Abstract
The purpose of this investigation was to study the sulfuric acid digestion of monazite sand, and to prepare rare-earths-thorium containing material from the resulting solution which would be suitable for further preparation of thorium and rare earth elements by ion-exchange. Digestion of crude monazite sand was treated in $95{\%}C$ sulfuric acid for 2.0 hours at 150∼$250^{\circ}C$. The acid to sand weight ratio were 1 : 1.9∼2.8. Optimum condition was 95% sulfuric acid for 2.0 hours at $200{\pm}5^{\circ}C$. Within this conditions monazite sand was decomposed up to 99%.
이온교환법에 의하여 토륨과 희토류들을 분리해 내기에 알맞은 용액을 얻기 위하여 모나자이트를 황산으로 분해하였다. 황산분해는 모나자이트를 2.0시간동안 150∼$250^{\circ}C$온도에서 $95{\%}C$황산으로 분해시켰다. 황산과 모래의 무게비는 1:1.9∼2.8로 실험하였으며 95% 황산을 사용했을 때 $200{\pm}5^{\circ}C$ 온도에서 2.0시간 처리하는 것이 가장 좋은 결과를 얻었으며 분해율은 99%를 넘는 것으로 밝혀졌다.