Soda ash: Extraction
How Wyoming trona is mined deep underground
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.Natural soda ash comes from trona and sodium-carbonate brines. The largest trona deposit is in Wyoming's Green River Basin, mined underground by room-and-pillar methods with about 45% recovery. Solution mining recovers about 30%. About 1.8 t of trona yields 1 t of sodium carbonate. Most of the world's soda ash, however, is synthetic. The Solvay process reacts brine with limestone, using ammonia, and needs more energy. In California, borax, salt and sodium sulfate are coproducts. Conway traces how the Leblanc process launched the modern chemicals industry before the cleaner Solvay process took over (pdf p. 120).
Soda ash (sodium carbonate) is made two ways. Natural soda ash is refined from trona ore or sodium-rich brines; it is cheaper and lower in emissions, and the US Green River Basin holds the world's largest deposit. Synthetic soda ash is made from salt and limestone by the Solvay process or variants. About 52 of 71 Mt produced in 2025 was synthetic, most of it in China (USGS). China's new natural capacity in Inner Mongolia has shifted the cost curve and driven a price slump.
Methods compared
| Method | Share of supply | Typical scale | Recovery / efficiency | By-products | Unit cost |
|---|---|---|---|---|---|
| Underground trona mining + monohydrate refining (natural) | natural output about 19 Mt of 71 Mt in 2025: US 12 Mt, Turkey 6 Mt (USGS 2026) | US five producers have 13.9 Mt/yr nameplate capacity (USGS 2026) | about 45% mining recovery (USGS) | Sodium bicarbonate, chemical caustic soda, sodium sulphite at some Wyoming plants (USGS) | natural costs roughly half of synthetic (GHCL via Outlook Business, Oct 2025); US average sales value $150/t f.o.b. in 2025 (price, not cost; USGS) |
| Solution mining of trona and brine recovery (natural) | part of natural output; Kenya 270 kt and Botswana 290 kt in 2025 (USGS) | n/a | about 30% for trona solution mining (USGS) | Borax, salt and sodium sulphate at the California plant (USGS) | n/a |
| Solvay (ammonia-soda) process (synthetic) | majority of the 52 Mt synthetic output in 2025, including most of China's 38 Mt and India's plants (USGS) | Tata Chemicals Mithapur produced 1 Mt in FY2026 (Tata Chemicals, March 2026); GHCL Sutrapada 1.2 Mt/yr capacity (Angel One 2023) | n/a | Calcium chloride effluent; sodium bicarbonate co-product | n/a |
| Dual (Hou) process with ammonium chloride (synthetic, China) | part of China's synthetic output; split not published | n/a | n/a | Ammonium chloride fertiliser | n/a |
How each method works
Underground trona mining + monohydrate refining (natural)Deep trona beds are mined by room-and-pillar with continuous miners. Ore is crushed and calcined to drive off water and CO2, dissolved, clarified and filtered, then recrystallised as sodium carbonate monohydrate and dried to dense soda ash.
Lowest cost and emissions; tied to a few large deposits and long rail hauls.
USGS MCS 2026; Outlook Business, Oct 2025 Solution mining of trona and brine recovery (natural)Hot water or dilute caustic is injected into trona beds, or lake brines are pumped (Searles Lake in California, Lake Magadi in Kenya), and soda ash is crystallised. Horizontal drilling between well pairs could raise recovery and reach deeper beds.
No underground labour and access to deeper beds; lower recovery.
USGS MCS 2026 Solvay (ammonia-soda) process (synthetic)Purified brine is saturated with ammonia and carbonated with CO2 from burning limestone; sodium bicarbonate precipitates and is calcined to soda ash, and ammonia is recovered with lime, leaving calcium chloride waste. Invented in Belgium in the 1860s, it replaced the dirtier Leblanc process (Conway).
Can be built wherever salt, limestone and energy exist; higher energy use, costs and waste (USGS).
USGS MCS 2026; Conway, Material World; Tata Chemicals; Angel One, Oct 2023 Dual (Hou) process with ammonium chloride (synthetic, China)A variant of Solvay links soda ash with an ammonia plant: instead of recovering ammonia with lime, ammonium chloride is crystallised and sold as fertiliser. It is common in China.
Less waste than Solvay; ties output to fertiliser demand.
Industry practice; no figure in sources 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 |
|---|---|---|---|---|---|
| WE Soda Company volume not published in sources reviewed; national output shown. | Turkey | natural soda ash (Turkish trona); bought a leading Wyoming producer with two trona mines in March 2025 | 6,000 kt (Turkey national output, mostly WE Soda and Sisecam) | 2025 | USGS MCS 2026 |
| Sisecam Volume not found in sources reviewed. | Turkey | synthetic (Turkey, Bosnia) and natural (Wyoming) soda ash | not published | 2025 | Company reports |
| Solvay Volume not found in sources reviewed. | Belgium | synthetic in Europe; natural trona in Green River, Wyoming | not published | 2025 | Company reports; Conway, Material World |
| Tata Chemicals Capacity, not output; consolidated production not published in sources reviewed. | India | natural (Green River, US; Magadi, Kenya) and synthetic (Mithapur, India; UK until 2025) | 3.29 Mt/yr total soda ash capacity (FY2023) | FY2023 | Angel One, Oct 2023 (third-largest soda ash player in the world); Lostock UK unit closed Feb 2025 (Tata Chemicals FY2025) |
| Inner Mongolia natural soda ash (Alxa, Boyuan/Yuanxing) Capacity, not output; USGS does not name the company. | China | natural trona soda ash, new since 2023 | 5,000 kt/yr capacity added mid-2023 | 2023 | USGS MCS 2026 (about 5 Mt/yr added in Inner Mongolia); GHCL says China added over 10 Mt in Inner Mongolia (Outlook Business, Oct 2025) |
| Chinese synthetic soda ash producers National output; company volumes not published. | China | Solvay and dual-process plants | 38,000 kt (China national output, mostly synthetic) | 2025 | USGS MCS 2026 |
Who does it: India
| Company | Country | Activity | Volume | Year | Source |
|---|---|---|---|---|---|
| Tata Chemicals (Mithapur, Gujarat) | India | synthetic soda ash and bicarbonate | 1 Mt soda ash produced | FY2026 | Tata Chemicals press release, March 2026; 230 kt soda ash and 140 kt bicarb capacity commissioned in FY2025 |
| GHCL (Sutrapada, Gujarat) Building a Rs 6,500 crore greenfield plant to reach 2.2 Mt/yr. | India | synthetic soda ash | 1.2 Mt/yr capacity at 98% utilisation; about 26% of Indian market | 2025 | Outlook Business, Oct 2025; Angel One, Oct 2023 |
| Nirma Not published. | India | synthetic soda ash (Gujarat) | not published | 2025 | Company not listed; volume not published |
| DCW Soda ash volume not published. | India | soda ash among other chemicals | not published | FY2023 | Angel One, Oct 2023: 1.04 Mt/yr total capacity, not split by product; soda ash 13.75% of FY23 revenue |
India makes only synthetic soda ash, mostly in Gujarat beside salt works, and imports have risen to 25-26% of supply from about 15%, much of it cheap Chinese material. A minimum import price of Rs 20,108/t applied from December 2024 and was extended, and DGTR is investigating dumping (Business Standard, Dec 2024; Outlook Business, Oct 2025). Soda ash is not on India's 2023 critical list.