Titanium Powder Production by Preform Reduction Process

摘要

To develop an effective titanium powder production process, a new preform reduction process (PRP), based on the calciothermic reduction of feed preform containing TiO_2 was investigated. The feed preform was fabricated from slurry, made by mixing TiO_2 powder, flux (e.g., CaCl_2) and binder. Preforms in the form of plates, pellets, or shots were prepared by a conventional technique, and heated at 1073 K before reduction to remove the binder and water. The sintered solid preform, containing TiO_2, was then placed in a stainless steel container, and reacted with calcium vapor at a constant temperature, ranging between 1073 and 1273 K, for six hours. Pure titanium powder with 99 mass % purity was recovered from the reduced preform after acid leaching. This process was found to be suitable for producing a fine, homogenous powder, when the flux composition and reduction conditions are controlled. This study demonstrated that this process has the advantage of purity control; contamination from the reaction container or reductant, can easily be avoided because they have no physical contact with the feed material in self-supporting preform. Furthermore, the developed process is highly scalable as demonstrated by its ability to simultaneously treat multiple pieces of preform in a single reduction chamber.