Ti—13Al—29Nb—2.5Mo合金ISM熔炼过程中多组元挥发损失

在基于活度系数计算模型的基础上，计算了ISM熔炼过程中不同熔炼温度下Ti-13Al-29Nb-2.5Mo(ω/%)熔体中Ti,Al,Nb元素的饱和蒸气压，计算结果表明，在熔炼温度范围内，Al元素的饱和蒸气压分别比Ti,Nb元素的饱和蒸气压大17倍和3070倍左右。在熔炼温度范围内对熔体中Al,Ti,Nb元素的挥发损失速率的计算表明，Al元素在损失速率比Ti,Nb的损失速率分别大43倍和144倍左右，在此基础上计算了Ti,Al,Nb元素的挥发损失量以及合金在熔炼后的化学成分，结果表明由于合金中各组元的挥发损失速率大小不一，使得熔炼前后合金的成分出现了变化。分析表明合理降低熔炼温度及增加真空室中压力可以减小成分的变化。本结果为ISM熔炼实践中合金成分控制提供有价值的理论指导。     

含Nb的TiAl合金PAM过程质量变化

对比研究了在相同的真空度条件下纯Ti、纯Al、TiAl二元合金和TiAl-Nb三元合金PAM过程纽扣锭质量变化。结果表明，纯Al在PAM过程中质量随重熔次数的增加而递减。纯Ti在第一次熔炼时质量损失较多，但重熔过程中质量变化趋于稳定。这说明PAM过程中Al的挥发是造成合金质量损失的主要因素。TiAl二元合金和TiAl-Nb系合金在基本相同的熔炼条件下熔炼时，均由于Al过热度的增加而使质量损失增加。Al的质量损失随着熔炼次数的增加而增大，并且随Al含量的增加而增大。Nb的加入方式对纽扣锭的质量变化有影响。以纯Nb方式加入时的损失量高于以中间合金方式加入的损失量。对于TiAl-Nb合金，重熔6次后，其质量变化趋于稳定，也就是合金成分趋于均匀。TiAl-Nb合金重熔6次后质量相对损失只有0．33％，低于其他方法熔炼所引起的Al的损失。     

青海德合龙洼铜(金)矿成矿物质来源

德合龙洼铜(金)矿床为青藏高原北东端的一个岩浆热液型矿床,成矿作用主要划分为岩浆热液成矿期,包含石英-黄铜矿和毒砂两个成矿阶段。在分析该矿床成矿地质条件的基础上,系统地研究了矿区矿石硫、铅同位素组成,流体包裹体以及稀土元素特征,探讨了成矿物质来源。研究表明:矿区矿石硫样品δ34(SCDT)值分布范围较宽(-3.08×10-3～7.00×10-3),具有岩浆硫性质,可能来源于矿区侵入的中酸性岩体。各类型矿石铅同位素组成稳定,显示正常铅的特征,U和Th放射性成因铅含量较低。对各类型矿石铅同位素进行特征参数示踪、铅构造模式示踪和-β—-γ图解示踪的结果表明:矿区矿石铅主要为地壳与地幔混合的俯冲铅,主要来源于俯冲造山背景下形成的岩浆侵入体。流体包裹体及稀土元素地球化学特征均表明矿区成矿物质可能主要来源于岩浆侵入体,少许成矿物质可能来源于周围地层。总结矿区矿石硫、铅同位素、流体包裹体以及稀土元素分析结果,表明成矿物质主要来源于深部岩浆,这种岩浆的形成可能与板片俯冲造山有关,地壳与地幔组分均可提供成矿物质来源。     

Hydrothermal synthesis of vanadium oxide nanotubes by a facile route

Vanadium oxide nanotubes were synthesized by hydrothermal treatment from V2O5·nH2O sols as precursor and dodecylamine as structure-directing template. The morphology and structure of the nanotubes were characterized by SEM, TEM, XRD, TG-DTA and FTIR. The experimental results reveal that the duration of the hydrothermal treatment is of importance for obtaining Vox-NTs which have a layered structure. TG-DTA study indicates that V5+ cations in nanotubes are partially reduced to V4+ cations. The results from FTIR spectra indicate the difference in V-O vibrations between before and after hydrothermal treatment. From the results, it suggests that during hydrothermal treatment, the rearrangement of the vanadium oxide structure leads to the formation of VOx nanotubes from lamellar structure because of the presence of V4+ species.     

山东原疃金矿区煌斑岩的地球化学特征及其地质意义

为了解山东招远原疃金矿区内煌斑岩成因及其形成环境,开展了岩石地球化学研究。结果表明:矿区内煌斑岩SiO2含量为49.29%～52.71%(质量分数)、K2O/Na2O比值范围为1.17～2.91,属钾质钙碱性系列;岩石稀土元素分配型式右倾,具弱负铕异常;Ti、Mn、Cu和Zn等过渡元素富集,Cr和Ni相对亏损。结合煌斑岩K-Ar全岩年龄(102.29～119.34 Ma),认为本区煌斑岩来源于富集地幔,与早期苏鲁洋板块消减俯冲及太平洋洋壳熔融产生的富集流体均关系密切,其形成与华北克拉通中生代构造体制转折和岩石圈减薄事件有关,是胶东中生代大规模岩浆活动的一部分。     

Shape and size effects for marine immersion coupons

Abstract

The conventional wisdom in corrosion testing is that the size of the coupon and its perimeter/area ratio (the surface area of the perimeter expressed as a percentage of the total surface area) are important parameters and that these will have an effect on the results obtained. In order to test this proposition, sets of mild steel coupons of the same exposed areas but having different perimeters were immersed in a marine environment. Corrosion mass loss was observed for area/perimeter ratios in the range 3·52-6·03%. Mass loss observations were taken at various times to 12 months. Sets of rectangular coupons of different sizes (50 × 100 mm and 100 × 200 mm) were also immersed. The results indicate that any variation caused by shape or size falls within the expected variability of corrosion at a test location.     

电火花沉积Ni基涂层的质量过渡及电极损失

采用逐层沉积的方法,在基材表面获得了1-8层Ni基电火花涂层,探讨了电火花沉积过程中Ni基电极的质量过渡规律及电极材料的流失形式。结果表明:Ni基电极向基材的平均质量过渡系数为0.76;电极的损失有气化、液态溅射和氧化三种形式;氩气保护在沉积过程中起重要作用;随着沉积层厚度的增加,基材对涂层的稀释越来越小。     

Sources of rare earth elements REE+Y (REY) in Bayili Coal Mine from Wensu County of Xinjiang,China

By analyses on the trace elements of coals, host-rocks and wall-rocks, this study aims to trace the sources and evaluate the utilization prospects of REE+Y (REY) in coals from Bayili Coal Mine (Wensu, Xinjiang, China). The distribution patterns of REY in the coals are divided into two groups, flat-type and heavy REE-enrichment type (H-type). The REY of the former was mainly from the gneisses of the basement of the coal-bearing basin, and that of the later was partly from hydrothermal solution. The host-rocks show two types of REY patterns, middle REE-enrichment type (M-type) and H-type, which are due to the injection of REY from acid terrestrial water and hydrothermal solution, respectively. Almost all the coal samples are plotted into the promising area on the diagram of percentage of critical elements (REY_{def, rel}) vs ratio of sum of critical elements to the sum of excessive elements (C_outl) and half of the coal samples have high contents of Ga closing to the cut-off grade of Ga deposit as by-product, which indicate that the REY and Ga in Bayili Coal Mine are of utilization prospects as by-product.     

Intensification of the anodic erosion in electrospark alloying by the employment of pulse group

A modified electrospark alloying (ESA) method and installation were designed. The method based on periodically employed identical pulse groups in which the order of individual pulses, their numbers, electrical parameters of each and pause between them were adjustable. This ESA could be set for various directions according to technological aim. In the present study, the technological aim was to increase the mass loss of the treating electrode (anode) and the mass gain of the substrate (cathode).Experiments were conducted using sequence of identical pulse groups. Mass loss of the treating electrode and mass gain of the substrate were measured. During the experiments the following pulse parameters in a group were used: pulse current amplitude, pulse duration and pause between the pulses of a pulse group with ranges of 200-500 A, 100-400 µs, and 0-1800 µs respectively.Using the modified processing method, in some cases it was possible to increase the mass loss of the treating electrode by 50% or more compared to the conventional method.     

Unloading of powder compacts and their resulting tensile strength

We examine the unloading of an agglomerate of perfectly plastic spherical particles that have been compacted beyond their elastic limit and that exhibit some adhesion. The behaviour at the contact scale is derived from the model of Mesarovic and Johnson for the decohesion of two spherical particles [1]. The resulting springback that the powder compact experiences is calculated using the Discrete Element Method. An analytical equation for the extent of springback is proposed and coincides well with simulation results. The alteration of the compact during unloading is investigated through contact loss and the decrease of the contact area. The tensile strength of the resulting compact is calculated in isostatic conditions. While isostatic conditions represent the basis of this work, the effect of closed die conditions on the anisotropy of springback is also investigated. Finally, the consequences of adding hard elastic particles to form a composite are analysed in terms of the springback extent and the resulting loss of tensile strength of the agglomerate.     

皖南障公山地区金锑矿地物化特征与成矿原因分析

皖南障公山地区位于江南古隆起带北东部,属于障公山锡金—铜金成矿带西部,金属矿化活动强烈,有多处金属矿床,隐伏构造岩浆岩带的地球物理异常明显,成矿元素具有相对富集的特征.文章通过系统总结该区地质背景及地球物理、地球化学特征,认为区内金锑铅锌多金属矿与断裂构造关系密切,成矿元素具有相对富集的特征,在深部热液作用下出现活化转...     

海军黄铜HSn62-1的长期大气腐蚀行为

通过在3种典型大气环境中进行为期20年的现场暴露试验,研究海军黄铜HSn62-1的腐蚀质量损失和力学性能损失,采用扫描电子显微镜和XRD观察和分析腐蚀外貌、横截面和腐蚀产物。结果表明:HSn62-1的长期大气腐蚀质量损失随暴露时间的关系遵循C=KT n,腐蚀质量损失在工业酸雨大气环境中最大,在海洋大气环境中最小;腐蚀速率在工业酸雨和海洋大气环境中随时间逐渐降低,而在半乡村大气中逐渐升高;暴露20年后,HSn62-1的力学性能损失在工业酸雨大气环境中最大,在半乡村环境中最小;HSn62-1在3种典型大气环境中均发生脱锌腐蚀,腐蚀产物主要为Cu2O和ZnO。     

Gold process mineralogy: Objectives,techniques, and applications

The extractive metallurgy of gold is largely driven by mineralogical factors such as gold particle size; association with other minerals; coatings; presence of cyanicides, oxygen consumers, and preg-robbers; presence of refractory gold minerals; and locking of submicroscopic gold in sulfide and sulfarsenide mineral structures. Gold process mineralogy addresses all issues related to gold ore processing by the detailed study of an ore or a mill product. The methodology is widely used as a predictive tool in feasibility studies and during the process development stage, and as a trouble-shooting tool for mineral processing and hydrometallurgical operations. For more information, contact J. Zhou, SGS Lakefield Research Limited, P.O. Box 4300, 185 Concession Street, Lakefield, Ontario K0L 2H0, Canada; (705) 652-2035; e-mail yzhou@lakefield.com.     

陕西省金厂沟金矿床地质及地球化学特征

金厂沟金矿是青木川-苍社金矿成矿带上最有价值的矿(床)点之一,该矿床赋存于青木川-关口垭韧性剪切带的碧口群二亚群三岩组第一岩性段(Pt2-3bk23-1),成矿地质条件好,找矿潜力巨大。通过对该矿床地质特征和矿石、含矿岩系以及围岩的化学成分、微量元素、稀土元素、流体包裹体和硫同位素特征的系统分析,初步认为矿体受控于韧性剪切带并且矿化与磁铁石英岩化、黄铁矿化等围岩蚀变关系密切,载金矿物为黄铁矿,成矿物质来源于地层围岩,黄铁矿中的硫为水岩过程中流体对碧口群源岩的萃取,金元素的富集可能经过了多个阶段,成岩与成矿处于不同时期。     

云南蒙自某锡多金属矿的工艺矿物学(英文)

通过以自动化电子探针为基础的矿物扫描和定量分析,研究云南某锡多金属矿的工艺矿物学。结果表明,矿石中锡(0.98%)为最有回收价值的金属,锡石和黝锡矿为锡的主要矿物,占锡总量的94.90%;其他金属,如铜(0.261%)、锌(0.612%)和铅(0.296%)可作为有价金属回收。磁黄铁矿、黄铁矿、毒砂、闪锌矿、方铅矿、黄铜矿等矿物呈浸染状分布在矿石中。石英、绢云母和白云石为主要的脉石矿物。选择0.037mm作为最佳的磨矿细度以确保锡矿物的单体解离。     

超长五重对称铜微米线的水热合成

利用简单水热法制备了高质量的超长铜微米线,并采用X射线衍射(XRD)仪、扫描电镜(SEM)氮气吸附表征了产品的结构和形貌、织构性质。结果表明,所得铜微米线具有五重对称的正五棱柱状孪晶结构。铜微米线的形成,被归因于CTAB对铜{100}面的吸附和铜晶体结构内部张力的协同作用。并且研究了产品对过氧化氢辅助的罗丹明B的催化脱色性能。在微米铜上过氧化氢辅助的罗丹明B脱色反应的表观反应速率常数(ka=0.004 84 min~(-1))为体相铜的(k_a=0.0014 min~(-1))3.5倍,这归因于前者较高比表面积和微米尺寸。本制备方法具有产率高(高达85.9%)、操作简单等优点,易于放大制备。     

Role of climatic conditions on corrosion characteristics of structural steels

Corrosion behaviour of low alloy (LASS) and plain carbon (PCSS) structural steels exposed in different types of climatic conditions and nature of rust formed on their surfaces have been studied after 2 years of exposures. The test sites were chosen to represent four types of environments who strongly influence the corrosion of metals and alloys. They include (a) humid-saline, (b) humid-saline-urban (c) humid-industrial and (d) plain dry-urban environments. Mass loss, Raman spectroscopy, scanning electron microscopy and electrochemical impedance spectroscopic studies have been performed to study the corrosion behaviour and characterise the nature of rusts formed on these steels. Mass loss measurement technique has been used to determine the loss of thickness of steels during their atmospheric and salt spray exposures. Results indicate that the corrosion rate of steels is strongly influenced by the climatic conditions prevailing at the exposure sites. The presence of SO₂ and salinity in the environments change the structure and protective properties of rust formed on the steels’ surface. Electrochemical impedance and cyclic polarisation studies of the steels in simulated environments have been performed to understand the mechanism of corrosion in different climatic conditions.     

基于地球化学的水热还原矿化稳定砷的技术思路

砷作为有色金属矿物的共伴生元素,在有色金属冶炼过程中以含砷“三废”形式大量产出。由于砷具有强致癌性及毒性,导致砷的安全处置问题严重困扰着有色金属冶炼企业。本文通过阐述含砷废水中砷的两种稳定化工艺的研究进展,对比了现有稳定化工艺的优缺点,结合药剂稳定化和矿物稳定化的优点,借鉴砷元素在地球化学中的成矿规律,提出了硫化沉砷?水热还原矿化稳定砷的技术思路。首先采用硫化法脱除含砷废水中的砷,砷的沉淀率高达99.65%,硫化沉淀物在TCLP毒性检测中砷的浓度达到212.9 mg/L。然后采用As-S系一元水热还原矿化法和As-Fe-S系二元水热还原矿化方法稳定砷,稳定化产物分别为雌黄和雌黄?铁硫系(黄铁矿、硫化亚铁)混合物,在TCLP毒性检测中砷的浸出浓度分别为3.86 mg/L和2.65 mg/L。水热还原矿化工艺实现了含砷废水中砷的脱除及稳定化的目的,为水溶液中砷的脱除和稳定化提供了新的思路。     

Na2 S2 O3 对 16Mn 钢材在碱性溶液中的腐蚀影响研究

目的研究16Mn钢在4 g/L Na2S2O3的碱性溶液中的腐蚀行为和腐蚀机理。方法对16Mn钢的腐蚀形貌进行深入观察,对腐蚀产物的成分进行EDS分析,通过质量损失法和动力学方法分析腐蚀速率的变化,确定腐蚀机理。结果腐蚀形貌随腐蚀时间的推移由最初的点蚀发展为均匀腐蚀,腐蚀所生成的产物主要由O,S,Na,Fe元素组成。结论腐蚀产物主要是非晶态和晶态的羟基氧化铁和赤铁矿,随着腐蚀时间的延长,腐蚀越发严重,腐蚀速率逐渐下降。     

Cu-SAPO-34/堇青石的原位制备及其催化脱除柴油机车尾气中NO x

利用水热合成技术将Cu-SAPO-34分子筛直接合成到蜂窝状堇青石上,研究模拟柴油机车尾气中选择性催化还原NO x的能力。采用SEM、XRD、ICP和XPS表征整体式催化剂的形貌、结构、Cu含量和价态变化。结果表明：原位制备技术制备的Cu-SAPO-34/堇青石整体催化剂中的活性金属Cu具有很高的选择性催化还原NO x的活性,Cu的最佳上载量质量分数为0.30%-0.40%。在12000 h-1的体积空速下,在400-670℃之间,可将大部分的NO x催化还原成N 2;在36000 h-1的空速下,在300-620℃之间,还能将60%的NO x转化成N 2。水热老化后的催化剂较好的保持催化活性,表明催化剂具有较好的水热稳定性。