著者

加瀬 薫

出版者

一般社団法人 資源・素材学会

雑誌

日本鉱業会誌 (ISSN:03694194)

巻号頁・発行日

vol.72, no.822, pp.915-918, 1956-12-25 (Released:2011-07-13)

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The operation at Sunamachi plant was commenced from 1944, and the output of the metallic tungsten was 7 t per month. The plant was severely destroyed by bombing in March, 1945, but it was reconstructed soon after the war. The present production of metallic tungsten is about 3.5-4.5t per month.The raw material is wolframite and tungsten in it is leached as paratungstic ammonia. The leached solution is thickened to crystallize out the parasalt, and the salt is reduced by the two steps of heating with hydrogen gas. At first it is reduced to blue oxide (W4O11) at the temperature of 410-450°C and then is reduced to metallic state at more higher temperature .