丁辛醇废铑催化剂焙烧铑回收工艺研究

每千克丁辛醇装置废铑催化剂中含有几百至几千毫克铑,铑价格昂贵,高效回收其中的铑十分必要,目前资料报道的铑回收方法或铑损失大,如萃取法、吸附分离法、焚烧法;或效率低,如液相消解法。针对这些问题,探索了一种焙烧和液相消解相结合的铑回收工艺,并重点对焙烧工艺进行了研究。结果表明,废铑催化剂首先经蒸馏浓缩得到铑渣,然后向铑渣中添加适当倍数的二氧化硅后,采取一定的程序升温焙烧,所得焙烧铑灰再液相消解得到可溶性铑盐,该过程效率高,铑收率大于99%。     

丁辛醇工业装置废铑催化剂回收技术综述

介绍了丁辛醇工业装置废铑催化剂的铑回收技术。对液相消解、燃烧法、共沉淀法以及沉淀法与焚烧法相结合的方法等铑回收工艺的特点进行了介绍与分析,指出了各工艺的优劣。液相消解、燃烧法、共沉淀法在实际回收过程中存在着一定的问题。沉淀与焚烧相结合的方法具有铑回收率高等优点,回收工艺稍显复杂。     

羰基合成废铑液焙烧回收铑制备三氯化铑工艺研究

铑资源稀少、价格昂贵，三氯化铑是制备铑催化剂等铑化合物的基础原料，羰基合成废铑液中铑含量通常在10²～10³ mg/kg，回收其中铑制备三氯化铑具有重要意义。目前废铑液回收铑主要采用焚烧法，此方法存在铑损失大、铑过烧及后续处理困难等问题。为解决这些问题，探索了一种羰基合成废铑液加入木炭粉先有氧后无氧的两段式焙烧回收工艺，该回收工艺操作简单，回收率高。主要流程为：废铑液蒸馏浓缩后得到浓缩铑渣，浓缩铑渣加入m(炭粉)/m(铑渣)=0.6的木炭粉后焙烧，室温升至600℃有氧焙烧，600℃保持3 h后，无氧条件下升温至1 100℃保持1 h后降至室温，得到活性铑灰，活性铑灰经酸浸溶、除杂浓缩得到三氯化铑，铑收率高于99.0%。     

丁辛醇废铑催化剂消解液制备高纯三氯化铑研究

液相消解是回收丁辛醇铑催化剂废液中铑的一种重要方法,通常消解液中除铑离子、氯离子外,还有硫酸根、磷酸根以及铁、镍、钙等贱金属离子。探索了一种丁辛醇废铑催化剂消解液制备高纯三氯化铑的工艺。首先,消解液在一定条件下加入过量氯化钡过滤除去硫酸根,滤液在一定条件下加入过量钼酸铵过滤除去磷酸根,所得滤液调节酸度后经氢型阳离子交换树脂除去Fe、Ni、Ca、Ba等阳离子杂质,蒸发浓缩干燥得到高纯度三氯化铑,杂质元素总量小于0.05%(质量分数),铑回收率大于99%。     

WFE成功处理液相法废铑催化齐

WFE（Wiped Film Evaporator）成功用于处理气相法废铑催化剂,但是,在反应部分进料由气相改进为液相以后,采用WFE处理液相法废铑催化剂时遇到了严重问题,对WFE处理液相法废铑催化剂进行工艺改进,成功解决了处理液相法废铑催化剂的问题。     

羰基合成醋酸的铑回收制三碘化铑的技术进展

论述了铑催化剂回收的现状,介绍从铑体系催化剂合成醋酸装置排出的废料中,回收铑,并将其转化成可供装置使用的三碘化铑的方法。从产品操作复杂程度、产品纯度、收率,对比三种制备三碘化铑工艺的方法,分析各工艺优缺点以及除杂对于铑纯度的影响。并对铑回收在醋酸行业的发展前景进行了展望。     

电感耦合等离子体原子发射光谱法测定化学合成反应液中铑含量

为了更加快速准确的测定化学合成反应液中铑含量，建立微波消解前处理与电感耦合等离子体原子发射光谱的组合监测方法。采用硝酸-硫酸混合酸体系对样品进行微波消解前处理，将有机铑络合物体系转化为无机酸体系。在相同的条件下分别选用铑元素233.477 nm、249.077 nm、343.489 nm三个波长进行样品的测定，铑元素的质量浓度在(0～1.0) mg·L^-1线性良好，线性相关系数r≥0.999 7,方法检出限分别为0.01 mg·L^-1、0.03 mg·L^-1、0.10 mg·L^-1。波长343.489 nm具有更好的灵敏度，更适合铑元素的检测，样品回收率98.0%～102.5%,相对误差为2.8%～3.4%,相对标准偏差为0.2%～1.1%。该方法是在密闭空间进行样品前处理，避免了元素的损失，操作简便，耗时短，精密度高，适用于化学合成反应液中铑含量检测。     

光亮镀铑新工艺

介绍新型镀铑液的配方;初步探讨添加剂的应用以及电镀工艺。工艺配方简单、操作方便、无毒无害、便于维护。镀铑层平整、光亮、酷似白金,可作为仿白金装饰性镀层的理想工艺。     

羰基合成废铑催化剂的回收利用技术

介绍了羰基合成反应产生的废铑催化剂的回收利用技术。     

羰基合成废铑催化剂的回收利用技术

介绍了羰基合成反应产生的废铑催化剂的回收利用技术。     

Process Intensification via Liquid Emulsion Membrane Technique in Extraction and Enrichment of Rhodium (III) from Chloride Media

A liquid emulsion membrane (LEM) system as a tool for process intensification has been studied for rhodium recovery using di-2-ethylhexylphosphoric acid (D2EHPA) as a metal carrier and Monemul 80 as a surfactant, dissolved in liquid paraffin. The various process parameters affecting the LEM process, such as extractant, surfactant, and strip phase concentrations, the speed of agitation, the batch contact time, and the treat ratio have been experimentally investigated to get better insight into the process. Perchloric acid was found to be a better stripping agent in the LEM process. It was observed that the extraction of Rh (III) can be significantly more in the absence of a water repelling agent. The maximum enrichment of Rh (III) in the internal phase obtained was 4.3 times with feed phase pH adjusted to 6, perchloric acid (1.5 mol/dm³), and contact time of 15 min. A mass transfer model to predict the performance of the LEM system was used and found to fit well with the experimental data.     

铑粉密度影响硫酸铑转化率的研究

重点研究了铑粉密度的测定方法以及密度对转化率的影响。由于铑粉的生产工艺不同,虽然铑粉纯度可以达到99．95％的要求,但其密度不同,因此影响铑粉的转化率。采用比重瓶法测定铑粉的密度并对其转化率进行了对比研究,发现密度低的铑粉转化为硫酸铑的转化率高。并研究了镀铑液的配制方法。     

硫化钠沉淀法从含铑溶液中富集铑工艺研究

用硫化钠作沉淀剂,从含铑强酸性水溶液中沉淀富集铑金属。通过实验确定了影响铑沉淀率的诸多因素,如沉淀剂加入量、沉淀温度、沉淀剂硫化钠加料速度、陈化时间及搅拌速度等。结果表明,当沉淀剂硫化钠与铑的物质的量比为10、沉淀温度为100 ℃、硫化钠加入速度为5 mL/min、陈化时间为1 h、搅拌速度为600 r/min时,铑沉淀率达到最大,铑沉淀率最高为99%以上。富集后溶液铑含量低于1 mg/kg,铑富集效果明显。     

Electrocatalytic Reduction of Nitrate on Activated Rhodium Electrode Surfaces

Electrodeposited rhodium films on titanium substrates have been electrochemically activated to produce a high area surface with a specific activity for nitrate electroreduction directly to N₂. The activation process involves oxidation/reduction cycles in an alkaline, KCl electrolyte containing nitrate ions. Surfaces of up to 230 times the geometric area are achieved, together with a surface morphological modification. While the active surface, once formed, is intrinsically unstable during long-term nitrate reduction, its activity can be maintained in situ by an electrochemical cycling procedure. The high area rhodium has the form of a nano-structured sponge, with a surface area of ca. 19 m² g^–1. The morphological modification is evidenced by a change in the hydrogen UPD structure, changes in the surface redox behaviour associated with OH adsorption, and a reduction in the activation energy for nitrate reduction from ca. 47 to 20 kJ mol^–1. The reduction in activation energy, however, is accompanied by a decrease in the pre-exponential factor, and this apparent compensation effect results in similar rate constants on the activated and unactivated surfaces. The enhancement in the catalyst's activity for nitrate reduction results from an increase in the relative activity of nitrate reduction over water reduction. The activated catalyst sustains steady state nitrate reduction at an increased over-potential before the reaction to N₂ decays, and hydrogen evolution and reduction to ammonia take place. The presence of nitrate ions is essential for the formation of the active surface, and specifically adsorbed nitrate ions and reductive intermediates are present at the surface when it is reformed. A mechanism for the elementary surface reaction steps involved in nitrate reduction, and the apparent habit growth of the active surface phase in the nitrate containing solution is discussed.     

含铑催化剂回收再利用技术进展

论述了含铑催化剂回收的现状,指出国内企业与跨国公司的差距。介绍了国内外不同方法从含铑催化剂中回收铑,简要列举了几种常用的回收铑除去贱金属及有机物的方法,比较了制备水合三氯化铑的各种方法及水洗除钠方法,列举了合成ROPAC的不同方法并简要的介绍了一种直接从含铑催化剂制备新催化剂的方法,最后对未来10年内国内铑回收技术发展进行了展望。     

环己酮生产中皂化废碱液的资源化利用及处理

介绍了环己烷液相氧化法生产环己酮过程中皂化废碱液的资源化利用及处理方法,该方法的工艺步骤为:向皂化废碱液中通入足量的二氧化碳气体进行碳酸化反应,固液分离后提取碳酸氢钠,经煅烧后获取碳酸钠;蒸发分离残液,脱出其中50%的水分,脱出的水经生化处理达标排放;在蒸发残液中加入硫酸进行亲电取代反应,固液分离后提取硫酸钠和皂化油,同时处理反应过程中产生的废气;将皂化油在蒸馏釜内进行蒸馏,提取一元有机酸和清洁燃料油。     

Sulfuric acid resistance of cement mortar impregnated with pulp waste liquid

In sulfuric acid for 56 days, the corrosion rate of the mortar treated with pulp waste liquid are 52% in 1% sulfuric acid solution, 55% in 2% solution, 26% in 5% solution, 29% in 10% solution, compared to that of the mortars not treated with liquid. It is assumed that the increase of sulfuric acid resistance is due to the protective coating action by a component of waste pulp liquid and also characteristic gypsum which was formed by reaction between the mortar and sulfuric acid.     

烟碱提取新方法研究

调节低、次烟叶的含水率,使w(H2O)=12%～13%。在密闭容器中,控制温度540～550℃,使低、次烟叶碳化脱羧。产生的气体和液体用w(H2SO4)=70%的硫酸吸收,可得到w(C10H14N2)=4%左右的硫酸烟碱稀溶液。负压下,将该溶液浓缩至w(C10H14N2)≥20%、用80～100℃的饱和Na2CO3水溶液碱化至无气泡冒出为止,再加入稍过量的Na2SO4·10H2O,使水相形成饱和溶液,密闭、静置24h,即可把烟碱从水相中盐析出来。分出烟碱,在氮气保护下,负压进行两次蒸馏,收集140～148℃/4 0×103Pa馏分,可得w(C10H14N2)=98%以上的烟碱产品,产率在83%以上。提取过程中基本没有三废排放。