碳热焙烧还原砷酸钙制备金属砷  

Preparation of metallic arsenic from calcium arsenate by carbon thermal roasting reduction

作　　者：熊民 史冠勇 田磊[1,3] 刘重伟 曹才放 张志辉[1] 徐志峰 XIONG Min;SHI Guan-yong;TIAN Lei;LIU Chong-wei;CAO Cai-fang;ZHANG Zhi-hui;XU Zhi-feng(Green Metallurgy and Process Intensification Research Institute,Jiangxi University of Science and Technology,Ganzhou 341000,China;Jiangxi Copper Lead-Zinc Metal Co.,Ltd.,Jiujiang 332500,China;Henan Yuguang Gold Lead Group Limited Liability Company,Jiyuan 454650,China;Jiangxi College of Applied Technology,Ganzhou 341000,China)

机构地区：[1]江西理工大学绿色冶金与过程强化研究所,赣州341000 [2]江西铜业铅锌金属有限公司,九江332500 [3]河南豫光金铅集团有限责任公司,济源454650 [4]江西应用技术职业学院,赣州341000

出　　处：《工程科学学报》2022年第5期886-893,共8页Chinese Journal of Engineering

基　　金：国家重点研发计划资助项目(2019YFC1907405);国家自然科学基金资助项目(52064021,52074136);中国博士后科学基金资助项目(2019T120625,2019M652276);江西省杰出青年科学基金资助项目(20202ACB213002);江西省博士后择优资助项目(2019KY09);江西省重点研发计划资助项目(20192ACB70017);江西省主要学科学术与技术带头人-青年人才培养计划资助项目(20204BCJL23031)。

摘　　要：致力于碳热焙烧还原砷酸钙制备具有商业价值的金属单质砷,为推进砷危废物无害化处理向砷资源化回收利用前进展开科学研究.其中热重分析表明,砷酸钙与碳粉混合热解的质量损失分为3个阶段,阶段1和阶段2为失水过程,阶段3为碳还原砷酸钙生成CaO和砷蒸气过程.且研究发现,可以利用相边界反应动力学模型解释阶段3反应机制.而单因素条件实验结果表明:在温度1000℃、碳配入系数1.4、恒温时长60 min条件下砷挥发率高达99.94%.X射线衍射仪(XRD)、扫描电镜能谱仪(SEM-EDS)对反应体系中有关产物表征表明,较优条件下产品砷主要为片状金属砷和粉末非晶体砷,焙烧残渣为CaO.Given the widespread application of the lime precipitation process for arsenic removal in the smelting of arseniccontaining minerals,the resourcefulness of calcium arsenate use has received increasing attention.In general,more types of arsenate have different high-temperature characteristics,and the slag type is complicated under mixed reduction roasting and difficult to recover.Additionally,arsenate in the form of calcium arsenate is a more common and inexpensive product in the metallurgical process.Because whether it is arsenic-containing wastewater,arsenic slag,arsenate,and so on,the material can be separated from the system by inexpensive lime precipitation or calcification transformation in simple metallurgical equipment to generate calcium arsenate.Therefore,this paper was devoted to preparing commercially valuable metallic monomers of arsenic by carbon thermal roasting reduction of calcium arsenate and to starting scientific research to advance the harmless treatment of arsenic hazardous waste to arsenic resource recovery and use.Among them,thermogravimetric analysis shows that the mass loss of calcium arsenate mixed with carbon powder pyrolysis is divided into 3 stages:stages 1 and 2 are water loss processes,and stage 3 involves the carbon reduction of calcium arsenate to generate CaO and arsenic vapor.It is found that the stage III reaction mechanism could be explained using the phase boundary reaction kinetic model.The experimental results of single-factor conditions show that the arsenic volatilization rate reaches 99.94% at a constant temperature of 1000 ℃ for 60 min and a carbon allotment factor of 1.4.The characterization of the relevant products in the reaction system by X-ray diffractometer(XRD) and scanning electron microscope energy spectrometer(SEM-EDS) show that the arsenic product is mainly flaked metallic arsenic and amorphous powdered arsenicunder better conditions,and the roasted residue is CaO.

关 键 词：砷酸钙 砷蒸汽 金属砷 单质砷 热重曲线 热分析动力学 

分 类 号：TQ126.4[化学工程—无机化工]