| In the reduction process of metallic tungsten powder from demestic APT, the thermal decomposition of APT and the reducibility of WO₃ were investigated. APT was completely decomposed to angular plane-shaped skeleton particles of WO₃ at 450℃ an 30 minute, which were easily crushed to primary fine particles. When 6 gr of WO₃ was packed into nickel boat 6㎜ in thickness with high packing density of 1.25g/㏄, it was completely reduced to metallic tungsten at 800℃ with hydrogen flow rate of 1,000㏄/min in 40 minutes and also at 900℃ with hydrogen flow rate of 1,500㏄/min in 20 minutes. It is expected that in industrial process WO₃, which has lower packing density, will be reduced to metallic tungsten with lower hydrogen flow rate and shorter reduction time than those limited conditions. Reducibility was retarded with decrease of reduction temperature and hydrogen flow rate and with increase of sample thickness and water content of hydrogen. |
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