ICP-MS法测定高纯钯中18个痕量杂质元素

以混合酸(盐酸-硝酸)溶解高纯钯样品,建立了电感耦合等离子体质谱法(ICP-MS)测定高纯钯中18个杂质元素的方法。确定了最佳测定条件为:采用普通模式测定Pt、Rh、Ir、Ru、Au、Ag、Cu、Fe、Zn、Ni、Mn、Mg、Al、Sn和Pb,氨气反应模式测定Si、Fe和Cr(氨气流速分别为0.2、0.3和0.7 mL/min);采用内标校正提高分析的准确性,其中Mg、Al、Zn、Ni、Mn、Cu、Ag、Rh、Ru和Si以Sc为内标,Fe以Y为内标,Sn、Cr和Pb以In为内标,Ir、Au、Bi、Pt以Re为内标。测定各元素的线性相关系数(r)不小于0.9997,方法检出限为0.0061~0.85 ng/mL。对高纯钯样品中18个杂质元素进行测定,相对标准偏差(RSD)为1.38%~6.11%,加标回收率86.2%~118.8%,可满足4N~5N高纯钯产品的测定要求。     

还原、沉淀分离ICP-AES法测定纯银中20个杂质元素

采用还原、沉淀分离ICP-AES法测定纯银中20个杂质元素:Al、As、Au、Bi、Cd、Co、Cr、Cu、Fe、 Mg、 Mn、 Ni、Pb、Pt、Pd、Sb、Se、Sn、Te和Zn.方法的相对标准偏差(RSD)和加标回收率分别为0.9%～6.9%和93%～108%;方法准确、快速、简便,已用于纯银中杂质元素的分析.     

ICP-MS法测定镍铂合金中17个杂质元素

试样以盐酸-硝酸溶解,建立了电感耦合等离子体质谱法(ICP-MS)测定镍铂合金中17个杂质元素的方法。采用标准模式测定Mg、Al、Ti、Cr、Mn、Co、Zn、Cu、Zr、Pd、Ag、Sn、Sm、和Pb,氨气反应模式测定Si和Fe(氨气流速分别为0.2和0.25 mL/min);氦气反应模式测定V(氦气流速为5 mL/min,考察了基体效应对测定结果的影响,采用内标校正提高分析的准确性,其中Mg、Al、Ti、Cr、V、Mn、Fe、Co、Zn和Si以Sc为内标,Cu、Zr、Pd、Ag和Sn以Y为内标,Sm和Pb以Re为内标。测定各元素的线性相关系数(r)不小于0.9996,方法检出限为0.0025~0.78 ng/mL。对NiPt5、NiPt15、NiPt60样品中17个杂质元素进行测定,相对标准偏差(RSD)为0.86%~13.07%,加标回收率89.0%~116.5%,方法满足镍铂合金靶材的测定要求。     

ICP-AES法测定Pd-Ag合金中的杂质元素

采用氢氧化钇共沉淀及氯化银沉淀法将合金成份Pd、Ag与被测杂质元素分离,研究了Pd—Ag合金中Pb、Sb、Bi、As、Sn、In、Al、Fe、V、Zr、Cr、Be、Cu、Ni、Ca、Mg、Co、Pt、Ir、Au、Zn、Cd等22个杂质元素的ICP—AES测定方法。相对标准偏差为0.41～5.6％。     

ICP-MS法测定纯铑中16个杂质元素

采用盐酸-过氧化氢微波消解铑粉样品,动态反应池(DRC)技术消除复合离子对Fe、Si的干扰,以内标校正法克服基体效应,建立了电感耦合等离子体质谱法(ICP-MS)测定纯铑中Mg、Al、Si、Mn、Fe、Ni、Cu、Zn、Ru、Ag、Pd、Sn、Ir、Pt、Au和Pb共16个杂质元素含量的方法。以Y、Re、Sc和In为内标元素,测定加标回收率为88.5%~116.2%,精密度(RSD)为0.63%~13.44%;方法测定下限低,除Fe(0.0001%)和Si(0.0005%)外,其余元素测定下限均不高于0.00005%,在无高纯铑基体匹配的条件下,可满足99.99%的高纯铑测定要求。     

ICP-AES法测定三苯基膦氯化铑中的微量杂质

将三苯基膦氯化铑用硝酸、高氯酸消解,以混合酸溶解样品,用ICP-AES法测定三苯基膦氯化铑中的微量Al、Cu、Fe、Mg、Pd、Ni、Pb、Pt、Zn杂质元素含量。选择合适波长消除光谱干扰,用背景点扣除的方式消除铑对Fe、Ni、Pb、Pt、Zn的基体干扰。各杂质元素的检测范围为0.001%~0.1%,加标回收率为93.25%~117.0%,精密度(RSD)为0.18%~15.41%。与直流电弧发射光谱分析方法相比,准确度和精密度均得到提高,高纯铑基体消耗减少,操作简化。     

过渡金属对Mg2Ni氢化物电子结构和热力学稳定性影响:第一性原理研究

采用基于密度泛函理论(DFT)的平面波赝势(PW-PP)方法,计算并分析了Mg2Ni1-xMx(M=Mn,Fe,Co,Ni,Cu,x=0.25)合金及其氢化物Mg2Ni1-xMxH4的电子结构和热力学稳定性。计算结果表明:Mg2NiH4和Mg2Ni1-xMx的晶胞参数与实验值吻合较好。对Mg2Ni1-xMxH4的电子结构分析发现:氢化物中的Ni—H和M—H键为共价键、Mg—H键为离子键,且Ni—H与M—H键的相互作用强于Mg—H键的。Mn、Fe和Co的部分替代对Ni—H键的相互作用影响较小,而Cu的替代则减弱了Ni—H键的相互作用,这可能是Cu替代后氢化物结构稳定性降低的一个原因。计算了Mg2Ni0.75M0.25H4(M=Mn,Fe,Co,Ni,Cu)的生成焓,分别为-57.7、-61.5、-61.4、63.4和41.6 kJ/mol,与实验值吻合较好。     

锌浴中元素对钢结构件热镀锌的影响

综述了锌浴中的杂质元素(Fe、Pb、Cu、Sn、Cd、Ge等)和合金元素(Al、Ni、Mg、Mn、Bi等)对热镀锌层组织及镀层生长的影响作用。     

镀锌钢-6016铝合金激光焊接组织性能与第一性原理计算

采用基于密度泛函理论的第一性原理方法,计算Fe8Al8及(Fe7X)Al8(X=Pb,Sn,Ti,Cu,Mn,Si,Zn)超胞模型的弹性模量与电子结构,在分析合金化元素改善FeAl金属间化合物力学性质的基础上,选取降低脆性效果较好的Cu和最好的Pb,对1.2 mm厚DC56D+ZF镀锌钢和1.15 mm厚6016铝合金平板试件进行加入中间夹层Cu和Pb的激光搭接焊试验。结果表明:FeAl金属间化合物为脆性相,其电子结构根源在于Fe的sd态与Al的sp态存在电子轨道杂化,为明显的共价键特征;FeAl合金化后,脆性降低,相应脆性由低到高的顺序为(Fe7Pb)Al8、(Fe7Sn)Al8、(Fe7Ti)Al8、(Fe7Cu)Al8、(Fe7Mn)Al8、(Fe7Si)Al8、(Fe7Zn)Al8、Fe8Al8,Pb合金化降低脆性效果最好,激光搭接焊加入中间夹层Pb,钢侧母材与焊缝界面区由母材侧较大晶粒和焊缝的细小晶粒交错形成,熔池金属与母材铝之间没有明显的分界线,焊接接头界面熔合良好;与未加夹层相比,加入中间夹层Cu和Pb后,焊接接头力学性能提高,其中Pb的作用优于Cu的,试样断口均具有韧性断裂特征。     

多元光谱拟合ICP-AES法同时测定钯中22个杂质元素

试样用HCl-HNO3溶解,采用多元光谱拟合(MSF)ICP-AES法同时测定钯中Pt、Rh、Ir等22个杂质元素,对基体钯的影响、MSF功能、元素分析谱线、背景校正、仪器分析参数等进行了研究,确定了最佳实验条件。杂质元素测定范围:Ag、Mg、Cu、Cr、Ti、Mn和Co为0.0004%～0.05%;Rh、Ru、Pb、Fe、Pt、Al、Zn、Si、Bi、Ca、Sb、Sn、Au和Ni为0.0005%～0.05%;Ir为0.001%～0.05%;方法的相对标准偏差(RSD)和加标回收率分别为1.9%～8.3%和85.3%～116.7%。此方法的测定元素包含国家标准GB/T 1420-2004钯中要求测定的全部杂质元素,满足SM-Pd 99.99合格性的判定要求,同时涵盖ASTM B589-94(2005)Grade 99.95的要求。     

Quantification of trace amounts of impurities in high purity cobalt by high resolution inductively coupled plasma mass spectrometry

An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of 24 elements (Be, Mg, Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn, Sb, Ba, Pt, Au, and Pb) in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCl. The matrix effects because of the presence of excess HCl and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the deter- mination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 μg?g?1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results.     

3d过渡金属在NiAl中占位的第一原理计算

采用第一原理赝势平面波方法研究了NiAl-X(X为3d过渡金属)合金体系的几何与电子结构.通过合金形成能的计算与分析发现:合金化元素的外层价电子数对其在B2-NiAl中的占位有非常明显的影响,低价电子数的前过渡金属Sc、Ti、V与后过渡金属Zn主要占据Al原子位,具有未满d壳层高价电子数的Mn、Fe、Co则主要占据Ni原子位,而含有半满或满d壳层的Cr与Cu,则既可占据Ni原子位也可占据Al原子位,但倾向于占据Ni原子位.随着合金化元素外层价电子数的增加,3d过渡金属优先占据Ni原子位的趋势增大,至Mn时达到最大,然后随着价电子数的进一步增加,这种趋势逐渐减小.通过对这些合金化元素价电子态密度图的变化,说明3d过渡金属在B2-NiAl中的占位优先趋势.     

合金化对ZrMn2基Laves相贮氢合金相组成的影响

研究了Ni、V、Cr、Co、Fe、Cu和Ti等合金化元素取代ZrMn2 基Laves相贮氢合金的B侧或A侧对合金相组成的影响。结果表明 ,采用不同的元素对A侧或B侧进行部分取代 ,将引起ZrMn2 基合金相组成的变化。采用Ni取代Mn后 ,ZrMn2 合金的主相结构转变为C15型Laves相 ,表明Ni为C15相稳定元素。对Zr Mn Ni三元合金 ,V为C14相稳定元素 ,而Co、Fe、Cu则为C15相稳定元素。取代量较少时 ,Cr为C15相稳定元素 ,取代量增加时 ,C15相稳定作用减弱。Ti元素为C14相稳定元素 ,Ti对Zr的部分取代将导致合金主相结构转变为C14型Laves相。合金化元素对ZrMn2 合金的相组成的影响与元素的电子浓度和原子尺寸不同有关     

多元光谱拟合ICP-AES法同时测定铂中22个杂质元素

试样用HCl-HNO3溶解,采用多元光谱拟合(MSF)功能ICP-AES法同时测定铂中22个杂质元素:Pd、Rh、Ir、Ru、Au、Ag、Cu、Fe、Zn、Ni、Mn、Cr、Mg、Cd、Al、Ca、Pb、Sn、Bi、Si、Mo、Ti。对基体铂的影响、MSF功能、元素分析谱线、背景校正、仪器分析参数等进行了研究,确定了最佳实验条件。杂质元素测定范围Ag、Pd、Cu、Cr、Ti、Mn和Mo为0.0004%~0.05%;Rh、Ir、Pb、Fe、Mg、Al、Zn、Si、Bi、Ca、Cd、Sn、Au和Ni为0.0005%~0.05%;Ru为0.001%~0.05%;方法的相对标准偏差(RSD)和加标回收率分别为1.5%~8.1%和85.1%~118.5%。方法准确、快速、简便,已用于铂中杂质元素的分析。     

Extraction and stripping of Cu and Ni from synthetic and industrial solutions of Sarcheshmeh Copper Mine containing Cu,Ni, Fe and Zn ions

The extraction and stripping of Cu and Ni ions from synthetic and industrial solutions of Sarcheshmeh Copper Mine containing Cu (770 mg/L), Ni (3200 mg/L), Fe (800 mg/L) and Zn (200 mg/L) were comprehensively investigated using D2EHPA, LIX 984, Cyanex 302, Chemorex CP 150 and Acorga 5774 diluted in kerosene. The influential parameters such as mixing speed and time, concentration of extractant, pH and temperature were considered in extraction stage. Furthermore, stripping of Cu and Ni was examined using different inorganic and organic acids (sulfuric, hydrochloric, nitric and citric acids) with different concentrations. The results indicated that the highest extractions of Cu and Ni occurred within 3 min, with the mixing speed of 500 r/min, 28 °C and A/O ratio of 1:1. Moreover, Cu was extracted by LIX 984 at the concentration of 10% (v/v), whereas Ni was extracted by Cyanex 302 at the concentration of 30% (v/v), efficiently. The optimal pH for Cu and Ni extraction is in ranges of 2−3 and 4−5, respectively. Cu and Ni were selectively extracted with the recoveries of 85%, 93% and 77%, 82% from synthetic and industrial solutions containing Ni, Cu, Zn and Fe ions, respectively. The results of optimal condition showed that 96% of Ni and 93% of Cu were stripped from the synthetic and industrial solutions. Finally, four elements Zn, Fe, Cu and Ni were extracted in three stages with D2EHPA, LIX 984 and Cyanex 302 extractants respectively with the least impurities.     

金属中高动量电子分布的实验研究

测量了Al,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Ga等金属的正电子湮没辐射Doppler展宽谱．采用双探头符合技术,可大幅度地降低谱线的本底,并获得正电子与原子内层电子湮没对谱线的贡献．实验结果表明：谱线的本底随样品与高纯Ge探头之间距离的增加而减小;Ni的商谱(以单晶Al为参考)的谱峰随谱线本底的降低而升高;元素周期表中第四周期的Ti,V,Cr,Mn,Fe,Co,Ni,Cu金属的商谱的谱峰随原子的3d电子数目的增多而升高．     

Preconcentrafion/separation and determination of mercury using microcrystalline phenolphthalein modified by ethyl violet

A novel method was developed for enrichment and separation of trace mercury using phenolphthalein modified by ethyl violet (EV).The effects of different parameters,such as stirring time, various metal ions and salts,and the amounts of phenolphthalein, NH4SCN,and EV on the extraction rate of mercury were studied,to select the experimental conditions.Under optimum conditions,mercury can be adsorbed on the surface of microcrystalline phenolphthalein by the intermolecular action strength.The possible reaction mechanism for the enrichment of mercury was discussed in detail.Hg(Ⅱ)could be completely separated from Fe(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Mn(Ⅱ),Cd(Ⅱ),Cr(Ⅲ), and Al(Ⅲ) in the solution.The proposed method has been successfully applied to the determination of trace mercury in industrial wastewater with the recoveries 1.4%,1.1%,and1.2%,respectively.The analytical results were very satisfactory.     

新型耐高压铸造锡青铜的研制

以ZCuSn3Zn8Pb6Ni1合金为基础,通过添加Fe和Co,开发了耐高压铸造ZCuSn3Zn8Pb6Ni1FeCo合金,研究了Fe和Co对合金组织和性能的影响.结果表明,ZCuSn3Zn8Pb6Ni1FeCo合金显微组织与ZCuSn3Zn8Pb6Ni1的相同之处在于均以α-{ Cu,Sn,Zn }为基体,存在硬脆相δ- Cu10Sn3,Pb以单质形式析出;ZCuSn3Zn8Pb6Ni1FeCo合金中还存在α-Fe和γ-Fe析出相,以及CoCu2Sn 、Fe3Co7、Fe4Zn9等硬质相,这些硬质相和基体之间为共格或半共格关系;ZCuSn3Zn8Pb6Ni1合金铸造组织为典型的枝晶组织,晶粒平均直径约3 mm,抗拉强度为180～230 MPa,而ZCuSn3Zn8Pb6Ni1FeCo合金为等轴晶组织,晶粒平均直径为20～60 μm,抗拉强度为400～450 MPa,伸长率在20%以上;ZCuSn3Zn8Pb6Ni1FeCo合金消除了明显存在于ZCuSn3Zn8Pb6Ni1合金中的Sn的宏观偏析.     

钽中杂质元素分析的DCA全谱直读方法研究

原子发射光谱中直流电弧光谱技术在众多粉末材料的检测中具有许多其它技术难以企及的优势,本试验无需样品分解,直接将钽及其化合物转化为氧化物,配制系列氧化钽光谱标样,通过选择采用94%光谱纯碳粉同6%氟化钠混合做载体,15 A分析电流,运用载体分馏效应,用直流电弧阳极激发,电极中实现杂质元素与基体分馏,依据时序分析和扫描峰,确定元素分析波长、元素积分时间、背景扣除点,建立Ta中Fe、Al、Si、Mn、Mg、Ni、Ti、V、Co、Pb、Bi、Sn、Zr、Sb、Cu、Ca、Cr、Nb、Mo、Y、Ga、Ba、In、Ag、As、Re、Zn、Hf、Cd、Te等30种杂质元素同时测定的分析方法,测定范围0.3⁶00μg/g,加标回收率在93%600μg/g,加标回收率在93%¹15%之间,RSD在6%115%之间,RSD在6%²0%之间。     

First-principles prediction of partitioning of alloying elements between cementite and ferrite

At long tempering times in steels when both cementite (Fe₃C) and ferrite (body-centered cubic (bcc) Fe-rich solid solution) phases are present, alloying elements tend to segregate to either of the two phases. The elements V, Cr, Mn, Mo and W are found to partition to the cementite phase, while Al, Si, P, Co, Ni and Cu partition to ferrite. We show that partitioning of alloying elements and cementite (de)stabilization by alloying in mixtures of bcc Fe and cementite are intimately related through the introduction of a partitioning enthalpy. The formation enthalpy of alloying-element-substituted cementite is shown not to be a proper gauge for addressing these questions.