Diatomite: Emissions
Why calcining raises diatomite's carbon footprint
Why calcining raises diatomite's carbon footprint What this tab covers The greenhouse-gas footprint of the commodity at a global level, split by lifecycle phase: extraction (or farming), refining and processing, movement, usage, and recycling or end of life. Intensities are per unit of product; the global total combines intensity with world output. Also covers other environmental impacts and the main levers to cut emissions. Emission intensity 0.30 t CO2e per t range about 0.05 (natural, dried) to 0.6 (flux-calcined) · cradle-to-gate; derived from drying raw ore of about 30-60% moisture and calcining at about 900-1,100 C, assuming about 3-6 GJ/t of natural gas at IPCC 2006 default of 56.1 kg CO2/GJ for natural gas, plus milling power Global emissions per year 0.50 Mt CO2e per year 2025 · about 0.2 t CO2e/t average (mix of calcined and natural grades) x 2.5 MtPer 1 t of calcined filter-aid diatomite at plant gate (cradle-to-gate); natural grades noted. Intensity: Indicative, derived; no public sector LCA found. Global total: Derived from USGS MCS 2026.
Share of footprint by lifecycle phase
Extraction 5% Refining / processing 85% Movement 10%Footprint by lifecycle phase
| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| Extraction | about 0.005-0.01 t CO2e/t (indicative) | 5% | open-pit scrapers and dozers in the US; underground mining common elsewhere | US deposits are at or near the surface, so mining is cheap (USGS) | USGS MCS 2026; indicative |
| Refining / processing | about 0.2-0.5 t CO2e/t (indicative) | 85% | flash drying, rotary kiln calcining with soda ash flux, classification, milling | Wet ore must be dried before calcining; kiln fuel dominates | Indicative; derived |
| Movement | about 0.01-0.03 t CO2e/t (indicative) | 10% | truck, rail and container shipping of bulky bags | Light, bulky product means high freight per t | IMO Fourth GHG Study 2020 (indicative) |
| Usage | not applicable directly; enabling | – | filtration of beverages, edible oils and drinking water; insulation | Spent filter cake is disposed of or used as soil amendment | USGS MCS 2026 |
| Recycling / end of life | not published | – | spent filter cake to landfill, compost or cement kilns | USGS reports no recycling; EU end-of-life recycling input rate 4% | USGS MCS 2026; EU CRM 2023 |
Other environmental impacts
Crystalline silica dust in calcined grades; land disturbance from open pits; spent filter cake waste from breweries and wineries.
Levers to cut emissions
- Mechanical dewatering or solar drying before kilns
- Kiln heat recovery and fuel switching to biomass or electricity
- Regenerable filter systems and cake reuse in cement or soil
- Natural (uncalcined) grades where flow rate allows
India
India is not a listed producer (USGS 2026) and imports small volumes for brewing and edible-oil filtration, so its footprint is embodied in imports.
Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.