熔融法に依る重石及びフ***タングステン中のタングステンの定量法に就て

概要

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Good results were obtained by applying the following method on the determination of tungsten in wolframite and ferro-tungsten. The procedure : - 0.5_g of the finely pulverized sample of wolframite or ferro-tungsten was weighed and fused with an alkaline fusion mixture (K_2CO_3 7_g+KOH 2_g+KNO_3 0.2_g) in a nickel crucible. After the melt had been leached with the warm water, a little quantity of H_2O_2 was added by dropping to precipitate the soluble permanganate. Then (NH_4)_2CO_3 was added and the solution warmed to precipitate the greater portion of the soluble silicate. The precipitate was filtered off and the filter was made slightly acid. The hydrochloric acid solution of cinchonine was added to the filterate to precipitate tungsten practically perfect. The precipitate was filtered again, ignited and finally weighed as WO_8.
社団法人日本鉄鋼協会の論文
1941-11-25