Aluminum potassium sulfate
Potassium aluminum sulfate dodecahydrate is an inorganic substance, also known as alum, with the chemical formula KAl(SO4)2·12H2O. It is a double salt of potassium sulfate and aluminum sulfate containing crystal water. Soluble in water, insoluble in ethanol. It can be used to prepare aluminum salt, baking powder, paint, papermaking, waterproofing agent, etc. It was often used for water purification in daily life.