铝钙包芯线中铝和钙的测定

铝钙包芯线是一种炼钢用的冶炼脱氧剂，由铝粉、铁粉和Ф1mm的钙粒按配比进行物理混匀，然后用薄铁皮包成包芯线。由于钙的化学性质非常活泼，很容易被空气氧化及吸收空气中的水分，使钙的化合物发生变化，按常规操作测定铝和钙，则测定结果与配比(铝20％～30％、钙20％～30％)相差很大，测定结果偏低。本文对铝钙包芯线的取样、制样及分析方法进行探讨，采用分段直接剪取试样、     

进口铜冶炼渣的取样及其分析试样的制备

针对大吨位量进口铜冶炼渣的不均匀性且有不能破碎的金属颗粒的存在，根据统计学及概率论的基础原理和实际经验提出了新的取样及制样方法，对整批铜冶炼渣渣料，以500t为一个取样单元，每个单元中取份样50～60个。根据渣料的粒径大小，决定每一份样的质量，粒径在20-50mm之间者，取份样量为4kg，粒径在10-20mm之间者，取份样量为2kg。将每一个取样单元所取的份样充分混合均匀作为副样，将每一副样进行粉碎，研磨并按需要多次缩分。收集在规定粒径条件下不能破碎的金属颗粒，并分别装在样袋中，另将通过100μm粒径的渣样收集于另一样袋，分别对不同样袋中铜，银，金的含量进行测定。按统计方法计算3元素的加权平均值，并最终得到整批渣料中上述3元素的含量。按所提出的方法，对两船进口的两批铜冶炼渣进行取样、制样并分析了其中铜、银及金的含量，所得结果与国外实验室的结果相吻合。     

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     

取样量对润滑油中微量水分检测结果的影响

研究取样量对润滑油中微量水分测定结果的影响。基于卡尔·费休滴定法,在选定的测量条件下,用发生电极为有隔膜的自动库仑水分仪对基础油、有机热载体油、压缩机油、膨胀机油等新油和发动机油、汽轮机油、涡轮机油、压缩机油、齿轮油、液压油、导热油、船用油、电器绝缘油、风动工具油、金属加工油等在用油在0.1~2.0 g内各取9组不同质量的样品进行测定,得到了润滑油中微量水分准确测定所需的取样量。实验结果表明,新油取样量大于1.0 g,在用油取样量在1.0~1.5 g范围内,可以准确测定润滑油中微量水分含量。测定结果的相对标准偏差为0.83%~3.51%(n=10),样品加标回收率为95.0%~103.0%。在选择的取样量下,该方法具有良好的精密度、准确度,可连续测定多个样品,满足测定需求。     

铜和镍阳极板化学物相分析方法

本文对镍冶炼过程中的铜和镍阳极板中铜、镍、铁和钴的化学物相分析方法作了介绍。铜阳极板中主要含铜、镍两元素(占99％)。用恒电流电解法分离金属相与硫化物。镍阳极板中铜、镍、铁、钴四元素采用选择性溶解的方法。测定结果令人满意,硫化物的结果以试样中总硫量验算,结果一致。     

甘露醇酸碱滴定法测定镍硼铝合金中硼

正硼能增加钢的淬透性,提高钢的热强性能,其在冶金机械行业得到广泛的应用。微量的硼(0.005%~0.05%)既可显著提高铜带的强度和耐腐蚀性,又可改善金属的性能,延长其使用寿命[1-4]。镍硼铝合金(含硼10%~22%)作为冶炼含硼合金的重要原料,市场需求逐年增加。冶炼生产企业以化验成分的含量来指导生产,镍硼铝合金价格昂贵,对化验成分准确度要求较高。因此,准确测定镍硼     

ICP—AES法测定陶瓷材料氮化硅中十三种杂质元素

采用超声波雾化进样,ICP—AES法对氮化硅中十三种杂质元素的测定进行了试验研究。取样量1g时,铝、钙、钴、铬、铜,铒、铁、镁、锰,镍、钛、钒和锌的测定范围为0.1～12.8μg·g~(-1),回收率为93％～110％,RSD(n=8)为0.8％～3.2％。     

ICP-SSEA 法测定铸铝合金中8种元素

将固体进样装置与电感耦合等离子体发射光谱仪(ICP-SSEA)联用，采用固体进样，直接测定铸铝合金中的铜、铁、镁、锰、镍、钛、硅、锌等元素含量。研究表明，该法与火花光谱法比较，具有很宽的的动态范围，测量精度和普通化学分析方法相当，同时又有火花光谱分析的速度。能满足工厂冶炼控制的要求。     

矿产品水分含量代表值Bootstrap模拟取样估计

在对矿产品水分含量基础统计学特征描述的基础上,采用内核密度估计对水分含量数据多态性进行了分析,根据双态分布的特点,使用Bootstrap模拟取样方法对试验样本值模拟重复取样,以多次Bootstrap模拟取样的均值与标准偏差作为矿产品水分含量有限样本代表值及标准偏差的稳健估计,实践证明Bootstrap模拟取样估计对矿产品水分含量代表值的估计是有效的,该项研究为矿产品水分含量代表值的准确评估提供了一种新方法.     

辛基膦酸单丁酯萃取钴(Ⅱ)、镍(Ⅰ)的结构-性能关系

在钴、在钻、镍的湿法冶炼工艺中,溶剂萃取技术己获得了广泛的应用.自1968年Ritcey等首次提出采用二(2一乙基己基)磷酸(DEHPA)作为硫酸盐介质中分离钻、镍的萃取剂以来,又先后出现了2一乙基己基麟酸单2一乙基己基醋(EHEHPA)     

A nondestructive and noninvasive method to determine water content in lyophilized proteins using low-field time-domain NMR

Determining the moisture content in lyophilized solids is a fundamental step towards predicting the quality and stability of lyophilized products, but conventional methods are time-consuming, invasive, and destructive. High levels of residual moisture in a lyophilized product can lead to cake collapse, product degradation, and reduced shelf life. The aim of this study was to develop a fast, noninvasive, nondestructive, and inexpensive method for determining the moisture content in a lyophilized monoclonal antibody (mAb) formulation using benchtop low-field time-domain nuclear magnetic resonance spectroscopy.     

火焰原子吸收光谱法测定铜冶炼渣中镍

通过对铜冶炼渣化学组成和性质的研究,确定了测定镍的实验方法。铜冶炼渣中二氧化硅含量在20%~40%,硫含量10%~20%,样品的分解具有一定的难度,必然影响镍的测定结果,因此需在样品分解过程中加入一定量的氟化氢铵、溴使二氧化硅生成四氟化硅、硫生成硫化氢挥发除去,溶液中其余共存元素主要有铜、银、铁、锌等元素不干扰测定结果,在硝酸(5%)介质中,用火焰原子吸收光谱法测定镍的含量,测定范围为0.01%~1%,加标回收率在99.5%~100.4%,测定结果的相对标准偏差(n=7)在0.61%~1.18%,检出限为0.004μg/mL,方法快速,简捷,能够满足日常生产检测需要。     

火焰原子吸收光谱法测定铜冶炼烟尘中铋

本文研究了测定铜冶炼烟尘中铋含量0.050% ~5.00%的火焰原子吸收光谱法。对铜冶炼烟尘试样的溶解、测定体系中酸介质的影响和各干扰元素进行了试验研究。制定了铜冶炼烟尘中铋含量的原子吸收光谱法。方法标准偏差为0.0013 %~ 0.057 %,相对标准偏差为0.78 % ~1.44 %,样品加标回收率为98.95%~101.87%。本方法具有灵敏度高、结果准确、操作简便等特点,适合铜冶炼烟尘中铋含量0.050 % ~ 5.00 % 的测定。     

Pyrolysis of Hailar lignite in an autogenerated steam agent

An in situ pyrolysis process of high moisture content lignite in an autogenerated steam agent was proposed. The aim is to utilize steam autogenerated from lignite moisture as a reactant to produce fuel gas and additional hydrogen. Thermogravimetric analysis revealed that mass loss and maximum mass loss rate increased with the rise of heating rates. The in situ pyrolysis process was performed in a screw kiln reactor to investigate the effects of moisture content and reactor temperature on product yields, gas compositions, and pyrolysis performance. The results demonstrated that inherent moisture in lignite had a significant influence on the product yield. The pyrolysis of L _R (raw lignite with a moisture content of 36.9 %, wet basis) at 900 °C exhibited higher dry yield of 33.67 mL g^?1 and H₂ content of 50.3 vol% than those from the pyrolysis of the predried lignite. It was also shown that increasing reaction temperature led to a rising dry gas yield and H₂ yield. The pyrolysis of L _R showed the maximum dry yield of 33.7 mL g^?1 and H₂ content of 53.2 vol% at 1,000 °C. The LHV of fuel gas ranged from 18.45 to 14.38 MJ Nm^?3 when the reactor temperature increased from 600 to 1,000 °C.     

Na2EDTA滴定法测定铜冶炼烟尘中铋含量

研究了测定铜冶炼烟尘中铋含量的Na_2EDTA络合滴定方法。对测定体系中的各干扰元素进行了研究,探讨了测定方法的各项测定条件。方法的相对标准偏差为0.40%～0.67%,样品加标回收率在99.9%～100%,方法精密度高,准确度好。适用于铜冶炼烟尘中铋含量为5.00%～16.00%的测定。     

Thermogravimetric analysis of single-walled carbon nanotubes synthesized by induction thermal plasma

A standard procedure for thermogravimetric analysis (TG) of carbonaceous materials including single-walled carbon nanotubes was developed based on a statistical design to precisely study the effect of three main TG parameters: temperature ramp (TR, °C), initial mass (IM) of the sample (mg), and the rate of flowing gas (sccm) on the TG results. In addition, the effect of sampling including sample morphology and moisture content on TG were studied. The results of statistical design clearly showed that TG was affected by these three parameters and particularly by IM and TR. Interestingly, it was observed that the TG results are affected insufficiently by the sample morphology and low moisture content. This study also confirmed the potential of TG combined with high-resolution scanning electron microscopy to be a simple and straightforward method for purity evaluation of SWCNT-containing samples with a complex TG behavior such as those of induction thermal plasma grown. A complementary study on nano-metric catalysts indicated that these types of materials enable to gain or loss mass in an oxidative ambient during TG. A mass loss of 6% and a mass gain of 23% were observed for pure nano-metric yttrium oxide and nickel, respectively. A simple calculation showed a total mass gain of 1?wt% particularly by the catalysts in the SWCNT sample during TG.     

电感耦合等离子体光谱法测定铜冶炼烟尘中锌

本实验介绍了电感耦合等离子体光谱法测定铜冶炼烟尘中锌含量的分析方法。针对样品碳,硅含量高的特点,有针对性的研究了样品的消解方法,确定采用盐酸、硝酸、氢氟酸、高氯酸对铜冶炼烟尘样品进行消解。同时进行了干扰试验,确定样品中高含量的铜,铅,砷等对样品测定结果没有影响。并对仪器的工作参数进行了优化。方法检出限为为0.011 mg/L,测定下限为0.019 mg/L,3个样品的相对标准偏差在0.54%~0.92%之间,加标回收率在96%~101.14%之间。该方法样品消解完全,流程短,操作简单,快速,测定准确度高,可以满足铜冶炼烟尘中锌含量的测定。     

Two-stage application of the optimised uncertainty method: a practical assessment

Uncertainty estimates from routine sampling and analytical procedures can be assessed as being fit for purpose using the optimised uncertainty (OU) method. The OU method recommends an optimal level of uncertainty that should be reached in order to minimise the expected financial loss, given a misclassification of a batch as a result of the uncertainty. Sampling theory can used as a predictive tool when a change in sampling uncertainty is recommended by the OU method. The OU methodology has been applied iteratively for the first time using a case study of wholesale butter and the determination of five quality indicators (moisture, fat, solids-not-fat (SNF), peroxide value (PV) and free fatty acid (FFA)). The sampling uncertainty (s(samp)) was found to be sub-optimal for moisture and PV determination, for 3-fold composite samples. A revised sampling protocol was devised using Gy's sampling theory. It was predicted that an increase in sample mass would reduce the sampling uncertainty to the optimal level, resulting in a saving in expectation of loss of over pounds 2000 per 20 tonne batch, when compared to current methods. Application of the optimal protocol did not however, achieve the desired reduction in s(samp) due to limitations in sampling theory. The OU methodology proved to be a useful tool in identifying broad weaknesses within a routine protocol and assessing fitness for purpose. However, the successful routine application of sampling theory, as part of the optimisation process, requires substantial prior knowledge of the sampling target.     

铜冶炼物料中铜的分析质量控制方法综述

目前国内铜精矿供应紧俏,铜冶炼行业的原料复杂,有些偏离了认证和认可标准方法的样品,在检测时,用认证、认可文件不能很好地进行质量管控,需要对分析方法加以改进,从技术上进行管控。结合国内铜冶炼企业的实际情况和多年的实践经验,从样品的加工和保存环节、铜分析的技术环节、人员培训、质量抽查、定期开展质量分析会等方面对铜的分析质量控制进行了总结。在具体的质量控制中,针对铜冶炼行业成分复杂、易变化的物料分析,应根据实际情况进行质量管控,以提高铜分析的准确度。