Sodium sulfate, sodium sulfate, Na2SO4 — sodium salt of sulfuric acid.
Properties
Colorless crystals. Anhydrous Na2SO4 stable above the temperature 32,384 °C, below this temperature in the presence of water forming a crystalline Na2SO4•10H2O.
Being in nature
In the nature of anhydrous sodium sulfate is found in the form of the mineral thenardier. The crystalline Na2SO4•10H2O forms mineral salts (Glauber's salt). There are also double salts of sodium sulfate other sulfates, for example astrahani Na2SO4•MgSO4•4H2O, glauberyt Na2SO4•CaSO4. A significant amount of sodium sulfate contained in the brine and sediments of salt lakes chloride-sulfate type and the Gulf of Kara-Bogaz-Gol. Them at low temperatures there is a reaction:
2NaCl + MgSO4 ? MgCl2 + Na2SO4
In Russia, the largest producer of natural sodium sulfate is the company JSC "Kuchuksulfate" — 600 thousand tons a year.
Getting
Industrial method of producing sodium sulphate and the interaction of NaCl with H2SO4 in a special "sulfate" furnace at 500-550 °C; at the same time it turns out the hydrogen chloride.

Currently, this method is almost never used, as there are quite large reserves of natural raw materials.
Also, the sodium sulphate obtained as waste (odour) in the production of bichromate.
Application
The world's a large amount of sodium sulfate was previously used in the manufacture of synthetic detergents, however, in many countries in recent years has been the transition to the concentrated (compact) washing powders, in which sulfate is either not used or used in small quantities. In Russia manufacturers of washing powders are purchasing more than 300 thousand tons of sodium sulfate.
The second number, the use of sodium sulfate — glass production. This substance also used in large amounts in the obtaining of cellulose sulfate method, as well as in textile, leather industry and nonferrous metallurgy.
Small amounts of sodium sulphate finds application in chemical laboratories as a dehydrating means. Despite the fact that he dehydrates organic solvents slower than magnesium sulphate, many prefer it this way for two reasons: cheap and easy to filter.
In smaller quantities were previously used in medicine and veterinary as a saline laxative and as a component in the means for washing the nose.
Was in a dietary Supplement E514.