【摘要】：銅冶煉煙氣制酸的洗滌凈化環(huán)節(jié)產(chǎn)生大量的酸性廢水,由于其酸度高,冶煉企業(yè)一般稱之為“污酸”。該污酸溶液體系非常復(fù)雜,組分多、濃度高,主要含有高濃度的硫酸根離子、氟離子、氯離子,同時還含有高濃度的砷,多種金屬如銅、鋅、鉛、鎘等,是一種危害大、難處理的礦冶工業(yè)廢水。如果不對此類酸性廢水進行有效的處理,不僅會嚴(yán)重的污染環(huán)境,而且會造成資源的極大浪費。針對此廢水的特點,研究能夠?qū)U水中的多種有價元素資源化回收的處理工藝具有重要的實際意義。針對銅冶煉污酸處理中目前普遍采用的硫化沉淀-中和鐵鹽、石灰中和等工藝方法存在的處理費用高、資源沒有得到回收、產(chǎn)生大量難以處理的危險固廢、出水水質(zhì)難以達到回用要求等不足,基于濃縮法綜合資源化(蒸發(fā)濃縮回收三氧化二砷、濃縮液硫化沉淀回收金屬、濃縮液除氟、氯后回收稀硫酸)的思路,本文研究在銅冶煉污酸蒸發(fā)濃縮得到污酸濃縮液的基礎(chǔ)上將污酸濃縮液進行綜合資源化的處理工藝技術(shù)。即以銅冶煉污酸蒸發(fā)濃縮液凈化處理與資源化回收為研究對象,實驗研究污酸濃縮液去除氟、氯、砷、重金屬的問題,主要的工作及得到的主要結(jié)果為:(1)研究了銅渣除氯法去除污酸濃縮液體系中氯的方法,實驗考察了銅粉與氧化銅加藥量、反應(yīng)溫度、反應(yīng)時間和攪拌速度等因素對氯去除率的影響,實驗結(jié)果表明:當(dāng)銅粉與氧化銅投加量為3倍以上理論用量,反應(yīng)溫度為20℃,反應(yīng)時間為1.5 h,攪拌速度為200r/min時,氯的去除率達到95%以上。(2)研究了采用硅藻土吸附凈化污酸濃縮液中氟的方法,實驗考察了硅藻土投加量、反應(yīng)溫度、反應(yīng)時間和攪拌速度等因素對氟去除率的影響,實驗結(jié)果表明:當(dāng)硅藻土投加量為5倍以上理論用量,反應(yīng)溫度為60℃,反應(yīng)時間為10 h,攪拌速度為200 r/min時,氟的去除率達到90%以上。(3)研究了在高酸條件下采用硫化沉淀方法去除污酸濃縮液中砷及其他重金屬的效果,實驗考察了硫化鈉加藥量、反應(yīng)溫度、反應(yīng)時間和攪拌速度等因素對砷及各種金屬去除效果的影響,實驗結(jié)果表明:當(dāng)硫化鈉的投加量為4倍以上理論用量,反應(yīng)溫度60℃,反應(yīng)時間為1 h,攪拌速度為150 r/min時,砷的去除率達到95%以上,鎘的去除率達到70%以上,銅的去除率達到99%以上,鐵的去除率達到50%以上,鉛的去除率達到75%以上,鋅的去除率達到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，

本文編號：2177477