초록
국내에서 산출되고 있는 반토혈암으로부터 고순도 $\alpha-Al_2O_3$를 얻기 위하여 황산암모늄을 사용한 염배소와 황산을 이용한 추출 그리고 하소 실험을 하였다. 황산의 농도, 반응시간, 온도 등이 알루미나 추출에 미치는 영향에 대하여 조사하였으며, 반응산물은 X-ray, DTA-TG, 화학분석, SEM 등으로 분석하였다. 추출조건은 전처리 조건으로 황산암모늄의 농도가 0.6M, 배소온도가 $650^{\circ}C$였으며, 황산추출은 황산농도 10%로 240분간 추출할 경우 96%의 수율을 나타내었다. 생성된 $Al_2O_3$ 분말을 X-ray 분석한 결과 $\alpha-Al_2O_3$였으며 그 순도는 99.23%였다.
In present study an attempt has been made to extract the high purity $Al_2O_3$from domestic aluminous shale. The processes of the salt roasting with ammonium sulfate, extraction with sulfuric acid and calcination were adopted. In the extraction of alumina, the effects of the sulfuric acid concentration, the reaction time and the temperature has been investigated. The reaction products were analyzed by X-ray diffraction, DTA-TG, chemical analysis and SEM. The results are summerized as follows: 1)The pretreatment conditions were 0.6M-$(NH_4)_2SO_4$and $650^{\circ}C$ in sintering temperature. 2) The optimum extraction conditions were $10%-H_2SO_4$ and 240 minutes in acid treating time. 3)Physical properties of sintering materials were confirmed as $\alpha-Al_2O_3$ by X-ray diffraction method and the purity of $\alpha-Al_2O_3$ was 99.23%.
