Process

Aluminum sulfate is a salt. In its formula: Al2(SO4) * n H2O, “n” is the number of molecules of crystallization water, varying in the commercial forms of the product between 14 and 18. For industrial uses two types are used: Type 1: White color and iron free, obtained from the reaction of sulfuric acid and aluminum hydrate. Type 2: Yellowish brown color, obtained from the reaction of sulfuric acid with the alumina and the ferric oxide content in bauxite.

To manufacture Aluminum Sulfate, sulfuric acid is made react with Aluminum Hydrate or with Bauxite, originating the following reaction: 2 Al(OH)3 + 3H2SO4 +  8H2O        Al2(SO4)3 + 14 H2O   In general the manufacturing process consists of introducing a batch of diluted sulfuric acid and aluminum hydrate in certain weight proportions in a reactor. The reaction between the aluminum hydrate and sulfuric acid is exothermic, reaching temperatures of 180°C and pressures near to 7 atmospheres. This pressure is used to discharge the product from the reactor. The product leaving the reactor is fed powdered aluminum sulfate to serve as a seed at the beginning of the crystallization process. The material is then poured on a slow moving belt where crystallization occurs. At the end of this process, the product is cooled, crushed and screened and finally bagged and stored for shipment. Our laboratory carefully monitors all steps of the process to assure a constant high quality product.