碲锌镉中碲的提取研究

发布时间：2018-04-13 23:16

  本文选题：碲锌镉 + 水热氧化　； 参考：《浙江理工大学》2015年硕士论文

【摘要】：从碲锌镉中提取金属碲不仅具有非常高的经济效益,而且是一项变废为宝的资源综合利用工程。本研究根据碲锌镉原料的成分和原料中碲存在的形态,提出先将碲锌镉水热氧化,接着酸浸,最后还原提取碲。碲锌镉氧化的探索实验表明：采用NaClO3和HNO3氧化,实验过程中会产生有害气体；采用H2O2和热处理氧化,碲的提取率不是很高；采用KMnO4氧化,提取出碲的纯度不是很高；采用水热氧化时,碲的提取率为58.80%,纯度为99.21%,且不会产生有害气体。因此,本实验碲锌镉采用水热氧化。本论文首先对碲锌镉水热氧化进行了研究,考察了H2O2加入量、水热温度、水热时间和溶剂浓度这四个因素对碲的提取率的影响,确定碲锌镉水热氧化的最佳条件为：H2O2加入量10.0 mL,水热温度180℃,水热时间6 h,溶剂稀硫酸的浓度2 m0l/L.碲锌镉水热氧化后酸浸还原提取碲,对第一种方案：H2SO4浸出--Na2SO3还原进行了研究,考察了：酸浸时硫酸浓度、液固比、酸浸温度、酸浸时间、碲锌镉粒径、氯化钠加入量、亚硫酸钠加入量、还原温度和还原时间这九个因素对碲的提取率的影响,确定最佳条件为：酸浸硫酸浓度8 mol/L,液固比12：1,酸浸温度85℃,酸浸时间4 h,碲锌镉的粒径120～300目,还原时NaCl/Te=6,Na2SO3/Te=10,还原温度80℃,还原时间80 min。在最佳条件下,碲的提取率为81.27%。在第一种方案的基础上,对第二种方案：H2SO4+NaCl浸出--Na2SO3还原进行了研究,主要考察了酸浸硫酸浓度、液固比、氯化钠加入量、亚硫酸钠加入量等因素对碲的提取率的影响,确定最佳条件为：酸浸时加入8.00 g氯化钠,硫酸浓度4mol/L,酸浸时间15 min,液固比10：1,还原NaCl/Te=6,Na2SO3/Te=10,其他条件与第一方案的相同。在最佳条件下,碲的提取率为91.39%。第二种浸出还原方式相对于第一种方案,减少了酸浸的时间和降低了酸浸硫酸的浓度,同时提高了碲的提取率。综上所述,本论文碲锌镉中提取碲的工艺为：先将碲锌镉水热氧化,接着H2SO4+NaCl浸出,最后用Na2SO3还原溶液中的碲。
[Abstract]:The extraction of metal tellurium from cadmium zinc tellurium not only has high economic benefit, but also is a comprehensive utilization project of transforming waste into treasure.According to the composition of zinc cadmium tellurium and the form of tellurium in the raw material, the hydrothermal oxidation of cadmium zinc tellurium was put forward, then the acid leaching was carried out, and finally the tellurium was extracted by reduction.The experimental results of cadmium cadmium tellurium oxidation show that harmful gases will be produced in the process of oxidation by NaClO3 and HNO3, the extraction rate of tellurium by H2O2 and heat treatment is not very high, the purity of tellurium extracted by KMnO4 oxidation is not very high.By hydrothermal oxidation, the extraction rate of tellurium is 58.80, the purity is 99.21, and the harmful gas will not be produced.Therefore, zinc cadmium tellurium was hydrothermal oxidized in this experiment.In this paper, the hydrothermal oxidation of zinc cadmium tellurium was studied. The effects of H2O2 addition, hydrothermal temperature, hydrothermal time and solvent concentration on the extraction rate of tellurium were investigated.The optimum conditions for hydrothermal oxidation of cadmium zinc tellurium were determined as follows: the amount of H _ 2O _ 2 was 10.0 mL / L, the hydrothermal temperature was 180 鈩，

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