Method For Producing Iron Free Aluminum Sulfate

Preparation of 2Al (OH) 3+3H2SO4=Al2 (SO4) 3+6H2O+Q aluminum hydroxide powder by adding sulfuric acid to aluminum hydroxide. Iron has been removed from the factory, resulting in low iron content in aluminum sulfate. The produced aluminum sulfate includes solid aluminum sulfate and liquid aluminum sulfate. The Al2O3 content in solid aluminum sulfate is 15.8-17%, while the Al2O3 content in aluminum hydroxide powder is 64-65%. Transporting 1 ton of aluminum hydroxide powder is equivalent to transporting 4 tons of solid aluminum sulfate. However, the price of local concentrated sulfuric acid is relatively cheap, so the production cost of reacting aluminum hydroxide powder with concentrated sulfuric acid is low.
Potassium permanganate iron removal method
The aluminum sulfate solution is adjusted to pH 3.0 with aluminum hydroxide. Under heating conditions, divalent iron is oxidized to trivalent iron with a 5% (mass fraction) potassium permanganate solution, generating iron hydroxide and manganese dioxide precipitates. The precipitates are cooled to 60 ℃ and filtered. The filter residue is discarded to achieve iron removal effect. The filtrate is concentrated and crystallized to obtain the final product. After removing iron through potassium permanganate oxidation of aluminum sulfate, the mass fraction of iron in aluminum sulfate can be reduced to below 0.01%, which can achieve the goal of producing low iron aluminum sulfate products
Solution extraction method
The extraction of iron is very complex. It is influenced by various medium conditions, the structure of the extractant, the composition of the extraction system, and other factors. Therefore, the application of extraction methods must be thoroughly and meticulously studied for specific situations, and can only be applied in industry after undergoing a certain scale of experiments.
After H: O: oxidation, the aluminum sulfate solution is extracted by adding 2608 sulfonated kerosene solution containing 20% (mass fraction) N1923. The resulting aqueous phase is the aluminum sulfate solution, which is then concentrated to obtain refined aluminum sulfate. Organic phase was added with dilute sulfuric acid for 4-stage countercurrent extraction to recover organic extractants. Taking primary amine extraction as an example, iron was removed by extraction with primary amine N1923 and sulfonated kerosene organic solvents. The solid appearance of aluminum sulfate was white, fine-grained crystals, and its data indicators are shown in Table 3. Fe: O in aluminum sulfate after iron removal. The quality score can be reduced to 0.051%