| abstract |
The invention relates to a process for treating acidic wastewater, namely, mine water and industrial wastewater. The process according to the invention consists in recovering the aluminum from the wastewater, in a semi-selective precipitation step at pH of 4.5 ... 5.5, in the form of hydroxylated products, mostly Al (OH) 3, amorphous, reactive in the reaction of formation of etringite, and the use of the products obtained for the precipitation of sulfate ions as etringite, either only after further steps of treatment, which allow to decrease the concentration of sulfate ions in water, by precipitation in the form of CaSO4x2H2O to 1450 ... 1750 mg / l, or directly to the extinguished precipitation reaction phase, for wastewater treatment, polluted with sulfate ions. |