高磷铁矿碳热还原同步脱磷的实验研究

为探索高磷铁矿的有效利用途径,对高磷鲕状赤铁矿进行碳热还原同步脱磷实验研究,在含碳球团中添加CaO和Na2C O3作为脱磷剂,采用D T A-T G- M S综合热分析、X R D、SE M、E DS等方法分别对高磷鲕状赤铁矿的碳热还原过程以及还原产物进行分析. 结果表明,添加适量的CaO和Na2C O3可以显著提高脱磷率;在1 573 K、Na2C O3添加量为2 %、含碳球团碱度为1 .2的条件下,高磷鲕状赤铁矿能够被快速还原成含磷0 .09 %、含碳4 .6 %的碳饱和铁,脱磷率达到95 %;生铁中碳过饱和后以片状石墨的形态析出,生铁中的磷以夹杂物Ca3（P O4）2和Na2Ca4（P O4）2SiO4的形式存在     

Removal of phosphorus from iron ores by chemical leaching

1 INTRODUCTION With the rise of the price of iron ores in the global market, the iron and steel companies in China have to increase the proportion of domestic iron ores in iron-making production. However, iron ores produced in China commonly contain many impurities, such as phosphorus, sulphur, silica, etc[1]. Phosphorus is one of the main harmful elements to ferrous metallurgy, and it will affect the quality of iron and steel products[2]. At present, China has explored some large mines,…     

梅山铁矿磷的赋存特征及降磷途径

采用化学分析、光学显微镜、电子探针等手段研究表明，梅山铁矿石中的磷是以磷灰石独立矿物形式存在的。对磷灰石在矿石中的嵌布特点、解离性，及其在选矿过程中的走向进行了详细研究。根据研究结果提出了该矿铁精矿脱磷的合理途径。     

Phase transformation and reduction kinetics during the hydrogen reduction of ilmenite concentrate

The reduction of ilmenite concentrate by hydrogen gas was investigated in the temperature range of 500 to 1200°C.The microstructure and phase transition of the reduction products were studied by X-ray diffraction(XRD),scanning electron microscopy(SEM),and optical microscopy(OM).It was found that the weight loss and iron metallization rate increased with the increase of reduction temperature and reaction time.The iron metallization rate could reach 87.5% when the sample was reduced at 1150°C for 80 min.The final phase constituents mainly consist of Fe,M 3 O 5 solid solution phase(M=Mg,Ti,and Fe),and few titanium oxide.Microstructure analysis shows that the surfaces of the reduction products have many holes and cracks and the reactions take place from the exterior of the grain to its interior.The kinetics of reduction indicates that the rate-controlling step is diffusion process control with the activation energy of 89 kJ·mol-1.     

深度还原工艺对铁颗粒粒度影响规律研究

采用深度还原技术处理浸染微细粒度的复杂难选铁矿石,控制铁颗粒粒度是分选出合格产品的关键.根据深度还原物料中铁颗粒的球形特征,通过测量铁颗粒二维截面参数,求取了其累计粒度特性曲线,定性地描述了不同深度还原工艺对铁颗粒粒度的影响规律.结果表明:适当的提高还原温度、延长还原时间、增大配碳系数,都有利于铁颗粒的长大,但还原温度过高、配碳系数过大将阻碍铁颗粒长大;适宜的工艺条件为:还原温度1 225℃,还原时间30min,配碳系数2.0,获得铁颗粒的d50为278.88μm.     

Utilization of waste polyethylene terephthalate as a reducing agent in the reduction of iron ore composite pellets

The increasing consumption of plastics inevitably results in increasing amounts of waste plastics. Because of their long degradation periods, these wastes negatively affect the natural environment. Numerous studies have been conducted to recycle and eliminate waste plastics. The potential for recycling waste plastics in the iron and steel industry has been underestimated; the high C and H contents of plastics may make them suitable as alternative reductants in the reduction process of iron ore. This study aims to substitute plastic wastes for coal in reduction melting process and to investigate their performance during reduction at high temperature. We used a common type of waste plastic, polyethylene terephthalate （PET）, because of its high carbon and hydrogen contents. Composite pellets containing PET wastes, coke, and magnetite iron ore were reduced at selected temperatures of 1400 and 1450℃ for reduction time from 2 to 10 min to investigate the reduction melting behavior of these pellets. The results showed that an increased temperature and reduction time increased the reduction ratio of the pellets. The optimum experimental conditions for obtaining metallic iron （iron nuggets） were reduction at 1450℃ for 10 min using composite pellets containing 60% PET and 40% coke.     

一种风化低品位铁矿石的可选性试验

随着铁矿资源的日益贫乏,对低品位矿石的开发利用成为选矿的发展趋势。山东省某矿业公司矿石属于风化程度较高的低品位铁矿石,样品粒度为10～0mm,含水量1％～2％。根据试样的性质和风化矿分选的经验,采用干式磁选抛尾、干选粗精矿再磨再选的试验流程,获得品位为66％的精矿产品,对低品位铁矿石的开发利用具有一定的借鉴意义。     

红格矿深还原一熔分过程及钒、铬走向的研究

深还原一熔分固相还原后的金属化球团生产钒铬生铁是利用红格矿的途径之一．由于V2O5与CrO3,的赋存、分布以及冶炼过程中的走向基本一致,综合回收利用二者可一起考虑．为了提高钒、铬回收率,实现钛和铁的有效分离,通过单因素试验考察了在氩气保护下,配料的碱度、深还原一熔分温度和配碳量对熔分过程和钒、铬走向的影响．结果表明,当熔渣碱度为1.2,配碳量为0.5％,熔分时间为15min,熔分温度为1610℃时,渣铁的分离效果较好,且有利于钒、铬熔于铁相．     

高磷铁水预处理环保脱磷渣系的相图计算和实验研究

采用FactsageTM软件对以B2O3、K2O、MnO2、TiO2代替CaF2助熔的4种高磷铁水预处理脱磷渣系在1 623K时的相图进行计算,发现相图中的多数区域都有液态渣出现。根据计算相图制定脱磷实验的配渣方案,实验过程中观察到的化渣情况与计算相图提供的信息基本一致。     

含铌铁矿粉氢气选择性还原实验研究

实验在自制底供气扩散床管式电阻炉内,研究不同还原时间（30～180 min）和温度（800～1 050℃）下,H2选择性还原含铌铁矿粉中铁氧化物的规律。得到950℃为最佳还原温度,还原2 h还原度达到90.98%,金属化率为86.47%,还原3 h还原度达到94.07%,金属化率为91.11%,而低于这一温度或高于这一温度时,还原度和金属化率在同样还原时间下都有所降低。     

Reduction of 1-3 mm iron ore by H_2 in a fluidized bed

The reduction of 1-3 mm fine powder of iron ore by H2 was conducted in a lab-fabricated kg class high temperature fluidized bed. The results show that the differential pressure in the fluidized bed, which has small fluctuation with time, increases with the increase of gas flowing velocity. The utilization ratio of gas decreases when the reaction lasts longer time indicating that the reaction is faster at the beginning of reduction and becomes slower in the latter process. The higher the reaction temperature...     

采用烧结法处理高铁赤泥回收氧化铝

利用氧化铝热力学数据库,对高铁赤泥炉料烧成过程中的相关化学反应进行热力学计算,并在此基础上,研究烧成温度、烧成时间、炉料配比等烧成工艺条件对高铁赤泥炉料烧成效果的影响。研究结果表明：赤泥炉料的配钙量可以在较宽的范围内变化,并且在烧成过程中可能生成不溶盐类,导致熟料中氧化铝的溶出率降低：延长烧成时间和增加配料铁酸钠含量均有利于烧结：高铁赤泥炉料的最佳配料是：熟料中Na2O-Fe2O3质量分数为10％12％,钙铁摩尔比为1．0-1．2：烧成工艺条件是：温度为1000-1050℃,烧成时间为30--40min。在最佳配料和烧成工艺条件下,当熟料中氧化铝含量为15％左右时,熟料中Al2O33回收率可达85％-90％。     

中贫氧化矿高梯度磁选试验研究

对白云鄂博中贫氧化矿进行了高梯度磁选试验，着重研究了磁感应强度、矿浆流速对磁选指标的影响．采用粗选（B=0．6T）-精选（B=0．15T）工艺，在矿浆流速5．6cm／s、矿浆浓度20％的条件下，选出的铁精矿品位为60．0％。回收率达到79．5％．     

反应温度、气氛对碳化铁制备过程的影响

研究了反应温度、气相成分对铁矿石用Ｈ２－ＣＨ４气制备碳化铁反应过程的影响。反应在８２３,８７３,９７３Ｋ温度下进行,实验结果表明,８２３,８７３Ｋ是用Ｈ２－ＣＨ４气制备碳化铁适合的反应温度,在制备碳化铁允许的气相成分范围内,应尽可能提高反应气体中的Ｈ２含量。     

Ferronickel enrichment by fine particle reduction and magnetic separation from nickel laterite ore

Ferronickel enrichment and extraction from nickel laterite ore were studied through reduction and magnetic separation. Reduction experiments were performed using hydrogen and carbon monoxide as reductants at different temperatures （700-1000℃）. Magnetic separa- tion of the reduced products was conducted using a SLon-100 cycle pulsating magnetic separator （1.2 T）. Composition analysis indicates that the nickel laterite ore contains a total iron content of 22.50wt% and a total nickel content of 1.91wt%. Its mineral composition mainly con- sists of serpentine, hortonolite, and goethite. During the reduction process, the grade of nickel and iron in the products increases with in- creasing reduction temperature. Although a higher temperature is more favorable for reduction, the temperature exceeding 1000℃ results in sintering of the products, preventing magnetic separation. After magnetic separation, the maximum total nickel and iron concentrations are 5.43wt% and 56.86wt%, and the corresponding recovery rates are 84.38% and 53.76%, respectively.     

Relationship between polymerization degree and cementitious activity of iron ore tailings

The aim of this study is to understand the relationship between the polymerization degree and cementitious activity of iron ore tailings.In light of the poor usage of iron ore tailings,stockpile samples from Tangshan were studied in terms of their ability to become cementitious materials.Compound thermal activation was used to improve the cementitious properties of the tailings,while analyzing methods,such as X-ray diffraction (XRD),infrared spectroscopy (IR),nuclear magnetic resonance (NMR),and X-ray photo...     

Phase,magnetism and thermal conductivity of glass ceramics from iron ore tailings

In order to develop the applications of ore tailings, the glass ceramics were prepared by using a conventional melting-quenching-sintering process. The phase component, microstructures, magnetic properties and thermal conductivities of the prepared glass ceramics were investigated by using X-ray diffractometer, scanning electron microscopy, vibrating sample magnetometer and thermophysical properties tester, respectively. The results show that orthorhombic olivine-type phase and triclinic sunstone-type phase formed when the glass was annealed at 700 oC, the concentration of olivine-type and sunstone-type phases decreased, the spinel-type cubic phase occurred and the amount increased when the annealing temperatures increased. The magnetic properties from the cubic spinel ferrites were detected in the glass ceramics, and the related saturation magnetization increased with the annealing temperature increasing. The porous glass ceramics with magnetic property showed much lower thermal conductivity, compared with the non-magnetic porous glass-ceramic and the dense glass-ceramics.     

Extraction of valuable metals from low-grade nickeliferous laterite ore by reduction roasting-ammonia leaching method

Nickel and cobalt were extracted from low-grade nickeliferous laterite ore using a reduction roasting-ammonia leaching method. The reduction roasting-ammonia leaching experimental tests were chiefly introduced, by which fine coal was used as a reductant. The results show that the optimum process conditions are confirmed as follows: in reduction roasting process, the mass fraction of reductant in the ore is 10%, roasting time is 120 min, roasting temperature is 1 023–1 073 K; in ammonia leaching process, the liquid-to-solid ratio is 4:1(mL/g), leaching temperature is 313 K, leaching time is 120 min, and concentration ratio of NH₃ to CO₂ is 90 g/L:60 g/L. Under the optimum conditions, leaching efficiencies of nickel and cobalt are 86.25% and 60.84%, respectively. Therefore, nickel and cobalt can be effectively reclaimed, and the leaching agent can be also recycled at room temperature and normal pressure.