This work adopted 1,10-phenanthroline spectrophotometric method, complexometric titration and X-ray diffractometer (XRD) to investigate active state of aluminum and iron impurities in semicoke of Huadian oil shale which was calcinated at different temperatures and the influence of calcination temperature on leaching rate of impurities (Al, Fe) with acid. The results show that after calcination of semicoke of Huadian oil shale at 700–800 °C, iron and aluminium exist in their maximum active state and turn into materials soluble in acids, which results in their maximum leaching rate. This process is important for the removal of impurities at preparation of high-quality amorphous silica from oil shale ash.
1. Grinberg, A., Keren, M., Podshivalov, V., Anderson, J. Producing electricity from Israeli oil shale with PFBC technology // Oil Shale. 2000. Vol. 17, No. 4. P. 307–312.
2. Arro, H., Prikk, A., Pihu, T., Öpik, I. Utilization of semi-coke of Estonian shale oil industry // Oil Shale. 2002. Vol. 19, No. 2. P. 117–125.
3. Trikkel, A., Kuusik, R., Maljukova, N. Distribution of organic and inorganic ingredients in Estonian oil shale semicoke // Oil Shale. 2004. Vol. 21, No. 3. P. 227–236.
4. Han Xiang-xin, Jiang Xiu-min, Cui Zhi-gan, Zhang Chao-qun. Study of combustion performance of oil shale semi-coke // Proceedings of the CSEE, 2005. Vol. 25, No. 15. P. 106–110 [in Chinese].
5. Zhang Xing-fa. The study of production silica white with kaolinite // Anhui Chemical Industry. 1994. No. 4. P. 31–33 [in Chinese].
6. Liu Xin-mei, Pan Zheng-hong, Li, Guo, Yan Zi-feng. Preparation of amorphous silica from coal-based kaolin // Journal of the University of Petroleum, China. 2005. Vol. 29, No. 2. P. 121–124 [in Chinese].
7. Wu Kun. Research into the development of polymer aluminum. Crystal aluminum sulphate, white charcoal and compound stuffing by making use of flying ash // Journal of Pingdingshan Institute of Technology. 1994. Vol. 3,
No. 3–4. P. 86–88 [in Chinese].
8. Wang Ping, Li Liaosha. Research on preparation of silica white from fly ash // China Resources Comprehensive Utilization. 2004. No. 7. P. 25–27 [in Chinese].
9. Tan Xin, Wang Fu-liang, Wang Rong-sheng, Wei Ming-an. Study on preparation of white carbon black from deoiled residue of oil shale // Mining and Metallurgy. 2004. Vol. 13, No. 1. P. 59–63 [in Chinese].
10. Liu Xinjin, Xu Musheng, Huang Tiegang. Studies on activation of kaolin // Bulletin of the Chinese Ceramic Society.1998. No. 1. P. 63–66 [in Chinese].
