On the basis of previous works

preparation of a series of fine chemicals by blast furnace slag was researched further and deeply

and the process route was developed. The first product

gypsum

was obtained by sulphuric acid hydrolysis. The optimum conditions for preparing aluminum silicate were:water-slag ratio 7:1

pH 4.0 and adding small pieces of Al plates to remove iron. The optimum conditions for preparing magnesium aluminum spinel were:mass percent of urea 65% and amount of Na2S2O4 5%. The chemical composition of the three products was in accord with the relative standards. This process had the advantages of short flow

low cost

etc. Almost all valuable contents in the slag were used

and no residue was discharged. Thus

it had better environmental benefit.