Clarifying the decomposition process of pyrite and SO2 release in the cyclone preheater of a dry rotary cement kiln system
Clarifying the decomposition process of pyrite and SO2 release in the cyclone preheater of a dry rotary cement kiln system
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阐明干法回转水泥窑系统旋风预热器中黄铁矿分解过程和SO2释放
DOI：
10.1016/j.jclepro.2019.118422
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发表时间：
2019-12
影响因子：
11.1
通讯作者：
Yu Qijun
中科院分区：
文献类型：
--
作者：
Zhang Tongsheng;Wu Chang;Li Bin;Wang Chao;Chen Xinzhi;Wei Jiangxiong;Yu Qijun
水泥工业中二氧化硫的排放主要是由于在旋风预热器中黄铁矿在300-600 ℃下的分解/氧化造成的。旋风预热器是一种多级悬浮加热装置，通常由5级旋风组成，与固定床、流化床和循环流化床完全不同。因此，在烟气脱硫之前，弄清预热器环境中黄铁矿的分解过程是非常重要的。采用多级夹带流反应器模拟旋风预热器，考察了加热阶段和温度、o2浓度、停留时间和粒度对黄铁矿分解过程的影响。结果表明：黄铁矿经过第一期加热转变为亚稳结晶，经过第二期加热和第三期加热逐步氧化为黄铁矿和磁铁矿/赤铁矿，并伴有so2的释放；硫铁矿的分解过程受硫气和o2在产物层中的扩散速率控制，分解过程中由于体积收缩而产生的径向裂纹加速了硫铁矿的分解过程。研究结果将对黄铁矿的分解、SO2的释放和捕获以及窑炉系统的硫流有更深入的了解，为水泥工业设计工艺相容的烟气脱硫技术奠定基础。
SO2emissions in the cement industry are mainly caused by the decomposition/oxidization of pyrite at 300–600 °C in a cyclone preheater, which is a multistage suspension heating apparatus normally consisting of 5-stage cyclones and totally differentiated from the fixed bed, fluidized bed, and circulating fluidized bed. Therefore, clarifying the decomposition process of pyrite in the preheater environment is very important prior to flue gas desulfurization. In the present study, a multistage entrained flow reactor was designed to simulate the cyclone preheater, and then the effects of heating stage and temperature, O2concentration, residence time and particle size on the decomposition process of pyrite were investigated. The results show that pyrite was transformed to a metastable crystalline state after first-stage heating, and then oxidized to pyrrhotine and magnetite/hematite after second-stage heating and third-stage heating step by step accompanied with SO2release. The decomposition process of pyrite was controlled by the diffusion rate of sulfur gas and O2in the product layer and accelerated by the radial cracks due to the volume shrinkage during decomposition. The results will give deeper insight into the decomposition of pyrite, release and capture of SO2, and sulfur flow of the kiln system, which are the fundamental to design process-compatible flue gas desulfurization technology for the cement industry.
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DOI：
10.3133/b1214d
发表时间：
1966
期刊：
--
影响因子：
--
作者：
A. Vlisidis
通讯作者：
A. Vlisidis
影响因子：
3.5
作者：
J. Dunn;G. C. De;B. O'Connor
通讯作者：
J. Dunn;G. C. De;B. O'Connor
DOI：
10.1002/pssa.2210870126
发表时间：
1985-01
期刊：
January 16
影响因子：
--
作者：
A. Prasad;R. M. Singru;Dr. Ashis Biswas
通讯作者：
A. Prasad;R. M. Singru;Dr. Ashis Biswas
影响因子：
15
作者：
G. Schwab;John Philinis
通讯作者：
G. Schwab;John Philinis
影响因子：
7.4
作者：
Bhargava, S. K.;Garg, A.;Subasinghe, N. D.
通讯作者：
Subasinghe, N. D.