X-ray spectral studies of the chemical composition of Irshansk ilmenite concentrates showed that it is leukoxenized mineral with a high (up to 79%) content of titanium oxide and inclusions of pseudorutile. The process of alkaline leaching of Ti4+ from ilmenite is investigated in the work. The study of the temperature effect on the reaction of ilmenite with potassium hydroxide at atmospheric pressure revealed that a temperature of 453 K is sufficient to obtain potassium titanate. A further increase in temperature does not provide a significant increase in the yield of water-soluble titanium. It is found that the optimal and sufficient ratio between ilmenite and potassium hydroxide is 1:2. An increase in the amount of potassium hydroxide in the reaction mixture is unsuitable, since it reduces the yield of soluble titanium and the final product will have a high alkalinity due to the presence of alkali which did not react. The main process of leaching with the formation of solid melt is completed in the first 30 minutes of the process. Infrared spectroscopy and X-ray diffraction showed that potassium titanate (K2TiO3) is formed under the studied conditions of alkaline leaching of ilmenite.

The thermodynamics of the alkaline leaching of ilmenite was investigated in this work. Thermodynamic parameters (enthalpy, entropy, Gibbs energy, etc.) are important and necessary for understanding both the course of the chemical reaction as a whole and the possibility of its implementation in the production process. The change in Gibbs energies at different temperatures during the chemical reaction of ilmenite leaching was calculated by the Temkin-Schwartzman method. The calculated values of the Gibbs energies of the reactions for the production of sodium and potassium titanates allowed us to state that the interaction of ilmenite with potassium hydroxide is energetically more advantageous. With the help of X-ray diffraction studies, it was established that ilmenite from the Irshansky deposit is leukoxenized. The identification of the main reflexes of the diffraction patterns confirmed that the interaction of potassium hydroxide and ilmenite yields potassium titanate.

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