Manufacture of cost-effective titanium powder from magnesium reduced sponge

Abstract

The cost-effective titanium powder is manufactured by (a) magnesium-thermic reduction of titanium chlorides characterized by the formation of a hollow block of the reaction mass having an open cavity in the center of the block, (b) thermal-vacuum separation of the hollow block from excessive Mg and MgCl at 850-950° C. and residual pressure of 10 mm Hg, (c) cooling of obtained titanium hollow block in a H -contained atmosphere at an excessive hydrogen pressure, (d) crushing the hydrogenated titanium block, (e) grinding the crushed titanium pieces into the powder combined with a hydro-metallurgical treatment of obtained titanium powder in a diluted aqueous solution of at least one chloride selected from magnesium chloride, sodium chloride, potassium chloride, or titanium chloride, and (f) drying and, optionally dehydrating the titanium powder ground to a predetermined particle size. The formation of the hollow block of the reaction mass with the open cavity in the center of the block is carried out by accelerating the reaction mass on the inside surface of the reactor. The hydro-metallurgical treatment of titanium powder is carried out in the solutions having the total content of chlorides of 0.5-10 wt. %, at the powder-to-solution weight ratio from 1:1 to 1:4. The cooling of the titanium hollow block in the hydrogen-contained atmosphere is carried out to the temperature of 550-450° C. at the excessive hydrogen pressure of 0.2 bar or higher. The productivity of the innovative process is higher, the energy consumption is lessened more than double, the duration of the processing cycle is decreased by 3. The shorter time of high-temperature stages results in significant improvement of titanium powder quality because it prevents the oxidation and nitrogenation of the metal. The powder dispersion is increased caused by porous and poorly sintered structure of the reaction mass. Cooling the block in the presence of hydrogen also increases the powder quality and the yield of fine powder fractions during the hydro-metallurgical treatment.