Potash refers to any potassium compound, although the name is most commonly used for water-soluble salts like potassium chloride and potassium carbonate. These pink or white salts occur naturally, and are often found in rock deposits that formed when ancient seas receded. Potash can also be made by boiling hardwood ash in water to create a runoff that is then processed into useable forms. Potassium, an essential nutrient for both plants and animals, makes most types of potash valuable as fertilizer, but it is also used to make soap, glass, and dyes, among other things.
The word potash has its roots in the Old Dutch word potaschen and is a compound of "pot" and "ash," reflecting how potassium carbonate was first made. In ancient times, people took tree leftovers, including damaged branches and roots, burned them on a dry day, and left the ashes in pots to decompose. The ashes were soaked in hot water and then filtered, producing lye — a rudimentary stage of potash. This lye filled huge pots in large kilns, and manufacturers baked it until the water evaporated, and all that was left was black ash, which could be used as fertilizer.
Modern Production Methods
In modern times, most potash comes from mining. Potassium is one of the most abundant elements on Earth, but it's usually only found in compound form. Deposits of potassium chloride can be found around the world where ancient oceans once covered the land; large deposits are widespread and can be found in places including Canada, Germany, and the southwestern part of the United States.
Potassium salts are usually found mixed with other minerals, including sodium chloride and ores like sylvanite. There are several ways to mine potash. Rocks containing the salt can be dug out of the ground through strip or conventional underground mining, or they can be soaked in water to make a brine and pumped out through solution mining. Once removed from the earth, the rocks or brine are processed to separate out the potash and refine it to a more usable form.
Plants need three primary nutrients to grow: potassium, nitrogen, and phosphorus. Potassium helps plants by protecting them from disease and pests, allowing them to adjust to changing weather conditions, strengthening stalks, and encouraging them to absorb more nutrients. Potash fertilizer is an easy to obtain and relatively inexpensive way of supplying the potassium that plants require.
Potash fertilizer is in demand in China, the United States, Brazil, and India. In this form, the potassium works well on major crops like corn, wheat, and vegetables, resulting in higher and more efficient yields. The resulting crops often taste better and are more nutritious.
Although the majority of potash is processed for fertilizer, it does have other uses. It is becoming more important in industrial processes, such as recycling, snow and ice melting, and water softening. Manufacturers use it in making cement, preparing textiles, and making soap. It's used in the production of television and computer screens, and even in brewing beer.