从铜冶炼废酸中沉淀铼的试验研究

研究了从铜冶炼废酸中沉淀铼,考查了沉铼剂种类、沉铼剂用量、反应时间、反应温度等因素对铼沉淀的影响,确定了最佳沉铼条件。结果表明:在最佳条件下,富铼渣中铼质量分数为0.68%,沉铼尾液中铼质量浓度低于0.5mg/L。该研究为综合回收铜冶炼废酸中的低浓度铼探索出了一种新方法。     

钼精矿焙烧烟尘中回收铼的研究进展

铼在自然界多以微量元素伴生于钼、铜、铅等矿物中。在钼精矿焙烧过程中,铼主要以氧化物形式挥发进入烟尘,钼精矿焙烧副产物烟灰是回收铼的二次资源原料。评述了钼精矿焙烧烟尘中铼的回收研究进展,重点介绍了烟灰中的铼浸出工艺和含铼溶液中铼的富集方法。     

四苯砷氯盐酸盐重量法测定粗铼化合物中铼

粗铼化合物高铼酸、铼酸钾、铼酸铵是湿法冶金新工艺从铂铼废催化剂中回收铼得到的中间产品,生产要求对铼含量进行准确测定。取含铼约100 mg的高铼酸、铼酸钾、铼酸铵样品于烧杯中,加入水至总体积为50 mL,加热溶液或溶解样品,加入0.2 mL过氧化氢氧化铼为铼、5 mL EDTA溶液掩蔽干扰离子、45 mL氨水、10 mL四苯砷氯盐酸盐溶液沉淀铼,沉淀于烘箱中110 ℃烘除水分1 h,恒重,建立了四苯砷氯盐酸盐重量法测定粗铼化合物高铼酸、铼酸钾和铼酸铵中铼的方法。实验表明:于选定条件下,铼与四苯砷氯盐酸盐沉淀完全,铂等20种共存离子不干扰测定。将方法分别用于3个管理样品、6个实际样品中45.30～84.34 g/L、40.93%～69.42%铼的测定,测定值与参考值基本一致,相对标准偏差(RSD,n=7～11)为0.023%～0.085%,加标回收率为99.8%～100.1%。     

铼技术研究进展

铼是一种难熔金属,铼化合物包含在从斑岩铜矿提取的钼精矿中,铼是焙烧这种钼精矿的副产品。含铼的产品主要包括高铼酸铵、铼粉和高铼酸。铼主要用于高温涡轮发动机和石油重整催化剂。本文评述了世界铼的供给、消费和价格,概述了铼的选矿、冶金、化工、材料等方面的研究进展。     

自热式回转窑钼精矿焙烧系统中铼走向研究

在钼精矿焙烧过程中,伴生的铼易挥发进入到烟气中,采用不同设备进行钼精矿焙烧,对应的铼挥发率也不尽相同。对自热式回转窑钼精矿焙烧系统产生物料中的铼含量进行了检测,包括焙砂、烟尘和废酸等,并对影响铼挥发率的关键性影响因素进行了分析。结果表明,焙烧过程铼平均挥发率为27.3%,布袋尘中铼含量142.4g/t,占总铼量的10.2%,废酸中铼含量7.7mg/L,占总铼量的5.0%。焙砂的氧化程度是影响铼挥发率的关键因素,较低的布袋收尘温度是铼无法大量进入废酸的原因。     

铜冶炼废酸提铼制备高铼酸钾的工艺研究

铜火法冶炼过程中,精矿中的铼大部分挥发进入烟气,烟气经洗涤后铼富集于废酸中。研究了采用"废酸选择性沉铼-富铼渣高压浸出-KCl沉铼"工艺从铜冶炼废酸中提铼制备高铼酸钾,结果表明,优化工艺条件下废酸中铼沉淀率99%以上,产品高铼酸钾纯度99.5%。该工艺过程无废水、废渣排放,可实现与现有废水处理工艺的较好匹配。     

从低浓度溶液提取钼铼工艺研究

阐述了从低浓度溶液中提取钼铼的优化工艺,利用N235萃取剂对铼钼的高选择性,通过从高酸硫酸体系共同萃取铼钼,同时利用铼钼的溶解度差异,对铼钼进行浓缩冷冻结晶分离,得到的粗铼酸铵作为下一步提取4N铼酸铵的主要原材料,从一次铼酸铵结晶母液中富集钼进行酸沉,得到粗钼酸铵脱铼脱杂,再次深度酸化二次萃取进一步选择性萃取富集钼,最终从反萃液中提取钼。该工艺钼的富集比大,对从高酸、高杂质的低浓度含钼含铼溶液中提取分离钼铼具有一定的参考价值。     

铼的回收技术研究进展

综述了从矿石、冶炼废液、废催化剂、废旧合金物料中回收铼的主要工艺技术,并对其关键技术进行了分析。结果表明,从矿石及冶炼废液中回收铼的技术相对较为成熟;高效、清洁的离子交换树脂、萃取剂的开发将会是铼冶金领域的重大革新。从废催化剂、废旧合金等铼的二次资源中回收铼的研究较少,尚需开发适合于规模化、工业化应用的回收技术,这是今后铼回收方面的重要研究课题。     

地质样品中铼的分离和测定方法研究进展

铼元素因其具有特殊的物理化学性质广泛应用于各种工业领域。自然界中铼贵重、稀散,准确测定其含量存在一定的困难。随着大型精密仪器的开发应用,铼样品的前处理、分离、富集以及测定方法都有不同程度的进展。本文综述了近些年来地质样品中铼的分离、测定方法的进展,重点介绍了多接收器电感耦合等离子体质谱法在测试铼中的应用,分析比较了各分析方法的优缺点,并展望了铼的分离、分析方法的发展方向。     

铜钼矿冶炼过程铼的行为研究与工业应用实践

在分析冶炼过程辉钼矿铜矿中伴生铼在物相变化以及分布的基础上,详细介绍了含铼料液、料渣中铼回收的方法及其原理与工艺,并对各回收方法做了简要评述,提出今后铼回收研究的主要方向。     

钼精矿焙烧烟道灰中铼的回收

含铼钼精矿经外加热式回转窑焙烧,伴生的稀贵金属铼进入烟尘,采用自激式高效收尘方式和装置进行回收,对焙烧烟尘中的主要成分进行分析,研究了浸出过程的主要影响因素:浸出剂、酸度、温度、时间、液固比等,把回收的含铼钼粉尘进行溶解,通过添加氧化剂,提高铼的浸出率,将含铼溶液,选择强碱性阴离子交换树脂201×7吸附,再用萃取剂萃取,用7N的氨水反萃,铼进入反萃液中,再用氨水解吸、蒸发、结晶得高铼酸铵。该工艺有效的回收了烟尘中的铼,粉尘回收率可达到98%以上,减少粉尘排放,降低环境污染;烟尘中的铼的浸出率在98%以上;溶液中铼的吸附率在99%以上,附铼树脂上铼的解析率在99%以上;铼酸铵纯度≥99.99%,总回收率≥98%;提高了矿产资源综合利用率及经济效益,为企业增加了新的经济增长点。     

Creep behavior of electron-beam-melted rhenium

Creep deformation in electron-beam-melted polycrystalline rhenium sheet was evaluated at 2200° to 4200°F (1477° to 2588°K) and 4 to 40 ksi (28 to 276 MN per sq m). Comparisons were made with powder metallurgy rhenium under similar conditions. Changes in creep-rupture behavior resulting from electron beam melting of rhenium were greater ductility, higher primary creep rate, and longer rupture life, especially at lower temperatures. The activation energy for creep was 72 kcal per mole for electron-beam-melted rhenium and 64 kcal per mole for powder metallurgy rhenium.     

Sorption of Rhenium from Sulfuric Acid Solutions with Trialkylamine-Containing Impregnates

The sorption of rhenium (VII) from sulfuric acid solutions with impregnates based on macroporous polymeric carriers (copolymers of styrene with divinylbenzene, a weakly acidic cation-exchange resin), which contain technical trialkylamine (TAA), is investigated in batch conditions. Equilibrium and kinetic characteristics of sorption of rhenium with the K-TAA impregnate based on macroporous cationite having the best capacitive characteristics with respect to rhenium are found. The maximal distribution coefficient of rhenium in the K-TAA impregnate is observed during sorption from solutions with pH 2. The sorption isotherm of rhenium is described by the Langmuir equation with constant K = 29 ± 2 mL/g. Integrated kinetic curves of sorption are found by the method of a limited solution volume at various temperatures and effective diffusion coefficients of rhenium in an impregnate, which are equal to 3.8 × 10^–11 (295 K) and 1.3 × 10^–10 (308 K) m²/s, are calculated allowing to the half-transformation time. Processing the kinetic data by linearization according to equations of models of the pseudo-first, pseudo-second, internal diffusion, and Elovich showed that kinetic curves are described with the highest degree of correlation by pseudo-second-order equations with rate constants 0.00056 (295 K) and 0.00059 (308 K) g mg^–1 min^–1. The apparent activation energy of sorption of rhenium of 39 ± 2 kJ/mol is calculated according to the Arrhenius equation. The K-TAA impregnate is approved for the sorption of rhenium from the eluate formed during the desorption of rhenium from the weakly basic anion-exchange resin (Purolite A170) preliminarily saturated with rhenium from a productive leaching solution of processing products of rhenium-containing off-balance copper-sulfide ores with a complex composition.     

从矿石中回收铼的研究进展

综述了铼的性质、分布及在砂岩型铀矿床中的存在形式,介绍了近年来铼的各种分析方法及铼产品制备研究现状,对比了含铼矿样溶解、铼的分离富集与测定方法特点,指出开发低成本、高选择性铼回收工艺是今后应重视的问题。     

树脂富集铼的研究

用201×7强碱性凝胶型离子交换树脂对钼精矿焙烧烟尘浸出液中的铼进行分离富集工艺条件进行研究。通过对溶液中主要金属离子存在状态的分析,选择用201×7树脂对溶液中铼进行离子交换吸附,对该树脂在实验溶液中的有关吸附交换的表观吸附容量、吸附溶液pH等进行了实验研究,另外选择出了对负载树脂上铼进行有效解吸的解吸剂,并进行了动态解吸。实验结果表明:烟尘浸出液经氧化预处理后,用201×7树脂在常温,pH=9.0时可以对浸出液中的铼有效富集,树脂对铼的表观饱和吸附容量为92 mg/g;采用1 mol/L的硝酸溶液可以对负载树脂上的铼进行有效的解吸。     

Influence of cold rolling and strain rate on plastic response of powder metallurgy and chemical vapor deposition rhenium

The plastic response of two kinds of rhenium processed via powder metallurgy (PM) and chemical vapor deposition (CVD) were investigated under uniaxial compression over a range of strain rates. The PM rhenium, further cold rolled to 50 and 80 pct of the original thickness, was also investigated to assess the influence of cold work on the plastic behavior. A strong basal texture was detected in all the preceding materials as a result of processing and cold work. Both CVD and PM rhenium exhibited an increase in yield strength and flow stress with increasing strain rate. In PM rhenium, cold work resulted in an increase in hardness and yield strength and a decrease in the work hardening rate. The deformed microstructures revealed extensive twinning in CVD rhenium. At large strains, inhomogeneous deformation mode in the form of classical cup and cone fracture was noticed.     

电感耦合等离子体原子发射光谱法测定铂铼废催化剂中铼

采用高温灼烧可除去铂铼废催化剂中碳、硫和有机物,但铼挥发损失严重。根据小于300℃时,高氯酸冒烟可除去碳、硫和有机物且铼基本不挥发损失这一原理,建立了采用硝酸-高氯酸消解样品,电感耦合等离子体原子发射光谱法(ICP-AES)测定铂铼废催化剂中铼的方法。确定的实验条件为:样品量为0.15g,加入2.0mL硝酸、1.0mL高氯酸, 260~290℃加热至刚冒烟;再加入2.0mL硝酸,加热至刚冒烟;重复2次至试液清亮;加入10.0mL盐酸,转入100mL容量瓶中,定容摇匀,于分析线Re 221.426nm处,ICP-AES测定铼。铝(Ⅲ)、铂(Ⅳ)、铁(Ⅲ)等共存离子不干扰测定。将实验方法用于1个铂铼废催化剂试验样品、4个铂铼废催化剂实际样品中铼(639.4~5854.8g/t)的测定,试验样品的测定值与推荐值基本一致,结果的相对标准偏差(n=11)为0.17%~0.63%,加标回收率为98.8%~100.3%。     

氢还原重量法测定铼酸铵制备铼粉产品中铼

通过先测定铼粉产品中杂质元素总含量,再用差减法计算铼含量的方法较为繁琐。根据低温氢还原时,除了铼氧化物Re_2O_7、ReO_2,共存金属杂质元素和他们的氧化物均被还原为金属单质而不挥发外,其余非金属元素和他们的氧化物,以及水分、铵盐均会被挥发除去这一基本原理,实验提出了采用低温氢还原样品,以氢还原前后样品质量之比计算铼的含量,最终实现了氢还原重量法测定铼酸铵制备铼粉中铼的方法。确定的实验条件如下:样品量约1.0g;采用分段升温方式进行氢还原,其程序为先室温升温至200℃,恒温30min后升温至400℃,接着恒温30min后升温至600℃,最后再恒温30min;将盛有氢还原后铼粉的石英舟置于干燥器中冷却30min,恒重1次。实验方法适用于铼粉中不挥发杂质元素总质量分数不大于0.010%时铼的测定。将实验方法用于3个铼粉管理样品、4个铼粉实际样品中99.824%~99.995%铼的测定,测定值与参考值基本一致,相对标准偏差(n=9~22)为0.001 2%~0.003 3%,加标回收率99.99%~100.01%。     

含铼钼精矿的焙烧及烟灰中铼的回收工艺研究

于低温450℃和高温550℃焙烧钼精矿各9 h,>95%的铼进入烟灰中;过氧化氢∶水∶烟灰=0.4 L∶4 L∶1 kg、60℃和2 h时,铼浸出率73.15%~74.00%;沉淀液含铼浓度20 g/L、氯化钾∶铼酸钾=2∶1、≤80℃、恒温搅拌1 h、重结晶2次和80℃烘干,粗铼酸钾中铼含量,铼的浸出率、回收率和总回收率分别为45.92%~56.30%、73.15%~74.00%、57.68%~58.25%和69.00%~69.10%。工艺简便、经济,已应用于生产实践中。     

Low-cycle fatigue of nickel superalloy single crystals at elevated temperatures

Single-crystal samples of nickel superalloys containing rhenium or rhenium plus ruthenium are subjected to low-cycle fatigue (LCF) tests under rigid cycle conditions at temperatures of 850 and 1050°C. It is found that the single crystals of the alloy containing rhenium with ruthenium have higher LCF resistance at 10⁴ cycles as compared to the alloy containing only rhenium. At a test temperature of 850°C, volume stress concentrators in the form of pores or their clusters represent fatigue crack nucleation zones; at 1050°C, surface corrosion cracks are the main fracture zones. The fatigue microcrack growth rate is anisotropic: it is higher in the [001] direction and lower in the [011] direction.