从氧化锌矿中制备纳米氧化锌新工艺研究

【作者】 许多丰；

【导师】 彭金辉； 何国才；

【作者基本信息】 昆明理工大学 ， 冶金工程， 2005， 硕士

【摘要】 本课题研究了从氧化锌矿中制备纳米氧化锌的新工艺,系统地完成了从氧化锌矿制备纳米氧化锌的全流程试验研究,并进行了微波脱水和煅烧纳米氧化锌的半工业化试验。 本论文的主要研究结果如下: 1、系统地进行了氧化锌矿的浸出试验研究,并讨论了影响氧化锌矿浸出率的各种因素。试验确定了氧化锌矿浸出的最佳条件:液固比5:1、搅拌速度200r/min、粒度-120+160目、酸浸时间4.0h和硫酸浓度25%:在此条件下,锌的浸出率大于92.0%。 2、全面地完成了联合法除铁的试验研究,并分析讨论了影响除铁效果的各种因素,确定了联合法除铁的条件:反应时间1.5小时、反应温度90-92℃、pH值5.2～5.4、过氧化氢达到理论值的1.8倍、过氧化氢的加入时间45min。在此条件下得到的除铁效果较好。同时确定了加锌粉除铜、镉等杂质的条件为:反应温度70-80℃、pH5.2～5.4、反应时间1～1.5h、加入锌粉的量为理论值的2.8倍。 3、引入超声波辐射制备纳米氧化锌前驱体碱式碳酸锌的新技术,研究了超声波辐射制备前驱体的机理,分析并讨论了影响前驱体质量的各种因素,确定了最佳的前驱体制备条件为:硫酸锌浓度1.8～2.0mol/L、碳酸氢铵的浓度1.4～1.6mol/L和超声波辐射23～28min。 4、采用微波加热煅烧前驱体制备纳米氧化锌的新技术,研究了微波辐射加热煅烧前驱体制备纳米氧化锌的机理,分析并讨论了影响纳米氧化锌质量的各种因素,确定了最佳的煅烧时间为8～15min。 5、采用日本岛津产EPMA-1600型电子探针对产物纳米氧化锌的微观结构、粒度和形态进行表征。结果表明:纳米氧化锌的形貌为球形,且分散均匀、粒度均匀,其平均粒径为110nm、比表面积为58.723m~2/g,锌的直收率大于91%。 6、最后,完成了微波加热脱水及煅烧制备纳米氧化锌的半工业化试验。 总之,本课题开发了一种节能、高效、高综合利用、环境友好的新型超细粉体制备技术,该研究方法在科学上具有创新性,在实践上具有重要的应用研究价值,特别是对于我国丰富的锌资源来说,该研究方法对开发附加值高的锌品具有重要的研究意义。更多还原

【Abstract】 A novel technology of preparation for nanometer-sized zinc oxide from zinc-oxide ore has been investigated and developed in this paper. The wholly technological process of preparation for nanometer-sized zinc oxide from zinc-oxide ore has been completed systematically. Pilot experiments of removal water of basic zinc carbonate and cacilnation under microwave irradiation heating have been carried out.Some main results of testing research were as follows:i.Experiments for leaching of zinc oxide ore with sulfuric acid were conducted systematically. The effects on the leaching rate of zinc were analyzed, the optimum conditions determined of leaching of zinc-oxide ore were as follows: liquid-solid ratio 5:1, stirring ratio 200r/min, particle size -120+160 mesh, the time of leaching 4.0h. the concentration of sulfuric acid 25%. The rate of leaching zinc is above 92.0% under above leaching conditions. ii. Research on the iron-removal in zinc sulfate leaching solution with the goethite process and oxidation- hydrolysis process was performed. The effects on the iron-removal rate of zinc sulfate solution was analyzed and discussed in detail. The optimum conditions of iron-removal were obtained as follows: the time of reaction 1.5h. temperature of reaction 90-92 ℃ , pH 5.2-5.4, the quantity of hydrogen superoxide above the quantity of theory counting 1.8 times and additive time of hydrogen superoxide 45min. Under these conditions, the iron-removal rate of zinc sulfate leaching solution reaches better effect. Moreover, the optimum purification conditions of lead-removal, cadmium-removal and cobalt-removal were obtained as follows: reaction temperature 70~80℃, pH 5.2-5.4, reaction time 1 - 1.5h. the quantity of zinc power above the quantity of theory counting 2.8 times.iii.Preparation for precursor of nanometer-sized basic zinc carbonate under the condition of ultrasonic irradiation was introduced, and a mechanism on preparation for precursor of nanometer-sized basic zinc carbonate with ultrasonic irradiation has been investigated emphatically as well as the effects on quality of precursor of basic zinccarbonate have been analyzed and discussed in detail. The optimum conditions obtained of preparation were as follows: the concentration of zinc sulfate solution 1.8~2.0mol/L. the concentration of ammonium bicarbonate solution 1.4-~1.6mol/L, the time of ultrasonic irradiation 23~28min.iv. Preparation for nanometer-sized zinc oxide of calcining precursor of basic zinc carbonate by microwave irradiation was adopted, and a preparation mechanism of ultra-fine nanometer-sized zinc oxide by microwave irradiation has been investigated emphatically as well as the effects on quality of nanometer-sized zinc oxide have been analyzed and discussed in detail. 8-15 min of the calcination time under microwave irradiation was determined.v.The microstructure, granularity and morphology of the product nanometer-sized zinc oxide were characterized by EPMA-1600. The analyzed results of EPMA-1600 showed that the nanometer-sized zinc oxide was spherical structure, distribution of particle was even, granules was uniform, average size was lOOnm and specific surface was 58.723m2/g. The direct recovery rate of zinc of the whole flow was above 91%.vi.Pilot experiments of removal water of basic zinc carbonate and cacilnation by, microwave heating have been performed.In a word, a saving-energy high efficient comprehensive environmental-friendly new-style process of preparation of ultra-fine power has been developed. Therefore, the research of this experiment was innovative scientifically as well as the research of this experiment was of importance in the practical research value of application. In particular, this method of research was of significance in research in devclopping zinc product with high value for our country being rich in resource of zinc.更多还原