Sodium carbonate (soda ash) The chemical formula is Na2CO3, commonly known as soda ash, also known as soda, alkali ash, an important chemical basic raw material, the main product of the soda ash industry. It is usually a white powder, which is easily decomposed at high temperature, easily soluble in water, and the aqueous solution is alkaline. Soda ash will deliquesce in the humid air, slowly absorb carbon dioxide and water, and some will become sodium bicarbonate, so the packaging should be strict, otherwise it will absorb moisture and agglomerate. Sodium carbonate and water will form Na2CO3·10H2O, Na2CO3·7H2O, Na2CO3· H2O three hydrates, of which Na2CO3·10H2O is the most stable, and the heat of dissolution in water is very small. Mostly used in the photographic industry, its trade name is carbon and oxygen. Na2CO3·10H2O is also called crystal base. In the past, crystal base was often used for household washing and washing wool, so it is also called “washing base”1. In the past, folks in China used to use “block alkali” which can be washed and noodles, which is made by mixing soda ash with a large amount of water (plus some baking soda (NaHCO3), which has a water content of more than 50%. When sodium is dissolved in water, it is endothermic and easily weathered in air. Na2CO3·7H2O is unstable and can be precipitated from saturated sodium carbonate only in the range of 32.5-36 ° C. Sodium carbonate is a weak acid and strong alkali salt. The Na2CO3 produced is purer than trona, which is why it is called "soda ash".
Soda ash is widely used and is generally made alkaline. It can be used to make glass, such as flat glass, bottle glass, optical glass and high-grade utensils; it can also be used to react soap with soda ash; in soft water softening, petroleum and oil refining, metallurgical industry to remove sulfur and phosphorus , beneficiation, and preparation of metals such as copper, lead, nickel, tin, uranium, aluminum, etc., and sodium salts, metal carbonates, bleaches, fillers, detergents, catalysts, and dyes used in the chemical industry. Soda ash is also used in the refractory and glaze in the ceramic industry.
Soda ash is an important large tonnage chemical raw material. Soda ash production includes Solvay method 1, Hou's alkali method 2 and trona processing method, and the materials used vary depending on the processing method. The main raw materials are raw salt (including sea salt, pool salt, mineral salt and underground brine), trona, limestone, ammonia and so on.