深井矿山膏体充填系统增阻减磨试验研究

针对深井矿山自流充填过程中的管道磨损问题,通过对浆体管输流动模式的分析,明确不满流是引起管道磨损的主要原因。从动量角度出发,研究了管道磨损机理及其影响规律。基于水力学理论推导,提出采用小管径增加系统阻力损失,减轻管道磨损的措施。会泽铅锌矿增阻减磨工业试验,将原Ф150mm管道部分更换为Ф85mm管道,管内压力值增加了6倍,满管率由7．4％提高至47％。研究结果表明,采用小管径管道是一种有效的减小磨损的措施,对于类似矿山具有借鉴意义。     

膏体充填管道冲洗技术研究及应用

应用膏体充填技术,对管道内粘结膏体及残渣的冲洗是关键的环节,本文对管道冲洗技术进行了研究,开发应用了满管自流冲洗技术,实现了对管道内粘结膏体及残渣的高效冲洗,保证了膏体料浆输送畅通,防止了管道内膏体粘结和膏体料浆输送意外事故的发生.     

深井膏体降压满管输送数值模拟研究

为提高深井矿山充填管道输送系统的可靠性,基于工程流体力学、计算流体动力学以及管道自流输送理论,结合某矿山实际情况,针对深井管道不满流输送带来的巨大冲击磨损以及管道输送不稳定等问题,提出低压满管流输送,对比3种管道组合方案特点,并运用FLUENT软件进行数值模拟与分析。研究结果表明,与高压满管流输送相比,低压满管流输送能使该矿山管道系统最大压力大大降低：当垂直管径与水平管径比值（k）约为0.53,系统流量提升到80 m³/h时,管道系统最大压力降为0.309 MPa,系统满管率由8.44%提高到65.6%,且方案3的管道组合可以保证浆体流动的稳定,管壁穿孔和磨损问题得到显著改善。     

深井似膏体充填管道输送特性研究

基于某金属矿深井开采充填料浆管道输送系统运行的工程实例,对充填料浆管道输送的动力学过程进行模拟分析。采用GAMBIT建立超深、超长似膏体管道输送二维动态模型,在此基础上运用FLUENT双精度解算器进行分离隐式模拟。研究结果表明:管道输送的阻力损失值小于重力产生的压力,可以实现自流输送;充填料浆在工作流速为3.06 m/s,自流输送的条件下,在弯管处得到最大速度4.10 m/s,水平段最大速度3.91 m/s,均满足稳定性要求。通过残差曲线监测所有相关变量的完整数据,证明模拟结果可靠,由此分析得出充填料浆管道输送系统安全可靠。     

深井矿山充填满管输送理论及应用

为了提高深井矿山充填管道的满管状态,提出以满管率作为系统满管状态定量描述指标,基于水力学输送理论推导了满管率的数学模型,并对其影响因素作了理论分析,明确减小管道直径及增大系统流量是提高满管率的最佳途径.基于管道两相流理论,建立了管径、流速以及满管率关系的数学表达式,为系统最佳输送参数的选取提供了理论依据.对某深井矿山充填系统进行的局部改造结果显示:将系统原φ150 mm水平管道替换为φ85 mm管道,同时增大流量至80 m³·h^-1,系统满管率为原来的6倍,有效减轻了管道磨损.     

全尾砂膏体充填系统充填质量稳定性研究

为研究武山铜矿全尾砂膏体充填系统充填质量稳定性,分别测试了充填系统的制浆输送稳定性、工业运行稳定性与充填体强度波动。试验结果表明,全尾砂膏体充填系统的深锥浓密机在储料时间不超过 3 d的情况下可实现相对稳定的排料与生产,若延长储料时间,物料易在深锥底部板结,进而导致排料流量与浓度的不稳定。考虑采矿充填的不平衡性,矿山应尽量避免深锥浓密机长时间储料,并可在深锥底部增加流态化活化造浆系统,保障排料稳定性。在工况条件相对稳定的情况下,武山铜矿全尾砂膏体充填系统工艺流畅,充填技术指标优异,超过设计和建设要求,且充填体 28 d 强度均能达到 4 MPa 以上,能够满足回采过程中充填体的强度需求。充填系统运行可靠、工艺参数稳定,极大地提高了充填体质量,为进一步实现安全高效开采提供了安全保障。     

我国西部矿区膏体充填开采技术浅析

我国西部矿区资源储量十分丰富,地表生态环境是非脆弱,如何在提高矿产采出率的同时保护西部矿区脆弱的生态环境是矿山工作者亟需考虑的现实问题。充填开采以充填材料支撑顶板控制覆岩破坏及地表下沉,即有效提高了采出率,又减少生态环境破坏等问题。技术可行,经济合理,安全可靠。     

早强剂在膏体充填中的作用机理及其应用研究

缩短充填料浆的凝结时间是提高充填体早期强度、降低充填成本的有效途径之一。为此,开展了早强剂在膏体充填中的应用研究。试验表明,充填料浆中添加水玻璃能满足采场对膏体凝结的要求。工业试验表明,添加10%水玻璃后膏体最终初凝时间为450 min,采场终凝时间为3 d。     

膏体充填系统的完善与发展研究

简要介绍了二矿区膏体充填系统投产的意义和价值，详细分析和探讨了该系统目前存在的问题，对该系统的完善和发展方向提出了作的见解。     

深井充填两相流管道沉积机理研究

为解决某深井矿山因管道沉积造成的安全生产问题,通过对深井充填管道沉积机理进行研究,基于固液两相流相关理论,分别从细颗粒结垢和粗颗粒沉积2个方面来阐释两相流管道沉积机理。运用FLUENT流体动力学软件进行建模和分析,将浆体中固体细颗粒与清水混合的均质悬液作为连续相,较粗颗粒作为离散相,根据浆体中粗颗粒的浓度分布和管道速度分布特点来确定管道内颗粒物沉积规律。结果发现,充填两相流管道沉积的主要原因是细颗粒结垢和粗颗粒沉积相结合。数值模拟的两相流充填管道沉积过程与理论分析提出的粗细颗粒沉积物理模型相吻合。     

振动筛合金篦条磨损机理及抗磨损技术

分析了山西焦化股份有限公司振动筛合金篦条磨损情况,对合金篦条磨损机理进行了研究,提出控制磨蚀和提高材料耐磨洼的方法。     

Wear Behavior and Mechanism of Spheroidal Graphite Cast Iron

Wear behavior and mechanism of spheroidal graphite cast iron were studied on a pin-on-disk elevated temperature wear tester. The phase and morphology of worn surfaces were examined by X-ray diffraction and scanning electron microscopy. Results show that with an increase of load, wear rate of spheroidal graphite cast iron gradually increases under low loads, rapidly increases or potentially increases under high loads; wear rate increases with increasing ambient temperature. At 25–200 °C, adhesive wear prevails; oxidative wear and adhesive wear coexist at 100 °C. As load surpasses 150 N at 100 °C, extrusive wear appears. The elevated-temperature wear of spheroidal graphite cast iron is a physical and chemical process including the following reactions: xFe + y/2O₂?Fe_xO_y, 2C + O₂?2CO and Fe_xOy + yCO?xFe+yCO₂. Hence, at 400 °C, the amount of graphite and tribo-oxides are substantially reduced because of reductive function of graphite. It can be suggested that wear-reduced effect of graphite and tribo-oxides is impaired.     

基于KPCA-IPSO-LSSVM的充填管道磨损风险预测

为克服传统预测模型存在的适用性差、预测精度不足和参数选取随意性强等缺陷,提出了一种将核主成分分析法(KPCA)、改进粒子群算法(IPSO)与最小二乘支持向量机(LSSVM)相结合的充填管道磨损风险预测新方法.通过KPCA对管道磨损影响因素进行特征提取,将提取结果作为LSSVM的输入,同时利用具有较强全局搜索能力的IPS...     

Selection of Heat Treatment Process and Wear Mechanism of High Wear Resistant Cast Hot-Forging Die Steel

 Dry sliding wear tests of a Cr-Mo-V cast hot-forging die steel was carried out within a load range of 50-300 N at 400 ℃ by a pin-on-disc high-temperature wear machine. The effect of heat treatment process on wear resistance was systematically studied in order to select heat treatment processes of the steel with high wear resistance. The morphology, structure and composition were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS); wear mechanism was also discussed. Tribo-oxide layer was found to form on worn surfaces to reduce wear under low loads, but appear inside the matrix to increase wear under high loads. The tribo-oxides were mainly consisted of Fe3O4 and Fe2O3, FeO only appeared under a high load. Oxidative mild wear, transition of mild-severe wear in oxidative wear and extrusive wear took turns to operate with increasing the load. The wear resistance strongly depended on the selection of heat treatment processes or microstructures. It was found that bainite presented a better wear resistance than martensite plus bainite duplex structure, martensite structure was of the poorest wear resistance. The wear resistance increased with increasing austenizing temperature in the range of 920 to 1120 ℃, then decreased at up to 1220 ℃. As for tempering temperature and microstructure, the wear resistance increased in following order: 700 ℃ (tempered sorbite), 200 ℃ (tempered martensite), 440 to 650 ℃ (tempered troostite). An appropriate combination of hardness, toughness, microstructural thermal stability was required for a good wear resistance in high-temperature wear. The optimized heat treatment process was suggested for the cast hot-forging steel to be austenized at 1020 to 1120 ℃, quenched in oil, then tempered at 440 to 650 ℃ for 2 h.     

Abrasive Wear Behavior and Mechanism of High Chromium Cast Iron

The abrasive wear behavior of high chromium cast iron(containing 12.9mass%chromium)austenitized at1 050 ℃for 2hand austempered in salt bath at 320℃for 4hwas evaluated.Abrasive wear was performed using alumina abrasive under four different loads,namely 50,100,150,and 200 N,for 36 000 cycles.The worn surfaces and wear debris were analyzed by scanning electron microscopy,laser confocal microscopy and X-ray diffraction.Microhardness profiles were also obtained in order to analyze the strain-hardening effects beneath the contact surfaces.Results indicate that the retained austenite in high chromium cast iron has experienced induced martensitic transformation after tests,for small amounts of retained austenite could be detected by X-ray diffraction.In addition,there is a close relationship between wear mechanism and test load.Under the condition of lower test load,the wear mechanism is an uninterrupted and repeated process,during which matrix is cut at first and then fine carbides flake off.As to higher test load,scratching and spalling induced by cleavage fracture of blocky carbide are the wear mechanism.     

奥氏体耐磨锰钢的研究现状与进展

在综述奥氏体耐磨锰钢的特点、微观结构、加工硬化机理、磨损与耐磨机理的基础上，提出应深入开展其微观结构与组织及性能的关系以及变形与磨损行为的系统研究，为该类钢的生产和应用提供了更充分的理论和实验依据。     

两相流抗磨蚀合金喷熔层的耐磨性

 采用氧 乙炔火焰喷熔工艺在45号钢表面喷覆两相流抗磨蚀合金(NiCrWCe)喷熔层，用扫描电子显微镜和X射线衍射仪分析了这种喷熔层的显微组织结构、物相组成和性能，并对喷熔层的耐磨性进行了试验研究。结果表明：两相流抗磨蚀合金喷熔层与基体形成了牢固的冶金结合，结合层中含有较高比例的硬质相；稀土可显著提高喷熔层的耐磨性；在试验条件下，两相流抗磨蚀合金喷熔层的耐磨性明显高于ZGCr5Mo及Cr18Ni12Mo2Ti合金。