... used in the manufacture of compound fertilizer, potassium sulfate, ammonium chloride, ammonium persulfate etc, and it is useful in food industry, ... fertilizers and for production of complex fertilizers,potassium sulphate,ammonium chloride and ammonium persulpate,ect. Also can be used for food processing ... the content of Fe,As,heavy metal and water insolubles. Ammonium Sulphate industrial grade