河南城建学院环境工程毕业论文

分类号学校代码 10487本科毕业论文铅膏浸出过程中的杂质迁移转化规律及湿法工艺设计姓 名： 刘 玲 静 专 业： 环 境 工 程 指 导 教 师： 杨 家 宽 教授 院（系、所）：环境科学与工程学院2012 年 6 月A Thesis Submitted in Fully Fulfillment of the Requirementsfor the Degree of Bachelor of EngineeringThe Study of Transformation of Impurities in the Leaching of Lead Pastes and the Design of Hydrometallurgical ProcessCandidate : Liu LingjingMajor : Environmental EngineeringSupervisor : Prof. Yang JiakuanHuazhong University of Science & TechnologyWuhan 430074, P.R. ChinaJune, 2012I摘 要铅膏的回收利用是废铅酸蓄电池回收的重点和难点。传统火法回收铅膏工艺会产生大量 SO2 及铅尘污染，且能耗很高。针对以上问题，本课题组开发了以乙酸- 柠檬酸钠浸出铅膏得到柠檬酸铅前驱体，再低温焙烧制备超细铅粉的低温清洁回收新工艺。本论文围绕新工艺中杂质去除重点开展以下内容：1、废铅膏湿法过程杂质在固液两相迁移转化实验原料选取经烘干、破碎筛分过 120 目筛的废铅膏。铅膏中的主要杂质为：Sb（0.18 wt%）和 Fe（0.036.wt%） 。湿法浸出过程包括硫酸预处理、湿法浸出与结晶两个步骤。预处理采用 3mol/L 硫酸，反应 4h，可以去除原料铅膏中约 54.8 wt%的 Fe 和 16.9 wt%的 Sb。浸出与结晶环节将铅膏转化为柠檬酸铅同时结晶长大，可以去除酸洗后铅膏中 74 wt%的 Fe 和接近 100 wt%的 Sb。 。结晶环节中结晶温度、结晶时间及是否投加晶种对晶体生长和杂质分离效果有重要影响。在 55左右温度范围内，晶体大小随结晶时间和温度升高不断增长，温度过高会抑制晶体生长。2、滤液循环过程杂质迁移转化及循环滤液萃取法除杂循环次数对铅膏转化率有重要影响。前三次滤液循环过程铅膏中 PbSO4 转化率在 97%以上，第四次循环后迅速下降至 70%左右。前三次循环滤饼中Fe、Sb 含量基本保持不变，第四次循环分别比第三次增加了 55%和 40%。随着循环使用次数的增加，进入滤液和洗涤液的 Fe 不断减少，Sb 的量基本一致。利用二（2- 乙基己基）磷酸（P204）对第四次循环后所得滤液中的 Fe 和 Sb 进行萃取和反萃取，Fe 的萃取率高达 87.0%，Sb 的萃取率为 49.0%。3、湿法过程工艺设计根据实验结果，对工艺涉及的酸洗、浸出与结晶、过滤洗涤和滤液循环四个单元进行 200 kg/批次中试设计。在物料衡算的基础上，对湿法过程中主要设备进行中试工艺设计计算和设备选型，并完成初步工艺设备图纸的设计。本论文的研究成果为乙酸-柠檬酸钠湿法浸出体系提供了除杂依据，对该工艺中试设计研究具有一定参考价值。关键词：铅膏 浸出 杂质 迁移转化 中试设计IIAbstractThe recycling of lead paste is the difficult part in the recycling of spent lead acid batteries. Since the emissions of SO2 and lead volatile particulates emission as secondary pollutants, as well as high energy-consumption co-exist in traditional pyrometallurgical process, a clean lead recovery process has been developed in our group. In this process, lead citrate is prepared from lead paste leaching with acetic acid and sodium citrate solution. And then ultrafine lead oxide is prepared via a low temperature calcination process by using lead citrate as a precursor. In this dissertation, the main researches include the following contents:1. Transformation of impurities in the hydrometallurgical process of treating lead pasteIn this experiment, spent lead battery pastes, after pretreated by drying, crushing and further separation, were used as the staring materials, which particle size was less than 120 m. The main impurities of lead pastes was Sb (0.18 wt%) and Fe (0.036 wt%). Acid pickling and leaching and recrystallization was included in the hydrometallurgy. 54.9 wt% of Fe and 16.9 wt% of Sb were removed in the acid pickling by leaching for 4 h in the 3 mol L-1 of sulfuric acid. Nearly 74 wt% of Fe and 100 wt% of Sb were removed during the leaching and recrystallization process, in which lead compounds were converted into lead citrate and crystals growed at the same time. 2. Transformation of impurities during the filtrate recirculation and removal of impurities from filtrate by extractionThe number of filtrate cycle has a significance impact on conversion rate of lead paste. The conversion rate had maintained above 97% during the first three cycles, but it decreased sharply to nearly 70% in the forth cycle. In the first three cycles, the content of Fe and Sb in the filter cake were retained constant, while they were increased to 55% and 40% respectively in the forth cycle. Meanwhile, the contents of IIIFe converted into filtrate and washing liquid had been decreased constantly every cycle, while Sb kept almost invariant. The extraction and stripping of Fe and Sb from the forth cycle filtrate by P204- sulfonated oil extraction system showed that, the extraction rate of Fe and Sb were 87.0% and 49.0%, separately.3. Design of hydrometallurgical processAccording to experimental results, four units for the pilot scale design of hydrometallurgical process were mainly involved in this paper: acid pickling, leaching and recrystallization, filtering and washing, and filtrate recycling. Based on the material balance calculation, the design focused on design calculation and type selection of major equipment for hydrometallurgical process and preliminary design of equipment drawings.The research results of this study has provided evidence for removing impurities in the leaching of lead paste in acetic acid-sodium citrate system, and it also supported for the pilot design of hydrometallurgical process.Key words: Lead paste Leaching Impurities Transformation Pilot design1目 录摘 要 .IAbstract.II1 绪论1.1 课题来源 .11.2 课题研究目的及意义 .11.3 国内外研究现状 .21.4 本论文研究内容 .42 实验原料与方法2.1 实验原料及主要药剂 .62.2 主要分析测试方法 .102.3 本章小结 .113 废铅膏湿法浸出过程杂质在固液两相迁移转化规律3.1 酸洗过程杂质去除研究 .123.2 湿法浸出过程杂质迁移转化 .133.3 柠檬酸铅结晶过程对杂质与柠檬酸铅分离的影响 .163.4 湿法过程杂质迁移转化 .243.5 本章小结 .264 滤液循环使用过程杂质迁移转化及萃取法除杂研究4.1 滤液循环使用过程杂质迁移转化 .2724.2 萃取法去除模拟循环滤液中的杂质 .294.3 萃取法去除实际循环滤液中的杂质 .304.4 本章小结 .315 废铅膏湿法回收新工艺物料衡算5.1 废铅膏湿法回收工艺流程和参数确定 .325.2 物料衡算 .365.3 本章小结 .406 新工艺设计计算和设备选型6.1 预处理设备计算与选型 .426.2 废铅膏湿法浸出设备计算与选型 .456.3 滤液循环系统的设计 .536.4 焙烧系统设备计算及选型 .546.5 辅助装置 .596.6 本章小结 .617 结论和建议7.1 结论 .637.2 建议 .64参考文献 .65附录：设计图纸清单 .68摘 要 .IAbstract.II31 课题来源1.2 课题研究目的及意义 .11.3 国内外研究现状 .21.4 本论文研究内容 .42 实验原料与方法2.1 实验原料及主要药剂 .62.2 主要分析测试方法 .102.3 本章小结 .113 废铅膏湿法浸出过程杂质在固液两相迁移转化规律3.1 酸洗过程杂质去除研究 .123.2 湿法浸出过程杂质迁移转化 .133.3 柠檬酸铅结晶过程对杂质与柠檬酸铅分离的影响 .163.4 湿法过程杂质迁移转化 .243.3 本章小结 .264 滤液循环使用过程杂质迁移转化及萃取法除杂研究4.1 滤液循环使用过程杂质迁移转化 .274.2 萃取法去除模拟循环滤液中的杂质 .294.3 萃取法去除实际循环滤液中的杂质 .304.4 本章小结 .315 废铅膏湿法回收新工艺物料衡算5.1 废铅膏湿法回收工艺流程和参数确定 .3245.2 物料衡算 .355.3 本章小结 .386 新工艺设计计算和设备选型6.1 预处理设备计算与选型 .416.2 废铅膏湿法浸出设备计算与选型 .446.3 滤液循环系统的设计 .526.4 辅助装置 .526.5 本章小结 .547 结论和建议7.1 结论 .567.2 建议 .57参考文献 .58附录：设计图纸清单 .6111 课题来源绪论1.1 课题来源国家自然科学基金资助项目“废铅酸蓄电池铅膏柠檬酸浸出转化规律及直接制备超细 PbO 的基础研究”，项目编号：50804017 。教育部新世纪人才支持计划：固废资源化与材