含锂铍的萤石矿尾矿中锂铍高效提取新工艺.pdf

学校代码10530学号 201721581741 分 类 号密级公 开 硕硕 士士 学学 位位 论论 文文 含锂铍的萤石矿尾矿中含锂铍的萤石矿尾矿中 锂铍高效提取新锂铍高效提取新工艺工艺 学学 位位 申申 请请 人人武 用 指指导导教教师师张小云 学学院院名名称称化工学院 学学科科专专业业化学工程 研研究究方方向向绿色化学工艺 二零二零年五月 万方数据 Effective extraction of lithium and beryllium from flourite flotation tailing CandidateWu Yong SupervisorZhang Xiaoyun CollegeCollege of Chemical Engineering ProgramChemical Engineering SpecializationGreen Chemical Tecnology DegreeMasert of Engineering UniversityXiangtan University DateMay.2020 万方数据 万方数据 I 摘要 锂和铍是重要的稀有金属元素，被国内外视为战略性资源。随着市场对锂、 铍的需求日益增大，从低品位锂、铍矿石中提取锂铍的研究逐渐被重视。本文以 湖南郴州一种含锂铍的萤石浮选尾矿为研究对象，探索一种“微波焙烧-硫酸浸 出-浸出液净化-萃取提锂-萃余液提铍”新工艺。对浸出、浸出液净化除杂、萃取 和反萃取等工序的影响因素进行了详细的考查，确定了最佳工艺条件，实现了高 效提取锂、铍的目的。 1浸出矿样的浸出阶段，分别采用常规酸浸与微波焙烧酸浸，进行了比 较研究。 常规酸浸的最佳条件为酸矿比为110、 液固比为2.0∶1、 浸出温度95 ℃ 条件下浸出 28 h，锂铍的浸出率较低，分别为 53左右和 43左右。采用微波 焙烧酸浸可以显著提高浸出率，达到理想浸出效果。将矿样预先在工业微波中 750 ℃焙烧 120 min，之后在酸矿比 80、液固比 1.5∶1、浸出温度 90 ℃的条 件下浸出 20 h，锂的浸出率可达 95左右，铍的浸出率可达 85左右。 2浸出液净化除杂浸出液中由于铁铝的含量较高， 通过调节 pH 容易生成 氢氧化铁与氢氧化铝胶体，不仅难于过滤，而且会造成锂铍的吸附损失。本文利 用黄钠铁矾法除铁， 钾明矾法与苯甲酸钠法两步除铝， 达到较好的净化除杂效果， 锂铍几乎无损失。 黄钠铁矾法除铁的最佳条件为 反应pH为2.0、 反应温度95 ℃、 反应时间 4 h、硫酸钠用量为 1.2 倍理论量，此时浸出液中的三价铁离子的去除 率 98以上，锂铍的损失低于 3。钾明矾法预除铝的最佳条件为pH 为 2.5、 反应温度为室温、搅拌反应 3 h、硫酸钾用量为 1.6 倍理论用量条件下有 65左 右的铝以钾明矾的形式沉淀下来。苯甲酸钠法除铝的最佳条件为pH 为 3.5、反 应温度为室温，反应时间 25 min，苯甲酸钠用量为 1.2 倍理论量条件下，铝的去 除率达到 95以上，整个除铝过程锂铍的损失率控制在 3以下。 3锂萃取与反萃萃取主要研究 TBP-煤油-FeCl3体系萃取浸出液中的锂， 并初步探讨了萃取反应机理。最佳的萃取条件为75TBP25磺化煤油，Cl- 浓度 285 g/L，SO42-浓度小于 40 g/L，相比为 21，铁锂比为 2.5，pH1.5，室温 下萃取 15 min，锂的单级萃取率 78左右，通过五级逆流萃取，锂的萃取率可 达 99左右。最佳的反萃条件为盐酸为反萃剂，控制 H浓度为 1.5 mol/L，反 萃相比O/A为 8∶1，室温下反萃 9 min，锂的单级反萃取率 82左右。通过四 级逆流反萃，锂的反萃率可达 97左右。通过化学分析法、斜率法、红外光谱分 析证明萃合物组成为 LiFeCl42TBP。 4铍产品制备分别采用氢氧化钠沉淀法和油酸钠沉淀法，进行铍产品制 备的研究。结果表明，氢氧化钠沉淀法不能得到合格的铍精矿产品，油酸钠沉淀 法可以制备质量较好的产品，BeO 含量 32.5。 关键词关键词锂；铍；浸出；微波；净化除杂；萃取 万方数据 II Abstract Lithium and beryllium are important rare metal elements, which are regarded as strategic energy sources at home and abroad. With the increasing market demand for lithium and beryllium, the research on the extraction of lithium and beryllium from low-grade lithium and beryllium ores has been paid more and more attention. In this paper a flotation tailing of fluorite containing lithium and beryllium in Chenzhou city was studied. The new technique for lithium and beryllium extraction, including the following steps as microwave roasting, sulfuric acid leaching, removal of harmful metals, extraction of lithium, extraction of beryllium, was explored. The related factors in the process such as leaching time and temperature, dosage of sulfuric acid, impurity removal of leaching solution, extraction were examined. The optimum process condition was determined and the purpose of high efficiency extraction of lithium beryllium was realized. 1 In the leaching process of ore samples, the conventional acid leaching and microwave roasting acid leaching were used for comparative study. The best experimental conditions of conventional acid leaching acid ratio was 110, liquid solid ratio was 2∶1, leaching temperature was 95 C, leaching time was 28 h. The results showed that the leaching rate of direct acid leaching was low, the leaching rate of lithium was about 53, and the leaching rate of beryllium was about 42. Microwave roasting acid leaching can significantly improve the leaching rate and achieve the ideal leaching effect. The samples were roasted in industrial microwave for 120 min at 750 ℃, and the best experimental conditions of Microwave roasting acid leaching acid ore ratio was 80, liquid solid ratio was 1.5∶1, leaching temperature was 90 ℃, leaching time was 20 h. The leaching rate of lithium was about 95, and the leaching rate of beryllium was about 85. 2 In the process of purification and impurity removal of leaching solution. Due to the higher content of iron and aluminum, it was easy to generate iron hydroxide and aluminum hydroxide colloid by adjusting the pH, which was not only difficult to filter, but also caused the adsorption loss of lithium and beryllium. In this paper, the of removing iron was jarosite , the of removing aluminum were potassium alum and sodium benzoate . It could achieve the better purification and impurity removal effect with almost no loss of lithium and 万方数据 III beryllium.The best experimental conditions for the removal of iron by jarosite process pH 2.0, reaction temperature 95 ℃, reaction time 4 h, the amount of sodium sulfate was 1.4 times of the theoretical amount. At this condition, the removal rate of ferric ions in the leaching solution was more than 98, and the loss of lithium and beryllium was less than 3. The best conditions of aluminum removal by potassium alum pH 2.5, reaction temperature 25℃, stirring time 3 h, and the amount of potassium sulfate was the 1.6 times of the theoretical amount, it was about 65 of aluminum precipitated in the of potassium alum. The best conditions of aluminum removal by sodium benzoate pH 3.5, reaction temperature 25 ℃, reaction time 25 min, the amount of sodium benzoate was 1.2 times of the theoretical amount, the removal rate of aluminum was more than 95, and the loss rate of lithium and beryllium was less than 3. 3In the process of extraction and reverse extraction, this paper mainly studies the extraction of lithium from leach solution by TBP-kerosene-FeCl3system, and the mechanism of extraction reaction was discussed. The best extraction conditions was extraction concentration was 75,[Cl-] was 285 g/L, [SO42-] was below 40 g/L, VO/VAwas 2∶1, [Fe3]/[Li] was 2.5, pH was 1.5, extraction temperature 25 ℃, extraction time 15 min,the single-stage extraction rate of lithium was about 78, through five-stage countercurrent extraction, the extraction rate of lithium could reach about 99. The best reverse extraction conditions was hydrochloric acid as the reverse extractant, [H] was 1.5 mol/L, VO/VAwas 8∶1, reverse extraction temperature 25℃, reverse extraction time 9 min ， and the single-stage reverse extractant rate of lithium is about 82. After four-stage countercurrent reverse extractant, the reverse extraction rate of lithium could reach about 97. By chemical analysis, slope , and IR spectra could prove the composition of extraction complex was LiFeCl42TBP. 4 In the process of extraction of beryllium from raffinate. Sodium hydroxide precipitation and sodium oleate precipitation were used to prepare beryllium product. The results show that qualified beryllium concentrate product could not be obtained by sodium hydroxide precipitation , and by the sodium oleate precipitation , a satisfactory product could be prepared, with a BeO grade of 32.5. Keywords lithium; beryllium; leaching; microwave; purification; extraction 万方数据 IV 目录 第 1 章引言.................................................................................................................................1 1.1 锂及锂盐的性质和用途.....................................................................................................1 1.1.1 锂的主要性质.........................................................................................................1 1.1.2 几种重要的锂盐及用途.........................................................................................1 1.1.2.1 碳酸锂.................................................................................................................1 1.1.2.2 氟化锂.................................................................................................................2 1.1.2.3 氢氧化锂.............................................................................................................2 1.1.2.4 氯化锂.................................................................................................................2 1.1.2.5 六氟磷酸锂.........................................................................................................3 1.2 锂资源概况.........................................................................................................................3 1.2.1 矿石锂资源.............................................................................................................4 1.2.1.1 锂辉石 LiAl[Si2O6]................................................................................................4 1.2.1.2 锂云母 K{Li2-xAl1xAl[Al2xSi4-xO10]F2}................................................................4 1.2.1.3 透锂长石 Li[AlSi4O10]..........................................................................................5 1.2.1.4 磷锂铝石 Li{Al[PO4]F}.....................................................................................5 1.2.2 盐湖卤水锂资源.....................................................................................................5 1.3 矿石锂资源提锂的研究现状.............................................................................................6 1.3.1 硫酸法.....................................................................................................................6 1.3.2 氯化焙烧法.............................................................................................................8 1.3.3 硫酸盐法.................................................................................................................9 1.3.4 石灰石烧结法.......................................................................................................10 1.3.5 纯碱压煮法...........................................................................................................10 1.4 铍及铍化合物的性质和用途...........................................................................................11 1.4.1 铍的性质...............................................................................................................11 1.4.2 几种重要的铍化合物及用途...............................................................................11 1.4.2.1 硫酸铍...............................................................................................................11 1.4.2.2 铍铜合金...........................................................................................................12 1.4.2.3 铍铝合金...........................................................................................................12 1.5 铍资源概况.......................................................................................................................12 1.5.1 绿柱石 Be3Al2[Si6O18]............................................................................................13 1.5.2 蓝柱石 BeAl[SiO4]OH...........................................................................................13 1.5.3 硅铍石 Be2[SiO4]....................................................................................................14 1.5.4 羟硅铍石 Be4[Si2O7]OH2.....................................................................................14 1.5.5 金绿宝石 BeAl2O4..................................................................................................14 1.6 铍的提取工艺...................................................................................................................14 1.6.1 氟化法.....................................................................................................................14 1.6.2 硫酸法.....................................................................................................................15 1.6.3 硫酸-萃取法........................................................................................................... 16 1.7 选题意及研究内容...........................................................................................................17 1.7.1 选题意义.................................................................................................................17 1.7.2 研究内容.................................................................................................................18 第 2 章 实验材料、试剂与方法.....................................................................................................19 2.1 实验材料分析...................................................................................................................19 万方数据 V 2.1.1 矿样的化学成分分析.............................................................................................19 2.1.2 矿样的 X-射线衍射分析....................................................................................... 20 2.1.3 矿样中萤石、含锂矿物及铍矿物的解离特征....................................................20 2.1.4 影响矿样中锂、铍回收的矿物学因素分析........................................................20 2.2 实验试剂与仪器设备.......................................................................................................21 2.3 分析方法...........................................................................................................................22 2.3.1 锂含量的测定方法.................................................................................................22 2.3.1.1 原理...................................................................................................................22 2.3.1.1 试剂和仪器.......................................................................................................23 2.3.1.2 分析步骤...........................................................................................................23 2.3.1.3 计算方法...........................................................................................................23 2.3.2 铍含量的测定方法.................................................................................................24 2.3.2.1 原理...................................................................................................................24 2.3.2.2 试剂和仪器.......................................................................................................24 2.3.2.3 测定步骤...........................................................................................................24 2.3.2.4 计算方法...........................................................................................................25 2.4 实验工艺流程...................................................................................................................26 第 3 章 微波焙烧-硫酸浸出工艺研究...........................................................................................27 3.1 浸出实验...........................................................................................................................27 3.1.1 微波焙烧温度对浸出率的影响............................................................................ 27 3.1.2 微波焙烧时间对浸出率的影响............................................................................ 28 3.1.3 浸出温度对浸出率的影响.....................................................................................29 3.1.4 浸出时间对浸出率的影响.....................................................................................30 3.1.5 酸矿比对浸出率的影响.........................................................................................31 3.1.6 液固比对浸出率的影响.........................................................................................31 3.1.7 微波焙烧前后矿样的变化.....................................................................................32 3.2 本章小结..............................