碱性加压氧化处理铅铜铳的工艺研究

【作者】 文剑锋；

【导师】 杨天足；

【作者基本信息】 中南大学 ， 有色金属冶金， 2011， 硕士

【摘要】 本论文根据目前铅铜锍污染大、能耗高的处理现状,开发研究了碱性体系加压氧化处理铅铜锍的工艺,有效回收了铜、硒、铅、银,同时不产生废气、废渣,基本实现清洁冶金,为铅铜锍的处理开辟了新途径。研究初期,在多种碱性体系进行了加压氧化的探索实验,最终选取氢氧化钠作为碱性浸出介质。在加压氧化的单因素条件实验中,主要考察反应起始温度、氢氧化钠浓度、氧气分压、搅拌速度、反应时间、液固比六大因素,对过程中铅、砷、硫、硒浸出率的影响,得出反应的最佳条件为起始温度125℃,碱过量系数0.08,氧气分压0.3-0.8MPa,搅拌速度1000r/min,液固比4：1,时间1.5h。在此条件下,硫、硒、铅、砷的浸出率分别为98.03%、96.96%、4.15%、0.45%。对氢氧化钠体系加压氧化最佳条件下得到的碱性浸出渣,进行了硫酸浸出的单因素条件实验,主要考察了硫酸浓度、反应终点pH,反应温度的影响。得出通过控制浸出终点pH值的方法,取得了较好的效果。硫酸浸出实验的最佳条件为控制浸出终点pH为2.5,温度60℃,此时铜的浸出率可达98.52%,铁、银的浸出率仅为1.66%、0.72%,浸出渣中Cu、Pb、Ag、Fe的含量分别为1.44%、64.57%、11.28%、0.4136%,铅、银被富集2倍以上。对酸性浸出得到的硫酸铜溶液直接进行了电积实验,考察了电流密度、温度、起始硫酸浓度、铁离子浓度对电流效率的影响,得出铜电积的最佳条件为电流密度320A/m2,温度50℃,当槽电压开始明显上涨时即为电积终点,为保证阴极铜的质量,通常控制电积终点铜离子浓度约15g/L,得到的阴极铜纯度大于99%。据1L高压釜试验的结果,开展了铅铜锍碱性加压氧化、碱性浸出渣的硫酸浸出、硫酸铜溶液的电积及电积残液返回浸出的工业试验,试验结果与小实验基本一致。更多还原

【Abstract】 In view of the existing lead-copper matte process which is high power consumption and serious pollution, this paper developed and studied on alkaline pressure oxidative processing of lead-copper matte. It succeeded in the recovery of copper, selenium, lead, silver, and no waste gases and slags, opening up a new channel for the treatment of lead-copper matte, at the same time, the clean production have been achieved.In the early studies, we proceeded to a conclusion through pressure oxidative experiment in several different alkaline systems, and chose the sodium hydroxide system as the alkaline system.The influence of Six factors, which are beginning temperature, excess ratio of sodium hydroxide, pressure of oxygen, Stirring Speed, time and V/W, was investigated in the single factor experiment of sodium hydroxide pressure oxidative processing. It was concluded that the optimized condition was beginning temperature 125℃, excess ratio of sodium hydroxide 0.08, pressure of oxygen 0.3-0.8MPa, Stirring Speed 1000r/min, V/W 4:1 and time 1.5h. In this condition, the leaching ratio was S98.03%, Se96.96%, Pb4.15%, As0.45%, respectively.Carried on the single factor experiment of sulphuric acid leaching into alkaline slag which was obtained from pressure oxidative processing under the optimized conditions, the influence of the concentration of sulphuric acid, the ending pH of leaching and the temperature was investigated. It was concluded that the concentration of sulphuric acid was an important factor, which determining the trend of the main metallic element and impurities. The method of controlling ending pH of sulphuric acid solution acquired remarkable achievement. The optimized condition of sulphuric acid leaching was ending pH 2.5, temperature 60℃, at this time, the leaching ratio of copper was almost 98.52%, the leaching ratio of iron and silver was just 1.66%,0.72%,in the slag, the content was Cu 1.44%, Pb 54.57%,Ag 11.28%, Fe 0.4136%,lead and silver were enriched by two times. The influence of the current density, temperature, the beginning concentration of acid and the concentration of ferri ion for current efficiency was investigated by the electrolytic deposition of copper sulphate solution. The optimized condition was current density 320A/m2,temperature 50℃, when the electrolytic voltage rised smartly, it was the end of electrolytic deposition.Generally, the ending concentration of copper ion is 15g/L, the purity of cathode copper is more than 99%.According to the result of 1L autoclave experiment, the plant test was developed, it contained the alkaline pressure oxidative processing of lead-copper matte, the sulphuric acid leaching of the alkaline leached slag, the electrolytic deposition of copper sulphate solution and the returning leaching of the residuary electrolytic solution. The result of the plant test was basically consistent to which of laboratory.更多还原