添加CaO对燃煤重金属元素富集效果的影响

选取CaO作为吸附剂,探究了不同燃烧温度下添加CaO对重金属元素在燃煤灰渣中富集效果的影响规律。实验结果表明:添加CaO对重金属元素Cr未起到富集作用,而对Mn,Ni,Cu,Zn,As,Cd,Pb 7种重金属元素的富集效果显著;随燃烧温度的升高,CaO对各赋存形态的Mn,Ni,Cu,Zn,As的富集效果先变好而后变差,对各赋存形态的Cd和Pb的富集效果越来越好;CaO添加比(预处理后的CaO颗粒与预处理后的原煤的质量比)越大,CaO对Mn,Ni,Cu,Zn,As,Cd,Pb的富集效果越好,燃烧温度为850℃时的最佳CaO添加比为4%。

Effects of CaO on enrichment of heavy metal elements in coal ashes

CaO was used as adsorbent and its effects on enrichment of heavy metal elements in coal ashes at different temperatures were studied. The experimental results show thatCaO has no enrichment effect to Cr,but significant enrichment effect to other 7 kinds of heavy metals,such as Mn,Ni,Cu,Zn,As,Cd,Pb;With the increasing of combustion temperature,the enrichment effects of CaO to Mn,Ni,Cu,Zn,As in all occurrence forms get better first and then get worse,while those to Cd,Pb are getting better and better;The greater the CaO addition ratio（the mass ratio of pretreated CaO and pretreated coal）is,the better the enrichment effects of CaO to Mn,Ni,Cu,Zn,As,Cd,Pb is,and when the combustion temperature is 850 ℃,the best CaO addition ratio is 4%.