Effect of steam on arsenic volatile characteristics during coal combustion
Wang Hefei
Wang Chunbo
Zou Chan
Yue Shuang
Guo Hui
Abstract：The combustion experiments of Qinghua coal were conducted on a customized isothemal thermogravimetric to study the effect of water on release characteristics of arsenic.Besides,XRD analysis was also used to make a further research on the mechanism of the effect of steam on release characteristics of arsenic.Results show that the presence of steam can accelerate the combustion rate of coal.At a certain temperature,the volatilization ratio of arsenic in steam atmosphere is larger than that without steam,and with the increase of steam concentration,the increase of arsenic volatilization ratio slow down.With the increase of temperature,volatilization ratio of arsenicincreased gradually,but the positive effect of steam on volatilization ratio of arsenic begins to weaken.Compared with air atmosphere,mineral compositionsin ash changed under the steam atmosphere,such as gypsum and other sulfate.It is mainly because the steam promoted the formation of gypsum and inhibited the formation of arsenate via avoiding the reaction between CaO and arsenic,resulting in the increase of arsenic volatilization ratio.
Keywords：steamarsenicvolatilizationcoal combustion
Publication Date：2017-01-01