Noun
potassium sulfate (uncountable)
(inorganic chemistry) The potassium salt of sulfuric acid, K2SO4, used as a fertilizer.
It is now allowed to stand for some time, decanted from any sediment, and finally mixed with the calculated quantity of potassium sulfate, well agitated, and the alum is thrown down as a finely divided precipitate of alum meal. Source: Internet
Other potassium salts can be separated by various procedures, resulting in potassium sulfate and potassium-magnesium sulfate. Source: Internet
The precipitate is then dissolved in sulfuric acid, the requisite amount of potassium sulfate added and the solution allowed to crystallize. Source: Internet