含锌粉尘高温反应特性及其协同制备氧化锌及铁酸锌的机理研究

This project intends to use zinc dust produced by iron and steel enterprises as raw materials, using high-temperature carbon reduction to obtain zinc oxide, which is the main component of ZnO and ZnFe2O4. After acid leaching (HCl), ZnO is dissolved in hydrochloric acid solution and converted into ZnCl2. ZnFe2O4 is insoluble in hydrochloric acid. And remain in the acid leaching residue. The ZnCl2 solution reacts with Na2CO3 to obtain zinc carbonate precipitate, and the zinc carbonate is calcined to obtain food grade nano zinc oxide. Zinc ferrite having a purity of 95% or more is obtained. The research focuses are: optimizing the technical conditions of the carbon reduction reaction, set up a collaborative optimization model for the activity of zinc ions and common coexisting ions in the acid leaching solution, reveal the electrochemical mechanism of impurities, find out the factors affecting the structure stability of zinc ferrite by impurities in the acid leaching slag and determine the existence and structural characteristics of the impurities in the zinc ferrite.slag and determine the existence and structural characteristics of the impurities in the zinc ferrite.

本项目拟以钢铁企业生产的含锌粉尘作为原料，利用高温碳还原得到ZnO和ZnFe2O4占主要成分的次氧化锌，经酸浸（HCl）后ZnO溶于盐酸溶液转变成ZnCl2，ZnFe2O4不溶于盐酸保留在酸浸渣中。ZnCl2溶液经除杂后与Na2CO3反应后得到碳酸锌沉淀，碳酸锌经煅烧后得到食用级纳米氧化锌。铁酸锌经除杂后得到纯度为95%以上的铁酸锌。研究重点为：优化碳还原反应的技术条件，建立酸浸溶液中锌离子与常见共存离子的组元活度协同优化模型，揭示电化学除杂过程中杂质的电化学机理；确定酸浸渣中杂质对铁酸锌结构稳定的影响因素，判断杂质在铁酸锌中的存在形式及结构特点，揭示除杂过程中杂质浸出的动力学以及电化学除杂过程中杂质的电化学机理。

本项目针对钢铁企业生产中所得的含锌粉尘的再利用问题，提出了以含锌钢铁粉尘为原料碳热还原制备次氧化锌，同时利用氨浸次氧化锌-酸浸提取铁酸锌的工艺路线。通过系统的研究，分析了高温碳还原含锌粉尘的热力学及动力学过程，分析浸出因素对次氧化锌浸出过程的影响规律，构建浸出动力学模型，研究浸出溶液中锌离子与常见共存离子的分离行为，以及对浸出渣中铁酸锌的再提取，从而提高锌的提取率。含锌粉尘的还原过程其速度主要是由界面化学反应或气体扩散步骤控制；反应过程受内扩散控制，符合收缩核模型，该反应的表观活化能为11.04 kJ·mol-1；浸出液中杂质分离电化学先后顺序为：铜、铅、镉，铅、铜的去除率均达到了99%以上；次氧化锌经过氨浸之后锌的浸出率以及对浸出渣中铁酸锌的再提取的收得率，可以得到次氧化锌中锌的提取率为96.62%。