【作者】 李华昌；

【导师】 周春山； 符斌；

【作者基本信息】 中南大学 ， 应用化学， 2002， 博士

【摘要】 贵金属由于具有许多独特的物理、化学性能，在国民经济中有着十分重要的作用。正是由于贵金属物理、化学性质的特殊性，从而导致了其提取工艺的复杂性。目前在已工业化的贵金属提取工艺中，除部分借助溶剂萃取法外，相当多的企业仍采用沉淀等经典的方法，不仅流程冗长、收率低、成本高，且环境污染较严重，劳动强度大。因此，开展贵金属元素高效经济、短流程、环境友好的分离提取新技术及有关理论的研究势在必行。本论文以建立铂、钯、铱、铑、金高效分离流程为目标，以铂钯精矿、铜阳极泥、铅阳极泥、粗铜、粗铅、贵金属二次合金等几类具有代表性的贵金属资源为对象，以离子交换色谱为手段，从理论和应用上为解决贵金属分离中普遍而长期存在的上述技术难题探索一条新的途径。 针对上述目标，从五个方面开展了研究：离子交换树脂静态分离、离子交换色谱动态分离、分离应用、反应动力学与热力学、吸附与洗脱机理。 静态分离研究是离子交换色谱动态分离的基础，为此，对影响离子交换反应的主要因素进行了试验，选定D301R阴离子交换树脂作为分离用的主要树脂，着力解决了制约离子交换树脂实际应用的吸附与洗脱选择性难题。 实现高效离子交换色谱动态分离是本论文的核心，为此，在静态分离试验的基础上，对影响离子交换色谱动态分离的主要因素进行研究，通过固定相、流动相的选择和分段淋洗，解决了离子交换色谱选择性淋洗和再生的技术难题，建立了高效离子交换色谱动态分离流程，用单级D301R阴离子交换色谱可实现Pt、Pd、Ir、Au与贱金属的组分离以及贵金属之间的相互分离，配合001×7阳离子交换色谱可实现Rh的分离，达到了高效分离的目的，通过模拟样品的分离，考察了流程的可行性。 用拟定的动态分离流程来解决贵金属分离的实际问题是本论文研究的最终目标，决定着本研究是否具有实践意义。为此，选择了铂钯精矿、铜阳极泥、铅阳极泥、粗铜、粗铅、贵金属二次合金等几类具有代表性的贵金属样品进行分离试验，贵金属回收率高，Pt、Pd、Ir、Rh、Au的回收率范围分别为93.72～100.16％、91.25～101.48％、93.15～99.33％、97.00～98.99％、92.94～101.55％，回收率均在90％以上。分离度好(R_s为1.50～2.17)，贵、贱金属之间及贵金属之间均达到基线分离。流程中南大学博士学位论文贵金属高效离子交换色谱分离理论及应用研究 适用范围广，即便贵金属以及贱金属在较宽含量范围变化，均取得了良好的分离效果。 扩大试验Pt、Pd、Ir、Au富集液纯度分别为:97.04%、98.28%、97.14%、98.67 %，产品纯度高。 动力学与热力学研究的目的是进一步在理论上了解影响离子交换反应进程和反 应程度的主要因素，以利于在实践中对这些因素进行控制。动力学研究考察了温度对 反应速率的影响，计算了反应活化能;反应热力学主要研究了离子交换反应分配系数 及生成焙变。研究得出:升高温度，对提高Au、Pt、Pd、Ir反应速率均有利;升高温 度，Au、Pt与树脂的交换反应更为彻底，而对Pd、Ir则不利;就反应热力学而言， 室温条件下进行试验是对Au、Pt、Pd、Ir的吸附均有利的折中条件。 反应机理研究运用了现代先进的扫描电镜与能谱、红外与拉曼光谱技术从微观上 研究了离子交换吸附、洗脱进程及机理，从而达到对离子交换吸附、洗脱历程以及色 谱行为的深层次了解，为宏观控制提供了理论指导。通过研究确证了树脂吸附的是贵金属配阴离子并确定了贵金属的形态，树脂对Aucl;一和对Ptcl6，一、Pdcl;2一、Ircl沪一厅尺可能是两种不同的作用机理;洗脱中NI卜SCN对Ir的洗脱是SC可取代树脂上吸附的lr与C1一的配阴离子，Al，的洗脱是M工BK与Au(llD的氯配阴离子形成离子缔合物，Pt、Pd的洗脱是洗脱剂将贵金属配合。 建立了高效离子交换色谱分离铂、把、铱、锗、金的新流程为: 阴离子交换色谱分离以D301R树脂为固定相，在盐酸介质中上柱，用稀盐酸、水、EDTA洗脱Rh与贱金属，吸附的Ir、Au、Pd、Pt分别用1m。l/LN圣右scN·十20酬L抗坏血酸、甲基异丁酮、lmol/L聪el+2001/L Nr么呼几。、0.5001/L Hel+509/L硫脉+50%甲醇选择性淋洗，实现Ir、Au、Pd、Pt与贱金属的分离以及贵金属之间的相互分离。色谱柱用3mol/L盐酸再生。 经阴离子交换色谱柱后的进样流出液与用盐酸、水洗脱的淋洗液合并注入。01 x7阳离子交换色谱柱，便可实现侧l与贱金属的分离，吸附有贱金属的阳离子交换色谱柱用6mol/L盐酸淋洗，使色谱柱再生。 该流程操作简便、回收率高、分离度好、所需时间短、成本低、适用范围广，为贵金属高效分离探索了一条新途径。在理论研究方而，谱结合起来，系统地从微观_七研究了离子交换吸附、将扫描电镜与能谱、红外与拉曼光洗脱进程与机理。采用了宏观研究与微观研究相结合、动力学研究与热力学研究相结合、在研究方法上，静态研究与动态中南大学博士学位论文摘要研究相结合、理论研究与应用研究相结合的多层面、多角度综合研究方法。经科技查新证实，类似的研究和技术国内外尚未见文献报道。更多还原

【Abstract】 Precious metals are very important in national economy due to their special physical and chemical performance. However, it is their particular physical and chemical properties that result in the complexity of their extraction process. As a result, except for solvent extraction being limitedly adopted in industrialized process, many enterprises are using conventional precipitation technique, which is tedious, with low recovery, high costs, and heavy pollution. It is necessary to carry out theoretical and applied research on high efficiency, economical short flow and friendly environment technique for the extraction of precious metals using ion exchange chromatography.The dissertation is aimed at establishing a new process for highly efficient separation of platinum, palladium, iridium, rhodium and gold, in which some representative samples such as platinum and palladium concentrates, copper and lead anode muds, crude copper and lead and alloys of precious metals were tested. In order to achieve the above goal, the dissertation focuses on the following studies, static separation by ion exchange resins, dynamic separation by high performance ion exchange chromatography, practical samples separation, reaction kinetics and thermodynamics, adsorption and elution mechanism.Static separation by ion exchange resins, in which D301R anion exchanger was employed as the principal resin for separation, was the basis of dynamic separation by ion exchange chromatography, so the main factors that influence ion exchange reaction were investigated. Great efforts have been made to solve the problem of selectivity for adsorption and elution, which restricted the application.Achieving dynamic separation by high performance ion exchange chromatography is the core of the dissertation. Based on the results of static experiments, the factors influencing dynamic separation were studied. The problems of selectively elution and regeneration in ion exchange chromatography were solved by the selection of stationary and mobile phase, and the stage elution technique. The flow chart for dynamic separation by high performance ion exchange chromatography is established, in which D301R anion exchanger chromatographic column is used to carry out the separation of precious metals from base metals, and the separation among precious metals. Combined with a 001 X 7cation exchanger chromatographic column, rhodium could be separated. The flow chart was tested by simulated samples, showing that it is practical and highly efficient.To solve the practical separation problems is the final object of the dissertation, so several kinds of precious metal samples such as platinum and palladium concentrates, copper and lead anode muds, crude copper and lead and alloys of precious metals were tested by the proposed method. Satisfactory results were obtained with high recovery of precious metals, good resolution, and wide application scope. The recoveries for platinum, palladium, iridium, rhodium and gold are in the range of 93.72~100.16% 91.25~101.48 %, 93.15~99.33%, 97.00~98.99%, 92.94~101.55% respectively. The separation between precious and base metals, the separation among precious metals are so complete that baseline resolution effect has been achieved, with the resolutions being in the range of 1.50~2.17. The purities, of the concentrated precious metals solution in the scaled-up experiments are 97.04% for platinum, 98.28% for palladium, 97.14% for iridium, and 98.67% for gold.The goal of kinetics and thermodynamics research is to get more information about the main factors, which influencing the reaction course and degree, and benefiting the control in practice. My kinetics studies focused on the relationships between reaction rate and temperature, the calculation of activation energy and thermodynamics studies focused on the distribution coefficients and reaction enthalpy. The higher the temperature, the faster the reaction. The ’exchange reaction would be carried out completely for gold and platinum with the increase of temperature, while th更多还原