Study on the Physico-chemical Properties and Microstructure of Lime Rapidly Calcined at High Temperature
Jinlin
Cai1; ZhengLiang
Xue2; Bin Hu
Hu3; Li-you
Wang3; Jian-li
Li3;
1WUHAN UNIVERSITY OF SCIENCE AND TECHNOLOGY, Wuhan, China; 2THE STATE KEY LABORATORY OF REFRACTORIES AND METALLURGY, WUHAN UNIVERSITY OF SCIENCE AND TECHNOLOGY, WuHan, China; 3THE STATE KEY LABORATORY OF REFRACTORIES AND METALLURGY, WUHAN UNIVERSITY OF SCIENCE AND TECHNOLOGY, Wuhan, China;
Type of Paper: Regular
Id Paper: 26
Topic: 2Abstract:
It is a vital measure of energy-saving and emission reduction for iron and steel industry that limestone is used instead of active lime in converter steelmaking process. The effect of the microstructure on the reactivity and physico-chemical properties of lime were investigated. The limestone (12.5-15mm) was calcined fastly at 1450ĦaC for 5min to 15min. The results show that the escape of CO2 promotes highly developed micropores forming after calcining at 1450ĦaC for 5min to 10min. With the extension of calcining time, CaO recrystallizes and grows up, resulting in the disappearance of micro pores and densification for the structure of lime. With regard to the physic-chemical properties, the porosity of lime quickly increases at first and then decreases, which reaches the maximum at 10min, with the extension of calcining time. However, the variation of bulk density is opposite. The specific surface area of lime decreases with the extension of calcining time. The reactivity of lime reaches the maximum when calcined for 10min. In the condition of high temperature and fast calcination, CaCO3 decomposition is from the outside to the inside. CaO grain on the surface of lime has recrystallized, grown up and become dense, but CaCO3 is still in the decomposition inside of lime, leaving a lot of micro pores.
Keywords:
CO2; Combustion; Emissions; Lime; Temperature;
References:
[1] Li Hong, Qu Ying. A method of using limestone instead of lime slag steelmaking in oxygen top-blown converter. China: ZL 200910082071. X, 2009.
[2] Xue Zhengliang, Ke Chao, Liu Qiang, etc. Study on the reactivity of lime fast calcined at high temperature. Steelmaking (in Chinese), 2011, 27(4): 37-40.
[3] Li Ziquan, Li Hong, Guo Luofang, etc. Preliminary research on the behavior of limestone charged into converter in the process of making slag. Steelmaking (in Chinese), 2011, 27(2):33-36.
[4] Tian Zhiguo, Tang Wei, Pan Xiquan. Application analysis of substituting limestone for some limes in BOF. Metal materials and metallurgy engineering, 2012, 40(3): 31-35.
[5] Wang Pengfei, Zhang Huaijun. Study on slagging effects with limestone instead of lime in steelmaking. Science and Technology of Baotou Steel (in Chinese), 2012, 38(4): 30-32.
[6] Wei Baosen. Limestone in converter steelmaking practice. Energy for Metallurgical Industry (in Chinese), 2012, 31(4): 10-12.
[7] Liu Yu, Wang Wenke, Wang Peng, etc. Steel-making operations by substituting limesone for some limes in converter. Angang Technology (in Chinese), 2011(5): 41-43.
[8] GB/T 2997-2000, Test method for bulk density, apparent porosity and true porosity of dense shaped refractory products.
[9] GB/T 19578-2004, Determination of the specific surface area of solids by gas adsorption using the BET method.
[10] YB/T105-2005, Methods of physical testing for metallurgical quicklime.
[11] Hao Suju, Jiang Wufeng, Fang Jue, etc. The measurement of the activity of high activity lime. Sintering and Pelletizing (in Chinese), 2008, 33(1):1-3.
[12] Chu Jianmin, Gao Shilin. Technical manual of metallurgical lime production. Beijing: Metallurgical Industry Press, 2009.
[13] Tang Yaxin. Factors influencing activity of lime. Steelmaking (in chinese), 2001, 17(3): 50-52.
[14] Bai Yandong, Hao Suju, Zhang Yuzhu, etc. Study on property of different activity lime. Jouranl of Heibei Institute of Technology (in Chinese), 2008, 30(2): 24-25.
[15] Song Yanhui, Zhang Xianfu. The production and application of active lime in metallurgy. Jouranl of Heibei Institute of Technology (in Chinese), 2006, 28 (1): 5-11.
[16] Liu Hongjuan. Study on the microstructure of limestone and active lime. Maanshan Iron and Steel Research (in Chinese), 1993 (2): 47-58.
[17] Wu Jiaxuan, Wu Bowen. Industrial test and research on active lime calcination. Refractories and Lime (in Chinese), 2009, 34(3): 4-7.
[18] Guo Hanjie, Yin Zhiming, Wang Hongwei. Optimum schedule in calcination process of metallurgical active lime. Journal of University of Science and Technology Beijing (in Chinese), 2008,30(2):148-151.
[19] Li Daozhong. Study on process conditions for active lime quickly calcined under high temperature. Refractories and Lime (in Chinese), 2008, 33(5): 1-3.
[20] Pol'shikov G. V, Bogomyakov V. I, Maksimov V. I, etc.. Influence of lime calcination on technical and economic factors in converter steelmaking. Steel in the USSR, 1989, 19(5): 212-214.
[21] Le Kexiang, Dong Yuanhu, Wang Shijun, etc. Experimental study on calcining active lime from the limestone. Journal of Anhui University of Technology (in Chinese), 2001, 18(2): 101-103.
[22] Shubin, A.F,Dmitrieva, A.A., Ivanov, R.G. Straightflow-and-counterflow shaft furnace for active lime production. Stal, 2001 (5): 80-83.
[23] Bhattacharya, A.K., Das, P. Dasgupta, A.K..Physico-chemical studies on ring formation in rotary kiln for calcinations of lime stone. SEAISI Quarterly (South East Asia Iron and Steel Institute), 1988, 17(3): 66-71.
[24] Deng Xinyun, Yan Xin, Lu Yunfeng. Optimization of active lime producing process technology conditions. Chemical Engineering Design (in Chinese), 2008, 18(2): 22-26.Full Text:
Click here to access the Full TextCite this article as:
Cai J, Xue Z, Hu B, Wang L, Li J. Study on the Physico-chemical Properties and Microstructure of Lime Rapidly Calcined at High Temperature. In: Kongoli F, Noldin JH, Takano C, Lins F, Gomez Marroquin MC, Contrucci M, editors. Sustainable Industrial Processing Summit SIPS 2016 Volume 1: D'Abreu Intl. Symp. / Iron and Steel Making. Volume 1. Montreal(Canada): FLOGEN Star Outreach. 2016. p. 289-299.