Hydrothermal purification and enrichment of Chilean copper concentrates. Part 2: The behavior of the bulk concentrates

The hydrothermal treatment of Chilean Codelco-type copper concentrates with copper sulfate solutions was investigated as a mean of removal of impurities and subsequent increase of the copper assay. The behavior of the mineral phases (digenite, chalcopyrite, covellite, bornite, pyrite and sphalerite) was similar to those obtained in previous works from pure mineral samples. An almost complete transformation of bornite, chalcopirite, covellite and sphalerite into Cu_2 ? xS phases was obtained at 225 °C–240 °C. The highest degree of elimination (around 80%) of impurities was in Zn, Cd, Tl and Bi. An intermediate elimination (40–70%) was achieved for Pb and Te, with only moderate elimination (20–40%) of Mo, Hg, Sb and As. Temperature was the variable having the greatest influence on the elimination of the impurities. A concentrate containing 33% Cu, 33% S, 22% Fe and 2% Zn was converted to a highly enriched concentrate containing 70% Cu, 19% S and 3% Fe. The advantages of a concentrate of this type would include: (1) raising by more than twice the smelting capacity due to the high copper content, (2) generation of a minimum amount of slag, (3) reduction by almost 50% in sulfur emissions, (4) substantial reduction of wastes containing hazardous metals and, finally (5), retention of the option to hydrometallurgical copper recovery since the neo-formed Cu_2 ? xS phases are more reactive than chalcopyrite to the chemical or biochemical leaching.     

Mathematical modeling of minor-element behavior in flash smelting of copper concentrates and flash converting of copper mattes

A mathematical model has been developed to describe the behavior of minor elements during flash smelting and flash converting. The model incorporates equations describing volatilization of minor elements from the molten particles and distribution of these elements between the molten phases in the settler. The basic premise of the volatilization model is that at the surface of the molten particle, the partial pressures of the minor-element species are those at equilibrium. Transport of the minor-element species to the gas then is described by external mass transfer. Good agreement has been obtained between observed and predicted behaviors. The effects of oxygen enrichment, matte grade, and wall temperature, as well as the bath temperature, on minor-element behavior have been elucidated. Formerly Assistant Professor, Department of Metallurgy and Metallurgical EngineeringUniversity of Utah, Salt Lake City, UT Formerly Metallurgical Engineer Kennecott, Salt Lake City, UT     

ICP-AES法测定钼精矿中铜、铅、铁、钙

采用电感耦合等离子体发射光谱法同时测定了钼精矿中的铜、铅、铁、钙。在选定的最佳测定条件下测定铜、铅、铁、钙的检出限分别为 2. 2 ,1.5 ,8.6,6.1ng/mL ,回收率为 95. 9%～ 10 1.6% ,相对标准偏差为 1.5 %～ 2.6%。方法准确、快速、简便 ,应用于钼精矿中铜、铅、铁、钙的测定 ,结果满意。     

The structure and annealing behavior of shock-loaded,cube-oriented copper

The substructure of cube-oriented Tough Pitch copper after shock loading to 433 kbar has been examined in the electron microscope. This is dominated by a well-defined subgrain structure with only small long-range misorientations. The nature and origin of the structure are discussed. The annealing response of the material has been followed by hardness measurements and is shown to be retarded compared with cold-rolled material. It has been shown by electron microscopy and texture determinations that conventional recrystallization is the dominant process during annealing.     

The ferric fluosilicate leaching of lead concentrates: Part I. Kinetic Studies

A new hydrometallurgical leaching process, which dissolves lead concentrates with acidified ferric fluosilicate solution, has been investigated for the selective extraction of lead and zinc from lead concentrates containing galena. The leaching of the Pine Point lead concentrate by ferric fluosilicate solutions was studied under various experimental conditions in the temperature range 20 °C to 95 °C. Temperature had a pronounced effect on the dissolution of the concentrates. The rates of lead leaching are very rapid over the temperature range 38 °C to 95 °C. The kinetics of zinc extraction are much lower than those of lead extraction. The reaction rates for the dissolution of galena were found to be controlled by surface chemical reaction. The apparent activation energy of the leaching reaction was calculated to be 62.1 kJ/mol. The initial concentrations of Pb²⁺, H⁺, and Fe³⁺ in the lixiviant do not have a significant effect on the rate or extent of lead extraction under the experimental conditions in this study.     

717型阴离子交换树脂分离富集 光度法测定

研究了717型阴离子交换树脂柱分离 富集钼的条件,建立了光度法测定铜精矿和尾矿中微量钼的方法。在pH为7.5的条件下,钼以MoO４２ 形式被717型阴离子交换树脂定量吸附后,采用2 mol/L HNO3和0.5 mol/L NH4NO3混合溶液定量洗脱,消除了绝大部分共存离子的干扰。通过树脂柱分离 富集后,用硫氰酸钾分光光度法测定钼的检出限为5.6 μg/L,相对标准偏差（RSD）为2.2 % (n=5),加标回收率在96.2 %～105.7 %之间,实际样品测定结果与ICP AES方法测定值基本一致。     

铜矿石和精矿氮类物催化加压浸出的应用与经济估算

目前评估生产铜的新处理方法兴趣日益浓厚。铜矿石和精矿湿法加压氧化是一种环境友好、经济上可行的方法。几种侯选工艺已经出现,目前正在以中间工厂或生产规模应用。其中,第一个已经工业生产验证的方法是氧压浸出中采用氯类物催化（NSC）,通过SX—EX生产铜。该法具有很多优点,是一种很有应用前景的方法。本文介绍了该工艺的最新进展,工艺开发史及在铜精矿和铜矿石中的应用,重点讨论了从黄铜矿精矿中有效回收贵金属的无氰化物方法。最后,介绍了两个最新工业应用研究及其现场经济估算．     

铜矿石和精矿氮类物催化加压浸出的应用与经济估算

目前评估生产铜的新处理方法兴趣日益浓厚.铜矿石和精矿湿法加压氧化是一种环境友好、经济上可行的方法.几种侯选工艺已经出现,目前正在以中间工厂或生产规模应用.其中,第一个已经工业生产验证的方法是氧压浸出中采用氮类物催化(NSC),通过SX-EX生产铜.该法具有很多优点,是一种很有应用前景的方法.本文介绍了该工艺的最新进展,工艺开发史及在铜精矿和铜矿石中的应用,重点讨论了从黄铜矿精矿中有效回收贵金属的无氰化物方法.最后,介绍了两个最新工业应用研究及其现场经济估算.     

Precipitate effects on the mechanical behavior of aluminum copper alloys: Part II. Modeling

This work focuses on a new hardening formulation accounting for precipitate-induced anisotropy in a binary aluminum-copper precipitation-hardened alloy. Different precipitates were developed upon aging at 190 °C and 260 °C, and corresponding work hardening characteristics were predicted for single and polycrystals. The use of single crystals facilitated the demonstration of the effect of precipitates on the flow anisotropy behavior. Pure aluminum was also studied to highlight the change in deformation mechanisms due to the introduction of precipitates in the matrix. The influence of precipitate-induced anisotropy on single-crystal flow behavior was clearly established, again relating to the precipitate character. Simulations are presented for several single-crystal orientations and polycrystals, and they display good agreement with experiments. The work demonstrates that precipitate-induced anisotropy can dominate over the crystal anisotropy effects in some cases.     

Precipitate effects on the mechanical behavior of aluminum copper alloys: Part I. Experiments

This article focuses on understanding the mechanical behavior of precipitation-hardened alloys by studying single and polycrystalline deformation behavior with various heat treatments. Aluminumcopper alloys are the focus in this work and their changing stress-strain behavior is demonstrated resulting from the different hardening mechanisms brought about by the various precipitates. Extensive transmission electron microscopy investigations facilitated the interpretation of the stress-strain behavior and the work hardening characteristics. The use of both single and polycrystals proved valuable in understanding the role of anisotropy due to crystal orientation vs precipitate-induced anisotropy. The experiments show that precipitation-induced anisotropy could offset the crystal orientation anisotropy depending on the orientation. This is clearly demonstrated with similar [111] and [123] behaviors under 190 °C and 260 °C aging temperatures. Experiments on pure aluminum crystals are also provided for comparison and understanding the crystal anisotropy in the absence of precipitates. Part I of this article will focus on experiments, and part II will describe the modeling of the effect of different metastable phases in the matrix acting as barriers to dislocation motion. FOGLESONG for-merly with the Department of Mechanical and Industrial Engineering, University of Illinois, Urbana, IL 61801     

Precipitate effects on the mechanical behavior of aluminum copper alloys: Part II. Modeling

This work focuses on a new hardening formulation accounting for precipitate-induced anisotropy in a binary aluminum-copper precipitation-hardened alloy. Different precipitates were developed upon aging at 190°C and 260°C, and corresponding work hardening characteristics were predicted for single and polycrystals. The use of single crystals facilitated the demonstration of the effect of precipitates on the flow anisotropy behavior. Pure aluminum was also studied to highlight the change in deformation mechanisms due to the introduction of precipitates in the matrix. The influence of precipitate-induced anisotropy on single-crystal flow behavior was clearly established, again relating to the precipitate character. Simulations are presented for several single-crystal orientations and polycrystals, and they display good agreement with experiments. The work demonstrates that precipitate-induced anisotropy can dominate over the crystal anisotropy effects in some cases. T. FOGLESONG formerly with the Department of Mechanical and Industrial Engineering, University of Illinois, Urbana, IL 61801     

Precipitate effects on the mechanical behavior of aluminum copper alloys: Part I. Experiments

This article focuses on understanding the mechanical behavior of precipitation-hardened alloys by studying single and polycrystalline deformation behavior with various heat treatments. Aluminumcopper alloys are the focus in this work and their changing stress-strain behavior is demonstrated resulting from the different hardening mechanisms brought about by the various precipitates. Extensive transmission electron microscopy investigations facilitated the interpretation of the stress-strain behavior and the work hardening characteristics. The use of both single and polycrystals proved valuable in understanding the role of anisotropy due to crystal orientation vs precipitate-induced anisotropy. The experiments show that precipitation-induced anisotropy could offset the crystal orientation anisotropy depending on the orientation. This is clearly demonstrated with similar [111] and [123] behaviors under 190 °C and 260 °C aging temperatures. Experiments on pure aluminum crystals are also provided for comparison and understanding the crystal anisotropy in the absence of precipitates. Part I of this article will focus on experiments, and part II will describe the modeling of the effect of different metastable phases in the matrix acting as barriers to dislocation motion.     

提高铜精矿中金测定的精密度和准确度

研究了铜精矿的粒度分布及各粒级中金含量的赋存规律，发现由于铜精矿的特殊生产工艺，铜精矿的粒度85％集中在－200目，金量的90％也集中在－200目；并从磨样时间和磨样量两个方面试验了铜精矿的加工条件，得出铜精矿中分析测试金的较佳加工条件和加工粒度，加工制成的样品具有均匀性和代表性；从而建立了铜精矿中金的火焰原子吸收快速分析法。该方法操作简便、快速，分析结果稳定、准确，RSD≤4％。     

铜电解液中As、Sb、Bi杂质净化研究进展

在铜电解过程中,粗铜中的有害杂质通过电化学溶解进入电解液并不断富集,从而严重影响阴极铜的质量,电解液及时净化对阴极铜质量有着重要的意义.本文阐述了铜电解过程中As、Sb、Bi等杂质的行为及影响,介绍了当今国内外净化除杂的研究现状,并对其发展前景进行了展望.     

NiTi and NiTi-TiC composites: Part 1. transformation and thermal cycling behavior

The transformation behavior of titanium-rich NiTi containing 0 vol pet, 10 vol pct, and 20 vol pct equiaxed TiC particles was studied by differential scanning calorimetry. The thermoelastic phase transformation of the unreinforced matrix exhibits multiple steps. Upon multiple transformation cycles, the rhombohedral phase (R phase) appears and all transformation temperatures decrease. The TiC particles inhibit the R phase and also lower some of the transformation temperatures. These effects can be explained by the internal misfit stresses resulting from both thermal expansion and transformation mismatch between matrix and reinforcement. The measured transformation enthalpy of bulk and reinforced NiTi is discussed in light of a thermodynamical model, taking into account the elastic energy stored upon cycling. The model indicates that a significant fraction of the matrix is stabilized and thus does not contribute to the transformation enthalpy. Formerly Postdoctoral Fellow, Department of Materials Science and Engineering, Massachusetts Institute of Technology.     

Thermodynamic behavior of bismuth in copper pyrometallurgy: Molten matte,white metal and blister copper phases

This study developed thermodynamic data relating to the behavior of bismuth in copper smelting, converting and refining processes. The activity of bismuth was set by establishing a known vapor pressure of bismuth over melts of various phases. The melts were equilibrated with the vapor, and the resulting bismuth content used to establish bismuth activity coefficients. Experiments were carried out, under controlled oxygen potentials, at 1200 and 1250 °C. Results show that bismuth deviates positively from Raoult's Law at both 1200 and 1250 °C in copper (γ_Bi = 2.17, 2.27), white metal (γ_Bi = 6.1, 6.1), Cu₂S with 2 wt pct FeS (γ_Bi = 8.0, 8.0), Cu₂S with 4 to 6 wt pct FeS (γ_Bii = 16.4, 16.4) and Cu2S with 8 to 70 wt pct FeS (γ_Bi = 13.6, 13.6), respectively. Sabri Arac formerly Research Assistant at University of Arizona Gordon H. Geiger formerly head of the Department of Metallurgical Engineering at the University of Arizona     

原子吸收光谱法连续测定金精矿中的银铜铅锌

针对金精矿日常化验中银、铜、铅、锌需分别溶样测定,浪费人力、时间,采用火焰原子吸收法一次溶样连续测定样品中的银、铜、铅、锌。金精矿采用盐酸-硝酸-氢氟酸-高氯酸混酸完全消解,盐酸(1+9)溶液定容,原子吸收光谱法进行测定。该方法加入标准物质回收率为96.9%~107.7%,相对标准偏差RSD(n=7)为1.17%~7.07%,检出限分别为Cu 0.001 5μg/m L、Pb 0.029 9μg/m L、Zn 0.011 2μg/m L、Ag 0.001 9μg/m L。该方法对金精矿中银、铜、铅、锌的测定结果与国家标准方法测定值相符。     

提高含砷铜金精矿焙烧-氰化工艺金、银、铜回收率的试验研究

提出了一种提高含砷铜金精矿焙烧-氰化工艺金、银、铜回收率的新方法。该方法是将金精矿加入硫化钠后进行焙烧预处理,可有效地提高金、银、铜的回收率。试验结果表明,金、银、铜的浸出率分别提高8．22％,57．43％,7．82％,且不影响制酸和电解铜工艺。     

从高硫多金属金精矿中提取金银铜试验研究

采用焙烧—酸浸—氰化工艺从高硫多金属金精矿中提取金、银、铜。其试验结果表明:在最佳条件下,金、银、铜的平均浸出率分别可达到96.56%、79.12%、91.33%。通过对比金精矿、焙砂、氰化渣中金、银的化学物相可知,硅酸盐包裹金、银不易被氰化浸出,而加入复合添加剂焙烧,硅酸盐包裹的金、银品位大幅度下降,由直接焙烧的2.05 g/t、163.35 g/t分别降到0.81 g/t、25.24 g/t。