ICP-AES法测定金镍合金中15种杂质元素

建立了一种王水溶样后直接采用电感耦合等离子体发射光谱仪同时测定金镍合金中铝、铋、镉、钴、铬、铜、铁、镁、锰、钼、铅、锑、锡、钛和锌等15种杂质元素的方法。对各杂质元素的分析谱线和基体干扰进行了研究，采用扣除背景的方法校正基体中金和镍的影响。该方法的检出限为0.00036~0.036 μg/mL，测定范围为0.001%~0.1%。加标回收率为89.1%~108.3%，相对标准偏差(RSD)为0.79%~3.54%。方法可满足实际样品分析要求。     

高温高压消解-ICP-AES法测定铱粉中15个杂质元素

在高温高压条件下用盐酸-氯酸钾消解铱粉样品,采用电感耦合等离子体-原子发射光谱法(ICP-AES)测定其中的15个杂质元素。进行了光谱干扰研究、谱线选择、加标回收、精密度以及基体匹配对比实验。结果表明,铱基体对个别杂质元素的某些谱线有光谱干扰;通过选取合适的测定波长及扣除合适的背景点可以消除大部分光谱干扰。方法的测定范围为0.001%~0.10%,加标回收率为87%~109%,相对标准偏差(精密度)为0.8%~6.9%,直接测定与基体匹配测定结果相当。方法可满足铱粉中铂、钯、铑、钌、金、银、铜、铁、镍、铝、铅、锰、镁、锡和锌等15个杂质元素的测定要求。     

ICP-AES测定闪锌矿中的9种元素的方法

闪锌矿是一种近乎无色的矿石,其中主要成分是硫化锌,同时还富含丰富的微量元素,如镉、铜、钴、铁、铅、锰、铟、镍等。本文使用ICP-AES对闪锌矿中的9种元素来进行测定。其测定结果经相关标准验证,相对测量误差(RE,n=8)在1.21%~8.46%之间,相对测量的标准偏差(RSD,n=8)在3.42%~8.58%之间。     

铜和硅对铸态球铁力学性能的影响规律

研究了铜和硅对铸态球铁井圈基体组织和力学性能的影响,并对铜和硅在铸态球铁中的作用机理进行了分析。制备了铸态球铁试块,测试了试样的力学性能,并观察了材料的金相组织结构。研究表明,在试验范围内,随着铜含量增加和硅含量减少,球铁基体中的珠光体数量增多。当球铁中的铜含量为0.40%~0.60%,硅含量为2.30%~2.70%,基体组织中的珠光体数量达到40%~60%时,可批量生产抗拉强度bσ≥620 MPa、伸长率δ≥10%的铸态球铁井圈铸件。     

响应曲面法优化复杂硫化铜矿选择性浸出工艺

研究复杂硫化铜矿中铜铅分离及选择性浸出铜的方法。在高铅铁硫化铜矿中加入氧化钙焙烧,解离铜、铁和铅,对焙砂进行选择性硫酸浸出铜;采用扫描电镜(SEM)、X射线衍射分析仪(XRD)及能谱分析仪(EDS)表征原料、焙砂和浸出渣的结构和形貌,揭示高铅铁硫化铜矿的焙烧和选择性浸出行为。用响应曲面法及中心复合设计原理,建立浸出温度、液固比、酸度及三者间交互作用对铜、铁浸出率影响的多元二次回归方程。结果表明:钙化焙烧能固硫和解离复杂硫化铜矿,以铜浸出率大于96.0%、铁浸出率最低为目标条件时,最佳选择性浸出条件如下:浸出温度70℃、液固比7.99:1、酸度102.44 g/L,最佳条件下铜的浸出率为96.05%,铁的浸出率为15.14%,与验证实验中铜和铁的平均浸出率分别为96.17%和15.20%相比,二者偏差较小,表明模型准确,优化方案可信。     

X射线荧光光谱法测定硬质合金高钴、高镍残次料中钴、镍、铬、铁量

硬质合金生产过程中产生的残次料中钴、镍、铬、铁通常采用《硬质合金化学分析方法 EDTA滴定法测定钴量和镍量》、《钨化学分析方法原子吸收分光光度法测定钴、镍、铁、锰、铜量》、《硬质合金化学分析方法硫酸亚铁铵滴定法测定铬量》等方法,周期长、效率低,在实际操作中存在高钴高镍样品滴定终点难判断问题,如何快速识别分类管理以便回收利用这些残次料对分析检测提出了更高要求。本方法将样品用丙酮脱成型剂后,采用经典的压片制样法,在X射线荧光光谱仪上建立钨钴混合样中钴、镍、铬、铁测定方法,校准曲线在Co质量分数6.00%~20.00%范围内相关系数为0.999,Fe质量分数0.05%~2.0%范围内相关系数为0.999,Ni质量分数7.00%~15.00%范围内相关系数为0.999,Cr质量分数0.5%~1.5%范围内相关系数为0.999,方法相对标准偏差(RSD,n=7)小于6.2%,准确度98.4%~100.7%之间,分析结果同化学方法一致,极大的提高了在线分析速度。     

稀土系贮氢合金中铅、镉量的测定-电感耦合等离子体原子发射光谱法

为建立适合的稀土系贮氢合金产品及原材料的分析方法,试样以硝酸溶解,在1%硝酸介质中,直接以氩等离子体光源激发进行测定。通过对酸介质、酸度、溶样酸量、基底浓度的选择和测定下限实验、波长的选择、精密度和回收率实验等的考察,确定了最佳的分析条件,采用标准加入法进行测试,精密度:铅量测定RSD 0.656%~2.809%,镉量测定RSD 0.366%~1.487%,回收率:铅量测定的回收率96.69%~107.48%,镉量测定的回收率98.17%~104.90%,证明方法可行。     

铜铬二元合金中微量元素的原子吸收光谱法测定

新型合金材料铜铬合金中的微量元素铁、铅难以用传统手工湿法分析方法完成.本文采用火焰原子吸收法进行测定,通过背景校正和基体干扰校正,分析结果令人满意。     

电感耦合等离子体原子发射光谱法测定铝钪锆合金中的钪锆铁钙铜锰镍铬含量

用30 mL盐酸(1+1)加1滴氢氟酸消解铝钪锆合金样品,电感耦合等离子体原子发射光谱法(ICP-OES)快速测定铝钪锆合金中的钪锆铁钙铜锰镍铬含量。用铝基体匹配法消除基体的干扰,通过共存元素干扰试验确定了各元素测定谱线。方法中各元素校准曲线回归方程的线性相关系数均大于0.999 5,测得各元素的方法检出限为0.000 12%~0.000 40%,测定下限为0.001 2%~0.004 0%,相对标准偏差(RSD)为1.44%~6.80%,通过加标回收实验测得各元素的回收率为95%~105%,能满足科研和生产快速检测的需求。     

政策

国土资源部公告铜稀土等七矿种“三率”指标 近日,为强化铁、铜、铅、锌、稀土、钾盐和萤石等矿产资源合理开发利用的监督管理,促进矿山企业节约与综合利用矿产资源,国土资源部公告《铁、铜、铅、锌、稀土、钾盐和萤石等矿产资源合理开发利用“三率”最低指标要求（试行）》     

涡流贫化法回收铜渣中的金、银、铜

采用熔融铜渣为原料,经过涡流贫化过程,回收铜渣中的金、银、铜,贫化渣进一步升温还原得到含铜铁水,最终可制备成耐磨铸铁。结果表明,通过涡流贫化,铜渣中的Fe_3O_4被还原为FeO,然后FeO与SiO_2结合,生成Fe_2SiO_4。经过涡流贫化后,金、银、铜的回收率分别达到了99.44%、93.97%和93.14%。贫化渣中Fe_3O_4和铜的含量分别为1.53%和0.61%(质量分数)。贫化渣涡流还原后得到的含铜铁水制备的耐磨铸铁成分满足高铬耐磨铸铁国标要求。     

Corrosion of porous iron electrodes containing metal additives in alkaline batteries

Abstract

Major problems currently associated with alkaline porous iron electrodes include the high rate of selfdischarge and the low utilisation efficiency of the active iron. The corrosion rates of porous iron electrodes electrodeposited with lead, mercury, silver, copper, or sulphur were analysed by the open circuit potential decay, cathodic potentiostatic polarisation, and gasometric methods. It was found that incorporation of elemental sulphur and copper produced the lowest corrosion rates.     

Copper electrodeposition from cuprous chloride solutions containing lead, zinc or iron ions

Cuprous chloride hydrochloric acid solutions were electrolysed in a two compartments cell without agitation for copper extraction. It is found that the current density affects the colour and the size of copper deposits. During electrodeposition of copper from cuprous solution in the presence of various concentrations of lead, zinc or iron ions at different current densities, it is observed that lead isIn all experiments, the current efficiency for the copper codeposited with copper by increasing current density.deposition reaction fluctuates between 88.50% and 95.50%。     

Responses of bacterial community to potential heap construction methods of fine-grained copper tailings in column bioleaching system

The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method (LM), agglomerate heap construction method (AM), and pellets-sintering heap construction method (PM). The bacterial communities of free, attached, weakly-attached, and strongly-attached microbes in the later bioleaching stage were investigated. In AM group, the addition of lump sulphide ore resulted in the low leachate pH, high ferric iron concentration, and rapid microbial adsorption, which obtained the maximum copper extraction (60.1%) compared with LM (54.6%) and PM (43.9%) groups. The relative abundance of dominant genera and microbial communities of different microbiota underwent changes in three heap construction methods. The alpha-diversity indexes of attached, weakly-attached, and strongly-attached microbes were different, while no significant change was observed in free bacteria. The variation of whole bacterial community was significantly associated with solution pH, total iron, and ferric iron concentrations. Pearson correlation analysis and partial least square path model both indicated that attached bacteria made larger contribution to the copper extraction of tailings.     

Microstructure and morphological study of ball-milled metal matrix nanocomposites

Due to the difficulty of preparation and beneficial properties achievable, copper and iron matrix nanocomposites are materials for which fabrication via the powder metallurgy route is attracting increasing research interest. The presence of ceramic nanoparticles in their matrix can lead to considerable changes in the microstructure and morphology. The effects of the type of metallic matrix and ceramic nanoparticle on the distribution of nano reinforcements and the morphology of ball-milled composite powders were evaluated in this study. For this purpose, 25 wt % of Al₂O₃ and SiC nanoparticles were separately ball-milled in the presence of iron and copper metals. The SEM, FESEM, and XRD results indicated that as-received nanoparticles, which were agglomerated before milling, were partially separated and embedded in the matrix of both the metals after the initial stages of ball milling, while prolonged milling was not found to further affect the distribution of nanoparticles. It was also observed that the Al₂O₃ phase was not thermodynamically stable during ball milling with copper powders. Finally, it was found that the presence of nanoparticles considerably reduce the average size of metallic powder particles.     

沉淀方式对ICP-AES法测定纯银中铅和镉的影响

用硝酸溶解纯银样品,分别加入盐酸和硫氰化钾沉淀分离银基体,用电感耦合等离子体原子发射光谱(ICP-AES)测定试液中的铜、锌、铬、铅和镉。结果表明,采用氯化银沉淀,铅和镉会被吸附,回收率和相对标准偏差(RSD)不能满足测定要求;采用硫氰化银沉淀可以避免对铅和镉的吸附,满足测定要求。     

Cathodic protection of XL 52 steel under the influence of sulfate reducing bacteria

The effect of sulfate reducing bacteria (SRB) upon the cathodic protection of XL 52 steel was determined, in order to identify if the potential value of ?0.950 V versus copper/copper sulfate electrode is good enough to protect the metal surface. During the experiments, different operational parameters were monitored: hydrogen sulfide production, iron concentration, electrolyte alkalinity, microorganisms' population, as well as the metal surface damage. At the same time, the corrosion rate was determined using two electrochemical techniques: polarization resistance (PR) and electrochemical impedance spectroscopy (EIS). According to the results, it was observed that the protection potential of ?0.950 V versus copper/copper sulfate electrode is not enough to control the microbiologically induced corrosion. This situation is reinforced by the fact that significant iron concentration was found in the electrolyte. The microbiological activity is not affected by the protection potential. On the contrary, the population growth is slightly strengthened. The alkalinity generated by the applied potential did not stop the SRB growth. A type of localized corrosion was developed during the experiments with microorganisms, even when the protection potential was applied to the system.     

Copper and elemental sulphur from chalcopyrite by pressure leaching

Processes employing direct oxidation under an over-pressure of air or oxygen in an aqueous sulphuric acid medium have been developed in the Sherritt Gordon Laboratories for iron, nickel, cobalt, zinc and lead sulphide concentrates. This study has recently also been extended to chalcocite, Cu₂S, concentrates. The rising interest in processes employing direct aqueous oxidation is stimulated by the fact that elemental sulphur can be produced as a by-product rather than sulphur dioxide or sulphuric acid.The present paper outlines a process which features the direct pressure oxidation of the most abundant copper sulphide mineral, chalcopyrite, CuFeS₂. The optimum conditions for a practical pressure leaching step have now been developed in the laboratory which results in the production of copper sulphate solution suitable for copper winninq by electrolysis, hydrogen reduction, solvent extraction combined with electrolysis, or other means. The leach residue yields pure elemental sulphur by-product. Copper and elemental sulphur recoveries of 98 and 85% respectively have been recorded. The fastest oxidation rate, corresponding to a leach retention time of 2.5 hr, was obtained when the copper concentrate was ground to 99.5% — 325 mesh, when a 50% stoichiometric excess of concentrate over the amount of available sulphuric acid for copper was used and when the oxygen partial pressure and temperature were maintained at 500 psi and 240°F, respectively. In an idealized form, the pressure leaching reaction can be expressed as follows:—CuFeS₂ + H₂SO₄ + 1 1/40₂ + 1/2H₂O → CuSO₄ + Fe(OH)₃ + 2S°After separation of the copper sulphate solution by filtration, elemental sulphur and excess concentrate ore recovered from the iron oxide tailing by flotation. The tailing, containing iron oxide and insolubles, is rejected. The elemental sulphur is separated from the concentrate by hot filtration, solvent extraction, distillation, or other means, and the unleached chalcopyrite is recycled to the leaching step.     

Sulfide precipitation flotation for treatment of acidic mine waste water

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云南某含银铜铅混合精矿分离试验研究

云南某铜铅混合精矿含Cu 8.14%、Pb 38.57%、Ag 251.62 g/t，对其进行浮选试验研究铜铅的分离。通过条件试验，确定在磨矿细度为-200目含量为93.85%的情况下，抑制剂CMC+亚硫酸钠用量选择1000 g/t，捕收剂Z-200用量选择10 g/t。采用“抑铅浮铜”一粗三精一扫的闭路试验流程，获得铜品位24.73%、回收率87.24%、含铅品位6.23%的铜精矿；铅品位62.71%、回收率84.48%，含铜0.86%的铅精矿。银在铜铅精矿中进一步富集的总回收率为73.04%，实现了该铜铅混合精矿的分离及银的进一步富集。