Diatomite: Characteristics
The intricate pores that make a superb filter
What this tab covers The supply and physical characteristics of the commodity. Supply: current production, inventories and stocks, capacity utilisation, geographic and producer concentration, how fast supply responds to price, the project pipeline and capital spending, and logistics and export flows. Material: the physical and chemical properties that set its grade, price and end uses (for example purity and conductivity for metals, API gravity, sulfur and energy content for fuels, moisture, protein and fibre quality for crops).Supply volume characteristics
| Characteristic | Figure | What it means | Source |
|---|---|---|---|
| Current production volume | about 2.5 Mt (2025e, USGS); 2.2 Mt in 2024 (World Mining Data) | US 720,000 t, Denmark 380,000 t (processed moler), France 250,000 t, Argentina 190,000 t, Turkey 150,000 t and China 140,000 t in 2025. | USGS MCS 2026; World Mining Data 2026 |
| Inventory and stock levels | not published; no exchange or strategic stocks | Stocks are producer and distributor inventories of bagged filter aid. Brewers and wineries hold working stocks of weeks. No government stockpile. | USGS MCS 2026 |
| Capacity utilisation | not published | US output fell from 998,000 t in 2021 to 720,000 t in 2025 at 9 processing plants (about 80,000 t per plant), so US plants run well below their 2021 throughput (derived). Prices rose from $410/t to $580/t over the same period. | USGS MCS 2026 |
| Geographic and producer concentration | US about 28%, top-3 (US, Denmark, France) about 52%, HHI about 1,250 (USGS 2025); WMD HHI 1,676 (2024) | Company concentration is high: Imerys (which bought Chemviron's French and Italian diatomite and perlite assets in January 2025), EP Minerals (U.S. Silica), Dicalite and Showa Chemical lead filter-aid supply. Volumes are not published. | USGS MCS 2026; World Mining Data 2026; Imerys release, Jan 2025 |
| Supply elasticity | moderate: existing pits can expand; new calcining plants take several years | Resources are adequate for the foreseeable future (USGS). Filter-aid grades need specific deposit quality and food-contact certified plants, which limits fast entry. | USGS MCS 2026 |
| Project pipeline and CapEx | not published | No new capacity totals found. The main change is consolidation (Imerys, January 2025). Membrane filtration competes with filter aids and limits investment. | USGS MCS 2026 |
| Logistics and export flows | world export value $172 million in 2024; US 35.0%, Germany 15.4%, China 12.4%, France 10.8% | US exports were 58,000 t, about 8% of output, in 2025. Product is light and bulky, so transport cost sets how far it can move (USGS). Bagged product ships by container; Brazil and Austria were the top importers. | UN Comtrade 2024; USGS MCS 2026 |
Material characteristics Industrial mineral
Diatomite is the fossil silica skeletons of diatoms. Its intricate pores make it a superb filter and absorbent, and its light weight and low conductivity suit insulation. Grades are set by permeability, density and purity. Calcining changes the pore structure and turns some amorphous silica into crystalline cristobalite, which raises flow rates but creates a health concern.
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Permeability (filter aids) | about 0.05 to more than 10 darcy across grades (indicative) | Sets filtration flow rate versus clarity for beer, wine, oils and water | Producer specifications (indicative) |
| Silica content | about 85-90% SiO2 in good deposits, mainly amorphous (indicative) | Higher silica means fewer clay and carbonate impurities | Producer specifications (indicative) |
| Crystalline silica (cristobalite) | natural grades low; flux-calcined grades can contain large shares of cristobalite (indicative) | Crystalline silica is a carcinogen above exposure limits; drives labelling and buyer choice | USGS MCS 2026; IARC (indicative) |
| Bulk density and porosity | wet density about 0.25-0.4 g/cm3; porosity about 80-90% (indicative) | Low density gives cake volume per kg and absorbency | Producer specifications (indicative) |
| Soluble metals (food grade) | limits on soluble iron, arsenic and lead under food-contact codes such as the Food Chemicals Codex (indicative) | Required for beverage and food filtration | Food Chemicals Codex (indicative) |
| Brightness (fillers) | high brightness after flux calcining (indicative) | Paint and plastics fillers sell on whiteness | Producer specifications (indicative) |