Production of Fine Titanium Powder from Titanium Sponge by the Shuttle of the Disproportionation Reaction in Molten NaCl–KCl

Abstract

Titanium and its alloys are key materials for various fields. Low cost and high-quality titanium powder production methods are crucial for powder metallurgy (PM) and additive manufacturing (AM) of titanium to significantly decrease the manufacturing cost. In this study, the production of titanium powder from raw material titanium sponge was achieved through the shuttle of the disproportionation reaction and the backward reaction of Ti²⁺ to Ti³⁺ and Ti metal in molten NaCl–KCl at 750°C. With the addition of a very small amount of TiCl₂, over 7∼70 times of titanium powder in mass comparing to the added Ti²⁺ was obtained. The primary particle size of the powder formed based on the disproportionation reaction was approximately 1 µm, while the secondary agglomerated particle size was in the range of 25∼50 µm. No significant difference of the particle size distribution was found for the experimental runs with different TiCl₂ concentrations and holding times. The proposed production method of titanium powder from titanium sponge is expected to significantly decrease the production cost of titanium powder.

Fig. 1 The principle of the titanium powder formation by shuttle of the disproportionation reaction and proportionation reaction of the titanium ions.