摘要
采用高硅铝含量的工业固废(煤矸石与高炉矿渣),作为生活垃圾焚烧飞灰热处理的添加剂,改善其熔融性与产物的物化特性.随着添加量的增加,产物的主要矿物成分从含氯的Ca_(10)(SiO_(4))_(3)(SO_(4))_(3)Cl_(2)与Ca_(6)Al_(5)Si_(2)O_(16)Cl_(3)向钙铝石、斜硅钙石、黄长石、钙长石依次转变.采用四元碱度(R4)评价熔融成分,酸性的工业固废(R4<1)能够中和碱性的垃圾飞灰(R4>1),形成中性混合灰(R4≈1),其中含30%煤矸石或40%高炉矿渣.中性灰的各项熔融特征温度最低,代表完全熔融的流动温度分别为1260与1200℃,在1300℃下玻璃化,冷却形成晶相为黄长石的微晶玻璃.玻璃化过程中,超过99%的氯元素从固相中分离;在挥发分离与固化稳定的共同作用下,重金属铬、镍、锌、镉、铅的浸出量减少了95%以上,铜减少了85%以上.
Industrial solid waste with high Si and Al content(coal gangue and blast furnace slag)was used as additive for thermal treatment of municipal solid waste incineration(MSWI)fly ash,to improve its fusibility and properties of products.With the increase of additive,main mineral composition of products were changed from chlorellestadite and wadalite containing Cl to mayenite,larnite,melilite and anorthite.Quaternary basicity(R4)was used to evaluate fusible composition.Alkaline MSWI fly ash(R4>1)can be neutralized by acidic industrial solid waste(R4<1),to form neutral mixed ash(R4≈1)which containd 30%coal gangue or 40%blast furnace slag.The fusibility temperatures of neutral mixed ash were the lowest and FT representing complete fusion was 1260 and 1200℃.At 1300℃glass-ceramics with crystal phase of melilite were formed by vitrification during cooling.Within vitrification,more than 99%of chlorine was separated from the solid phase.By volatilization separation,solidification and stabilization,the leaching capacity of heavy metals Cr,Ni,Zn,Cd and Pb was reduced by more than 95%,while that of Cu was reduced by more than 85%.
作者
赵昂然
任强强
佟会玲
ZHAO Ang-ran;REN Qiang-qiang;TONG Hui-ling(Department of Energy and Power Engineering,Tsinghua University,Beijing 100084,China;Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第2期686-693,共8页
China Environmental Science
基金
中国科学院青年创新促进会资助项目(Y201932)
华能集团总部科技项目“基础能源科技研究专项(二)(HNKJ21-H31)”。
关键词
城市生活垃圾焚烧飞灰
煤矸石
高炉矿渣
热处理
玻璃化
municipal solid waste incineration(MSWI)fly ash
coal gangue
blast furnace slag
thermal treatment
vitrification
