FURNACE SMELTING AND EXTRACTIVE METALLURGY OF RED MUD - RECOVERY OF TIO2, AL2O3 AND PIG-IRON

Turkish red mud (bauxite waste) has been mixed with dolomite and coke, pelletized and sintered at 1100 degrees C, and finally smelted at 155 0 degrees C to produce pig iron and a slag. The slag was leached with 30% H2SO4 at 90 degrees C. The leachate was diluted, ferric iron was r educed with SO2, and extracted with 5% D2EHPA solution in kerosene. Si lica and Al2O3 were recovered from the remaining aqueous solution, whi le the organic extract was stripped with 10% Na2CO3 solution, finally hydrolysed and calcined to produce pigment-grade TiO2. The titanium re covery efficiency on the basis of slag weight was 84.7%. The extractiv e separation of titanium from both valencies of iron was investigated as a function of pH and time. A stoichiometric flowsheet for the whole process has been developed.