铜冶炼污酸浓缩液资源化处理实验研究

发布时间：2018-08-11 16:02

【摘要】：铜冶炼烟气制酸的洗涤净化环节产生大量的酸性废水,由于其酸度高,冶炼企业一般称之为“污酸”。该污酸溶液体系非常复杂,组分多、浓度高,主要含有高浓度的硫酸根离子、氟离子、氯离子,同时还含有高浓度的砷,多种金属如铜、锌、铅、镉等,是一种危害大、难处理的矿冶工业废水。如果不对此类酸性废水进行有效的处理,不仅会严重的污染环境,而且会造成资源的极大浪费。针对此废水的特点,研究能够将废水中的多种有价元素资源化回收的处理工艺具有重要的实际意义。针对铜冶炼污酸处理中目前普遍采用的硫化沉淀-中和铁盐、石灰中和等工艺方法存在的处理费用高、资源没有得到回收、产生大量难以处理的危险固废、出水水质难以达到回用要求等不足,基于浓缩法综合资源化(蒸发浓缩回收三氧化二砷、浓缩液硫化沉淀回收金属、浓缩液除氟、氯后回收稀硫酸)的思路,本文研究在铜冶炼污酸蒸发浓缩得到污酸浓缩液的基础上将污酸浓缩液进行综合资源化的处理工艺技术。即以铜冶炼污酸蒸发浓缩液净化处理与资源化回收为研究对象,实验研究污酸浓缩液去除氟、氯、砷、重金属的问题,主要的工作及得到的主要结果为:(1)研究了铜渣除氯法去除污酸浓缩液体系中氯的方法,实验考察了铜粉与氧化铜加药量、反应温度、反应时间和搅拌速度等因素对氯去除率的影响,实验结果表明:当铜粉与氧化铜投加量为3倍以上理论用量,反应温度为20℃,反应时间为1.5 h,搅拌速度为200r/min时,氯的去除率达到95%以上。(2)研究了采用硅藻土吸附净化污酸浓缩液中氟的方法,实验考察了硅藻土投加量、反应温度、反应时间和搅拌速度等因素对氟去除率的影响,实验结果表明:当硅藻土投加量为5倍以上理论用量,反应温度为60℃,反应时间为10 h,搅拌速度为200 r/min时,氟的去除率达到90%以上。(3)研究了在高酸条件下采用硫化沉淀方法去除污酸浓缩液中砷及其他重金属的效果,实验考察了硫化钠加药量、反应温度、反应时间和搅拌速度等因素对砷及各种金属去除效果的影响,实验结果表明:当硫化钠的投加量为4倍以上理论用量,反应温度60℃,反应时间为1 h,搅拌速度为150 r/min时,砷的去除率达到95%以上,镉的去除率达到70%以上,铜的去除率达到99%以上,铁的去除率达到50%以上,铅的去除率达到75%以上,锌的去除率达到85%以上。
[Abstract]:A large amount of acid wastewater is produced in the process of washing and purifying the acid from copper smelting flue gas. Because of its high acidity, smelter enterprises generally call it "dirty acid". The waste acid solution system is very complex, has many components and high concentration, mainly contains high concentration of sulfate ion, fluorine ion, chloride ion, and also contains high concentration of arsenic, many kinds of metals such as copper, zinc, lead, cadmium, etc. Refractory waste water from the mining and metallurgical industry If this kind of acid wastewater is not treated effectively, it will not only pollute the environment seriously, but also cause great waste of resources. According to the characteristics of the wastewater, it is of great practical significance to study the treatment process which can recycle many valuable elements in the wastewater. Aiming at the high treatment cost of sulphide precipitation-neutralization iron salt and lime neutralization, which are widely used in the acid treatment of copper smelter sewage, the resources are not recovered, and a large number of dangerous solid wastes are produced, which are difficult to deal with. The effluent quality is difficult to meet the requirement of reuse. Based on the idea of comprehensive resource recovery by concentration (evaporation and concentration recovery of arsenic trioxide, sulphide precipitation of concentrated solution to recover metal, defluorination of concentrated liquid, recovery of dilute sulfuric acid after chlorine), and so on, the water quality of effluent is difficult to meet the requirement of reuse. On the basis of evaporating and condensing waste acid from copper smelting, the technology of synthetically recycling waste acid concentrate was studied in this paper. That is to say, the purification treatment and recycling of waste acid concentrate from copper smelting were taken as the research object, and the problem of removing fluorine, chlorine, arsenic and heavy metals from waste acid concentrate was studied experimentally. The main results are as follows: (1) the method of removing chlorine from waste acid concentrate by copper slag was studied. The amount of copper powder and copper oxide and the reaction temperature were investigated experimentally. The effects of reaction time and stirring speed on chlorine removal rate were studied. The experimental results showed that when the dosage of copper powder and copper oxide was more than 3 times, the reaction temperature was 20 鈩，

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