Effect of crystal structure on the desulfurization reactivity ofmagnesium slag

doi:10.16085/j.issn.1000-6613.2018-1903

Abstract

Abstract:

The change of crystal structure of magnesium slag during chilling hydration and its effect on the desulfurization activity were studied. The crystal structure and morphology were identified by XRD and TEM. The results showed that the irregular Ca²⁺ coordination in β-C₂S caused the hydration activity higher than that of γ-C₂S. As the chilling temperature increased, the content of β-C₂S and the degree of grain refinement increased. The former promoted the generation of C—S—H with developed pore structure, enhancing the physical adsorption capacity, and the latter caused more lattice defects, enhancing the chemical adsorption capacity. The desulfurization performance of magnesium slag was the highest at 950℃, and the calcium conversion rate reached 24.6%.

Key words: magnesium slag, hydrate, calcium sillicate, crystal structure, adsorption, reactivity

摘要：

研究了激冷水合过程中镁渣晶体结构的变化，结合钙转化率研究了晶体结构对镁渣脱硫活性的影响。借助X射线衍射和透射电镜分析了镁渣的晶体结构和形貌特征。结果表明：β-C₂S中的Ca²⁺配位不规则是其水合活性高于γ-C₂S的原因。随着镁渣激冷温度升高，β-C₂S增加，促进了具有发达孔隙结构的C－S－H生成，提高了物理吸附能力；晶粒细化程度增大，晶胞参数变化引起的晶格缺陷增多，增强了化学吸附能力。950℃激冷温度下镁渣脱硫活性最高，钙转化率达到24.6%。

关键词: 镁渣, 水合物, 硅酸二钙(Ca₂SiO₄), 晶体结构, 吸附, 活性

CLC Number:

Fei HAN, Li JIA, Xiaolei QIAO, Yan JIN, Baoguo FAN. Effect of crystal structure on the desulfurization reactivity ofmagnesium slag[J]. Chemical Industry and Engineering Progress, 2019, 38(07): 3319-3325.

韩飞, 贾里, 乔晓磊, 金燕, 樊保国. 镁渣晶体结构对脱硫活性影响实验[J]. 化工进展, 2019, 38(07): 3319-3325.

Figures/Tables 11

References 16

1	United States Geological Survey (USGS). Magnesium statistics and information[EB/OL]. [2018-08-09]. .
2	孟树昆. 中国镁工业进展[M]. 北京: 冶金工业出版社, 2012.
	MENGS K. Progress in China’s magnesium industry[M]. Beijing: Metallurgical Industry Press, 2012.
3	王建峰, 崔自治. 镁渣的研究利用现状[J]. 能源与节能, 2015(3): 89-91.
	WANGJ F, CUIZ Z. The present research and utilization situation of magnesium slag[J]. Energy and Energy Conservation, 2015(3): 89-91.
4	FANB G, JINY, ZHENGX R, et al. Experimental study on the desulfurization performance of magnesium slag[J]. Cleaner Combustion and Sustainable World, 2013(1): 503-508.
5	段丽萍. 炽热镁渣激冷水合产物分形特征研究[D]. 太原: 太原理工大学, 2015.
	DUANL P. Study on fractal characteristics of hydration products from quenching magnesium slag[D]. Taiyuan: Taiyuan University of Technology, 2015.
6	姬克丹. 炽热镁渣激冷水合反应动力学的研究[D]. 太原: 太原理工大学, 2017.
	JIK D. Study on hydration reaction kinetics of quenching magnesium slag[D]. Taiyuan: Taiyuan University of Technology, 2017.
7	杨靖. 镁还原渣水合制备脱硫剂的试验研究[D]. 太原: 太原理工大学, 2013.
	YANGJ. Experimental study of hydrated magnesium slag as desulfurizer[D]. Taiyuan: Taiyuan University of Technology, 2013.
8	王兴. 金属镁渣在流化床反应器内脱硫性能的实验研究[D]. 太原: 太原理工大学, 2011.
	WANGX. Experimental research on magnesium slag for desulfurtion by fluidized bed reactor[D]. Taiyuan: Taiyuan University of Technology, 2011.
9	YACOUBIA E, MASSITA, MOUTAOIKELS E, et al. Rietveld refinement of the crystal structure of hydroxyapatite using X-ray powder diffraction[J]. American Journal of Materials Science and Engineering, 2017, 5(1): 1-5.
10	单小兵, 张其土, 李玉华. X射线K值法在水泥物相中的应用[J]. 理化检验(物理分册), 2002, 38(8): 342-345.
	SHANX B，ZHANGQ T，LIY H. Application of XRD K value method in cement[J]. PTCA(Part A: Physical Testing), 2002, 38(8): 342-345.
11	刘建路, 林金辉. 纳米粒子的平均晶粒尺寸和晶格畸变的同时测定[J]. 现代技术陶瓷, 2002, 23(1): 34-38.
	LIUJ L, LINJ H. Simultaneous determination of mean particle size and ctystal lattice distortion of nanometer particles[J]. Advanced Ceramics, 2002, 23(1): 34-38.
12	阎守义. 我国皮江法炼镁的现状与分析[J]. 轻金属, 2005(6): 37-40.
	YANS Y. The current status and analysis of making magnesium by means of pidgeon process in China[J]. Light Metals, 2005(6): 37-40.
13	李胜荣. 结晶学与矿物学[M]. 北京: 地质出版社, 2008.
	LIS R. Crystallography and mineralogy[M]. Beijing: Geological Publishing House, 2008.
14	WANGQ Q, LIF, SHENX D, et al. Relation between reactivity and electronic structure for α′_L-, β- and γ-dicalcium silicate: a first-principles study[J]. Cement and Concrete Research, 2014, 57: 28-32.
15	KRISKOVAL, PONTIKESY, ZHANGF, et al. Influence of mechanical and chemical activation on the hydraulic properties of gamma dicalcium silicate[J]. Cement and Concrete Research, 2014, 55(1): 59-68.
16	刘东亮, 金永中. 纳米镍粉的尺寸效应[J]. 化工时刊, 2005, 19(8): 7-9.
	LIUD L, JINY Z. The size effect of nanoscale nickel powder[J]. Chemical Industry Times, 2005, 19(8): 7-9.

元素	质量分数/%	元素	质量分数/%
Ca	42.04	Mg	1.93
Si	14.25	Al	0.43
Fe	4.61	O	36.74

元素	质量分数/%	元素	质量分数/%
Ca	42.04	Mg	1.93
Si	14.25	Al	0.43
Fe	4.61	O	36.74

成分	质量分数/%	成分	质量分数/%
Ca₂SiO₄	87.73	CaO	0.93
Fe₂O₃	6.58	Al₂O₃	0.81
MgO	3.95

成分	质量分数/%	成分	质量分数/%
Ca₂SiO₄	87.73	CaO	0.93
Fe₂O₃	6.58	Al₂O₃	0.81
MgO	3.95

项目	晶胞参数/?^①
项目	a	b	c
标准物质	5.0762	11.2136	6.7583
镁渣	5.0666	11.2026	6.7426