火试金法测定铅冶炼渣中的金、银含量

建立了铅冶炼渣中的金银含量的测定方法,采用火试金法富集铅冶炼渣中的金、银,铅扣经灰吹后,形成金银合粒,合粒中除有金银外,还残留微量的铅铋杂质,合粒经硝酸分金后,实现金银分离,得到金粒和分金溶液。合粒中杂质保留在分金溶液中,分金溶液经酸处理,采用电感耦合等离子体发射光谱(ICP-OES)法测定其中杂质量和微量的金量。金粒质量补正分金溶液中微量金量即为样品中的金量,合粒质量减去金粒质量和杂质量即为银量。ICP-OES法测定杂质解决了合粒中铅铋残留和分金失误造成微量金进入分金溶液现象。方法精密度较好,加标回收率分别为银98.6%～100%,金96.2%～102%。方法准确、方便、快捷,能很好地满足铅冶炼渣中金、银含量的测定。     

火试金法测定铅冶炼渣中的金、银含量

建立了铅冶炼渣中的金银含量的测定方法,采用火试金法富集铅冶炼渣中的金、银,铅扣经灰吹后,形成金银合粒,合粒中除有金银外,还残留微量的铅铋杂质,合粒经硝酸分金后,实现金银分离,得到金粒和分金溶液。合粒中杂质保留在分金溶液中,分金溶液经酸处理,采用电感耦合等离子体发射光谱(ICP-OES)法测定其中杂质量和微量的金量。金粒质量补正分金溶液中微量金量即为样品中的金量,合粒质量减去金粒质量和杂质量即为银量。ICP-OES法测定杂质解决了合粒中铅铋残留和分金失误造成微量金进入分金溶液现象。方法精密度较好,加标回收率分别为银98.6%～100%,金96.2%～102%。方法准确、方便、快捷,能很好地满足铅冶炼渣中金、银含量的测定。     

乙酸乙酯萃取-氢化物发生-原子荧光光谱法测定金锭中锑和铋

1引言铋和锑是金锭中的主要杂质元素,依据国家金锭标准[1],铋和锑是必检项目。测试铋和锑的国家标准方法[2]不可同时测定,且检出限太高,对于高纯金锭无法做到精确测定。氢化物发生-原子荧光光谱法具有灵敏度高、检出限低、仪器相对便宜的优点,已广泛应用于冶金、地质和生物样品分析[3,4]。本研究采用乙酸乙酯萃取-氢化物发生-原子荧光光谱     

乙酸除铋火试金法测定粗铋中的金银含量

建立了用乙酸分离粗铋中铋-火试金重量法测定粗铋中金和银含量的方法。首先把粗铋焙烧氧化,然后用乙酸溶解粗铋的氧化物,过滤除去铋,消除铋对火试金法的干扰,将沉淀物灰化后,配料、高温熔融,熔态的金属铅捕集试样中的贵金属形成铅扣,将铅扣灰吹,得到金银合粒,用硝酸溶解分离金,用重量法测定金含量。方法准确度高,精密度好,金的加标回收率为99.2%～101%,银的加标回收率为98.2%～99.7%。能很好地满足粗铋中金、银的测定。     

X射线荧光光谱法快速测定铅铋合金中的铅、铋、金、银、铜、砷、锑、锡和碲

建立快速测定铅铋合金中铅、铋、金、银、铜、砷、锑、锡、碲含量的X射线荧光光谱法。采用自制的铅铋合金样品作为标准样品,用台式车床制样,用X射线荧光光谱法快速测定铅铋合金中各元素含量,并用α理论系数法和经验系数法相结合对基体效应进行校正。各组分校准曲线的相关系数均大于0.998,检出限为5.54～101μg/g,测定结果的相对标准偏差为0.06%～7.73%(n=9)。用该方法对3个铅铋合金样品进行分析,测定结果与参考值吻合,相对误差小于8.33%。该方法简便快捷,结果准确,能满足铅铋合金中各元素检测要求,对炉前分析具有很强的实用价值。     

铜,铅精矿中金,银分析取制样方法研究

本文围绕铜、铅精矿中金、银分析取样代表性及制样均匀性等问题，和对铜、铅精矿中金、银品质波动及制样加工粒度对金、银分析的影响进行了系统的研究。划分了金、银品质波动区间，选择了最佳制样加工料度。本研究结果应用于ＹＳ／Ｔ９６－９６《散装浮选铜、铅精矿中金银分析取制样方法》行业标准中。     

银基钎料中铈与杂质元素铅、铋作用机制

研究了银基钎料中铈与铅，铋的作用机制，发现在银基钎料中铈与铅，铋易形成高熔点的CePb,CeBi化合物，从而抑制了铅单质相和铋单质相的形成，消除了杂质元素铅，铋对银基钎料铺展性能的有害作用。金属学分析和量子力学成键理论分析结果表明铈与铅，铋有极强的化学亲和力，X射线衍射分析结果证明了上述分析结果的正确性。     

焙烧脱硫-火试金法测定铅精矿和铜精矿中金和银

将铅精矿或铜精矿样品30.00g平铺于预先铺有20g二氧化硅的方舟中,于试金炉中在750℃焙烧脱硫60min。将脱硫后的样品混合物转移至黏土坩埚中,加入50g碳酸钠,200g氧化铅,20g四硼酸钠作为助熔剂,4.0g淀粉作为还原剂,搅匀后在表面覆盖约5mm厚的氯化钠,在试金炉中于1 100℃进行熔融(一次试金),获得30～40g的铅扣。将铅扣在850℃进行灰吹,得到金银合粒。将一次试金的熔渣和灰皿粉碎后置于一次试金用的坩埚中,加入40g碳酸钠,20g四硼酸钠,25g二氧化硅及4.0g淀粉,搅匀并在表面覆盖约5mm厚的氯化钠后,再进行火试金和灰吹处理,得到第二颗金银合粒。两次所得金银合粒合并后,用热硝酸(1+7)溶液进行分金。用重量法或原子吸收光谱法测得金量,用差量法得到银量(用电感耦合等离子体原子发射光谱法测定铜、铅、铋、砷和锑等杂质的含量)。回收试验得到金的回收率为99.2%～100%,银的回收率为100%,测定值的相对标准偏差(n=7)为0.37%～2.8%(金)和0.28%～2.4%(银)。     

铋盐共沉淀分离富集火焰原子吸收法测定酱中的微量铅

研究了铋盐共沉淀分离富集及火焰法测定铅的最佳备件,在pH8.9的溶液中,用氨水定量沉淀铅。样品中微量铅测定结果的相对标准偏差为1.2％-1.8％,加标回收率为98.8％-101.5％。方法可用于酱中微量铅的测定,且共存物不产生干扰。     

铜中杂质成分标准物质的研制

介绍铜中9种杂质成分标准物质的研制方法。以1号纯铜为基体，配入硫、铁、铅、锌、镍、铋、锑、磷、砷及锡共10种杂质成分，采用雾化喷粉加工工艺，保证了样品的均匀性。对样品表面作了抗氧化保护处理。采取多家实验室协作定值的方式对除砷外的9种杂质成分进行定值。5年的跟踪检验结果表明，该标准物质稳定性良好。     

A simplified sampling technique for use with the Weisz ring oven: application to qualitative analysis of some gold and silver alloys

Up to 100 microg of sample can be collected from gold or silver alloys by rubbing the specimen with the ground hemispherical tip of a 4-mm Pyrex glass rod. Gold alloys are then dissolved in potassium cyanide solution containing hydrogen peroxide; silver alloys are exposed to vapours of nitric acid. Procedures for transfer, ring oven separation and identification of alloy constituents in the sample solutions are described.     

原子吸收光谱法测定金银样品前处理的讨论

讨论了在岩石、矿物及化学探矿样品中金、银的原子吸收光谱分析时,样品前处理应关注的一些问题实践经验表明要注意样品的加工过程和金银的赋存状态,以保证样品有足够的代表性;针对不同矿种类型,选择合适的样品前处理方法,尽量避免样品在处理过程中的挥发损失、包夹、共沉淀吸附等情况的发生;对单矿物金、银的连续测定,建议采用多次湿法酸处理来保证样品的分解,并根据其含量进行必要的分离富集或稀释,以满足测定的要求．     

Strategies for the analysis of coal by laser ablation inductively coupled plasma mass spectroscopy

A comparison between a laser-induced breakdown spectrometry-partial least squares (LIBS-PLS) method and methods based on some well-known techniques, such as induced-coupled plasma-atomic emission spectrometry (ICP-AES), flame atomic absorption spectrometry (FAAS), and atomic scanning microscopy (ASM) is presented in order to both validate the content of gold and silver in alloys to be used as solid standards and develop an alternative to the established methods for the hallmark of gold and silver in jewelry pieces. 17 alloys with gold concentrations ranging from 100 to 50% and 8 alloys with silver concentrations between 100 and 80% and variable concentrations of other metals usually present in jewels were used as solid standards in LIBS in order to develop a method as general as possible. The results obtained in the analysis of some alloys (9 for gold and 7 for silver) show that the proposed method is comparable with the official one.     

Improvements in the Grinding of Gold-Bearing Geochemical Samples and Their Sampling for Fire Assay

The effect of fine grinding of gold-bearing geochemical samples on the representative sample size and the recovery of gold and silver in fire-assay fusion was studied experimentally. A method is proposed for the improvement of grinding and sampling procedures in fire assay.     

Voltammetric determination of traces of silver in some metals after dissolution of the sample in mercury

The general possibility of analysing metals and alloys by dissolution of the sample in mercury and recording the anodic voltammogram is examined for the determination of silver in some metals. In order to obtain good separation of the silver peak from the anodic limit, acetonitrile is used in the supporting electrolyte. If the main component of the sample is more noble than mercury, analysis is simple and takes ? 20 min. Significant amounts of base metals in samples must be removed from the amalgam prior to the anodic stripping; optimum conditions for the removal are given. The detection limits found for the determination of silver in gold and lead and in indium amalgam are 4 × 10^?3, 4 × 10^?4 and 4 × 10^?6 % respectively. Dissolution of the lead button in mercury seems to be a successful alternative to the cupellation procedure. Silver in mercury does not form intermetallic compounds with gold.     

硫酸分离–火试金重量法测定碲化铜中的金和银

建立了用硫酸分离-火试金重量法测定碲化铜中的金和银含量的方法。用硫酸溶解碲化铜样品,过滤,除去铜和碲,得到含金、银的沉淀物,沉淀物经灰化、配料、高温熔融制得铅扣。将铅扣灰吹,得到金银合粒,用硝酸溶解分离金,用重量法测定金含量。用金银合粒的质量扣除金粒的质量和分金液、洗液中杂质的质量即为银含量。采用灰皿、残渣熔融法补正,或用含碲、铜物料做基体加入纯金、纯银同试样方法测定,根据金、银的回收率加以补正,从而得到试样中的碲含量。实验结果表明,浓硫酸的加入量为30 mL,残余量应不少于15 mL。火试金中硅酸度为1左右,试样进炉温度以900℃为宜。该方法金、银测定结果的相对标准偏差分别为0.33%~1.97%,0.28%~1.27%(n=9)。金的回收率为98.5%~100.2%,银的回收率为95.5%~101.4%。该法满足生产控制检测和贸易结算的要求。     

Analytical Analysis of Different Karats of Gold Using Laser Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Time of Flight Mass Spectrometer (LA-TOF-MS)

Laser induced breakdown spectroscopy (LIBS) coupled with a laser ablation time of flight mass spectrometer (LA-TOF-MS) has been developed for discrimination/analysis of the precious gold alloys cartage. Five gold alloys of Karats 18K, 19K, 20K, 22K and 24K having certified composition of gold as 75, 79, 85, 93 and 99.99% were tested and their precise elemental compositions were determined using the laser produced plasma technique. The plasma was generated by focusing beam of a Nd:YAG laser on the target in air and its time integrated emission spectra were registered in the range 250–870 nm. The calibration free LIBS technique (CF-LIBS) was used for the quantitative determination of the constituent elements present in different Karats of gold. Elemental compositions of these gold alloys were also determined using a Laser Ablation time of flight mass spectrometer (LA-TOF-MS). The LIBS limit of detection was calculated from the calibration curves for copper, silver and gold. Results of CF-LIBS and LA-TOF-MS are in excellent agreement with the certified values. It is demonstrated that LIBS coupled with LA-TOF-MS is an efficient technique that can be used to analyze any precious alloys in a fraction of a second.     

火试金-重量法测定阳极铜中的金和银

阳极铜是铜电解过程的重要产品,其中含有一定量的金、银等贵金属,快速准确地测定阳极铜中的贵金属含量,具有重要的现实意义。采用火试金重量法可以同时且快速地测定出样品中的金量和银量,试样与适量的熔剂经高温熔融,铅将金、银富集起来形成铅扣,灰吹得到金、银合粒,用硝酸分金,重量法测得金量;用电感耦合等离子体发射光谱(ICP-OES)法测定分金液中的杂质量和金量,合粒质量减去金量及杂质量即为银量。此方法精密度好,准确度高。金、银的加标回收率在97.6%~102%,可以很好地满足阳极铜中金、银含量的测定。