Extraction of titanium dioxide from titanium-bearing blast furnace slag was studied.Firstly

the titanium-bearing blast furnace slag reacted with ammonium sulfate to obtain NH3 and TiOSO4 solution

and then titanium dioxide was precipitated from TiOSO4 solution by using ammonium as precipitant. Finally

the filtered precipitate was calcined in a muffle furnace at 600℃ for 2 h.The effects of quantities of chelate reagent added

pH and holding time on the precipitation rate of titanium were investigated.The results showed that the precipitation rate of titanium

aluminum and iron increased with increasing solution pH since NH3 was used as precipitant and during this stage iron ion hydrolyzed to form Fe(OH)3.The hydrolysis of Fe3+ was restrained by EDTA addition into the solution.At the same time

the content of iron in production decreased and the content of TiO2 increased.The precipitation of silicon was restrained by citric acid(a novel additive)addition into the solution.At the same time

the content of silicon dioxide in production decreased and the content of TiO2 increased.The TiO2 content of the production increased with increasing EDTA/Fe3+ molar ratio.TiO2 with purity 96.35% was obtained when EDTA/Fe3+ molar ratio increased to 3

citric acid /Si molar ratio was 1

solution pH was 2.0 and holding time was 90 min.