高银铅铜混合精矿选矿试验研究

某高银铅铜混合精矿为铜铅混浮产品,表面受到浮选药剂严重污染,导致铜矿物与铅矿物可浮性差异微小,给铜铅分离带来非常不利的影响,其银品位达到4208.0 g/t,铅品位43.28%,铜品位3.39%,98.80%的银赋存于方铅矿。采用“活性炭脱药-抑铅浮铜”工艺流程处理,环保高效的方铅矿抑制剂GYC,高效铜捕收剂SAC,全流程试验获得银品位4839.2 g/t,银回收率97.36%,铅品位50.05%,铅回收率97.90%的银铅精矿;铜品位20.16%,铜回收率91.23%,银品位724.6 g/t,银回收率2.64%的铜精矿,实现了混合精矿中银铅与铜的高效回收。     

云南某含银铜矿伴生银矿物强化回收实验研究

云南某含银铜矿石银品位为21.77 g/t,主要赋存于黄铜矿、游离银和磁黄铁矿中,在选别过程中铜硫分离时兼顾银的回收具有一定的难度。采用抑硫浮铜流程,研究筛选出石灰及Z200作为合适的调整剂和高效捕收剂,在抑制黄铁矿、磁黄铁矿的同时强化银的回收。最终闭路试验获得了品位23.92%、回收率97.10%的铜精矿,且含银136.38 g/t,银的回收率达到77.05%,实现了铜硫分离的同时强化银的回收。     

某含银高硫铜矿的综合回收试验

某含银高硫铜矿含铜0.76%、硫24.35%及银34.92 g/t,有价矿物种类多、矿石性质复杂,采用抑硫优先浮选铜-活化浮选硫的原则工艺流程进行试验,配合石灰作为硫化铁矿物抑制剂以及筛选出丁基黄药+酯-105作为硫化铜矿物的组合捕收剂,强化了银在铜精矿中的富集。在选定工艺条件下,可获得铜品位21.60%、银品位602.84 g/t的铜精矿(铜和银回收率分别为89.30%和54.39%),硫品位45.60%、银21.55g/t的硫精矿(硫和银回收率分别为89.79%和29.59%),实现了铜、硫和银的综合回收利用。     

高铁富金铜硫多金属矿选矿实验研究

某高铁富金铜硫多金属矿铁品位为31.81%,金品位为1.37 g/t,铜品位为0.70%,硫品位为6.52%,矿石中71.83%的金赋存于铜矿物、黄铁矿、磁铁矿等矿物,而铜矿物、黄铁矿、磁铁矿的嵌布粒度均较粗,普遍在+0.04 mm。采用“优先浮选铜-活化浮选硫-硫尾磁选回收铁”联合工艺处理该矿石,并采用ZA作铜捕收剂,全流程实验获得金品位27.80 g/t,铜品位20.60%,金回收率59.05%,铜回收率83.29%的铜精矿;金品位2.16 g/t,硫品位45.07%,金回收率20.24%,硫回收率86.25%的硫精矿;金品位0.80 g/t,铁品位60.83%,金回收率14.25%,铁回收率45.90%的铁精矿。实现了矿石中金铜铁及载体矿物的高效回收。     

纳米比亚某含银硫化铜矿选矿试验研究

纳米比亚Karas矿区罗雷铜矿区的原生矿铜主要以黄铜矿、斑铜矿等硫化铜矿物形式存在,银分别以银黝铜矿为主的独立银矿物和以黄铜矿为载体的载体银矿物形式存在,铜、银品位分别为0.60%和3.03 g/t。浮选试验结果表明,矿样适当细磨至-0.074 mm占80%,以石灰做调整剂,Z200做捕收剂,在矿浆p H值为8的条件下,可获得铜品位22.3%,银品位61.8 g/t的含银铜精矿,铜、银回收率分别为90.6%和51.8%。     

云南某含银铜铅混合精矿分离试验研究

云南某铜铅混合精矿含Cu 8.14%、Pb 38.57%、Ag 251.62 g/t，对其进行浮选试验研究铜铅的分离。通过条件试验，确定在磨矿细度为-200目含量为93.85%的情况下，抑制剂CMC+亚硫酸钠用量选择1000 g/t，捕收剂Z-200用量选择10 g/t。采用“抑铅浮铜”一粗三精一扫的闭路试验流程，获得铜品位24.73%、回收率87.24%、含铅品位6.23%的铜精矿；铅品位62.71%、回收率84.48%，含铜0.86%的铅精矿。银在铜铅精矿中进一步富集的总回收率为73.04%，实现了该铜铅混合精矿的分离及银的进一步富集。     

河北某石英脉型金矿石选矿试验研究

河北某石英脉型金矿石金品位5.4 g/t,银品位6.4 g/t。针对该矿石性质,开展浮选试验,在最佳药剂制度条件下浮选闭路试验获得精矿金回收率为78.9%,银回收率35.6%,金品位44.0 g/t,银品位23.5 g/t。为提高选矿指标,开展重选与浮选工艺联合试验。与单一浮选工艺相比,重、浮联合工艺获得混合精矿金回收率提高6.8%,银回收率提高2.2%。     

云南某铜尾矿中铜和金的选矿回收试验

云南某铜尾矿主要金属矿物有黄铜矿、黄铁矿、磁黄铁矿等,黄铜矿以原生硫化铜为主,金以裸露金和黄铜矿包裹金为主。为综合回收其中有价铜、金,进行了选矿试验。试样在磨矿细度为-200目占85%的情况下采用两次粗选、第二次粗选后扫选、两次精选、第二次精选后扫选、混精矿再磨至-325目占85%、粗选后扫选精矿再磨至-325目占85%、中矿循序返回流程处理。最终获得铜品位15.51%、回收率68.34%、产率1.41%的铜金精矿,其中的金品位19.93 g/t、回收率54.04%,银品位231.72 g/t、回收率41.89%。     

提高锌浸出渣中银浮选回收率的研究

某湿法炼锌厂低酸度锌浸出渣中53.8%的银存在于难完全回收的闪锌矿上,其回收是提高浮选回收率的关键。经对比浮选和正交试验获得了浮选粗选最佳药剂制度,捕收剂为丁铵黑药(900g/t)和Z-200(50 g/t),载体活性炭(2000 g/t),起泡剂2#油(100 g/t)。一粗一精一扫开路试验表明,在非强充气和非强搅拌条件下,浮选精矿银品位为8210 g/t,较现有工艺(3000 g/t)大幅提高;银回收率为64.7%,与现有工艺(60%~64%)相当。     

湿法炼锌酸浸出渣浮选回收银试验

传统锌精矿伴生银回收,均是从挥发窑渣中进行,由于矿物性质变化,导致银无法有效回收。进行了从锌酸浸出渣中浮选回收银的研究,解决了锌精矿中伴生银回收的问题。某湿法炼锌浸出渣含Ag 350 g/t,Au0.01 g/t,Pb 3.87%,Zn 17.45%,Cu 1.38%,银主要以自然银存在,占60.13%。采用高效捕收剂HT-1#、起泡剂HT-2#进行浮选,经过一粗四精三扫工艺,获得银精矿产率4.39%,含银6616 g/t,银回收率82.98%,取得良好的经济技术指标。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。