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。     

X射线衍射法快速测定矿产品中的主要物相和主元素含量

采用X射线衍射法(XRD)分析铜精矿、铅精矿、锌精矿和氧化皮中的主要物相,利用TOPAS软件测定矿产品的主要元素含量。铜精矿的主要物相为黄铜矿、黄铁矿和石英,铅精矿主要物相为方铅矿、铅矾和白铅矿,锌精矿主要物相为闪锌矿,氧化皮的主要物相为氧化亚铁、四氧化三铁和三氧化二铁。通过TOPAS软件对XRD图谱进行拟合,测定铜精矿中铜的含量、铅精矿中铅的含量、锌精矿中锌的含量和氧化皮中铁的含量,分析结果与标准法测定结果基本一致。     

X射线荧光光谱法测定铜精矿中砷、铅和镉

铜精矿是国家重要资源性商品,砷、铅和镉属于铜精矿产品中的有害元素,国家质量监督检验检疫总局、商务部、国家环保总局联合发布的第49号公告,以及国家强制性标准GB 20424—2006规定了铜精矿产品中所含有害元素的限量。目前,砷、铅和镉等元素的分析通常采用火焰原子吸收光谱法、滴定法、氢化物发生-原子荧光光谱法、电感耦合等离子体原子发射光谱法(ICP-AES)等,上     

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。     

ICP-AES法测定进口铜精矿中有害元素

研究了ICP-AES法测定进口铜精矿中铅、锌、钴、镍、镁、镉、砷、锑、铋、汞的含量，采用测定标样、加标回收试验，并与AAS方法比较和参加全国水平测试等多种方法对该方法进行考察，证明该方法准确可靠、简便快速，可用于进口铜精矿的快速检验。     

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。     

直接测汞仪测定重金属精矿产品中汞的含量

正重金属精矿产品是指有色金属中重金属精矿的总称,一般包括铜精矿、铅精矿、锌精矿、混合铅锌精矿、锡精矿、镍精矿等~([1])。重金属精矿产品中的汞是产品中必检的有害元素。汞不仅对冶炼工艺有害,还可能对环境造成污染,且对人体有明显毒性。因此需要制定测定汞的准确和快速的分析方法,以     

热重分析法测定矿产品中的吸附水及烧失减量

采用热重分析法(TGA)测量矿产品中的吸附水及烧失减量,验证了方法的准确性及精密度。对多种矿产品样品采用TGA法和常规马弗炉加热法进行测量,对比结果表明,这两种方法没有显著性差异。TGA法具有方便快捷、准确可靠等优点,是矿产品吸附水及烧失减量检验的首选。     

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。     

聚(3,4-乙烯二氧噻吩):聚苯乙烯磺酸盐热电性能的 提升策略研究进展

近十年,有机聚合物及其复合热电材料与柔性器件取得了显著进展,在废热回收利用、可穿戴电子学、软体机器人和物联网等领域有广泛的应用.其中,聚(3,4-乙烯二氧噻吩):聚苯乙烯磺酸(PEDOT:PSS)是迄今研究最多也是性能最高的聚合物体系.本文对近年来有关PEDOT:PSS热电性能有效提升主要策略的文献报道进行了总结.首先,从PEDOT:PSS的二次掺杂/去掺杂、酸或碱处理和离子液体处理方面等,重点论述了掺杂/去掺杂策略的研究进展;然后,分别从改善聚集态结构、构筑PEDOT微纳米结构和与碳纳米材料复合等3个方面,重点介绍了采用此3种策略提升PEDOT:PSS热电性能的研究进展;最后,对该领域进行总结,提出了开展进一步研究的建议,并对其未来发展前景进行展望.     

Thermodynamic and kinetic analysis of the polymetallic copper concentrate oxidation process

This paper presents the experimental investigation results of the polymetallic copper concentrate oxidation process with the oxygen from the air. Concentrate characterization included chemical analysis, X-ray diffraction (XRD), energy dispersive X-ray fluorescence (EDXRF), and light microscopy. Chemical analysis and EDXRF results showed that the investigated copper concentrate consisted mainly of copper, iron and sulphur, with small amounts of zinc, lead, arsenic and other minor elements. XRD analysis showed that metals were bonded to sulphur in sulphide minerals: chalcopyrite, pyrite, luzonite, sphalerite and enargite. Those minerals were mutually bonded into aggregates, confirmed by light microscopy. The results of DTA/TG analysis were used for determining the mechanism of the oxidation process. Comparison between experimental data obtained by XRD, DTA/TG and data obtained from the phase stability diagrams, implied that the oxidation process of the investigated concentrate can be divided in two stages: the first stage consisted of sulphide oxidation reactions with the characteristic exothermal effects below 973 K while forming sulphates and oxysulphates, and the second stage, which consisted of sulphates and oxysulphates decomposition reactions and forming copper and iron oxides, with endothermal effects above 973 K. Kinetic studies were carried out in isothermal conditions in the temperature range (573–873) K. Calculations were done according to Sharp’s method of reduced half-time reaction. Calculated values for the activation energies were 82 kJ mol^?1 for the initial stage of the oxidation process (up to 723 K), and 42 kJ mol^?1 for the stage of the process where desulphurization degree reached 68–86 % for the oxidation temperatures 748 K and higher. Calculated activation energy values indicated that the reaction of oxidation is a chemically controlled reaction.     

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。     

运用综合手段研究铅锌硫化物精矿的氧化和鉴定其产物

南京关口每年从国外进口铅、锌精矿达几百万吨,随着我国国民经济的发展,作为重要有色金属来源的该矿种的进口量仍将逐年增加。硫化物精矿在运输和储存过程中都有可能发生氧化,由此导致金属品位的波动是常见现象,然而此前在这方面的报导甚少。为此,作者以铅锌硫化物精矿为例对其进行了模拟状态下的氧化实验并采用能谱、光学显微镜、化学物相分析、X射线衍射分析、扫描电镜等手段对氧化前及氧化后的样品进行了鉴定。结果表明,在模拟精矿储运条件下两种精矿的氧化皆甚为明显,铅精矿为1.5%,而锌精矿达到了14.5%,由此引起的品位变化是不可忽视的。鉴于有色金属硫化物精矿在储运过程中呈现了它们的易氧化性并对品位产生影响,所以有关这类矿产品的商贸过程中涉及取样、样品加工和保管、公证等问题,均应在科学实验基础上规范化。     

Usage of Empore™ membrane in alcoholic media for copper(II) distribution studies

The sorption of copper(II) on a solid, iminodiacetic based, chelating material, the Empore™ membrane, in alcoholic solutions is considered. Determination of the acid-base properties, kinetic of metal sorption and complexing properties, in solutions with different percentages of ethanol, ranging from 0 to 40% is undertaken. The results are compared with those obtained using the classical iminodiacetic resin Chelex 100 in beads. No significant differences are found in the thermodynamic properties, but the kinetics of the metal sorption on the membrane is slower and a dependence of the process rate with the alcoholic content is observed. In the present investigation, the detection of copper(II) species both in alcoholic Italian distillate “grappa” and in its intermediate product (“flemma”), is carried out by the Resin Titration (RT) method using, as competitive reagent, the Empore™ membrane. To validate the procedure, synthetic solutions containing different percentages of ethanol are analysed.     

Interaction of datolite concentrate with ammonium hydrodifluoride

The interaction of datolite concentrate with ammonium hydrodifluoride were studied. Under heating, ammonium hydrodifluoride fluorinates datolite to form complex fluoroammonium salts of boron, silicon, and impurity metals. The activation energy and rate constants were calculated for the reaction of datolite concentrate with ammonium hydrodifluoride in the range 100–150°C. The composition of the volatiles formed upon the heating of the fluorinated concentrate was studied, the temperature parameters of the evolution of boron and silicon to the gas phase were determined, and a process for separating these elements was proposed.     

电感耦合等离子体光谱法(ICP-AES)测定银精矿中铜、铅、锌、砷、镉、钙、镁、锰含量

针对银精矿样品复杂,难消解的特点,研究了不同酸溶法和碱熔法对样品的消解情况,建立了硝酸,盐酸,氢氟酸,高氯酸消解银精矿的方法。根据元素灵敏度和抗干扰性,选定各元素的测定波长。通过酸溶样和碱熔样测定结果比对,验证了方法准确性。建立了四酸消解-电感耦合等离子体光谱法测定银精矿中铜、铅、锌、砷、镉、钙、镁、锰含量的方法,元素的线性相关系数均在0.9999以上。通过共存元素干扰实验,确定了银精矿中高含量元素(铜、铅、锌、铁、锑、铋等)对测定元素结果没有影响。方法检出限：Cu 0.0063 mg/L, Pb 0.0159 mg/L ,Zn 0.0090 mg/L,As 0.0192 mg/L, Cd 0.0093 mg/L ,Ca 0.0084 mg/L, Mg 0.0075 mg/L, Mn 0.0081 mg/L。测定下限：Cu 0.0105mg/L,Pb 0.0265 mg/L, Zn 0.0150 mg/L, As 0.0320 mg/L, Cd 0.0155 mg/L, Ca 0.0140 mg/L, Mg 0.0125 mg/L,Mn 0.0135 mg/L。3个样品的相对标准偏差在0.87%~3.56%之间,加标回收率在95.00%~103.56%之间。方法流程短,操作简单,快速,灵敏度和再现性高,结果准确可靠,可以满足银精矿中铜、铅、锌、砷、镉、钙、镁、锰含量的测定。     

Thermoanalytical investigations of decomposition course of copper oxysalts

The thermal decomposition of basic copper carbonate (malachite; CuCO₃·Cu(OH)₂) in a dynamic atmosphere of air or nitrogen was studied via TG, DTA and DSC at different heating rates. The non-isothermal kinetic and thermodynamic parameters were estimated. The decomposition course was thoroughly followed by examining the structural and morphological consequences of calcining the material at elevated temperatures by IR, XRD and SEM. The results obtained showed that in air CuCO₃·Cu(OH)₂ released 0.5 H₂O at 195°C, transforming into the azurite structure 2CuCO₃·Cu(OH)₂. Decomposition then commenced, through two endothermic steps maximized at 325 and 430°C. The resultant product maintained the water released from the decomposition process up to 650–750°C. A schematic decomposition pathway has been proposed in terms of the thermal and physicoanalytical results.     

Extraction-spectrophotometric determination of traces of gold in copper in silver, lead, blister copper, copper concentrate and anode slime with 4,4'-bis(dimethylamino)-thiobenzophenone

A sensitive spectrophotometric method has been developed for the determination of gold in copper, silver, lead, blister copper, copper concentrate and anode slime. Optimal conditions have been established for the extraction and determination of gold. Gold is extracted as its bromo complex with tri-n-octylamine and determined photometrically with 4,4'-bis(dimethylamino)thiobenzophenone; the absorbance of the organic phase is measured at 540 nm and the apparent molar absorptivity is about 1.2 x 10(5) 1.mole(-1). cm(-1). As little as 0.1 or 0.2 ppm of gold in these materials can be determined.