Aluminum sulfate – salt with chemical formula Al2(SO4) 3. Appearance – the white crystals having shades of different flowers. Let's well dissolve in water. Usually exists in the form of crystalline hydrate where one molecule of salt "holds" the whole 18 molecules of water – Al2(SO4) 3 x 18 H2O. How it is possible to receive aluminum sulfate?
Instruction
1. Aluminum sulfate crystalline hydrate when heating easily loses water. At the subsequent strong heating, there will be a disintegration of salt on oxide of aluminum and sulfuric anhydride: Al2(SO4)3 = Al2O3 + 3SO3Sootvetstvenno, sulfuric anhydride at a temperature over 770 degrees decays on sulphurous anhydride and oxygen: 2SO3 = 2SO2 + O2
2. The main way of receiving this product in the industry – processing by sulfuric acid of any aluminum ore, for example, bauxites. Bauxites contain aluminum hydroxide, along with essential impurity of other substances, mainly – oxides of silicon and iron. In the simplified look, reaction can be written down so: 3H2SO4 + 2Al (OH)3 = Al2(SO4)3 + 6H2O
3. When using this way, the "polluted", technical sulfate of aluminum is formed. Certainly, except bauxites, also other ore, for example, kaolinic or nepheline will approach. It is possible to receive sulfate of aluminum and from some industrial wastes containing aluminum hydroxide (etching solutions, etc.).
4. If rather clean product is necessary, then at first receive aluminum hydroxide in any suitable way, and then influence it the hot concentrated sulfuric acid. Reaction goes according to the same above scheme: 3H2SO4 + 2Al2(SO4) 3 = Al2(SO4)3 + 6H2O