5—Br—PADAP—过氧化氢光度法测定钒

在H_2O_2存在下,用2-[(5-Br-2-吡啶)偶氮]-5-二乙氨基苯酚(简称5-Br-PADAP)光度法测定钒(V~(5+)),常遇到Fe~(3+),Cr~(3+),Cu~(2+),Ni~(2+)等离子的干扰。为此选用了磷酸介质中直接显色,这可允许大量的铁离子存在,但钢铁中常见的有色离子如Cr~(3+)、Cu~(2+)、Ni~(2+)、Co~(2+)干扰严重,其中铬铜镍离子不能形成三元络合物。三元络合物的生成适宜酸度0.1～1M,方法选用0.6M磷酸介质中显色,在该酸度下,钒与5-Br-PADAP不     

Cu~(2+)印迹磁性壳聚糖微球的制备及选择性识别特性

通过金属离子印迹技术,以磁性Fe3O_4为磁核,Cu~(2+)为模板离子,壳聚糖为功能单体,制备了Cu~(2+)印迹磁性壳聚糖微球(MIPs)。通过考察壳聚糖、Fe_3O_4以及交联剂的用量确定了制备MIPs的最佳工艺条件。并采用扫描电镜(SEM),振动样品磁强计(VSM)和傅里叶变换红外光谱仪(FTIR)对MIPs进行了表征。结果表明:Cu~(2+)印迹磁性壳聚糖微球具有三维网状的多孔结构,其饱和磁化强度为0.39 A·m-1。通过静态吸附法研究了MIPs对Cu~(2+)的吸附特性。吸附等温研究结果表明,MIPs对Cu~(2+)的吸附符合Langmuir方程,为单分子层吸附。通过MIPs在Cu~(2+),Zn~(2+),Co~(2+)和Ni~(2+)的多元混合溶液中的吸附研究了其选择性识别特性,结果表明:MIPs对Cu~(2+)有较高的选择性识别性能,对Cu~(2+)/Zn~(2+),Cu~(2+)/Ni~(2+),Cu~(2+)/Co~(2+)的选择吸附系数(K)分别为40.13,71.21,128.13。MIPs再生-重复使用10次吸附容量没有明显降低。     

2-(5-溴-4-甲基-2-吡啶偶氮)-5-二甲氨基苯胺与镍(Ⅱ)显色反应的研究

研究了新试剂2-(5-溴-4-甲基-2-吡啶偶氮)-5-二甲氨基苯胺(5-Br-4-CH_3-PADMA)与镍(Ⅱ)的显色反应,建立了分光光度法测定镍的新方法。结果表明,在pH值为4.2~6.0的HAc-NaAc缓冲溶液中,在阴离子表面活性剂十二烷基硫酸钠(SDS)存在下,镍(Ⅱ)与5-Br-4-CH_3-PADMA形成稳定的组成比为1∶2的紫色配合物,其最大吸收波长位于567nm处。镍(Ⅱ)的质量浓度在0~0.40μg/mL范围内遵守比尔定律,校准曲线的线性相关系数r=0.999 2,表观摩尔吸光系数ε=1.22×10~5 L·mol~(-1)·cm~(-1)。以硫脲和氟化铵做掩蔽剂可消除Cu~(2+)、Fe~(3+)和Pd~(2+)等离子的干扰。方法用于铝合金中微量镍的测定,结果的相对标准偏差(RSD,n=6)为0.58%~0.98%,并与火焰原子吸收光谱法测定值一致。     

镧系元素—2—羧基喹啉二元配合物的表征及其光谱特性的研究

2-羧基喹啉(Qld)是属于喹啉类的衍生物,它可以与许多金属形成稳定的络合物,可以作为Cu~(2+),Zn~(2+),Cd~(2+)和UO_2~(2+)的重量测定和Fe~(2+)的比色分析试剂,近年来,2-羧基喹啉被开发用作溶剂萃取试剂。喹啉类也是一类常用的荧光试剂,已用于Al~(3+),Gd~(3+),In~(3+),Zn~(2+),Cd~(2+),Zr~(4+)等元素的测定中,但在稀土离子的荧光测定中尚未见报道。     

Cu~(2+),Fe~(3+)对萤石浮选的活化作用机制

针对萤石选别流程复杂,浮选分离成本高以及浮选药剂对萤石的影响效果问题,本文通过单矿物浮选实验,采用溶液化学计算、Zeta电位测试和红外光谱分析的方法,研究了Cu~(2+),Fe~(3+)对萤石浮选过程的影响,并分析了Cu~(2+),Fe~(3+)对萤石浮选过程的活化机制,试验分析结果表明:油酸钠作为萤石捕收剂时,在p H=8~10范围内萤石的浮选回收率为83%;而采用Cu~(2+),Fe~(3+)作为活化剂对萤石进行活化后,萤石回收率分别达到96%和91%,提高了8%和13%,使萤石浮选效果显著提升,有明显的活化作用。溶液化学计算和XRD结果表明在p H=8~10范围内的萤石浮选溶液中,Cu~(2+)和Fe~(3+)主要以Fe(OH)3和Cu(OH)2沉淀的形式存在,进一步验证Fe~(3+),Cu~(2+)阳离子作用的有效组分是氢氧化物或者络合物沉淀;Zeta电位结果表明Fe~(3+)和Cu~(2+)两种金属离子都能使萤石的Zeta电位发生正移,而且Fe~(3+)使萤石的Zeta电位偏移幅度大于Cu~(2+)的偏移幅度,说明萤石表面的Fe~(3+)吸附量多于Cu~(2+);红外光谱分析结果表明油酸钠在分别经过Cu~(2+),Fe~(3+)活化后的萤石表面的作用方式主要为化学吸附。     

阳离子对嗜酸氧化亚铁硫杆菌氧化活性的影响

以嗜酸氧化亚铁硫杆菌(Acidthiobacillus ferrooxidans,At.f,FN811931)为研究对象,研究了脉石矿物溶出阳离子(K~+,Mg~(2+),Ca~(2+)和Al~(3+))对At.f菌氧化活性的影响。研究结果表明:不同阳离子对At.f菌氧化活性的影响效应不同,其影响由大到小的顺序依次为Mg~(2+),Al~(3+),K+,Ca~(2+),当Mg~(2+),Al~(3+),K~+浓度分别超过1,5,10 g·L~(-1)时显著降低了At.f菌的氧化活性,而Ca~(2+)在所研究0~2 g·L~(-1)浓度范围内对At.f菌氧化活性影响不大。培养25 h时,低浓度条件下(0.5 g·L~(-1)),K+,Ca~(2+),Al~(3+),Mg~(2+)作用下的Fe~(2+)的氧化率分别为67.78%,68.76%,65.27%,61.28%,均高于不添加任何离子作用下的Fe~(2+)的氧化率(60.74%);高浓度条件下(15 g·L~(-1)),K+,Al~(3+),Mg~(2+)作用下的Fe~(2+)的氧化率分别为35.82%,25.25%,21.47%,均低于不添加任何离子作用下的Fe~(2+)的氧化率。阳离子Mg~(2+),Al~(3+),K~+随离子浓度的增加,Fe~(2+)的氧化率均呈现逐渐降低的趋势。     

石煤提钒反萃液中杂质离子对酸性铵盐沉钒的影响

以V_2O_5浓度为17.85 g·L~(-1)的模拟一步法石煤提钒反萃液为研究对象。以沉钒产品纯度及其中杂质离子存在状态、杂质离子存在时多聚钒酸铵(APV)晶体状况为指标,讨论了模拟反萃液中的Fe~(3+),Al~(3+),Ca~(2+),K~+等金属杂质离子对酸性铵盐沉钒效果的影响。研究结果表明:Fe~(3+),Al~(3+)妨碍沉钒过程的顺利进行且会降低产品V_2O_5的纯度,并造成沉钒母液的p H值改变,增加后续母液处理的成本和难度;而Ca~(2+),K~+仅会影响产品V_2O_5的纯度,对沉钒率和母液p H值的影响并不显著;4种杂质离子均会使产品多聚钒酸铵(APV)的晶体形貌发生改变,但是每种杂质改变APV晶体形貌的方式各异:Fe~(3+)会破坏APV晶体的完整性并改变其晶体颗粒大小,K~+破坏APV晶体的完整性;Ca~(2+)使APV晶体表面粗糙,晶体颗粒之间黏连,形成大块颗粒;Al~(3+)形成的杂多酸的非晶体状态阻碍APV晶体的顺利长大。同时得到了反萃液沉钒指标良好时,4种杂质离子浓度的控制范围:Fe~(3+)浓度应0.1 g·L~(-1),Ca~(2+)浓度应0.9 g·L~(-1),K~+浓度应2.0 g·L~(-1),Al~(3+)浓度应3.0 g·L~(-1).     

铜磷锌钎焊剂中铜、锌和磷的分析

铜磷锌焊料的分析大多采用沉淀分离,然后进行络合滴定,手续繁琐、费时。我们在文献的基础上将铜的高灵敏度光度试剂3,5-Cl_2-PADAP应用到络合滴定中进行Cu~(2+)、Zn~(2+)的连续滴定获得了成功。方法简便、快速,结果满意。 Cu~(2+)、Zn~(2+)在pH4.5的介质中,用EDTA标准溶液滴定。然后用邻菲罗啉、抗坏血酸、硫脲联合掩蔽剂释放Cu-EDTA中的Cu~(2+),再用EDTA标准溶液滴定Cu~(2+)。用差减法求得锌量。     

溶剂萃取法分离铋、锑、锡

本文报道了溶剂萃取法从电解锡阳极泥的盐酸浸取液中提取分离Sb~(3+),Bi~(3+),Sn~(4+),Sn~(2+)的情况.考察了溶液中只有单个组分存在时,萃取剂(TBP)的浓度、温度、初始水相盐酸浓度对其萃取分配比的影响,Bi~(3+)的萃取在较高的TBP浓度(50％),较低的盐酸浓度(<1.0mO1/L)下,效果较好;Sb~(3+),Sn~(4+),Sn~(2+)的萃取在中等TBP浓度(25％)及中等盐酸浓度(3～6mol/L)下即可达到较好的效果。实验中探讨了TBP萃取Sb~(3+),Bi~(3+)、Sn~(4+),Sn~(2+)的萃合物的形式及萃取反应热效应,萃取反应均为放热反应,其热效应的数值就绝对值而言,Sb~(3+)相似文献   

Ho~(3+)-Yb~(3+)掺杂β-NaYF_4纳米晶的近红外荧光与能量传递

用共沉淀法制备了Ho~(3+),Yb~(3+)掺杂的β-NaYF_4纳米晶,测量并分析了不同Yb~(3+)掺杂浓度下NaYF_4∶Ho~(3+),Yb~(3+)的荧光光谱与荧光衰减曲线。结果表明,在447 nm泵浦光激发下,较强的近红外光发射主要来源于Ho~(3+)-Yb~(3+)之间高效的能量传递过程。被泵浦光激发的Ho~(3+)通过~5F_4,~5S_2能级与~5F_5能级将能量传递给Yb~(3+),使Yb~(3+)从基态~2F_(7/2)能级跃迁到~2F_(5/2)能级。同时,处于~2F_(5/2)能级的Yb~(3+)可以将能量再传递给Ho~(3+)的~5I_6能级从而增强Ho~(3+)离子~5I_6→~5I_8的跃迁发光。在所研究的样品中,NaYF_4∶3%Ho~(3+),3%Yb~(3+)表现出最强的近红外荧光发射,其980 nm附近的荧光强度是NaYF_4∶3%Ho~(3+)样品的18倍。较强的近红外光发射使得NaYF_4∶Ho~(3+),Yb~(3+)材料在提高太阳能电池的光电转换效率以及进行荧光标记等方面有潜在的应用价值。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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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.