Aluminium sulphate is form by reacting alumina which contains in kaolin with sulphuric acid solution in a stirred reactor. Reaction occurs in variance of different time and temperature. The result of reaction is paste aluminium which will be extracted about 3 times using hot aquadest and consentration of aluminum analized by titrimetric methode. https://www.allfixelectricales.shop/product-category/magnetic-earpiece/