... original technology, low price, as the flocculant, ferrous sulfate could replace polyaluminium, alkali, polyblend of iron and ... reductant, ferrous sulfate is strong, can be the following proportions of chromium-containing waste water reduction hexavalent chromium cr3 +, replace ... amount) dosage. 3 dosing: will melt into ferrous sulfate solution, and according to the proportion of dosage, can cast ...