brazil. Bentonite forms from altered volcanic ash and swells in water. Both are mined in open pits. Kaolin is slurried, degritted, magnetically cleaned and bleached to raise brightness, then dried, delaminated or calcined. Bentonite is dried, ground and sometimes chemically activated. Common clay feeds brick and cement. Clays can also host metals: Thacker Pass in Nevada is a lithium-bearing clay never before processed commercially (Scheyder).
Clays are mined cheaply in open pits; the value is in processing. Common clay is dug and used almost as is beside brick and cement plants. Kaolin for paper and paint goes through a wet refining plant that can raise its value many times. Bentonite is dried, ground and often chemically activated. Ball clay is mostly blended and shredded. Because prices range from about $20/t to $170/t, only the processed grades are traded across oceans.
Methods compared
| Method | Share of supply | Typical scale | Recovery / efficiency | By-products | Unit cost |
|---|---|---|---|---|---|
| Wet-processed kaolin (Georgia, US; Brazil; Cornwall, UK) | US 4.8 Mt in 2025, about 10% of world kaolin (USGS) | n/a | n/a | Scrap mica at some plants (USGS Mica chapter) | Not published; US kaolin averaged $170/t ex-works in 2025, up from $151/t in 2021 (USGS) |
| Crude and dry-processed kaolin and ball clay for ceramics (India, China, Uzbekistan) | India 8.4 Mt (including crude ore), China 7.8 Mt and Uzbekistan 6.0 Mt in 2025 (USGS) | n/a | n/a | Silica sand from washing | Not published; US ball clay $47/t ex-works in 2025 (USGS) |
| Bentonite drying, grinding and activation (Wyoming, Gujarat, Turkey) | US 4.1 Mt, India 3.7 Mt and Turkey 2.5 Mt in 2025 (USGS) | Ashapura's two Indian plants have 770,000 t/yr of bentonite grinding capacity (Aug 2025) | n/a | n/a | Not published; US bentonite $110/t ex-works in 2025 (USGS) |
| Common clay pits attached to brick and cement plants | US common clay 13 Mt in 2025, half of US clay tonnage (USGS) | n/a | n/a | n/a | US common clay about $21/t and fire clay $17/t in 2025 (USGS) |
How each method works
Wet-processed kaolin (Georgia, US; Brazil; Cornwall, UK)Crude kaolin is mixed with water into slurry, degritted, classified by particle size, cleaned by high-intensity magnetic separation and chemical bleaching, then dewatered and spray dried or calcined for paper, paint and plastics.
High-value grades for export; tied to a shrinking paper market.
USGS MCS 2026 Crude and dry-processed kaolin and ball clay for ceramics (India, China, Uzbekistan)Clay is dug, sun- or kiln-dried, sorted and sometimes washed, then trucked to nearby tile and sanitaryware clusters. Much Indian and Chinese tonnage is reported as crude ore.
Cheap and close to users; quality is variable and output is poorly measured.
USGS MCS 2026 Bentonite drying, grinding and activation (Wyoming, Gujarat, Turkey)Bentonite is mined from shallow beds, air- or kiln-dried, crushed and ground; calcium bentonite may be sodium-activated with soda ash, or acid-activated for bleaching clays.
Large, simple operations; drilling demand swings with rig counts.
USGS MCS 2026; Ashapura Minechem investor note (Aug 2025) Common clay pits attached to brick and cement plantsClay and shale are dug next to the kiln and used with little processing besides crushing and blending.
Lowest cost; value too low to transport far.
USGS MCS 2026 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 |
|---|---|---|---|---|---|
| Imerys Clay volumes not published | France | kaolin, ball clay and other ceramic and performance minerals | not published | 2025 | Company information |
| KaMin Volume not published | US | kaolin mining and processing in Georgia | not published | 2025 | Company information |
| Thiele Kaolin Volume not published | US | kaolin mining and processing in Georgia | not published | 2025 | Company information |
| Sibelco Volumes not published | Belgium | ball clay, kaolin and other ceramic minerals | not published | 2025 | Sibelco 2025 results |
| Minerals Technologies Volume not published | US | bentonite (pet litter, foundry, drilling, construction) | not published | 2025 | Company information |
| Ashapura Minechem Capacity, not output; sales volumes not published | India | bentonite and specialty kaolin; says it is India's largest and the world's third-largest bentonite maker | 770 kt/yr bentonite grinding capacity (kaolin capacity 108 kt/yr) | FY2026 (Aug 2025) | Ashapura Minechem press release and investor note, Aug 2025 |
Who does it: India
| Company | Country | Activity | Volume | Year | Source |
|---|---|---|---|---|---|
| Ashapura Minechem Capacity, not output; sales volumes not published | India | bentonite, specialty kaolin, bleaching clay (Perfoclay JV) | 770 kt/yr bentonite grinding capacity | Aug 2025 | Ashapura investor note, Aug 2025 |
| 20 Microns Volume not published | India | kaolin and other industrial mineral processing | not published | FY2025 | Company information |
| English Indian Clays Volume not published | India | kaolin mining and processing (Kerala) | not published | FY2025 | Company information |
| Morbi ceramic cluster (Gujarat) Tile exports, not clay tonnage; clay intake not published. Morbi supplies about 80-90% of India's ceramic exports, worth about Rs 15,000 crore in 2024-25 (Gujarat government via IANS) | India | largest consumer of ball clay and kaolin: about 800 active tile plants | 565 million sq m tiles exported by India (2025) | 2025 | Ceramic World Web citing MECS (July 2026) |
India is the largest kaolin producer (8.4 Mt including crude ore) and second in bentonite (3.7 Mt) in 2025 (USGS). Kaolin, china clay and ball clay became state-regulated minor minerals in 2015 (bentonite earlier), so IBM no longer publishes output. Export values rose sharply in 2022-23: kaolin Rs 344 crore (+43%), ball clay Rs 378 crore (+469%) and bentonite Rs 661 crore (IBM).