Preparation of High Purity Tungsten Powders from Tungsten Oxide by SHS Process

摘要

99 percent Pure tungsten powders were prepared by self-propagating high temperature synthesis (SHS) process from a mixture of ammonium paratungsten(APT) and Mg powders. The concurrently formed MgO in the product was leached with an HCl solution. The optimum molar ratio of APT to Mg is 1:46 and the compaction pressures range from 2000 to 4000 psi. The propagation velocity and combustion temperature increased, as the compact diameter increased. The weight change and elongation of the SHS product were affected by compaction pressure on the green pellet. The tungsten product had a purity of 99 percent and mean size of 2 approx 3 mum.