Synthetic fluorspar for conditioning electric furnace slags

In an electric furnace steelmaking process employing a slag conditioner to lower the viscosity of the molten slag, the improvement comprising employing as the slag conditioner a composition prepared by reacting an aqueous scrubber solution from wet-acid processing of phosphate rock, said scrubber solution containing about 1 to 10 percent of fluosilicic acid and about 0.05 to 3 percent phosphoric acid, with about 18 to 180 grams of calcium hydroxide per liter of scrubber solution at a temperature of about 50.degree.to 90.degree. C. and a pH of about 7 to 9.