含硫物质对大洋多金属结核金属化还原的影响

在还原温度1 100℃、还原时间2.5h、无烟煤配入7%、添加剂4%的条件下,研究不同含硫物质的加入对大洋多金属结核金属化还原—磁选分离效果的影响。结果表明,含硫物质的加入在一定程度上提高了精矿产率和有价金属回收率,但是磁选精矿品位有所下降。通过扫描电镜观察,发现精矿中大部分硫形成铁锰硫化物与合金颗粒连生在一起。     

锰含量对超细晶粒C-Mn钢显微组织和机械性能的影响

研究了锰含量对两种超细晶粒C-Mn钢(碳含量为0.2%)显微组织和机械性能的影响.大压下量温变形和连续退火可形成超细晶粒显微组织,最终钢的显微组织由含有细小渗碳体颗粒的超细粒状铁素体组成.渗碳体颗粒内锰富集,因此,铁素体晶粒的平均尺寸随锰含量的增加而减小(锰含量从0.74%增加到1.52%时,晶粒尺寸由1.3μm减小到0.8μm).锰含量越高,晶粒越细.延展性和韧性相同的情况下,增加锰含量将提高钢的强度.     

脉冲电场对锰铁氧化物还原特性的影响研究

本实验以常温常压条件下锰铁氧化物还原、凝固的研究为基础,推广到外场(脉冲电场)作用下锰铁氧化物还原规律的研究,用不同脉冲电场电压处理锰铁氧化物熔体,促进C的还原反应,用Im ageJ软件统计锰的晶粒尺寸和各个面积区间锰的晶粒个数,得到脉冲电场能促进锰铁氧化物二次还原,且与电场电压和锰铁氧化物的组成有关,电场处理的二次反应析出颗粒尺寸分别为3.383μm、4.332μm、3.224μm、4.356μm,还原锰的面积含量分别为6.2%、5.5%、6.4%、5.1%。     

Y_2O_3对WC-10Co硬质合金性能的影响

采用真空烧结工艺制备了WC-10Co硬质合金。研究了Y_2O_3添加量对WC-10Co硬质合金晶粒尺寸、力学性能、磁性能的影响。结果表明,添加Y_2O_3能使合金晶粒细化且颗粒尺寸更加均匀;Y_2O_3的加入可提高合金力学性能,当Y_2O_3添加量为0.4%时合金的力学性能最佳,合金硬度为94.5 HRA,抗弯强度为2 250 MPa;添加Y_2O_3能提升硬质合金的钴磁、矫顽磁力。     

红土镍矿高料层碳热还原试验

 红土镍矿是生产镍铁合金的主要原料之一,其碳热还原后的镍铁金属颗粒尺寸对后期磁选分离至关重要。基于此,进行了红土镍矿在高料层条件下的碳热还原试验研究,考察了还原温度、时间及添加剂CaO等对还原后镍铁金属颗粒尺寸的影响规律和作用机理。试验结果表明,在配碳量C/O(质量比)为1.0、还原温度为1400 ℃、还原时间为45 min的条件下,还原效果最佳,还原后大于40 μm的金属颗粒约占70%,最大颗粒约为100 μm。对该还原条件下得到的金属化球团进行磁选分离可得到镍铁合金,基本可以将金属镍回收。研究结果可为红土镍矿碳热还原工艺的应用提供操作参数和理论依据。     

粉碎方式对细颗粒碳化钨性能的影响

采用球磨粉碎和气流粉碎两种方式,对相同细颗粒碳化钨块进行粉碎加工,对粉碎后的碳化钨利用X射线衍射、扫描电镜及激光粒度仪等进行分析,同时制备成硬质合金并对样品进行金相检测,对比两种粉碎工艺制备碳化钨的质量。结果表明:球磨粉碎法制备的碳化钨粒度分布宽泛,团聚颗粒多,比表面低,亚晶尺寸大,合金中的粗晶粒较多;而气流粉碎法制备的碳化钨粒度分布集中,团聚颗粒少,比表面高,亚晶尺寸较小,制备的合金晶粒更均匀。     

磁记录用铁磁金属超微粒子及其稳定性

本文探讨了采用氢还原法,以硫酸亚铁盐为原料制取高密度、高质量磁记录所需针状铁磁金属(合金)超微粒子的工艺过程及工艺条件。着重研究了铁磁金属(合金)超微粒子的稳定性以及掺杂处理对其磁性能及物理性能的影响。结果表明,在采用氢还原法制取针状铁磁金属(合金)超微粒子时,均匀、密实、表面平滑的针状α-FeOOH超微粒子的制取是关键之一;同时,合适的热处理及还原工艺,可减少颗粒的孔洞,防止颗粒的断裂、球化和烧结;而在α-FeOOH中掺加适量的Al、P杂质,可改善铁磁金属超微粒子的物理性能及磁性能。颗粒经过钝化后,由于每个颗粒的表面均形成一层致密、连续的氧化膜从而可减缓其进一步氧化。     

红土镍矿深度还原-磁选富集镍铁实验研究

采用深度还原-磁选工艺,以煤粉为还原剂,添加氧化钙作助溶剂,在微熔化,不完全造渣的条件下,将矿石中镍和铁的氧化物还原成金属镍铁,然后经磁选方法使金属镍铁在磁性产品中得到富集.结果表明,深度还原最佳工艺条件为:还原温度1 300℃,还原时间60 min,配煤过剩倍数2.在此工艺条件下得到镍、铁质量分数分别为5.01%,22.46%的镍铁产品,镍、铁回收率分别为96.05%,79.69%.对深度还原过程研究表明,还原物料中镍和铁以金属合金颗粒形式存在,高温有利于镍铁金属相凝聚,适当延长还原反应时间有利于镍铁颗粒的还原和聚集长大,进而有利于磁选富集.     

热处理方式对MIMFe-50Ni合金磁性能的影响

以羰基铁粉和羰基镍粉为原料粉末,采用金属注射成形(MIM)工艺制备Fe-50%Ni软磁合金,分别采用炉冷、空冷、油冷和液氮冷等4种冷却方式对该合金进行热处理,借助TEM分析和居里温度测量等检测技术系统研究冷却方式对其磁性能的影响,并对不同热处理方式导致试样磁性能差异的根本原因进行分析。结果表明:热处理冷却方式对注射成形Fe-50%Ni软磁合金的密度、杂质含量和晶粒尺寸影响都不大,但对磁性能的影响非常明显,随冷却速率加快,该合金的矫顽力先增大后减小。液氮冷却的试样磁性能最好,其饱和磁感应强度为1.45T,矫顽力为7 A/m,最大磁导率为72.47 mH/m,初始磁导率为10.12 mH/m。油冷和液氮冷却试样中存在亚稳FeNi有序相,导致合金的磁性能大幅提高。     

高温合金800H的动态再结晶及其模型的建立

采用单道次热压缩实验分析了变形参数对高温高强合金800H热变形的影响。结果表明:初始晶粒尺寸越小、变形温度越高、变形速率越小,越容易出现动态再结晶现象;同样,在能够发生动态再结晶的情况下,变形量的增大促使动态再结晶充分进行;利用拟合得到了800H合金的动态再结晶激活能、临界变形量模型、再结晶动力学模型、再结晶运动学模型和再结晶晶粒尺寸模型。采用Deform-2D进行晶粒度模拟,仿真模拟结果与金相统计出的再结晶晶粒尺寸变化趋势一致,平均误差为4.5μm。极小的平均误差表明所建模型与实际情况相符合,可以用于预测800H合金热变形过程中再结晶的晶粒尺寸。     

海底多金属结核理化特性分析

对海底多金属结核矿合同区样品进行了物理化学性质分析,掌握其基本的物理化学特性。结果表明,本研究结核形状多样,粒径在1~100mm,-50mm占90%,绝大部分集中在10~50mm;主要金属Mn、Fe、Ni、Co、Cu含量分别为23.84%、5.80%、1.04%、0.17%、0.87%,其他成分中硅和铝含量较高,总含水量22%,含水率高;平均堆密度1.04g/cm^3,平均真密度3.25g/cm^3;结晶程度相对较好,绝大部分锰呈10水锰矿存在,少量岩屑矿物为石英及长石。添加适量的CaF2对于降低样品熔融点温度效果明显,可以使相变向低温方向移动。经还原焙烧-湿式磁选处理工艺,很好地实现了锰和镍钴铜铁选择性还原分离富集。     

Solid-State Metalized Reduction of Magnesium-Rich Low-Nickel Oxide Ores Using Coal as the Reductant Based on Thermodynamic Analysis

The solid-state metalized reduction of magnesium-rich low-nickel oxide ore using coal as a reductant was studied based on thermodynamic analysis. The major constituent minerals of the ore were silicates and goethite. The former was the main nickel-bearing mineral, and the latter was the main iron-bearing mineral. Single factor tests were conducted to investigate the effects of reduction temperature, duration, and coal dosage on the beneficiation of nickel and iron such that optimal conditions were achieved. Considering the low recoveries of nickel and iron (Ni, 13.9 pct; Fe, 30.3 pct) under the obtained optimal conditions, an improved process, adding CaF₂ before the reaction, was proposed to modify the solid-state metalized process. The results showed that the recoveries of nickel and iron reached to 96.5 and 73.4 pct, respectively, and that the grades of nickel and iron in the concentrate increased from 2.5 and 62.6 wt pct to 6.9 and 71.4 wt pct, respectively. Nickel and iron in the absence of CaF₂ were metalized; nevertheless, the size of ferronickel particles was only 1 μm. Furthermore, alloys in the presence of CaF₂ aggregated and exhibited bands with a length greater than 200 µm. These observations suggested that CaF₂ could effectively reduce the surface tension of the newly generated alloy interface and promote the migration and polymerization of the alloy particles, which improves the beneficiation of nickel and iron by magnetic separation.     

Studies on the Extraction of Manganese from Sea Nodule Residue as Ferrosilicomanganese

Most of the extraction processes developed for the polymetallic sea nodules concentrated mainly on the recovery of strategically important metals viz. Cu, Ni and Co. The residue generated in such processes is quite high enough to upset the environmental balance for industrial scale operation. The economics of the process too cannot be favourable if manganese in the residue is not recovered. In this study an attempt has been made to utilize this residue, containing appreciable amount of manganese (about 20%) for producing ferrosilicomanganese, an important ferroalloy primarily used for deoxidation in the steel industry, through smelting process. In order to have an alloy of standard grade, the residue is enriched in its manganese content, by blending it with ferromanganese slag. Bench scale studies indicate that it is possible to produce ferrosilicomanganese, of the grade required by the steel industry, by reduction smelting of the sea nodule residue with ferromanganese slag. Metal recovery, however, was less because of metal entrapment.     

铁硫合金制备工艺的优化

在火法炼铜过程中,用密度和熔点合适的铁硫合金消除沉降电炉过厚的炉结是较为理想的方法。结合前期研究,对制备铁硫合金工艺进行了优化。运用金相显微镜、XRF进一步探索了制备铁硫合金的过程中,二元碱度（R=m（CaO）/m（SiO₂））、碳粒度及碳添加比对铁硫合金密度和汇聚率的影响。结果表明:二元碱度为1.3、碳粒度为0.25~ < 0.42 mm、碳添加比为1时,制备出的铁硫合金密度和汇聚率较优;较优制备条件下铁硫的实际利用率为85.11%,损失在渣中的铁远高于硫,因此制备出的铁硫合金实际硫含量偏高。      

水雾化制备FeSiCr软磁粉末磁性能研究

采用水雾化工艺制备FeSiCr软磁合金粉末,经筛分合批后制成粒径（D₅₀）5～40 μm的样品。研究了不同粒径FeSiCr软磁粉末对磁性能的影响,为产品应用提供指导性实验。研究结果表明,随着粉末粒径的增大,粉心的磁导率逐渐增大,在100～1000 kHz的频段范围内,磁导率衰减幅度小于5%,具有较好的频率特性。随着粉末粒径增大,粉心的抗直流偏置能力降低,损耗性能恶化,其中增加的损耗主要来源于颗粒内部的涡流损耗。     

Upgrading of Low-Grade Manganese Ore by Selective Reduction of Iron Oxide and Magnetic Separation

The utilization of low-grade manganese ores has become necessary due to the intensive mining of high-grade ores for a long time. In this study, calcined ferruginous low-grade manganese ore was selectively reduced by CO, which converted hematite to magnetite, while manganese oxide was reduced to MnO. The iron-rich component was then separated by magnetic separation. The effects of the various reduction parameters such as particle size, reduction time, temperature, and CO content on the efficiency of magnetic separation were studied by single-factor experiments and by a comprehensive full factorial experiment. Under the best experimental conditions tested, the manganese content in the ore increased from around 36?wt?pct to more than 44?wt?pct, and almost 50?wt?pct of iron was removed at a Mn loss of around 5?pct. The results of the full factorial experiments allowed the identification of the significant effects and yielded regression equations for pct Fe removed, Mn/Fe, and pct Mn loss that characterize the efficiency of the upgrading process.     

铜精矿与铜冶炼渣的物相鉴别

按国别收集我国主要进口铜精矿及铜冶炼渣样品,采用X射线荧光光谱仪(XRF)、X射线衍射仪(XRD)、矿相显微镜、扫描电子显微镜(SEM)等多仪器联用的方法检测铜精矿、铜冶炼渣物相特点,判断两者是否存在显著的差异。结果表明,铜冶炼渣主要物相是硅酸铁,其颗粒表面有分布均匀、大小一致的气孔等外观特征。进口铜精矿的主要物相为硫化铁铜或氧化铜,颗粒表面平滑、不规则的分布一些形态各异的气孔。铜冶炼渣与铜精矿相比在物相及颗粒特征方面有明显的差异,可以作为鉴别依据。按比例在铜精矿中混入铜冶炼渣,制备含有不同含量梯度铜冶炼渣的混合样品11个,用上述4种检测手段进行鉴别,发现X射线荧光光谱仪无法确定样品中是否掺杂铜冶炼渣;电子显微镜、矿相显微镜、X射线衍射光谱仪可鉴别出铜精矿掺杂铜冶炼渣,检出限分别为1%、5%、10%。最终确定铜精矿与铜冶炼渣的物相鉴定方法为应用X射线荧光光谱仪初查,辅以X射线衍射仪、矿相显微镜及扫描电子显微镜找到铜冶炼渣的特征物相和颗粒。鉴别方法的确立达到了从源头堵住入境铜冶炼渣易名铜精矿和铜精矿掺杂铜冶炼渣闯关的目的,为海关监管和资源利用提供了技术支持。     

轻质高锰钢的组织及力学性能

摘要：高锰钢作为耐磨材料,被广泛应用于高载荷或冲击磨损的工况下。轻量化是钢铁材料发展的趋势之一,也是满足工业节能降耗需求的重要途径。为了明确轻质化元素铝对此类钢种的影响,以高锰钢ZGMn18Cr2为基础,通过控制铝含量,得到成分不同的轻质高锰钢。利用金相显微镜（OM）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）及电子探针（EPMA）等手段对其微观组织进行表征,并采用硬度测试、室温冲击和拉伸实验测试了其力学性能。结果表明,随着铝的质量分数在0~11%范围内不断增大,高锰钢的密度得到明显降低,铁素体相逐渐稳定,晶粒得到细化。同时,材料的抗拉强度、屈服强度、伸长率和室温断裂冲击功先升高后下降;硬度则先下降后升高。这些性能的改变与铝含量的变化、第二相铁素体的出现以及含铝碳化物的数量有重要关系。     

Experimental study on preparation of manganese rich slag by direct reduction melting separation of low manganese high iron ore

In this experiment, low manganese high iron ore with manganese grade of 27.7% and iron grade of 18.1% was used as the research object to reduce and prepare manganese rich slag. The obtained manganese rich slag can be used for smelting silicon manganese alloy to achieve the purpose of efficient utilization of low grade manganese ore. According to the results of composition analysis, XRD analysis and particle size analysis of the ore, the reduction melting separation method was used to prepare manganese rich slag from low manganese ore. The experimental results show that each parameter has a greater impact on the mass fraction of manganese and iron in the reduction melting separation slag of low manganese high iron ore and the recovery rate of manganese under the single factor test. At the same time, combined with the Box Behnke principle design scheme, three experimental factors including temperature, alkalinity and carbon content were selected. The influence of each factor on the recovery rate of manganese was studied by response surface method. The experimental results were analyzed to establish the corresponding polynomial model, and the optimal process conditions were as follows: reduction temperature of 1402℃, alkalinity of 0.10, carbon content of 10.04%, and the recovery rate of manganese was 97%. A verification test was conducted under the optimal conditions; the recovery rate of manganese was 95.80%, and the error was 1.24%, which proved that the response surface method was a reliable and accurate prediction model. At the same time, the results are instructive for the application of low manganese and high iron ore.     

低锰高铁矿直接还原-熔分制备富锰渣试验研究

摘要：试验以锰品位27.7%,铁品位18.1%的低锰高铁矿为研究对象还原制备富锰渣,生产得到的富锰渣可用于冶炼硅锰合金,以达到高效利用低品位锰矿的目的。根据该矿的成分分析、XRD分析和粒度检测分析结果,采用还原 熔分法对低锰矿进行还原制备富锰渣试验,试验结果表明：单因素试验下各参数对低锰高铁矿的还原-熔分后渣中Mn、Fe元素的含量和Mn元素的回收率均有较大影响,同时结合Box-Behnke原理设计方案,选取温度、碱度以及配碳量3个试验因素,通过响应曲面法研究各因素交互作用下对Mn元素回收率的影响规律,对试验因素进行优化分析,建立相应的多项式模型。模拟优化得到最优的工艺条件为：还原温度1402℃,碱度0.10,配碳量10.04%,Mn元素回收率为97%。在最佳条件下做验证试验得出Mn元素回收率为95.80%,误差1.24%,证明响应曲面法预测模型具有可靠性,同时对低锰高铁矿的应用有重要指导意义。