Titanium Recovery From Aluminium- And Titanium Dioxide Production Residues
EURO-Titan project aims upscaling Ti-metal powder manufacturing from metallurgical residues, abundantly available in Europe. The demonstration of the overall process is planned at the Al-Doo Aluminium plant (Bosnia-Herzegovina) and at ORANO (France). For Ti extraction from red mud, reduction was applied at 1600 ?C in an electric arc furnace to remove most of the iron through magnetic separation. Then the slag is leached by sulfuric acid at variable pressure to obtain the highest yield of titanium oxysulfate. Highest Ti-leaching efficiency (95%) was reached at 150 ?C using 5 mol|L sulfuric acid at 9 bar oxygen in 2 h. For Ti-leaching by sulfuric acid from tionite, a byproduct of the titanium dioxide production through sulfate processing, gave lower leaching efficiency under high pressure in an autoclave, altered Ti-compounds resist to dissolution. Nanosized and submicron TiO2-powders were prepared from Ti oxysulfate, using ultrasonic spray pyrolysis and hydrogen reduction between 700 and 1350°C.