Susumu Nishigaki

Extraction of Beryllium Oxide from Beryl Ore.

ケイフッ化ソーダ法により緑柱石中の酸化ベリリウムを高収率,高純度で疏解分離する方法について,ケイフッ化ソーダの添加量,焼成温度,焼成時間等について検討した。その結果,緑柱石微粉末と等量のケイフッ化ソーダを加え,850℃で2時間焼成した場合が最もよい条件であることがわかった。その場合のSiO2含有量は3%以下で,93～95%の比較的純度の高いBeOを90～93%の収率で得た。更に塩化ナトリウムを第二のフラックスとして若干加えることにより,有効かつ有毒なフッ素分は完全に回収され,ケイフッ化ソーダ添加量を0.75倍量に節約でき,SiO2量が2%以下の純度の高い酸化ベリリウムを94%の収率で得た。

A Colorimetric Determination of Micro Amounts of Baron, and Its Applications for the Analysis of Beryllium Metals

The accurate determination of minute amounts of boron contained in materials and fuels for reactors is one of the very important problems because of the large cross section of boron for thermal neutrons.The method studied by the present authors is based on the coloration of boron with curcumin.The procedure is as follows.Methanol and sulphuric acid are added into a distilling flask and 25ml of methanol is distilled to expel boron contained in the reagents. A sample containing 0.052μg of boron is weighed into the distilling flask, and dissolved in sulphuric acid.Immediately 2025ml methanol is distilled and the distillate is caught in calcium hydroxide suspension.After evaporating the suspension to dryness on a water bath, hydrochloric acid and oxalic acid-curcumin are added and the dish is placed in a thermostat held at temperature of 58±0.5°C.The boron complex is extracted from the residue with ethanol and the color is measured at the wave length of 540mμ.This method makes it possible to determine 0.050.1ppm of boron within the error of 5%, and is applied to determine the amount of boron in metal beryllium and beryllium hydroxide.