从铀钼矿石碱浸液中分离铀钼试验研究

研究了从某铀钼矿石碱浸液中分离回收钼和铀,确定了碱浸液酸化—溶剂萃取钼—沉淀钼、铀工艺流程,考察了萃原液酸度、酸洗相比等参数对铀、钼分离的影响,绘制了钼萃取平衡曲线。试验结果表明:碱浸液酸化至pH=2.5,用三脂肪胺萃取钼、硫酸洗涤负载有机相,可以实现钼与铀的分离,反萃取液可直接沉淀钼,钼萃余水相可直接沉淀铀产品。     

从铀钼合金燃料中选择性分离铀、钼试验研究

研究了以硝酸溶液为沉淀剂,从U-10%Mo合金中选择性沉淀分离铀和钼,考察了硝酸浓度、硝酸过量系数对铀、钼分离的影响。试验结果表明:在n(HNO3)/n(Mo)一定条件下,硝酸浓度对铀溶解率影响较小;随n(HNO3)/n(Mo)增大,铀溶解率增大至95.2%,钼沉淀率先降低后升高,铀钼分离系数(β)先减小后增大;[HNO3]≥12 mol/L时,n(HNO3)/n(Mo)≥94有利于铀钼分离,且工艺上容易实现。     

铀钼共存体系中低浓度铀和钼的测定

研究了铀钼共存体系中低含量铀和钼的测定方法。体系中铀含量高而钼含量低时，可采用CL-TBP萃淋树脂先分离铀。然后以硫氰酸盐光度法测定钼；体系中钼含量高而铀含量低时，可在1mol／L HNO3介质中沉淀分离铀，再用萃淋树脂富集铀，用水淋洗后，再以溴代光度法测定铀。结果表明，铀、钼回收率均在95％～105％之间，方法的相对标准偏差小于5％。     

从铀钼共生矿中回收钼和铼

本文叙述了从碳酸盐铀石高压碱法浸出溶液中,综合回收钼、铼的方法。高压浸出矿浆经液固分离后,清液进行硫酸化,采用分步萃取法,从溶液中依次萃取分离铀、钼、铼,达到三种有用金属的分离和纯化。     

铀、钼分离工艺中铀和钼的测定(Ⅰ).铀的测定

介绍了铀、钼分离工艺中钼铀矿、浸出渣、淋浸液、离子交换树脂和产品中铀的快速测定方法。矿石和浸出渣样品用混合铵盐熔解 ,树脂样品经高温灼烧灰化 ,以磷酸溶解。在 60 %磷酸介质中 ,用硫酸亚铁铵将铀( )还原成铀 ( )。在 40 %磷酸和铵盐存在下 ,用亚硝酸钠氧化过量的亚铁 ,并立即用尿素破坏过剩的亚硝酸钠 ,以消除钼的干扰。用二苯胺磺酸钠和苯基邻氨基苯甲酸作指示剂 ,以钒酸铵容量法快速测定铀。对钼含量较高的样品 ,在测定铀之前 ,可在硝酸介质中将钼以钼酸形式析出 ,使铀与大量钼分离 ,然后 ,在 3 0 %～ 40 %磷酸溶液中用亚铁还原 -溴水氧化 -钒酸铵容量法快速测定铀。铀产品 (化学浓缩物 )中的铀 ,可借助适量的盐酸溶解试样 ,然后直接用钒酸铵容量法滴定。本法操作简单、快速 ,适用于从铀、钼共生矿中提取铀的工艺过程中各种样品体系中铀的测定。大量实际样品的例行分析结果表明 ,所得结果准确可靠 ,方法精密度优于± 1 0 % ,标准加入回收率为 98%～ 1 0 5 %     

ICP-AES法测定载铀树脂中的微量钼和锆

建立了电感耦合等离子体发射光谱(ICP-AES)法同时测定载铀树脂中的微量钼和锆,研究了树脂样品灰化条件、溶样方法等对测定结果的影响。采用CL-TBP萃淋树脂色层分离技术分离铀,然后以ICP-AES法测定钼和锆,6次测定结果的相对标准偏差均小于3%,钼、锆加标回收率分别为94.4%~104.8%、96.0%~101.5%,测定结果的精密度和准确度均较好。     

印度贾杜古达铀矿副产钼

贾杜古达铀矿石中含有少量的硫化铜、镍、钼,还含有一些磁铁矿。这些矿物除镍之外都在副产品厂回收。在回收铀之前,从磨碎粉矿中浮选出硫化铜及硫化钼。回收铀之后的尾矿送磁铁回收厂浮选得到混合精矿再把钼与铜分离。钼精矿运出制成氧化物及钼铁合金,然后销售给坎普尔的工厂制造枪炮筒。副产回收钼、铜、磁铁的年收入对开采、选冶低品位铀矿石帮助很大。     

从高钙质煤灰渣中综合回收钒、钼、铀的工艺探索

某地煤灰渣中含有多种金属元素,其中V_2O_5～1.3％,Mo～0.10％,U～0.020％。由于该原料中含CaO在10％以上,使对钒、钼、铀的综合回收在技术上造成了许多困难。1978～1979年,我们进行了实验室的工艺流程探索试验,所设计的技术方案,较理想地实现了钒、钼、铀三者的分离,获得了较好的试验指标。     

铀钼共生矿加压碱法浸出试验

针对某低品位铀钼伴生矿复杂矿性的特点,开展了加压碱法浸出试验,分析了难处理铀钼伴生矿加压碱法浸出的主要反应原理及反应机理,查明了浸出的主要难点是硫化物包裹体中钼的有效浸出以及胶硫钼矿的有效破解溶解和氧化。试验结果表明,在矿石粒度-0.147 mm、总压0.7 MPa(氧分压0.5 MPa)、碱总用量16%(碳酸氢钠4%、碳酸钠12%)、反应温度110℃、浸出液固比1.5、反应时间3 h的条件下,尾渣中铀和钼的品位分别降至0.009%和0.125%以下,浸出率分别达到89.77%、84.62%以上。解决了包裹型难处理硫化钼的高效分解的难题,实现了铀、钼金属的高效回收,为该类型矿石处理提供了技术路线选择的依据。     

铀、钼分离工艺中铀和钼的测定(Ⅱ).钼的测定

介绍了铀、钼提取工艺各种样品中钼的测定方法及其应用，铀钼矿及其浸出渣样品，首先用混酸分解，然后在硝酸介质中，用二氯化锡将钼（Ⅵ）还原到钼（Ⅴ）与硫氰酸盐反应形成橙红色配合物，可用分光光度法测定；淋浸液，吸附-淋洗液和反萃取液中的钼可直接采用光度法测定，离子交换树脂中的钼，需在加热条件下，用氢氧化钠溶液浸取，然后以快速光度法测定；铀产品（化学浓缩物）和高含量铀样品中的微量钼，在硫酸介质中，钼（Ⅴ）与硫氰酸盐反应形成可溶性配合物，可用异戊醇萃取分离，光度法测定；对钼产品（多钼酸铵）中高含量的钼，则采用氢氧化钠溶液溶解样品，以EDTA容量法测定，在pH2～5的硫酸溶液中，用盐酸羟胺将钼（Ⅵ）还原到钼（Ⅴ）与EDTA反应形成（1：1）配合物，过量的EDTA用铋盐反滴定，简述了各种方法的基本原理，最佳测定条件，应用范围和操作步骤。经大量样品的例行分析证实，所得结果均准确可靠，而且操作简便快速，各方法的精密度和准确度较好，精密度优于5%，标准加入回收率为98.5%～104%。     

Molybdenum Metallurgy Review: Hydrometallurgical Routes to Recovery of Molybdenum from Ores and Mineral Raw Materials

With the vigorously growing demand of the steel industry, oil and gas industry, corrosion resistance alloys, cast iron, and catalyst industries, high-grade molybdenum ores are being exhausted gradually in the world. Thus, much attention have been drawn to the recovery of molybdenum from low-grade molybdenum ores in recent years. With the increasingly stringent environmental requirements, the shortcomings due to SO₂ emission in the roasting process of traditional technology becomes obvious. This review outlines metallurgical processes for molybdenum production from various resources, particularly focusing on recent developments in direct hydrometallurgical and recovery processes to identify potential sources of molybdenum products and by-products such as uranium which can be economically produced.

Several methods have been extensively reviewed for molybdenum separation and purification from solution which are potentially applicable to leach solutions of molybdenum ores and raw materials. The main methods include solvent extraction, ion exchange, membrane-based separation, and precipitation. Solvent extraction is highly selective for recovery of molybdenum and the most promising method recommended for future research and development. Membrane-based separation is the next preferred method for selective extraction of molybdenum, purification of molybdenum solutions, or co-recovery of other valuable metals. Ion exchange offers useful means for purification and/or co-recovery of other base metal impurities, although the scale of application of ion exchange in the industry is limited.     

Leaching of molybdenum and arsenic from uranium ore and mill tailings

A sequential, selective extraction procedure was used to assess the effects of sulfuric acid milling on the geochemical associations of molybdenum and arsenic in a uranium ore blend, and the tailings derived therefrom. The milling process removed about 21% of the molybdenum and 53% of the arsenic initially present in the ore. While about one-half of the molybdenum in the ore was water soluble, only about 14% existed in this form in the tailings. The major portion of the extractable molybdenum in the tailings appears to be associated with hydrous oxides of iron, and with alkaline earth sulfate precipitates. In contrast with the pattern seen for molybdenum, the partitioning of arsenic into the various extractable fractions differs little between the ore and the tailings.     

铀钼共生矿的细菌浸出试验研究

介绍了用T．f菌浸出铀钼共生矿石的试验结果。经过耐钼驯化培养的菌种对铀钼共生矿石浸出210d，铀的浸出率达98％以上，钼的浸出率达41％。浸出过程中，细菌氧化矿石中的硫化矿物产生的酸，能满足浸出过程中的酸耗。     

Bacterial catalytic processes for transformation of metals

Microorganisms actively participate in the transformation of metals and metalloids by various processes including adsorption, absorption, alkylation, oxidation and reduction reactions. Bacteria of the genera Thiobacillus and Sulfolobus have a chemolithotrophic mode of metabolism and catalyze various metal transformations. These bacteria are primarily involved in oxidation-reduction reactions of metals. Metal sulfides can be either directly oxidized by the microbes or oxidized by ferric iron, an end-product of microbial metabolism. These processes result in solubilization of iron, copper, molybdenum, uranium, and many other metals as well. Bacteria capable of these reactions are found, and they function in a variety of environments. Conditions which favor their growth are acidic pH (1.5 to 3.5) and temperatures which can be as high as 75 degrees C for Sulfolobus. The microbes have potential for mobilization of pollutants, or toxic elements, during resource extraction processes. In the absence of oxygen, iron, molybdenum and chromium may be reduced by microbes.     

High-temperature interaction of uranium mononitride with refractory metals. Interaction with rhenium

The interaction of uranium mononitride UN with a refractory metal (rhenium) is studied in the temperature range 1773–2273 K. The coefficients of uranium diffusion from UN into polycrystalline and single-crystal rhenium and their temperature dependences are determined. The diffusion mobility of uranium in rhenium is shown to be lower than that in molybdenum and to be higher than in tungsten.     

Solvent Extraction in Production and Processing of Uranium and Thorium

Abstract

Solvent extraction plays a vital role in the production and processing of uranium and thorium for use as fuels in the front-end of the nuclear fuel cycle. The development of solvent extraction technology in the nuclear field in the last five decades has contributed to advances in the non-nuclear hydrometallurgy. In turn the large scale applications in the field of base metals such as copper have led to development of new equipment and techniques as well as better understanding of the process chemistry and hydrodynamics. Advances in the field of solvent extraction of relevance to the nuclear fuels, are reviewed in this paper. The significant results from the research and development work in India are also included. Various aspects discussed include chemistry of process flowsheets for uranium and thorium recovery and refining including recent improvements, diluents for use in the processes, thermal effects in extraction, process instrumentation including on-line measurements, solvent loss by entrainment, purification of feed streams prior to extraction, solvent-in-pulp processing, separation of uranium and thorium, binary ex-tractants and application of solvent extraction in uranium enrichment.     

新型三烷基胺萃淋树脂合成及提取分离铼钼研究

阐述了一种新型三烷基胺(N235,R3N,R=C8-C10)萃淋树脂合成方法,研究了N235萃淋树脂对铼(VⅡ)与钼(VⅠ)的提取作用,并通过等摩尔量系列法和斜率法对N235萃淋树脂提取铼的机理进行了探讨。结果表明在不同的酸度下可以通过该萃淋树脂实现钼(VⅠ)和铼(VⅡ)分离。     

HBL101从镍钼矿焙烧料高酸浸出液中直接萃取钼的研究

采用新型萃取剂HBL101从镍钼矿焙烧料高酸浸出液中直接萃取钼。考察有机相组成、料液酸度、相比、振荡频率、平衡时间、温度对钼萃取过程的影响,并绘制了HBL101萃钼等温曲线。结果表明,在优化的工艺条件下,钼萃取率达96.8%以上,有机相饱和容量为12.09g/L;负载有机相用纯水洗涤后经3级逆流氨水反萃,钼反萃率达99.9%以上,实现了钼镍分离及钼的富集转型。     

酸性体系中钼的溶剂萃取研究进展

目前酸浸工艺已广泛应用于各种含钼物料的处理,而由含钼酸浸溶液中萃取分离钼已愈来愈受到关注.文中在综述酸类萃取剂、中性萃取剂、胺类萃取剂从酸浸液中萃取分离钼工艺研究现状的基础上,对各类萃取剂萃钼机理及优缺点进行了分析,并指出了进一步研究的方向.