Volume and Surface Properties of a Bismuth-Containing Separating Nickel Melt

The influence of a bismuth impurity on the properties of solid and liquid alloys in the concentration range that obeys Henry’s law is considered. The structural and physicochemical properties, specifically, the density and the surface tension, of real melts are studied on relatively pure metals. The changes in the properties of the melts are estimated from changes in the temperature dependences of the density and the surface tension upon heating and cooling and in the concentration dependences of these parameters at a constant temperature. These dependences exhibit a correlation between the volume and surface properties of the melts: the density and the surface tension increase or decrease simultaneously. The introduction of bismuth in the nickel melt is accompanied by the appearance of a relatively strong compression effect (i.e., a decrease in the melt volume). At a certain bismuth content in the melt, the compression effect weakens because of the appearance of an excess phase or its associates and melt separation.     

Influence of phosphorus addition on the surface tension of liquid iron and segregation of phosphorus on the surface of Fe-P alloy

This article presents a study of the surface tension and phosphorus surface segregation in Fe-P alloys. The surface tension was measured by the sessile drop technique. The result of the dynamic surface tension for the low phosphorus content alloys shows that the alloy surface vaporization has a clear effect on the surface tension and causes a positive surface tension temperature coefficient. However, from this article, it is evident that phosphorus in liquid iron acts as a surface active element similar to arsenic. The surface segregation was determined using Auger electron spectroscopy. The result on the surface analysis of as-solidified sample indicates that the adsorption of impurity elements, such as oxygen, carbon, and nitrogen, can conceal phosphorus segregation on the free surface. Phosphorus segregation was also examined in the samples as-cleaned by Ar⁺ and then treated 30 minutes at 650°C. Phosphorus was found to segregate extensively on the surface of the alloys. On the basis of the analysis of the published data, the surface active intensity sequence of some nonmetallic elements was arrayed, and the surface active intensity of fluorine and boron in liquid iron was estimated.     

Density and surface tension of a concentrated lead melt in nickel

The influence of a lead impurity on the properties of metallic melts in the composition range that obeys Henry’s law is studied. The formation of the structural and physicochemical properties of real concentrated melts can be traced from changes in the temperature and concentration dependences of structure-sensitive properties, namely, density and surface tension. The surface properties of a solution depend on its volume properties and differ from them in enhancement effect. The lead saturation of the nickel melt is found to be accompanied by a compression effect (decrease in the melt volume), which is enhanced to a certain lead concentration. As this concentration is exceeded, the compression effect weakens because of volume separation and the appearance of an excess lead phase. As the lead content in a nickel base increases, the surface tension decreases, a second phase forms, and the melt undergoes separation.     

Composition and thermodynamics of the surface layer of binary melts based on iron,cobalt, and nickel

The composition, thickness, thermodynamic activities of components, Gibbs energy and excess energy of formation of the surface layer on binary melts of iron, cobalt and nickel-based alloys with different interatomic interactions were evaluated with the aid of data from the literature and the authors measurements of the concentration dependence of the surface tension and molar volume.     

The temperature coefficient of the surface tension of pure liquid metals

The surface tensions of liquid Fe, Co, Ni, Cu, Ag, Zn, Pb, Cd, and Sn have been measured by the sessile droplet method and/or the levitated droplet method over wide ranges of temperature. The values of surface tension obtained by the levitated droplet method have always been found to be higher than those measured by the sessile droplet method, a result which is attributed to decreased droplet contamination with the containerless levitation method. Negative temperature coefficients of surface tension have been obtained for all of the metals investigated in this work. Based on a literature survey of the available experimental data, it is shown that the values of both surface tension and the temperature coefficient are influenced in a systematic manner by the presence of surface active impurities. On this basis, positive values of the temperature coefficient of surface tension for liquid Zn and Cd found in the literature may be explained in terms of impurity effects which tend to be particularly pronounced in volatile metals. Formerly Research Associate in the Department of Metallurgy and Materials Science, University of Toronto     

氢化物发生-原子荧光光谱法同时测定镍基高温合金中铋和碲

采用盐酸、硝酸混合酸溶解样品,在盐酸介质中加热预还原,以柠檬酸和氟化铵作干扰抑制剂,盐酸(1+9)为载流,控制硼氢化钾的质量浓度为20 g/L,建立了氢化物发生-原子荧光光谱法同时测定高温镍基合金中痕量铋和碲的方法。实验表明:铋和碲的质量浓度均在2～10 μg/L以内与相应的荧光强度呈线性关系,方法的检出限分别为0.000 3 μg/L和0.002 μg/L。干扰试验表明:铋、碲在10 μg/L以内对彼此无干扰;加入5.0 mL 400 g/L柠檬酸溶液、5.0 mL 200 g/L氟化铵溶液可消除钴、铌、钼、铜对铋、碲测定的干扰;基体镍和主量元素铬、铁对铋、碲测定的干扰可通过基体匹配法消除。采用方法对高温镍基合金标准样品进行测定,测定值与认定值相符,结果的相对标准偏差(RSD,n=6)均不大于5％。     

温度对镍基高温合金粉末氧化行为的影响

通过化学分析、扫描电子显微镜观察、X射线衍射分析及X射线光电子能谱分析等方法, 研究了温度对镍基高温合金粉末氧化行为的影响。结果表明, 室温条件下, 粉末氧含量(质量分数)较低(0.012%), 粉末表面发生部分氧化, 表面存在Ni、Cr、Ti等元素的单质态和以Ni (OH)₂、Cr₂O₃、TiO₂为主的氧化物/氢氧化物; 当温度上升至150 ℃, 氧含量增加不明显; 随着温度进一步提高至250 ℃, 粉末氧含量明显增加, 达到0.034%, 粉末表面全部氧化, 表面主要由Ni (OH)₂、Cr₂O₃、TiO₂组成。温度对镍基高温合金粉末氧化行为影响显著, 合理控制温度可以获得低氧含量的粉末, 本研究所用镍基高温合金粉末大气条件下最高处理温度为150 ℃。     

Volume and Surface Properties of Antimony-Containing Nickel Melts

A decrease in the detrimental effect of an antimony impurity in nickel is considered using structure-sensitive parameters, namely, density and surface tension. Samples of experimental heats containing 0.01–0.05 wt % Sb are prepared from a preliminarily cast master alloy. Antimony additions are found to increase the density of the nickel melt substantially. A negative density hysteresis appears in the temperature dependences recorded upon cooling. Antimony in the nickel melt is found to have a high surface activity and to decrease its surface tension strongly. When the melt is heated, its surface tension increases, which is accompanied by the passage of antimony into the volume and by changes in the volume and surface solution compositions.     

含铬转炉渣黏度和表面张力的计算模型

为预测含铬转炉渣的黏度和表面张力,基于炉渣离子与分子共存理论,并结合前人实测的系列含铬转炉渣黏度和表面张力数据,建立含铬转炉渣黏度和表面张力关于温度和结构单元之间的计算模型。模型的计算值与文献的实测值吻合较好,通过模型,有助于预测含铬转炉渣的黏度和表面张力。结果表明,随着Cr₂O₃含量的增加,炉渣黏度升高,表面张力增大,Cr₂O₃对表面张力的影响最大;随着FeO含量的增加,炉渣黏度降低,表面张力减小;随着碱度的增加,炉渣黏度升高,碱度对黏度的影响最大,而对表面张力的影响是先增加后减小,在碱度为1.8时存在极大值。     

高铋铜电解系统的生产实践

介绍了高铋电解系统的形成原因和铜电解过程中杂质铋对电铜质量的影响,采取了跟踪阳极板 Bi 含量,稳定电解工艺参数控制,提升电解系统自净化能力,加强电解液过滤,提高净液能力,加强大修期间电 解生产组织等措施,实现了高铋电解系统的稳定控制。     

Surface segregation and surface tension of liquid mixtures

A model has been developed in which surfaces are treated as separate phases with a thickness corresponding to a monolayer. It is argued that the surface tension of liquids is a measure of the excess surface chemical potential of the surface atoms relative to the bulk atoms. Equations for the calculation of the surface composition and surface tension of liquid mixtures are developed. Using only the surface tension and molar volume data of the pure components, excellent correspondence between calculated and experimental surface tension values was obtained. The method was also tested on liquid systems showing immiscibility. The surface coverage calculated from the present model is compared with that calculated using Gibbs adsorption equation. The surface coverage of the solute species increases with increasing solute concentration. However, depending on the surface properties of the system, the excess surface coverage may pass through a maximum value and then decrease with increasing solute concentration.     

Composition and thickness of surface oxide films on aluminum alloy granules

Conclusions The composition of oxide layers on granules is affected most by magnesium, the magnesium content of the layers being strongly dependent on the conditions of casting of granules. The thickness of surface oxide films on aluminum alloy granules produced by vibratory casting in water does not exceed 5–6 nm. In the casting of granules in water it is necessary to control the latter's impurity content. This applies particularly to closed water circulation systems, in which the degree of contamination of water increases with time.Translated from Poroshkovaya Metallurgiya, No. 8(260), pp. 4–9, August, 1984.     

The surface tensions of indium and cadmium

The surface tensions of 99.9999 pct In and Cd have been measured by the sessile drop method. The surface tension/temperature behavior of liquid indium is nonlinear and within a certainty of 99.5 pct, can be represented by the following quadratic equation:γ _In = 568.0 − 0.04t − 7.08 × 10⁻⁵ t ² ± 5 dyne per cm At its melting point, the surface tension of liquid indium is 560 ± 5 dyne per cm. The slope of the temperature coefficient of the surface tension of liquid cadmium is strongly positive at the melting point, becomes zero about 100°C above the melting temperature (at which point the surface tension is a maximum), and is negative at higher temperatures. At the melting point, the surface tension of cadmium is 590 ± 5 dyne per cm. The surface tension of cadmium is not as readily affected by nonequilibrium thermal conditions as is the surface tension of zinc. The form of the surface tension/temperature curve of indium and cadmium together with similar data for Zn, Cu, Pb, and Sn support a theoretical scheme which generalizes liquid metal surface tension behavior and which, on the basis of calculations, lists liquid metals according to their propensity for surface ordering.     

脱铜终液气液硫化除杂回用铜电解系统研究与运用

随着原料铜精矿杂质含量的上升,原有净液除杂能力无法满足要求,每天需开路脱铜终液,一方面增加废水处理成本,另一方面造成金属镍、酸的损失,同时铜电解过程中需额外补充损失的酸。通过对开路脱铜终液处理的研究,采用硫氢化钠气液硫化除杂处理后,脱铜终液砷、锑、铋去除率达98%以上,而镍、酸基本不损失,且处理后液返回电解系统不会对高纯阴极铜产品质量产生不利影响。具有投资少、指标稳定、效益显著的特点。     

Formation of metallic phase on reducing-gas injection in multicomponent oxide melt. Part 2. Density and surface properties

The density and surface tension of melts of ferronickel (0–100% Ni) and oxidized nickel ore are measured by the sessile-drop method, as well as the interface tension at their boundary in the temperature range 1550–1750°C. The composition of the nickel ore is as follows: 14.8 wt % Fetot, 7.1 wt % FeO, 13.2 wt % Fe₂O₃, 1.4 wt % CaO, 16.2 wt % MgO, 54.5 wt % SiO₂, 4.8 wt % Al₂O₃, 1.5 wt % NiO, and 1.2 wt % Cr₂O₃. In the given temperature range, the density of the alloys varies from 7700 to 6900 kg/m³; the surface tension from 1770 to 1570 mJ/m²; the interface tension from 1650 to 1450 mJ/m², the density of the oxide melt from 2250 to 1750 kg/m³; and its surface tension from 310 to 290 mJ/m². The results are in good agreement with literature data. Functional relationships of the density, surface tension, and interphase tension with the melt temperature and composition are derived. The dependence of the alloy density on the temperature and nickel content corresponds to a first-order equation. The temperature dependence of the surface tension and interphase tension is similar, whereas the dependence on the nickel content corresponds to a second-order equation. The density and surface tension of the oxide melt depend linearly on the temperature. The results may be used to describe the formation of metallic phase when carbon monoxide is bubbled into oxide melt.     

火花源原子发射光谱法测定银中铜铋铁铅锑钯硒碲

探讨了火花源原子发射光谱法分析银中杂质元素铜、铋、铁、铅、锑、钯、硒和碲的分析条件、样品处理方法, 确定了各杂质元素测定范围。采用对测定结果无明显影响的车床或压样机加工样品表面, 用盐酸(1+9)去除试样表面的沾污, 校准曲线采用仪器内置的纯银标准曲线, 并通过内部质量控制样品和校正样品监控。实验方法用于纯银标准样品中8种元素的分析, 测定值与认定值一致;对银锭样品进行分析, 各元素11次测定结果的相对标准偏差在1.0%~4.0％之间。方法可用于纯银和银锭中包括钯的杂质元素分析。     

铜火法冶炼过程中新型脱杂剂的应用实践

通过对铜火法吹炼、精炼过程中铅、砷、锑、铋等主要杂质的分布状态、脱除机理和物相进行分析研究,开发出一种新型脱杂剂(主要成分为含钠钙的高活性碳酸盐),通过新型脱杂剂在铜火法吹炼、精炼段的生产应用,形成了铜火法吹炼、精炼联合除杂工艺,砷、锑、铋脱除率分别由42.19%、22.98%、74.02%提高至54.18%、36.35%、80.41%,确保了高杂原料条件下的阳极铜质量稳定,拓宽了公司原料适应范围。      

火试金法测定铜精矿中的金和银量

本文讨论了PbO的作用及用量,建立了排除试样中铜、镍、铋杂质所需要PbO量的函数关系,论述了清除高含量铋的特殊方法,说明了熔渣硅酸度和铅扣量的选择原则和方法。     

EDTA滴定法测定高铋铅中铋

高铋铅中含有锑、锡、碲、银等干扰元素。按照常规溶解粗铅的方法,锑或锡在硝酸介质下易发生水解,生成不溶物,影响铋的测定;按照常规EDTA滴定铋含量的方法,高铋铅中碲或银的存在可使试液变黑而影响滴定颜色的观察,锡的存在会出现试液变亮黄色后颜色返红的现象,严重影响了铋含量的测定。试验使用硝酸-酒石酸溶解高铋铅试样,探讨了抗坏血酸加入量和加入顺序,考察了杂质元素锡、银和其他共存元素对铋测定的影响。结果表明,称取5.0000g高铋铅试样采用40mL酒石酸(100g/L)-80mL硝酸(1+1)溶解;抗坏血酸加入量是0.2g,加入顺序是调节pH值之后;锡量小于0.4mg时,对铋的测定无影响;锡量大于0.4mg时,分取试液后采取添加氢溴酸低温除锡的方法,消除锡对铋的影响;该实验条件下,银不会发生氧化还原反应;其他共存元素对铋的测定基本没有影响。实验方法用于测定5个高铋铅试样中铋,结果的相对标准偏差(RSD,n=5)为0.038%~1.3%。按照实验方法溶解其中1个高铋铅试样,分别采用实验方法和电感耦合等离子体原子发射光谱法(ICP-AES)测定铋含量,结果相吻合。按照实验方法对3个高铋铅试样进行加标回收试验,回收率为99.8%~101%。     

X射线荧光光谱法用于粗铜中铜和13种杂质元素的测定

铜冶炼过程的中间产品粗铜中铜质量分数在97.5%以上,常含有砷、锑、铁、铅、锌、锡等杂质元素。使用X射线荧光光谱法(XRF)测定粗铜中铜时,铜元素含量过高导致其X射线荧光强度与铜含量的线性度变差,而且试样的光洁度和密度的差异等因素也导致铜含量测定值偏离真实值。试验首先选取各元素含量均具有梯度的粗铜生产样品,使用多种化学湿法对各元素进行定值。在对XRF测定条件优化的前提下,通过车床加工制样,建立了X射线荧光光谱法(XRF)测定粗铜中13种杂质元素(硫、铁、锑、铋、砷、铅、锌、镍、硒、锡、银、钴、碲)的方法。结合测氧仪提供的氧含量值,通过差减法可计算出粗铜中的铜含量。实验方法用于测定1个粗铜样品中铜和13种杂质元素,测定结果的相对标准偏差(RSD,n=11)小于5%。按照实验方法测定4个铜块中铜和13种杂质元素,测定结果与化学湿法值进行比对,结果表明各杂质元素测定值与湿法测定结果相吻合;而使用差减法计算的铜含量(质量分数均大于97.5%)和化学湿法测定结果差值很小,完全满足生产需要。