Evaluation of red sludge use efficiency for water purification from sulphates

In this work the reagent purification of aqueous solutions from sulfates with use red sludge Nikolaev alumina plant processes were investigated. This sludge, according to chemical analysis, contains a sufficiently large amount (up 18 %) and calcium oxide 10 along silicate iron oxides sodium aluminates. The ability aluminate be deposited solution in form sulfoaluminates was used purify water sulfate anions. process takes place when treating lime suspension. It is shown that applied 1–50 g/dm3 during magnesium liming, purified degree reaches 50–70 %. found efficiency extraction significantly dependent on consumption increases slightly increasing over 1 g/dm3. dependence their initial concentration determined. at up 1000 mg/dm3 expense 3–12 mg-eq/dm3 residual decreases 236–460 mg/dm3, anions about 2000 550–830 30 regardless consumption. 40–73