Synthesis of TiO2 from Ilmenite ore using the molten salt method

Abstract

In this study, the titanium dioxide was synthesized from ilmenite ore concentrate (containing 80,48 % TiO2; 9,65 % SiO2; 4,84 % ZrO2; 1,36 % Fe2O3,...) using the molten alkali method. The alkali roasting process was investigated under various conditions: NaOH/ilmenite mass ratio (0.9 - 1.2), reaction temperature from 500 to 650 oC for 60 minutes. These experimental results showed that the highest roasting efficiency was 95 % when NaOH/ilmenite ratio was 1,1/1,0 at a temperature of 550 oC for 60 minutes. The roasted product was then leached in water to form H2TiO3 solid and remove soluble impurities. The solid was further leached in HCl acid under different conditions: acid concentration (10 - 25 %), temperature (25 - 80 oC), time (45 - 90 minutes). The highest leaching efficiency of 97 % was achieved under the condition of 20 % acid concentration at a temperature of 60 oC for 60 minutes. At the end of the process, the leached solution was hydrolyzed at 100 oC, resulting in a precipitate that was calcined at 900 oC for 120 minutes, producing a product with 92 % TiO2.