硫化铅精矿中铊的脱除工艺研究

发布时间：2018-04-23 00:16

  本文选题：铊 + 硫化铅精矿　； 参考：《湘潭大学》2017年硕士论文

【摘要】：铊是一种有毒稀散重金属元素,常伴生于方铅矿、黄铁矿、闪锌矿、辉锑矿、黄铜矿、辰砂等硫化矿物中。硫化铅锌矿选矿过程中,部分铊在硫化铅精矿中富集,并在冶炼过程中释放而危害生态环境。因此,研究出经济实用的铅精矿预处理脱铊技术,实现从源头控制铊污染,成为当今有色金属工业面临的重大难题。目前,未见到关于硫化铅精矿预处理脱铊方面的相关研究报道。本文以湖南宝山有色金属公司提供的浮选硫化铅精矿为研究对象,该矿样中铊的品位达48.75 g/t。铊连续分级提取试验(BCR)结果表明,铊主要赋存于矿样可氧化态部分,占总铊72.6%。本文针对铊在矿样中各结合态分布不同,研究了三种脱铊工艺:直接酸浸、氧化剂氧化-酸浸、碱式氧化-酸浸,分析了三种工艺脱铊可行性和最佳工艺条件。(1)采用直接酸浸工艺脱铊效果不理想,其最佳工艺条件为:磨矿细度-0.074mm90%,浸出体系硫酸用量5%,浸出温度60℃,浸出时间8 h,此时硫化铅精矿中铊去除率仅为18.5%。在浸出体系中加入NaCl,可缩短浸出时间并提高铊的去除率至23.1%。(2)进行氧化剂预氧化-酸浸脱铊试验研究中,分别选取次氯酸钠、氯酸钠、硫酸铁和氯化铁作为氧化剂对矿样预处理,试验结果可知,在最佳工艺条件下,铊的去除率分别为36.1%、50.2%、22.2%和27.4%。矿样经氯酸钠预氧化后可得较好的脱铊效果,但铅的回收率降低,为79.8%。(3)碱式氧化预处理-酸浸脱铊工艺试验结果表明,铊去除率高达83.4%,其最佳工艺条件为:磨矿细度-0.074 mm90%,NaOH用量5%,充气速率为1.25L/min,矿浆浓度20%,氧化温度为50℃,氧化时间32 h;浸出体系硫酸用量12%,搅拌速率350 r/min,浸出温度40℃,浸出时间3.5 h。湿法脱铊后,铅精矿中铊的品位为8.06 g/t,铅的品位为61.9%,铅的回收率96.9%,达到了硫化铅精矿预处理脱铊目的,完全满足冶炼厂要求。
[Abstract]:Thallium is a kind of toxic and scattered heavy metal element, which is often associated with sulphide minerals such as galena, pyrite, sphalerite, stibnite, chalcopyrite, cinnabar and so on. Some thallium is enriched in the lead sulfide concentrate during the processing of lead zinc sulphide ore and released in the smelting process which endangers the ecological environment. Therefore, it is an important problem for the nonferrous metal industry to study the economical and practical thallium removal technology for the control of thallium pollution from the source. At present, there are no reports on thallium removal by pretreatment of lead sulfide concentrate. The flotation lead sulphide concentrate provided by Baoshan Nonferrous Metals Company in Hunan Province is taken as the research object. The thallium grade in the sample is 48.75 g / t. The results of continuous grading extraction of thallium show that thallium mainly occurs in the oxidizable part of the ore sample and accounts for 72.6% of the total thallium. Aiming at the different distribution of thallium in mineral samples, three processes of thallium removal are studied in this paper: direct acid leaching, oxidant oxidation acid leaching, basic oxidation acid leaching. The feasibility and optimum process conditions of thallium removal in three processes were analyzed. The effect of direct acid leaching was not satisfactory. The optimum technological conditions were: grinding fineness -0.074 mm 90 mm, leaching system sulfuric acid dosage 5, leaching temperature 60 鈩，

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