Potash: Extraction

Mining the salt floors of long-vanished seas

Potash lies in evaporite beds left by ancient inland seas. Major ones are the Williston Basin under Saskatchewan (USGS), Belarus's Pripyat basin and Russia's Solikamsk basin (Conway, pdf p. 140). The usual ore is sylvinite, a mix of potassium chloride and rock salt. Most is mined in deep underground workings. Some deposits are dissolved through wells and recrystallised in solar ponds. Israel and Jordan evaporate Dead Sea brine. Flotation separates the potassium chloride from salt, giving muriate of potash (MOP). Salt is the main by-product; no other metal depends on potash mining.

Almost all potash comes from deep evaporite deposits or from salty lakes. In Canada, Russia and Belarus, miners cut sylvinite ore underground like coal or salt and separate KCl by flotation at the surface. Where beds are very deep or folded, water is pumped down to dissolve the potash and the brine is evaporated. Israel, Jordan, China (Qinghai), Chile and Utah use solar evaporation of natural brines. The product is mostly muriate of potash; sulphate of potash comes from sulphate brines or chemical conversion. Large fixed costs and few deposits mean a handful of firms supply world trade.

Methods compared

How each method works

Shafts reach sylvinite beds at about 1,000 m. Continuous boring machines cut ore in room-and-pillar panels and conveyors bring it to surface mills, where it is crushed, deslimed and floated to separate KCl from sodium chloride. Product is dried, sized and compacted. This is the dominant route in Saskatchewan, the Urals and Belarus.

Lowest operating cost at scale; very high capital cost and 8-10 year build times; flooding risk in deep mines.

Hot water or brine is injected into deep or irregular potash beds and the saturated brine pumped back. KCl is recovered by cooling crystallisation or, in sunny climates, in solar ponds followed by flotation. Used at Mosaic's Belle Plaine in Saskatchewan and in Utah and New Mexico.

Reaches deposits too deep for shafts and avoids underground labour; high energy use where solar evaporation is not possible.

Lake or salar brine is pumped into chains of shallow ponds where sun and wind evaporate water and salts crystallise in sequence. Carnallite or sylvinite harvested from the ponds is processed to KCl or, from sulphate-rich brines, to SOP. ICL and Arab Potash work the Dead Sea; Qinghai Salt Lake works the Qarhan lake in China; SQM recovers potash alongside lithium in Chile.

Low energy cost and valuable co-products; limited by climate, water rights and lake levels.

KCl is reacted with sulphuric acid in Mannheim furnaces to give SOP and hydrochloric acid, or SOP is crystallised directly from sulphate-rich brines such as the Great Salt Lake. Langbeinite (potassium magnesium sulphate) is mined in New Mexico.

Premium product for chloride-sensitive crops; higher cost than MOP.

Who does it: global

Who does it: India

India has no potash mine and imports all its MOP, taking 6.1% of world potash import value in 2024 (Comtrade) and 6% of Canpotex sales in 2025 (Nutrien). IPL, the state-linked importer, signs annual contracts that set the floor for Asian prices. Potash is on India's 2023 critical list, and potash blocks in the Nagaur-Ganganagar basin of Rajasthan are being explored. MOP is sold under the nutrient-based subsidy (NBS) scheme. The Kharif 2026 NBS budget for 28 P and K grades was about Rs 41,534 crore (Cabinet, April 2026).