锍试金和锑试金富集贵金属 Ⅰ.光谱法测定铜镍硫化矿中的微量铂族元素

研究了用锍扣和锑扣试金富集贵金属,然后用光谱进行测定的方法,拟订了铜镍硫化矿中铂族元素分析的方案,矿石中的铂族元素先用锍扣捕集,酸处理除去贱金属硫化物,再经锑试金把铂族元素富集于毫克量的金属珠中进行光谱测定。一份取样和一次摄谱可以同时分析6个铂族元素。     

试金-光谱法测定矿石中微量铂族元素

用锍试金法富集矿石中铂族元素,目前已引起广泛的重视。但是,经锍试金富集后的铂族元素如何测定尚存在许多问题。国内普遍采用锑试金富集,灰吹除去大部分锑,光谱法测定锑珠中的铂族元素,方法仍较繁琐,且大量锑的挥发对操作者身体也不利。本文试验了锍扣经酸处理、除去贱金属硫化物后,酸不溶性铂族元素硫化物富集渣(以下简称富集渣)在高温灼烧滤纸时的行为。发现在少     

锑试金-电感耦合等离子体质谱法测定黑色页岩中6种铂族元素

正分析黑色页岩中铂族元素多以锍镍试金预富集~([1-3]),但样品中硫、碳等还原性组分含量差异显著~([4-6]),选用的试金配料需有针对性,因此增加了额外的工作量,亦对操作者经验有较高要求。相比硫镍试金,锑试金通过灰吹可以富集铂族元素且试剂无需纯化。本工作参考X射线荧光光谱法熔融制样预氧化操作流程~([7])及铼的氧化镁烧结法~([8]),     

富钴结壳铂族元素超细标准物质的研制

2个富钴结壳铂族元素(PGEs)标准物质MCPt-1和MCPt-2的原样分别由中国和俄罗斯取自中太平洋海山和西太平洋麦哲伦海山区.样品经风干、选配,先经球磨制备成74 μm(200目)粉体样品,再用气流磨将其进一步加工成具有超细粒度的均匀样品.采用激光粒度仪检测样品的粒度分布,其平均粒度分别为1.8和1.5 μm(约2 000目).采用高精度的X射线荧光光谱法(XRF)和电子探针方法分别检验了6个主、次元素在mg和μg取样量水平上的均匀性,用LA-ICP-MS检验了包括Pt在内的40多个痕量元素在μg量水平上的均匀性.样品采用锍镍火试金和Carius管预富集和酸溶消解,除Rh外均采用同位素稀释电感耦合等离子体质谱测定(ID-ICP-MS),确定了MCPt-1和MCPt-2中6个铂族元素的标准值;采用XRF和ICP-AES、ICP-MS方法相结合给出了62个主、次和痕量元素的信息值.最小取样量分别为1 g(测定PGEs)和2 mg(测定其他元素).     

电感耦合等离子体质谱（ICP-MS）法测定碳质板岩样品中铂族元素

碳质板岩属黑色岩系,与多种金属(包括贵金属)成矿有密切的联系。按照常规的分析方法,硫镍试金溶剂配方都不能对贵金属元素有较好的富集,影响贵金属元素的测定。根据石墨岩中样品的成份特征,对测定铂族元素的常规硫镍试金配方进行了改进,增加了硝酸钾和氧化镁,且无需加入锇稀释剂。通过实验选择了合适比例配料,熔融后粉碎镍扣,加入盐酸分解,碲共沉淀剂富集。过滤沉淀用王水溶解。用电感耦合等离子体质谱(ICP-MS)法测定,Lu作内标,对碳质板样品中的铂族元素进行了测定。结果表明,加标回收率为85%～105%,能够满足碳质板岩中铂族元素的分析测定要求。     

低空白镍锍试金预富集中子活化分析测定地球化学标准物质中的铂族元素

研究了镍锍试金预富集中子活化分析测定岩石样品中的铂族元素。纯化捕集剂氧化镍,大大降低了化学分离全流程铂族元素的空白。取样量为50g时,所需溶剂各元素的空白值为(ng/g):Pt<0.05、Pd<0.05、Os<0.01、Ru<0.05、Rh<0.05、Ir=0.002。用平面锗探测器测定Rh使测定下限降低了两个数量级,对几种国标地球化学标准物质的测定结果与推荐值基本符合。     

锑试金-电感耦合等离子质谱法测定铬铁矿中铂族元素

建立了一种可定量富集铬铁矿中6种铂族元素的锑试金-电感耦合等离子体质谱分析方法。针对铬铁矿难溶的问题,选择硼酸、碳酸钠与六偏磷酸钠的熔剂组合,将取样量与熔剂用量等比例缩小(10:1),以XRF用熔样机开展预实验,以确定熔剂配比、熔融温度及时间等参数,而后以标准物质验证,相比试金条件实验省时省力,且易于判断溶解效果。因铬铁矿样品还原性弱,选择锑试金,经灰吹可同时预富集全部6种铂族元素,配料中加入锑粉作为捕集剂,即简化配料又避免了试金过程中熔体溢出。锑扣经灰吹获得合粒,而后经微波密闭消解,ICP-MS KED模式分析。各待测元素检出限在0.03~0.88 ng/g间,重现性RSD为4.5%~13%,铬铁矿标准物质分析结果与认定值吻合,适用于不同品位的铬铁矿样品。     

锑试金-电感耦合等离子质谱法测定铬铁矿中铂族元素EI北大核心CSCD

建立了一种可定量富集铬铁矿中6种铂族元素的锑试金-电感耦合等离子体质谱分析方法。针对铬铁矿难溶的问题,选择硼酸、碳酸钠与六偏磷酸钠的熔剂组合,将取样量与熔剂用量等比例缩小(10:1),以XRF用熔样机开展预实验,以确定熔剂配比、熔融温度及时间等参数,而后以标准物质验证,相比试金条件实验省时省力,且易于判断溶解效果。因铬铁矿样品还原性弱,选择锑试金,经灰吹可同时预富集全部6种铂族元素,配料中加入锑粉作为捕集剂,即简化配料又避免了试金过程中熔体溢出。锑扣经灰吹获得合粒,而后经微波密闭消解,ICP-MS KED模式分析。各待测元素检出限在0.03~0.88 ng/g间,重现性RSD为4.5%~13%,铬铁矿标准物质分析结果与认定值吻合,适用于不同品位的铬铁矿样品。     

火试金预浓集结合中子活化和电感耦合等离子体质谱法测定铂族元素

建立了两种以火试金预浓集为基础的、可用于准确测定铂族元素的方法;中子活化法和电感耦合等离子体质谱法。讨论了它们的分析检出限、准确度及其适应性。并用这两种方法测定了5种候选地质参考物质中铂族元素的含量。     

碱熔-电感耦合等离子体质谱法测定硫铁矿单矿物中的金、银及铂族元素

<正>单矿物分析在地质样品分析中属于较难解决的问题之一,原因是现成的分析方法少。而单矿物中微量元素的地球化学特征研究又需要矿物成分中微量元素含量的准确测定。铂族元素可以作为一种新的地球化学示踪剂,对岩石学特征和地幔源区的演化提供重要的信息。铂族元素通常采用火试金的方法测定[1-5],需要至少20g以上的样品,而单矿物的样品量通常比较少。这就要求用较少的试样量,不仅提供矿物主成分,而且要测定多种痕量元素,铂族     

Application of fluoroxidants for the decomposition and analysis of platinum metals and gold in black shale ores

In order to develop a reliable method for the platinum group metals (PGMs) determination in ores of organic origin like carbonaceous black shale a decomposition method with fluoroxidants like BrF₃ and KBrF₄ was established which avoids the commom losses of PGM organometallic compounds by volatilazation or chemisorption. The recovery from different trapping solutions is discussed. Platinum metals are evidently found in the carbonaceous black shale ores from the “Natalka” deposit situated in the Magadan area. PGMs are very inhomogenously distributed in the ores and ore concentrates and their total contents in ore are 5–18 g/t. The carbonaceous concentrate of black shale ore contains up to 23 g/t of the sum of platinum metals. ≥ 8% of the sum of platinum and palladium contained in this carbonaceous concentrate are soluble in organic solvents. Received: 16 July 1998 / Revised: 16 April 1999 / Accepted: 5 May 1999     

Application of fluoroxidants for the decomposition and analysis of platinum metals and gold in black shale ores

In order to develop a reliable method for the platinum group metals (PGMs) determination in ores of organic origin like carbonaceous black shale a decomposition method with fluoroxidants like BrF₃ and KBrF₄ was established which avoids the commom losses of PGM organometallic compounds by volatilazation or chemisorption. The recovery from different trapping solutions is discussed. Platinum metals are evidently found in the carbonaceous black shale ores from the “Natalka” deposit situated in the Magadan area. PGMs are very inhomogenously distributed in the ores and ore concentrates and their total contents in ore are 5–18 g/t. The carbonaceous concentrate of black shale ore contains up to 23 g/t of the sum of platinum metals. ≥ 8% of the sum of platinum and palladium contained in this carbonaceous concentrate are soluble in organic solvents. Received: 16 July 1998 / Revised: 16 April 1999 / Accepted: 5 May 1999     

Chemical speciation study of platinum metals and other siderophile elements in Precambrian/Cambrian black shale, south China

Chemical speciation of platinum metals and some other siderophile elements in Precambrian/Cambrian black shale, south China, were studied using stepwise dissolution, fire assay preconcentration, inductively coupled plasma mass spectrometry and instrumental neutron activation analysis. The results indicate that platinum metals in Precambrian/Cambrian black shale, south China, are enriched through a syngenetical mineralizing process.     

Determination of gold and the platinum group elements in geological samples by ICP-MS after nickel sulphide fire assay: difficulties encountered with different types of geological samples

Problems involved in the determination of Au and the platinum group elements by the nickel sulphide fire assay (NiS-FA) procedure for black shale samples, samples containing magnetite, and samples containing As, Cu, and Fe were studied. The interference of the graphite in black shale samples was eliminated either by roasting the sample prior to fusion or by adding an oxidant to the fusion flux. Addition of a reducing agent to samples, containing the oxygen-rich mineral magnetite, enabled the NiS-FA procedure to be carried out for this sample type. The interference of Cu on Rh in the ICP-MS determination was corrected by establishing a linear correlation between the interference of Cu on (103)Rh and (105)Pd.     

Determination of precious metals in ores and rocks by thermal neutron activation/γ-spectrometry after preconcentration by nickel sulphide fire assay and coprecipitation with tellurium

The six platinum group elements (Ru, Rh, Pd, Os, Ir and Pt) can be determined in geological samples down to the μg kg^?1 level, by using nickel sulphide fire assay and neutron activation of the residue ramaining after dissolution of the nickel sulphide button in concentrated hydrochloric acid. Losses for the platinum group elements during this dissolution step are usually insignificant, except when the elements are present at ultra-trace levels. The can be recovered from the filtrate by coprecipitation with tellerium. The latter approach also permits determination of silver, which is significantly lost in the hydrochloric acid treatment (recovery <98% instead of typically ≈ 10%). The coprecipitation with tellurium considerably improves the results for gold (recovery ≈ 95% instead of typically 75%).     

电荷注入检测器电感耦合等离子体光谱仪测定铂族元素的性能

研究了用电荷注入检测器等离子体光谱仪测定铂族元素的分析性能。结果表明铂族元素有较好的检出限和10^4以上的线性动态范围，铂族元素间光谱干扰很少，在元素浓度＞1mg/L时测量精度可优于1％，钠对铂族元素的影响是轻微的。     

Determination of Platinum Group Elements in Sulfide-Containing Minerals by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry with Synthetic Calibration Standards

This paper develops sulfide calibration standards for quantitative determination of platinum group elements in natural sulfide-containing minerals by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). A series of sulfide calibration standards containing different concentrations of platinum group elements were prepared using a home-made high temperature furnace. Homogeneity of element distribution expressed as the RSD of signal intensity were less than 10%. The effective concentrations of platinum group elements in synthetic calibration standards were obtained both by pneumatic nebulization ICP-MS and by LA-ICP-MS. Relative percentage differences of these results obtained by two methods were mainly less than 11%. The synthetic calibration standards were then employed as calibrators for quantitative determination of platinum group elements in two natural chalcopyrite samples. The valid results demonstrated that our synthetic standards could be considered for quantitative microanalysis of platinum group elements in natural sulfide-containing minerals.     

A new procedure for the wet chemical analysis of the lead—noble metals button

Thiobarbituric acid can be used as a group precipitant for the recovery of Pt, Pd, Rh and Au from the lead perchlorate—perchloric acid solution, obtained after the lead—noble metals button has been parted with perchloric acid. By integration of this procedure with the recovery of Ir, Ru and Os from the parting residue, a scheme is evolved which makes possible the determination of all the platinum metals and gold from a single button. The results of analyses of various platiniferous materials by the proposed lead—wet method and the classical lead-cupellation method are compared.     

Substoichiometric and non-destructive determination of trace impurities in high-purity optical glasses by neutron activation analysis

A method of radioactivation analysis has been developed for the determination of 17 elements as impurities in high-purity optical glasses. The substoichiometric extraction of platinum with dithizone was studied and a simple procedure was proposed for the determination of platinum. Copper and manganese were also determined substoichiometrically by the extractions with dithizone and with thenoyltrifluoracetone, respectively. The non-destructive γ-ray spectrometry using a Ge(Li) detector has been applied for the determination of the other 14 elements (Ag, Co, Cr, Eu, Fe, Ir, Sc, Zn, Cs, Hf, Rb, Sb, Ta and Tb). Impurity elements at the ppb level were analysed by the proposed method and it is shown that the method is reliable for the determination of trace impurities in high-purity optical glasses.