摘要
为了研究O2摩尔分数和紫外光照射对烟气浸出煤中砷的影响,以N2、O2和摩尔分数为1%的SO2气体模拟烟气,通入鼓泡反应器中的煤浆,测定了不同O2摩尔分数、遮光和紫外光照射条件下煤中砷浸出率、液相中三价砷As(Ⅲ)与总砷的比值随浸出时间的变化规律,分析了砷浸出的动力学过程。结果表明,提高O2摩尔分数能够有效提高煤中砷的浸出率,但即使O2摩尔分数达到20%,液相中As(Ⅲ)与总砷的比值仍有50%左右;紫外光照射也能提高砷浸出率,尤其能使液相中As(Ⅲ)与总砷的比值减小到5%以下,这是因为紫外光照射下浆液中形成了具有强氧化性的自由基。紫外光照射的这种作用有利于浸出砷的沉淀分离等后续处置过程。动力学分析结果表明,砷浸出过程满足反应控制的缩核模型。
In order to study the effects of O2 mole fraction and ultraviolet(UV) irradiation on arsenic leaching from coal with flue gas, N2, O2 and SO2(1% mole fraction) were used to simulate flue gas which was introduced into a bubbling reactor containing coal slurry. Profiles of arsenic leaching ratio and the ratio of As(Ⅲ)to total arsenic leached were determined at different O2 mole fractions, and under dark and UV irradiation conditions. The arsenic leaching kinetics was analyzed. The results show that increasing O2 mole fraction can effectively increase the leaching ratio of arsenic from coal. However, the ratio of As(Ⅲ) to total arsenic leached is about 50% even the O2 mole fraction is increased to 20%. UV irradiation can also increase the leaching ratio of arsenic. It can reduce the ratio of As(Ⅲ) to total arsenic leached to less than 5%, which is due to the formation of strong oxidizing free radicals in the slurry under UV irradiation. This is particularly favorable for the subsequent disposal processes of leached arsenic, such as precipitation and separation. Kinetic analysis results show that the arsenic leaching process follows the reaction-controlled shrinking core model.
作者
鲁真真
孙文寿
郭远峰
陶琳琳
张敬帅
陈思铭
LU Zhen-zhen;SUN Wen-shou;GUO Yuan-feng;TAO Lin-lin;ZHANG Jing-shuai;CHEN Si-ming(College of Environmental Science and Engineering,Qingdao University,Qingdao 266071,China)
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2019年第4期989-997,共9页
Journal of Chemical Engineering of Chinese Universities
关键词
煤炭
砷
紫外光
烟气
二氧化硫
自由基
coal
arsenic
ultraviolet light
flue gas
sulfur dioxide
free radical
