Ilmenite Sand Direct Leaching Kinetics in Hydrochloric Acid Solution

Indonesia has many mineral resources that have not been properly processed and utilized, such as ilmenite. Banten ilmenite is one of the Indonesia’s potential ilmenite deposits. Iron and titanium are the primary components of Banten ilmenite, with titanium being processed into titanium dioxide (TiO2). Direct leaching is one of the ilmenite processing methods that can be done on a large scale. The purpose of this research is to investigate and to develop an appropriate mathematical model for the direct leaching process of Banten ilmenite using hydrochloric acid. Ilmenite that passed through the 250–149 µm sieve was leached with 360 mL of hydrochloric acid at a stirring speed of 300 rpm and a solid/liquid (S/L) ratio of 1:4. The different acid concentrations used were 3 M, 7 M, and 11 M, with process temperature variations of 30 °C, 60 °C, and 90 °C. At 5, 10, 15, 20, 30, 90, and 150 min, 5 mL samples of the solution were taken. The results indicate that the concentration of hydrochloric acid and the temperature had an effect on the Ti recovery results. Ti recovery increases as the concentration of hydrochloric acid and process temperature increase. The highest Ti recovery was 84.52%, achieved at a concentration of 11 M at 90 °C for 150 min. The Lump model is used to simulate ilmenite leaching kinetics, in which the leaching process is controlled by the ash layer's diffusion step and chemical reactions. The Lump model is a mathematical model that can illustrate the phenomenon of ilmenite Banten direct leaching.