Investigation into the Carbothermic Method of Digestion of Titanium Raw Materials by the Example of Artificially Synthesized Perovskite

Abstract

The advantages of the carbothermic method of digesting the perovskite concentrate when compared with hydrometallurgical methods are noted. Works in which the carbothermic method was used are mentioned. Data on the known processing methods of perovskite, which had not found application in industry, are given. The results of the investigation into digestion of the titanium raw materials by the example of artificially synthesized perovskite CaO · TiO₂ are presented. Artificial perovskite is synthesized in a muffle furnace; herewith, the oxide mixture (41.2 wt % CaO and 58.8 wt % TiO₂) is preliminarily stirred for 15 min and briquetted into pellets in a steel mold 15 mm in diameter using a hydraulic press with a force of 147 MPa. The synthesis temperature of CaTiO₃ is 1300°C with a holding time of 4 h. Experiments with different carbon excesses (20 and 30 wt % of that stoichiometrically necessary to reduce the perovskite components) are performed. The carbothermic digestion process of artificial perovskite (pellets 4 g in weight) is performed in a vacuum furnace with a graphite heater in two stages: at 1500°C, holding time of 10.1 kPa, and a residual pressure of 10.1 kPa in argon at the first stage and at t = 1750°C, τ = 1 h, and a residual pressure in a chamber of 1.3 Pa at the second stage. Reaction products are studied by X-ray phase analysis using a D8 ADVANCE BRUKER AXS diffractometer. The results of experiments show the practical possibility of recovering titanium and calcium from perovskite by the carbothermic method.