水泥窑协同处置Cr污染土壤过程中Cr的化学形态转化  

TRANSFORMATION OF Cr CHEMICAL FORMS IN CEMENT KILNS CO-PROCESSING Cr CONTAMINATED SOIL

作　　者：杨柳阳 王雷 崔长颢 刘美佳 李丽[2] 闫大海[2] YANG Liu-yang;WANG Lei;CUI Chang-hao;LIU Mei-jia;LI Li;YAN Da-hai(School of Environmental Science and Engineering,Nanjing Tech University,Nanjing 210000,China;Research Institute of Solid Waste Management,Chinese Research Academy of Environmental Sciences,Beijing 100012,China)

机构地区：[1]南京工业大学环境科学与工程学院,南京210000 [2]中国环境科学研究院固体废物污染控制技术研究所,北京100012

出　　处：《环境工程》2021年第10期185-190,共6页Environmental Engineering

基　　金：国家重点基础研究发展计划项目(2019YFC1906900)。

摘　　要：为了对水泥熟料中的水溶性类Cr(Ⅵ)化合物从源头入窑废物控制以达到合理处置铬污染土壤的目的,以生料中Cr(Ⅲ)转化为熟料中Cr(Ⅵ)及水溶性Cr(Ⅵ)转化率为切入点展开探究。采用实验室模拟实验结合现场实验分别对含Cr污染土壤(CCS)中Cr元素煅烧前后质量平衡,Cr(Ⅲ)转化为Cr(Ⅵ)的转化率以及水溶性Cr(Ⅵ)的转化率进行研究。结果发现:Cr总量在煅烧前后基本未发生改变;在模拟煅烧实验中,Cr(Ⅲ)→Cr(Ⅵ)的转化率仅为40%左右,但在现场实验中可达到90%左右;水溶性Cr(Ⅵ)仅在现场实验工况下的熟料中检测到,Cr(Ⅵ)中水溶性Cr(Ⅵ)占比为60%~69%,水溶性Cr(Ⅵ)的转化率为35.40%。水泥产品中的水溶性Cr(Ⅵ)检测结果中复合型硅酸盐水泥中水溶性Cr(Ⅵ)含量低于GB 31893—2015《水泥中水溶性铬(Ⅵ)的限值及测定方法》中的相应限值10 mg/kg。To control water-soluble Cr(Ⅵ) compound in cement clinker from the waste source into the kiln, and make sure the reasonable co-processing of chromium contaminated soil, this paper put forward the conversion rate from Cr(Ⅲ) in raw materials to Cr(Ⅵ) and water soluble Cr(Ⅵ) in the clinker as the breakthrough point and then conduct a research. The experiments were carried out under simulated and field test conditions, and the results were calculated through mass balancing method and conversion rate of Cr(Ⅵ). It was found that the total amount of Cr changed slightly before and after calcination, and the conversion rates of Cr(Ⅲ) to Cr(Ⅵ) in simulated calcination experiment and field test were 40% and 90%, respectively. The water-soluble Cr(Ⅵ) was only detected in clinker in filed test, with a proportion of 60%~69% of total Cr(Ⅵ). Eventually, the conversion rate of water-soluble Cr(Ⅵ) was calculated to be approximately 35.40%. The mixing degree of air and raw material showed an significant impact on the conversion rate of Cr(Ⅲ) to water-soluble Cr(Ⅵ). The analysis of cement product revealed that the concentration of water-soluble Cr(Ⅵ) was slightly higher in composite Portland cement, but still below the allowable limit in China’s nation standard GB 31893—2015.

关 键 词：水泥窑 污染土壤 协同处置 Cr(Ⅵ) 转化率 

分 类 号：X53[环境科学与工程—环境工程]