混酸体系-电感耦合等离子体质谱法测定进口铜精矿中稀土元素的含量

铜精矿中元素组成具有地质成因意义,建立进口铜精矿痕量特征成分分析方法,在产地溯源和掺假识别方面能够发挥重要作用,为口岸入境通关执法提供可靠依据.本方法对8个国家不同矿区的198份进口铜精矿中的稀土含量进行了分析,由于不同矿区的铜精矿成分组成存在差别,已有报道的消解方法不能完全适合所有样品,提出了常压高温HF-HClO4...     

高温消解-电感耦合等离子体质谱法测定铜精矿中铅、砷、汞、镉、铬的含量

<正>中国自产铜精矿不能满足冶炼的需求,每年需要进口大量铜精矿^[1]。为保护环境和保障人民健康安全,我国对进口铜精矿中有害元素铅、砷、汞、镉、铬的含量进行了严格限定^[2]。如何快速、高效测定铜精矿中的有害元素含量已引起越来越多学者的关注^[3-7]。目前,测定铜精矿中铅、砷、汞、镉、铬含量的方法包括冷原子吸收光谱法、原子荧光光谱法、电感耦合等离子体原子发射光谱法(ICP-AES)、电感耦合等离子体质谱法(ICP-MS)等^[8-11]。其中,ICP-MS因具有检出限低、线性范围宽、可以同时测定多种元素等特点而被广泛应用于食品^[12]、矿产品^[13]、环境监测^[14]等领域。铜精矿样品的常用溶解方法有微波消解、电热板加热消解、石墨消解、高温消解等。本工作采用高温环绕式加热消解铜精矿,以ICP-MS同时测定铜精矿中铅、砷、汞、镉、铬的含量,并采用有证标准物质和加标回收的方法验证方法的准确度。     

红外吸收光谱法鉴定进口中亚铜矿和含铜物料

基于阿拉山口口岸重要地理位置,结合进口中亚铜矿和含铜物料情况,按照国别收集阿拉山口口岸进口铜矿和含铜物料样品。利用红外吸收光谱可根据未知物在红外吸收光谱中吸收峰的强度、位置和形状,确定该未知物分子中包含有哪些基团,从而推断该未知物结构的性质,通过优化实验条件,对铜矿和含铜物料进行定性鉴定技术的研究,并建立符合新疆口岸进口中亚国家铜矿产品谱图库,便于快速确定矿产国别及品质源头,防止低含量铜冶炼残渣易名高含量铜精矿进口,危害国家利益。     

进口中亚铜矿和含铜物料红外光谱法鉴定方法的研究

基于阿拉山口口岸重要地理位置,结合进口中亚铜矿和含铜物料情况,按照国别收集阿拉山口口岸进口铜矿和含铜物料样品。利用红外光谱可根据未知物在红外光谱中吸收峰的强度、位置和形状,确定该未知物分子中包含有哪些基团,从而推断该未知物的结构的性质,通过优化实验条件,对铜矿和含铜物料进行定性鉴定技术的研究,并建立符合新疆口岸进口中亚国家铜矿产品谱图库,便于快速确定矿产国别及品质源头,防止低含量铜冶炼残渣易名高含量铜精矿进口,危害国家利益。     

进口铜精矿属性鉴别过程中的思考

随着我国铜精矿进口量的日益增加及物料性质趋于复杂,有必要采用科学高效的方法对矿产品开展属性鉴别,来规避矿产品进口贸易中潜在的风险。本次对某疑似“掺杂明铜”的进口铜精矿开展物性鉴定,采用矿物自动分析仪（BPMA）、光学显微镜、X-射线衍射仪等综合手段查明了产品中的物质组成和结构特征,并从矿床成因、冶金机理、选矿工艺等多角度对该铜精矿的产出来源和生产工艺进行了深入研究和探讨,论证产品中未掺杂有冶金组分,最终确定其为天然铜精矿。从而协助了海关部门对该货源顺利通关,也保障了贸易双方的权益,实现境外战略资源的有效利用。     

我国进口铜精矿检验方法的研究进展

介绍了铜精矿的相关背景,着重综述了进口铜精矿分析时采样、制样、水分测定及主量元素和有害杂质元素的测定方法,包括国家标准方法,原子吸收光谱法,电感耦合等离子体发射光谱法、原子荧光光谱法等(引用文献54篇)。     

固体进样直接测定法测定铜精矿中汞

建立了固体进样直接测定法测定铜精矿中汞含量的方法。铜精矿样品在测汞仪的分解炉中经300℃干燥和750℃高温热分解后,汞被催化分解为汞原子,于850℃齐化成金汞齐。汞蒸气被氧气流带入单波长光学吸收池,在波长253.7 nm处测量汞的吸光度,采用标准曲线法计算汞量。方法的线性范围分别为0~1.00,0~100μg/mL,线性相关系数为0.9999,检出限分别为0.10,0.04 ng/g。5个汞含量不同的铜精矿样品测定结果的相对标准偏差为2.14%~4.35%(n=11),样品加标回收率为92.00%~104.02%。采用该方法分别对2个铜精矿样品和铜精矿国际标准物质进行测定,测定结果与标准分析方法测定值和标准物质标示值基本一致。该方法简便、快速、准确,可以作为标准方法推广使用。     

硫化铜精矿物相分析及氧化机理研究

在海轮运输及样品的制备过程中,进口硫化铜精矿氧化的现象普遍存在,使得货物的重量和铜品位发生变化,但该种现象的机理研究不多。针对硫化铜精矿的物相进行分析,并对硫化铜精矿的氧化机理进行研究。首先,利用显微镜、扫描电子显微镜、X射线荧光光谱(XRF)、X射线衍射(XRD)等方法对两个硫化铜精矿进行物相分析,并对其中的主要元素和含铜主要物相进行定量化学分析。再次,利用热重分析(TGA)研究这两个硫化铜精矿发生氧化反应的温度,结果表明在400℃时铜精矿样品重量开始增加,在约650℃重量达到顶峰,随后重量开始下降。最后,分别在400、650和900℃对两个铜精矿样品进行灼烧,并利用XRF和XRD方法进行测定,从而研究铜精矿的氧化机理,结果表明在400℃时,出现了铁的氧化物和铜的硫氧化物,说明黄铜矿和黄铁矿开始氧化,但还没有完全氧化,在650℃时,化合物中的氧含量继续增加,硫含量逐步减少,在900℃时,铜和铁的化合物只剩氧化物,硫已全部被氧化。结果表明,硫化铜精矿中的铜、铁等元素在温度和时间的作用下逐步氧化,硫氧化物的产生为中间态,氧化物的产生为最终态。实验解释了进口硫化铜精矿氧化的原理,有助于贸易双方减少分歧,有助于海关技术中心更规范地制备样品,降低数据误差。     

微波消解-电感耦合等离子体发射光谱测定铜精矿中的银

铜精矿试样利用HCl和HNO3混酸于微波消解仪中进行溶解,电感耦合等离子体发射光谱(ICP-OES)法测定铜精矿中的银含量。试验了不同比例消解体系的消解效果,研究了不同浓度铁、铜基体的影响,结果表明王水体系消解效果最佳,1 000mg/L以下的铁、铜或铁、铜的混合基体对银的测定没有影响,10%HCl体系作为测定酸度。该方法对银的线性范围为0.73~1 500g/t,标准物质测定值与标准值无显著性差异。该方法前处理试剂消耗少、速度快,分析浓度范围宽,可用于铜精矿中银的快速测定。     

铜精矿中氧化镁的原子吸收快速测定

铜精矿中氧化镁的测定,一般都采用沉淀分离,EDTA滴定法。该法手续繁杂,费时长。本文利用燃烧器转角90度以降低灵敏度的方法,将原子吸收法成功地应用于铜精矿中高含量镁的测定。本法经不同单位的生产考验,证明具有选择性好、简便、快速,容易掌握等优点,精密度、准确度满意。试剂氧化镁标准溶液(1毫克/毫升)按常规     

连续滴定法测定铅精矿中的铅、铜

建立了铅精矿中主量元素铅和次量元素铜的连续滴定分析方法。将铅滴定分析中经硫酸沉淀分离后的滤液,再经硫酸冒烟,用去离子水溶解后,通过滴定法对铅精矿中高含量铜进行分析。该方法铅精矿中铅的检出限为1.4 mg/g,铜的检出限为1.0 mg/g。对3个实际样品中铅、铜分别进行测定,测定结果的相对标准偏差均小于3.0%(n=7),铅的加标回收率为99.71%~100.19%,铜的加标回收率为99.33%~100.47%。该方法通过一次溶样,对铅精矿中的铅、铜连续进行滴定分析,方法快速、准确,适用于铅精矿中含量大于1.4%的铅和含量大于1.0%的铜的测定。     

石墨消解-ICP-MS法同时测定铜精矿中4种有害元素

为弥补标准检测方法的不足,建立了石墨消解-ICP-MS法同时检测铜精矿中Pb、Cd、As 和Hg等4种有害元素。确定了样品前处理和仪器分析条件。用铜精矿标准样品和参考样品分别进行7次重复实验,Pb、Cd和As的检测结果均在标准值范围内,Hg的检测结果与参考值基本一致。7次重复检测结果的变异系数符合GB/T 27417-2017《合格评定 化学分析方法确认和验证指南》要求。选择5种不同物相铜精矿作为待测样品,通过与标准方法比对,两种方法检测结果的绝对差符合标准方法的再现性要求,说明本方法适用于不同种类的铜精矿。本方法操作简单,可同时测定多种有害元素,实用性强。     

速差动力学分析法同时测定铁、锌、铜

将化学计量学方法引入速差动力学分析方法中,在不预知动力学模型参数(速率常数)的情况下,用人工神经网络(ANN)依据铁、锌、铜的EGTA配合物与PAR置换反应的速度差异,对其三组分混合体系进行了同时测定.并对人工神经网络和偏最小二乘法对多波长、多时间点的三维量测模型的解析能力进行了比较,结果表明前者总体上优于后者.混合体系中铁、锌、铜测定的相对标准偏差分别为1.63%,3.29%和4.41%.本法还被用于饲料添加剂中微量元素的测定.     

Copper determination in ethanol fuel samples by anodic stripping voltammetry at a gold microelectrode

A linear sweep anodic stripping voltammetric method was developed for copper determination in commercial ethanol fuel samples by using a gold microelectrode. Under the optimized conditions, a linear range from 0.05 to 1.0 μM was obtained, with detection limit of 22 nM. The method was employed to determine copper ions in six commercial ethanol fuel samples and the results were compared with those obtained by FAAS. This study showed that for most samples both methods produced concordant results. However, for two samples, copper is distributed in its labile and complexed forms leading to copper contents contrasting with those obtained by flame atomic absorption spectroscopy (FAAS). It was observed that acidification of the samples is a very efficient way to recover copper from its complexed forms. After acidification, the copper contents obtained were concordant with those obtained by FAAS. Thus, the method can be employed to the reliable copper determination in commercial ethanol fuel samples. Moreover, this is the first work providing some insights about copper speciation in commercial ethanol fuel samples.     

Simultaneous determination of multicomponents by flow injection analysis: determination of copper and zinc in serum by using zincon as colouring reagent

A flow injection system is described for the simultaneous determination of copper and zinc with a single detector. Two sample plugs are injected into the same carrier stream sequentially. One is for zinc determination and the other is for the sum of copper and zinc. For zinc determination, copper masking reagent is simultaneously injected into a parallel carrier stream and merged with the sample plug by using the merging zone technique. Zincon is used as the colour reagent for the spectrophotometric determination of copper and zinc. The results for the analysis of serum by the proposed method correspond well with those obtained by an AAS method. The rate of analysis is about 45 samples/hr.     

Usage of deep eutectic solvents for the digestion and ultrasound-assisted liquid phase microextraction of copper in liver samples

In this study, we used deep eutectic solvents for digestion and ultrasound-assisted emulsification liquid phase microextraction (UA-ELPME) of copper in liver samples. Different types of DESs were prepared for digestion and microextraction steps. DESs consisting of lactic acid and choline chloride for the digestion step and DESs consisting of tetrabuthylamonium chloride and decanoic acid for ultrasound-assisted emulsification liquid phase microextraction were used in this method. The liver samples were digested by using DES-based digestion method. After digestion step, Cu(II) ions in aqueous phase were complexed with sodium dimethyl dithiocarbamate (NaDMDTC) and the obtained hydrophobic complex was extracted to tetrabuthylamonium chloride-decanoic acid DES phase. A microsample injection system coupled with flame atomic absorption spectrometer (MS-FAAS) was used in the detection of copper. LOD, LOQ, PF and % RSD were determined as 4.00, 13.2 µg L^??1, 10 and 3.2%, respectively. The proposed microextraction procedure was successfully applied to copper contents of the liver samples.     

Determination of wear metals in lubricating oils by flame atomic absorption spectrophotometry

A simple, rapid and reliable method was developed for the determination of copper, nickel, iron and lead in fresh and used lubricating oil samples by flame atomic absorption spectrophotometry (FAAS). In the present study, a mixture of organic solvents containing propionic acid and iso-butylmethyl ketone (1: 1) was used to extract the metals from lubricating oil samples followed by FAAS analysis. Aqueous standard solutions can be easily employed with the proposed mixed solvent system instead of organometallic standards. The analytical results obtained by employing the proposed solvent extraction system were found to be in good agreement with the results for aqueous media obtained after the destruction of oil samples matrix. Percentage recovery studies showed 88–98% for Cu, 92–95% for Fe, 96–106% for Ni and 84–100% for Pb with relative standard deviation of 2–6%. The developed method was effectively applied to routine determination of Cu, Ni, Fe, and Pb in lubricating oil samples.     

Spectrophotometric determination of selenium in concentrates and high-purity copper metal with 3,3'-diaminobenzidine after separation by xanthate extraction

A method for determining 0.0001-0.10% of selenium in copper, nickel, molybdenum, lead and zinc sulphide concentrates is described. After sample decomposition, selenium is reduced to the quadrivalent state by heating in a 4M hydrochloric acid-5M sulphuric acid medium, then extracted into chloroform as the xanthate, and ultimately determined spectrophotometrically with 3,3'-diaminobenzidine. Small amounts of iron, lead and copper, and an appreciable amount of molybdenum are co-extracted as xanthates but do not interfere. More than 5 mg of antimony will cause low results. The proposed method was developed primarily for concentrates, but it is also applicable to high-purity copper.