How is potassium sulfate salt formed

Potassium sulfate K2SO4 
Colorless or white,
crystalline powder
Natural occurrence   
Minerals that occur as double salts,
e.g. polyhalite or schoenite
molar mass 174.260 g / mol

AGW not specified
density 2.66 g / cm3   
Melting point +1069 ° C
Water solubility 
100g H2O dissolve 11.11 g at 20 ° C
--disposal G 4
Print a labelGerman nameEnglish name
CAS 7778-80-5Potassium sulfatePotassium sulfate
Potassium sulfate is sold as a white, crystalline powder. The orthorhombic crystals are relatively hard and very stable in the air. They taste salty bitter. Potassium sulphate is fairly soluble in water, the solution reacts neutrally. It does not dissolve in ethanol.

Potassium sulphate was already known to the alchemists, who extracted it from naturally occurring minerals. Johann Rudolph Glauber succeeded in chemical production for the first time in the 17th century, presumably by heating potassium chloride with sulfuric acid:
2 KCl + H2SO4 K2SO4 + 2 HCl

Industrial production takes place through the reaction of magnesium sulphate with potassium chloride. Magnesium sulfate is accessible from the mineral kieserite. The double salt MgSO is formed as an intermediate product during the reaction4• K2SO4. The overall reaction is as follows:

MgSO4 + 2 KCl K2SO4 + MgCl2
Potassium sulfate is a component of many fertilizers. It is also used to represent other potassium compounds such as potassium carbonate or potassium aluminum sulfate. It is approved as a food additive E515 as a firming agent or acid regulator. It is also contained in extinguishing powders of fire classes B and C.