Analysis and Calculation on Recycling of the Sulfuric Acid Waste from Sulfate Titanium Dioxide Production

To investigate recycling of sulfuric acid waste from titanium dioxide production,the material balance of sulfuric acid during production was analyzed and the effect of heat released from acidolysis reactants diluted with concentrated sulfuric acids instead of water on the temperature of the reaction system was also calculated.Finally,conditions to achieve a 100% recycled use of the 50% concentrated sulfuric acid in sulfate TiO₂ production were discussed.The results indicated that the minimum concentration of the spent acid for acidulation of ilmenite was 50% and the acid concentration for reaction should be no more than 81% to achieve a 100% recycled use of concentrated acid waste without external heat supply.