石灰石高温快速煅烧对石灰微观结构及其物化性质的影响
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- 英文论文题名：Effect of Fast Calcination for Limestone at High Temperature on Microstructure and Physico-chemical Properties of Lime
- 论文作者：蔡金林 ; 薛正良 ; 胡彬 ; 王理猷 ; 李建立
- 英文论文作者：Cai Jinlin ; Xue Zhengliang ; Hu Bin ; Wang Liyou ; Li Jianli ; The State Key Laboratory of Refractories and Metallurgy ; Wuhan University of Science and Technology
- 年：2016
- 作者机构：武汉科技大学省部共建耐火材料与冶金国家重点实验室;
- 论文关键词：石灰石 ; 高温煅烧 ; 物化性质 ; 微观结构 ; 活性度
- 英文论文关键词：limestone ; calcined at high temperature ; physico-chemical properties ; microstructure ; activity of lime
- 会议召开时间：2016-05-19
- 会议录名称：第十九届（2016年）全国炼钢学术会议大会报告及论文摘要集
- 语种：中文
- 分类号：TF702
- 学会代码：ZGJS
- 会议名称：第十九届（2016年）全国炼钢学术会议
- 会议地点：中国湖南长沙
- 主办单位：中国金属学会炼钢分会
- 学会名称：中国金属学会
- 页数：1
- 文件大小：58k
- 原文格式：O
- 会议级别：全国
摘要
转炉炼钢用石灰石代替活性石灰造渣是钢铁工业低碳和节能减排的重要举措。本文研究了粒径为12.5~15mm的石灰石在1450℃下快速煅烧5~15min时得到的石灰的物理化学性质、活性度及其与微观结构变化之间的关系。结果表明:石灰石在1450℃下煅烧5~10min后,CO_2逸出留下的微气孔十分发达;继续延长煅烧时间CaO再结晶长大使微气孔逐渐消失,石灰结构致密化。反映在物化性质上,随着煅烧时间延长,石灰的气孔率迅速增加,10min时达到最大值,之后迅速下降;体积密度的变化规律刚好相反;比表面积则随煅烧时间延长而下降。石灰的活性度在煅烧10min时达到最大值。在高温快速煅烧条件下,CaCO_3分解由表及里,表层的CaO晶粒已经开始再结晶长大而致密化,颗粒内部CaCO_3仍在分解留下大量微气孔。
Active lime was replaced by limestone in converter steelmaking processes,which was a vital measure of low-carbon,energy-saving and emission reduction for iron and steel industry.The relationships between activity,physico-chemical properties of lime and changes of microstructure were investigated respectively.The limestone whose particle size was between12.5~15mm was calcined fast at 1450℃ for 5min to 15 min.The results show that CO2 escapes,leaving highly developed micropore after calcining at 1450℃ for 5min to 10 min.With the extension of calcining time,CaO recrystallizes and grows up,resulting disappearance of micropore and densification for structure of lime.Reflect on the physic-chemical properties,with the extension of calcining time,the porosity of lime quickly increases at first and then decreases,which reaches the maximum when calcined for10 min.However,the variation of bulk density is opposite.The specific surface area of lime decreases with the extension of calcining time.The activity of lime reaches reaches the maximum when calcined for 10 min.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 decomposed inside of lime,leaving a lot of micro-pores.
Active lime was replaced by limestone in converter steelmaking processes,which was a vital measure of low-carbon,energy-saving and emission reduction for iron and steel industry.The relationships between activity,physico-chemical properties of lime and changes of microstructure were investigated respectively.The limestone whose particle size was between12.5~15mm was calcined fast at 1450℃ for 5min to 15 min.The results show that CO2 escapes,leaving highly developed micropore after calcining at 1450℃ for 5min to 10 min.With the extension of calcining time,CaO recrystallizes and grows up,resulting disappearance of micropore and densification for structure of lime.Reflect on the physic-chemical properties,with the extension of calcining time,the porosity of lime quickly increases at first and then decreases,which reaches the maximum when calcined for10 min.However,the variation of bulk density is opposite.The specific surface area of lime decreases with the extension of calcining time.The activity of lime reaches reaches the maximum when calcined for 10 min.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 decomposed inside of lime,leaving a lot of micro-pores.
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