镁热剂/铝热剂体系SHS法固化处理无钙焙烧铬渣  

Immobilization of COPR from lime-free roasting process by self-propagating high-temperature synthesis of Al-Fe_2O_3 and Mg-Fe_2O_3 systems

作　　者：徐亚红[1,2] 徐中慧[1,2] 蒋灶 肖博[1,2] 

机构地区：[1]西南科技大学固体废物处理与资源化教育部重点实验室,四川绵阳621010 [2]西南科技大学非煤矿山安全技术四川省高等学校重点实验室,四川绵阳621010

出　　处：《化工学报》2017年第11期4309-4315,共7页CIESC Journal

基　　金：四川省教育厅青年基金项目(13ZB0183);固体废物处理与资源化教育部重点实验室专职科研创新团队建设基金项目(14tdgk04);固废资源化利用与节能建材国家重点实验室开放基金项目(SWR-2013-005)~~

摘　　要：采用Al-Fe_2O_3(铝热剂)和Mg-Fe_2O_3(镁热剂)2种自蔓延高温合成体系(SHS)对无钙焙烧铬渣(COPR)进行固化处理,并通过浸出毒性试验对自蔓延产物的无害化效果进行评估。研究结果表明:2种反应体系均可实现铬渣的高效无害化,其中铝热剂体系和镁热剂体系铬渣含量分别高达80%和85%,其自蔓延产物浸取浓度ρ(总铬)和ρ(六价铬)分别低于4.5、1.5 mg·L^(-1),符合生活垃圾填埋场污染控制标准GB 16889—2008,可进行填埋处置。在SHS反应过程中,六价铬还原率均高于90%,还原后的六价铬主要以非晶形式弥散分布于自蔓延产物中,且部分铬离子参与MgAlCrO_4尖晶石等矿物的形成,铬元素同时以物理和化学固定化的形式存在于自蔓延产物中。Two self-propagation high-temperature synthesis systems（SHS）,Al-Fe2O3（thermite） and Mg-Fe2O3（magnesium thermite）,were utilized to immobilize the chromite ore processing residue（COPR） from lime-free roasting process.The solid waste-extraction procedure was adopted to evaluate the treatment efficiency of COPR.The results showed that the SHS was an effective remediation technology for COPR with maximum solidify rate of 80% and 85%,respectively.The leaching toxic concentrations of total Cr and Cr（Ⅵ） in solidified products were less than 4.5 and 1.5 mg·L^-1 respectively,and the final products could be disposed in the landfill site according to GB 16889—2008.During the SHS process,the reduction rate of Cr（Ⅵ） was higher than 90% and the reducing substance was dispersed in the solidified products in the form of amorphous state.Meanwhile,parts of the chromium ions were participated in the formation of minerals such as Mg Al Cr O4 spinel.Eventually,the chromium element was incorporated into the wasteforms in the form of chemical immobilization and physical encapsulation.

关 键 词：无钙焙烧铬渣 自蔓延高温合成 浸取 还原 固定化 

分 类 号：X781[环境科学与工程—环境工程]