论文关敏.docx

1、论文关敏分类号： TQ 学校代号：10150UDC： 密级： 学 号：2002094硕士学位论文锌矿硫酸浸出制备超细氧化锌及氧化锌晶须的研究Study on Preparation of Ultra-fine Zinc Oxide and Zinc Oxide Whiskers fromLeaching of Zinc Ores by Sulfuric Acid研究生姓名：关敏指导教师姓名：李彦生 教授学科门类：工学专业名称：环境科学申请学位级别：硕士论文提交日期：2005年5月日论文答辩日期：2005年6月日学位授予单位：大连交通大学摘 要本文以锌矿为原料，采用硫酸湿法浸出工艺，通过离子交换

2、树脂法制备超细氧化锌及氧化锌晶须。优选了浸出工艺条件，确定了净化除杂方案，主要研究了氧化锌合成工艺条件对产物的产率及形貌的影响。以X射线衍射分析（XRD）、扫描电镜（SEM）、能谱仪（EDS）对产物的结构及形貌进行了表征。通过正交试验确定了锌矿酸浸优化工艺条件：硫酸浓度为1.3mol/L，液固比为8：1，浸取温度为60，浸取时间为2.5h。在此条件下锌的浸出率可达98%以上。在净化过程，选用高锰酸钾作氧化剂氧化去除铁、锰的适宜条件为：氧化温度8090，反应时间为50min，反应溶液的pH值为5.25.4。在此条件下铁的去除率高于99%，锰的去除效果也较好。置换法去除铜、镉、镍等重金属的适宜条件

3、为：反应初始温度为90，全部锌粉投加完毕后，将温度控制在50，反应时间为45min。采用离子交换树脂法制备超细氧化锌及氧化锌晶须，可以得到较好的产率、纯度及分散性。由于选用树脂为沉淀剂，通过化学沉淀法制备氧化锌前驱体，从而解决了以往沉淀法阴离子洗脱困难的问题，同时利用离子交换树脂特有的孔径控制产物的形貌。通过控制工艺条件合成出各种形貌的超细氧化锌及氧化锌晶须。以强碱性阴离子交换树脂为沉淀剂时，反应温度为20时，生成的氧化锌为颗粒状，粒径约为100nm；反应温度为40时，得到针状氧化锌晶须，针长接近1m，根部直径约50nm；反应温度为60时，生成的氧化锌为一维纳米棒，棒长约1m，直径约为8010

4、0nm；反应温度为80时，生成氧化锌为长径比较小的短棒，长度为300nm，直径约为100nm。当反应物浓度较低时，产物为针状氧化锌晶须；当反应物浓度较高时，产物为片状氧化锌颗粒。以锌型阳离子交换树脂与NaOH、Na2Zn(OH)4混合液反应制备超细氧化锌，制得的超细氧化锌为均为颗粒状。以离子交换树脂法制备超细氧化锌及氧化锌晶须，具有实验设备简单，操作方便，清洁环保等优点。这为氧化锌的制备开辟了一个新的途径，该研究方法也适用于其它超细无机粉体的制备，为超细微粒及晶须材料合成提供了一种新方法。关键词：锌矿；硫酸浸出；离子交换树脂；超细氧化锌；氧化锌晶须ABSTRACTIn this thesis,

5、 the preparation of ultra-fine zinc oxide and zinc oxide whiskers through wet-process leaching of zinc ores by sulfuric acid and ion-exchange resin method has been investigated. The optimization of the leaching process conditions, the establishment of the purifying scheme and the effects of the synt

6、hetic conditions of zinc oxide on the yield and images of the products were mainly discussed in this paper. The structure and image of the product have been characterized by XRD, SEM and EDS.The optimum acid-leaching process conditions through the orthogonal test were determined as follows: the conc

7、entration of sulfuric acid of 1.3mol/L, the liquid-solid ratio 8:1, the temperature 60, the time 2.5h, and under these conditions, the extraction rate is above 98%.In the purifying process, the optimum conditions of the iron-removal and manganese-removal by the oxidizing method with potassium perman

8、ganate were determined as fellows: oxidizing-temperature 8090, heated-time 50min, pH=5.25.4. Under these conditions, the iron-removal rate was above 99%, and the result of manganese-removal was also better. The optimum conditions of the removal of the heavy metal such as copper, nickel, cadmium and

9、so on by adding zinc powder were determined as fellows: the initial temperature 90, the replacing temperature after all the zinc powder was added 50, the displacement reaction time 45min.Prepared through the ion-exchange resin method, better yield, purity and dispersivity of ultra-fine zinc oxide an

10、d zinc oxide whiskers can be obtained. Because the precursor of zinc oxide was prepared through the chemical precipitation method using ion-exchange resin as precipitating agent, the problem is solved, which is difficult to wash off the anions in the former precipitation method, and the particle dia

11、meter was controlled by the special pores in the ion-exchange resin.Ultra-fine zinc oxide and zinc whiskers with various images have been synthesized through controlling the process conditions. Using the strongly basic anion ion-exchange resin as the precipitating agent, when the reaction temperatur

12、e was 20, the product was granular zinc oxide powder with the particle diameter of 100nm; when the temperature was 40, zinc oxide whiskers were obtained, which the length of the needle was nearly 1m and the diameter of its root is about 50nm; when the temperature was 60, the one-dimensional nanorods

13、 of zinc oxide was acquired, which the length of rod was about 1m, and the diameter was about 80 100nm; when the temperature was 80, zinc oxide was granular short-rod with the length of 300nm and the diameter of 100nm. While the reaction concentration is lower, the product was zinc oxide whisker; wh

14、ile the concentration is higher, the product was platy zinc oxide powder.The ion-exchange resin method by which ultra-fine zinc oxide and zinc oxide whiskers have been prepared has many advantages such as simple equipment, convenient operation, cleanness and protecting environment. This method found

15、 a new channel for the preparation of ultra-fine zinc oxide and zinc oxide whiskers, and it also suits for the preparation of other ultra-fine powders, which provides a new way for the synthetic of the ultra-fine powders and whisker materials.Key Words: zinc ores; leaching by sulfuric acid; ultra-fi

16、ne zinc oxide; zinc oxide whiskers目 录摘 要 I_Toc101027306第一章 绪论 1_Toc1010273081.2 锌矿概述及湿法冶金工艺 2_Toc1010273101.2.2 湿法冶金工艺 2_Toc1010273121.3.1超微粉体及其性质 3_Toc1010273141.3.3 超细氧化锌的应用 6_Toc1010273161.4 超细氧化锌及氧化锌晶须合成方法 10_Toc1010273181.4.2 氧化锌晶须的合成方法 14_Toc1010273201.5 本课题拟研究的内容、方法及分析方法 16_Toc1010273221.5.2 试验分析方法 17_Toc101027324第二章