摘要
针对目前酸泥处理技术存在处理成本高、有价金属回收率低等问题,以云南某铅锌冶炼企业产生的酸泥为原料,采用盐酸加过氧化氢体系开展选择性氧化浸出从铅锌冶炼酸泥中分离回收有价组分硒、汞的研究。采用X荧光光谱及X射线衍射对酸泥的成分和物相进行了分析,结果表明,酸泥中主要元素为铅、硒、汞等,其主要以硫酸铅(PbSO_(4))、氯化铅(PbCl_(2))和Hg_(3)Se_(2)Cl_(2)(HgSe和HgCl_(2)共生物)的形式存在。直接用盐酸进行浸出时,由于酸泥中的汞和硒主要是以HgSe和HgCl_(2)共生物的形式存在,不易于盐酸发生反应,因此酸泥中的硒和汞几乎不浸出。在氧化浸出试验中,研究了盐酸浓度、双氧水用量、反应时间、反应温度、反应固液比、硫酸浓度对金属浸出率的影响,确定了最佳工艺参数。结果表明:采用氧化浸出法回收硒、汞,在盐酸浓度60 g/L、反应时间1 h、固液比为1∶2.5、30%双氧水60 g/100 g酸泥、反应温度室温(20~30℃)、浓硫酸浓度10 g/L条件下,汞浸出率稳定达到99%以上,硒浸出率达到90%以上。本工艺可以将硒、汞安全有效的分离,且硒、汞浸出率较高,是一种具有应用前景且绿色高效的酸泥处理技术。
Acid sludge produced by lead and zi nc smelters contains elements such as selenium,mercury,lead,cadmium,arsenic,etc.,of which the content of selenium and mercury elements can be up to 30%~70%,which are high-value hazardous wastes,therefore,if they are not reasonably recycled,they not only pollute the environment,but also result in the waste of resources,which is not conducive to coping with the trend of global resource depletion.At present,the commonly used acid sludge treatment methods are mainly divided into two kinds:fire roasting and wet leaching.The fire process has high efficiency,but high energy consumption,pollution of the environment,and is gradually being replaced by the wet process.The current wet process has problems such as low leaching rate,high requirements of experimental equipment,severe corrosion,and poor economic benefits,so it is of great significance to explore an efficient,clean,and economic recovery process.Aiming at the problems of high treatment cost and low recovery rate of valuable metals in the current acid sludge treatment technology,the acid sludge produced by a lead and zinc smelting enterprise in Yunnan Province was used as raw material,and the system of hydrochloric acid plus hydrogen peroxide was used to research the separation and recovery of selenium and mercury from lead and zinc smelting acid sludge in the form of selective oxidative leaching.The specific research contents are as follows:1)The composition and physical phase of the acid mud were analyzed by X-fluorescence spectroscopy and X-ray diffraction.The results showe that the main elements in the acid mud are lead,selenium and mercury,which mainly exist in the form of lead sulfate(PbSO_(4)),lead chloride(PbCl_(2))and Hg_(3)Se_(2)Cl_(2)(HgSe and HgCl_(2)symbiosis).2)When leaching is carried out directly with hydrochloric acid,selenium and mercury in the acid sludge are hardly leached because the mercury and selenium in the acid sludge mainly exist in the form of HgSe and HgCl2 symbiosis,which are not easy to react with hydrochloric acid.3)In the oxidative leaching experiment,the effects of hydrochloric acid concentration,hydrogen peroxide dosage,reaction time,reaction temperature,reaction solid-liquid ratio,and sulfuric acid concentration on the metal leaching rate were investigated,and the optimal process parameters were determined.The results showed that:the recovery of selenium and mercury by oxidative leaching method,under the conditions of hydrochloric acid concentration of 60 g/L,reaction time of 1 h,solid-liquid ratio of 1∶2.5,30%hydrogen peroxide of 60 g/100 g acid sludge,reaction temperature of room temperature(20—30℃),and the concentration of concentrated sulfuric acid of 10 g/L,the leaching rate of mercury stabilized to more than 99%,and that of selenium reached more than 90%.This process can separate selenium and mercury safely and effectively,and the leaching rate of selenium and mercury is high;it is a green and efficient acid sludge treatment technology with application prospects.
作者
杨万鑫
徐刚
邹维
保佳懿
朱红旭
段鑫宇
董铁广
YANG Wanxin;XU Gang;ZOU Wei;BAO Jiayi;ZHU Hongxu;DUAN Xinyu;DONG Tieguang(Kunming Metallurgy Research Institute,Kunming 650503,China;State Key Laboratory of Advanced Metallurgy for Non-ferrous Metals,Kunming 650503,China;Yunnan Chihong Resource Comprehensive Utilization Co.Ltd.,Qujing 655011,China)
基金
云南省科技平台与人才计划(202305AD160053)
中铝集团青年科技人才培养对象(351202250003)
重大科技专项计划(202302AB080016)。
关键词
氧化浸出
硒
汞
酸泥
分离回收
oxidative leaching
selenium
mercury
acid sludge
separation and recovery
作者简介
杨万鑫(1997-),男,硕士,工程师,主要从事生态环境修复及铜铅锌冶金技术研究工作;通信作者:徐刚(1987-),男,本科,工程师,主要从事铅锌冶炼。
