低共熔溶剂处理含锌烟尘的研究

发布时间：2018-05-09 13:38

本文选题：低共熔溶剂 + ZnO　；参考：《昆明理工大学》2017年硕士论文

【摘要】：在当前锌资源供应日益紧张的情况下,含锌烟尘等二次锌资源的综合利用是解决该问题的有效途径之一,每年全球所生产的锌大约有30%来自再生锌资源,回收含锌烟尘等二次锌资源日益紧迫。低共熔溶剂(DES)作为一种新型绿色溶剂,因其毒性低、可生物降解、价格低廉、合成简单等优点,将其作为处理含锌烟尘的溶剂,有望克服浸出体系中成份复杂,分离困难等问题,具有重要的理论指导和广阔的应用前景。本文采用低共熔溶剂作为研究体系,以金属氧化物纯物质作为研究对象,通过金属氧化物纯物质在低共熔体系内的行为,分别采用胆碱类低共熔溶剂溶出各类金属氧化物的纯物质,并且对成分复杂的含锌烟尘进行浸出。测定了 ZnO在ChCl-urea和CC-OA DES中的溶解度,测定了两个体系温度对其黏度的影响,通过质谱分析ZnO在两个体系内的存在形式,测定了 ZnO浓度和温度对ChCl-urea-ZnO电导率的影响。通过循环伏安测试手段研究了在ChCl-urea-ZnO制备金属锌的电化学行为,并通过浓度的变化,确定颗粒尺寸、形貌等的影响。通过单因素实验和响应曲线实验设计,考察了各个因素对锌浸出率的影响,通过CC-OA DES体系对含锌烟尘的处理的前期研究,为后期处理含锌烟尘提供了实验指导。主要研究内容及结论如下:(1)合成的低共熔溶剂在室温下均可以呈液态稳定存在,符合后续研究对体系熔点的要求,且温度对两体系的黏度均具有显著影响;且两个体系黏度的对数lnη与温度的倒数1/T呈良好的线性关系;ZnO在两个体系中的溶解度受温度影响较大,ZnO在实验温度范围的溶解度符合含锌烟尘的浸出要求,ZnO溶解在两个体系中的存在形式分别为[ZnOCl·urea]-和[ZnO · HC2O4]-。(2)温度和ZnO浓度对ChCl-urea-ZnO体系的电导率均具有显著影响,电导率随温度的升高而增大,随ZnO浓度的升高电导率先增大。当CznO0.24mo1·L-1时,溶液电导率随ZnO含量的增加而趋于不变,这主要是因为配离子较大的离子半径导致体系的淌度减小,黏度增加。在ChCl-urea体系的电化学窗口内,电化学测试表明,锌的析出电位Ezn(Ⅱ)/Zn和阴极峰值电位均随ZnO浓度和温度的增加均正移,通过峰值电流与扫速平方根的线性关系和阴阳极峰值电位差,可以得出Zn(Ⅱ)在钨电极上的还原过程是一个受扩散控制的准可逆过程,算出343K下Zn(Ⅱ)在溶液中的扩散系数D=1.2×10 7cm2·s-1;锌沉积物的形貌特征与ZnO浓度密切相关,随着ZnO浓度的上升,沉积层颗粒变大,当ZnO浓度为0.32 mol-L-1,沉积层更平整致密。(3)用ChCl-urea低共熔溶剂作为溶剂、氨三乙酸(NTA)作为螯合剂,可以实现含锌烟尘中锌的有效浸出,通过实验结果发现浸出温度和液固比对锌浸出率影响较为显著;通过响应实验设计,通过分析发现对锌浸出率的影响浸出时间浸出温度NTA浓度液固比;使用CC-OA对含锌烟尘进行浸出,发现通过降温与加水稀释可反溶、分离含锌烟尘中的锌铁,CC-OA-ZnO和CC-OA-含锌烟尘溶出体系析出焙烧物,其结构为方形和长条形,微观结构为分层多孔的结构,最小组成颗粒尺寸为纳米级。
[Abstract]:In the current situation of increasing supply of zinc resources, the comprehensive utilization of two zinc resources such as zinc smoke and dust is one of the effective ways to solve this problem. Every year, about 30% of the zinc resources produced in the world are from the regenerated zinc resources, and the recovery of two zinc resources, such as zinc containing smoke and dust, is increasingly urgent. Low eutectic solvent (DES) is a new green solvent, because it is a new kind of green solvent. It has the advantages of low toxicity, biodegradation, low price and simple synthesis. It is used as a solvent for the treatment of zinc dust. It is expected to overcome the problems of complex composition and difficult separation in the leaching system. It has important theoretical guidance and broad application prospects. On the basis of the behavior of pure metal oxide pure substance in the low eutectic system, the pure substances of all kinds of metal oxides were dissolved in the low eutectic solvent of choline, and the complex zinc soot dust was leached. The solubility of ZnO in ChCl-urea and CC-OA DES was measured, and the viscosity of two system temperatures was determined. The effects of ZnO concentration and temperature on the electrical conductivity of ChCl-urea-ZnO were measured by mass spectrometric analysis in the two systems. The electrochemical behavior of zinc in ChCl-urea-ZnO was investigated by cyclic voltammetry, and the effects of particle size and morphology were determined by the change of concentration. The effect of various factors on the zinc leaching rate was investigated. The preliminary study on the treatment of zinc containing smoke and dust by CC-OA DES system provides experimental guidance for the later treatment of zinc containing dust. The main contents and conclusions are as follows: (1) the low eutectic solvent can be stable in liquid state at room temperature. The requirements for the melting point of the system are studied, and the temperature has a significant influence on the viscosity of the two system; and the logarithmic ln of the viscosity of the two systems has a good linear relationship with the reciprocal 1/T of the temperature; the solubility of ZnO in the two systems is greatly influenced by the temperature, and the solubility of the ZnO in the experimental temperature range is in accordance with the leaching requirements of the zinc containing dust and the dissolution of ZnO. In the two systems, the existence of [ZnOCl. Urea]- and [ZnO. HC2O4]-. (2) temperature and ZnO concentration have significant influence on the conductivity of ChCl-urea-ZnO system. Electrical conductivity increases with the increase of temperature. The conductivity increases with the increase of ZnO concentration. When CznO0.24mo1. L-1, the conductivity of the solution tends to increase with the increase of ZnO content. In the electrochemical window of the ChCl-urea system, the electrochemical measurements show that the precipitation potential of Ezn (II) /Zn and the peak potential of the cathode are both shifted positively with the increase of the ZnO concentration and temperature, and the peak current is linearly related to the square root of the sweep speed. The peak potential difference of the Zn (II) is a quasi reversible process under the control of the tungsten electrode. The diffusion coefficient of Zn (II) in the solution is D=1.2 * 10 7cm2. S-1 under the 343K. The morphology of the zinc deposits is closely related to the concentration of ZnO. With the increase of ZnO concentration, the particles of the deposition layer become larger, when ZnO concentration is concentrated. The degree is 0.32 mol-L-1 and the deposition layer is more smooth and compact. (3) the effective leaching of zinc in zinc containing dust can be achieved by using ChCl-urea low eutectic solvent as solvent and ammonia three acetic acid (NTA) as chelating agent. The results show that leaching temperature and liquid solid ratio have a significant influence on the zinc leaching rate. The leaching rate affects the liquid and solid ratio of the leaching temperature NTA concentration, and the leaching of zinc containing smoke and dust by CC-OA is found. It is found that the zinc iron, CC-OA-ZnO and CC-OA- containing zinc smoke and dust are separated from the zinc smoke and dust, and the structure is square and long strip, and the microstructure is a layered porous structure. The smallest size of the particle is nanoscale.

【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X701;TF813

【参考文献】