铜（Ⅱ）催化硫脲还原硫氰酸盐光度法测定钼

在硫酸介质中，以Fe2＋和Cu2＋作催化剂，用硫脲还原Mo（Ⅵ）为Mo（Ⅴ），Mo（Ⅴ）与硫氰酸盐生成橙黄色络合物进行测定。有色络合物λmax为470nm，ε＝1．2×104L·mol－1·cm－1，钼量在0－140μg／50mL范围内符合比尔定律。方法用于复杂物料中微量钼的测定，结果满意。     

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%。     

矿石中钼的快速氧化还原滴定法

高含量钼的分析,一般采用经典钼酸铅重量法,用酸打开矿样,过滤钼酸铅沉淀称量,残渣进行比色测定,钼含量以重量和比色合量计算。此法操作流程长,对含大量W、P、As、Cr的样品处理较为困难。湖南冶金研究所通过试验拟定了以过氧化钠碳酸钠熔融,干滤后取部分溶液以草酸络合钼,盐酸酸化硫酸肼还原,钒酸铵直接滴定的钼容量法。该法简     

氧化还原滴定法测定矿石中的钼

拟订了以硫酸肼还原，钒酸盐直接滴定五价钼的分析方法。矿样以过氧化钠，碳酸钠熔融，干滤分取部分滤液，以草酸络合钼，盐酸酸化，加入适量硫酸肼和8-羟基喹啉，煮沸还原后以钒酸盐滴定。多种杂质均不干扰，干扰元素铀和钒可用8-羟基喹啉分离除去。本法简便快速，特效性高，准确度不低于钼酸铅重量法。适于含钼3％以上各种钼矿。     

铜钼矿中钼的滴定法测定

用盐酸羟胺作还原剂,将钼（Ⅵ）还原到钼（Ⅴ）,Mo（Ⅴ）与EDTA形成稳定配合物.过量的EDTA用铋盐返滴定,测定铜钼矿中的钼.试验表明,该测定方法缩短了分析周期,具有准确性和重现性均好的优点.     

钒（Ⅴ）一次磷酸钠-偶氮胂Ⅲ体系催化动力学光度法测定痕量钒

基于0．016mol／L的H2SO4介质中，痕量钒(Ⅴ)对次磷酸钠(NaH2PO2)还原偶氮肿Ⅲ(AsAⅢ)的褪色反应有明显的阻抑作用，建立了测定痕量钒（Ⅳ）的动力学光度法。钒（Ⅴ）质量浓度在0～4．0μ／L范围内服从比尔定律，方法检出限为0．058μg／L。在25mL溶液中，测定0．1μg钒(Ⅴ)的相对标准偏差为1．5％(n=11)。讨论了酸度、反应物浓度、温度、反应时间、干扰离子等因素的影响，研究了反应的最佳条件，并测定了一些动力学参数，催化反应的表观活化能为46．80kJ／mol。用于测定人发和茶叶样品中痕量钒(Ⅴ)，相对标准偏差为3．0％～4．2％，标准加入回收率为98．2％～101．4％。     

硫氰酸盐分光光度法快速测定钼铁中钼

研究以高氯酸铁为抑制剂,抗坏血酸为还原剂的硫氰酸盐分光光度法测定高含量钼的方法。钼铁试样用硝酸和高氯酸溶解,硫酸冒烟,盐类溶解后在高氯酸铁的存在下,以抗坏血酸还原Mo(Ⅵ)为Mo(Ⅴ),Mo(Ⅴ)与硫氰酸铵生成橙色络合物,在460 nm波长处测定其吸光度。用本法测定3个钼铁标样中钼,测定值与认定值相符,6次测定的相对标准偏差为0.29%~0.35%,分析时间只需50 min。     

高纯五氧化二钒中微量硅的测定

本文研究了用正丁醇萃取硅钼杂多酸,使硅与基体钒分离,以1,2,4-酸-亚硫酸钠-抗坏血酸混合还原体系使硅钼黄还原为硅钼蓝,于680纳米处测定吸光度。方法简便,灵敏度高,变异系数3.8％,用于高纯钒中微量硅测定,获得满意结果。     

差示分光光度法测定镍钼铁合金中高含量钼

测定微量钼,常用硫氰酸盐比色法。将Mo(VI)还原为Mo(V)所使用的还原剂甚多,诸如硫脲、氯化亚锡、抗坏血酸、硫酸肼等。Tинэбург(I)建议用碘化钾和亚硫酸钠为还原剂。应用比色法测定高含量的钼,一般误差较大,不能得到精确的结果。Hiskey提出的差示分光光度法大大提高了测定的精确度。田笠卿曾对差示分光光度法作了介     

细菌浸出液中微量钼的测定

在硫酸介质中,以Cu2+作催化剂,用抗坏血酸还原Mo(Ⅵ)为Mo(Ⅴ),Mo(Ⅴ)与硫氰酸盐生成桔红色络合物进行测定.有色络合物λmaλ=460nm,ε=1.2×104L·mol-1·cm-1,钼量在0～120μg/25mL范围内符合比尔定律.方法用于重点实验室细菌浸出液中微量钼的测定,结果满意.     

China's Major Non-ferrous Metals Imports & Exports

正~~     

Zinc Production by Province in 2014

正~~     

80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.