包钢低硅烧结矿的冶金性能

 在通过红外微型烧结试验，确定温度、碱度、MgO含量及SiO2含量对包钢低硅烧结矿黏结相强度影响强弱顺序以及黏结相强度最优、较好、较差及最差的包钢低硅烧结工艺条件基础上，采用烧结杯对上述4种烧结矿的黏结相强度进行验证，并对其冶金性能进行研究。结果表明，低硅烧结的最佳工艺条件为：SiO2含量(质量分数，下同)4.0%、碱度2.5、MgO含量1.6%、配碳量3.8%。在此工艺条件下获得的包钢低硅烧结矿具有优良的冷态强度(转鼓强度83.1%)，软熔滴落性能(tS为1307.3℃，tD-tS为98℃)优于包钢烧结矿，还原性(RI为83.65%)较好。尽管低温还原粉化性与目前包钢烧结矿相当，但综合评价，包钢低硅烧结矿可以满足高炉炼铁的需求。     

Influence of magnesia on iron ore sinter properties and productivity

Abstract

Dolomite and other MgO bearing materials are being increasingly used as basic flux constituents for production of fluxed sinters. Addition of flux materials in sinter influences the resultant sinter microstructure and chemical properties. The physical and metallurgical properties of sinter mainly depend on mineralogy of the sinter. Dolomite is the source of double carbonate of calcium and magnesium. Recent studies reveal that, apart from the additional fuel needed, the addition of dolomite and MgO bearing material greatly influences the magnetite content and the properties of the sinter produced. The increasing use of MgO bearing fluxes in the blast furnace burden, and the trend to incorporate a major part of fluxes in the sinter mix led to an investigation of the influence of MgO on sinter properties and productivity. In this study, the systematic investigation has been made on the influence of MgO% (1·4 to 2·6) on sinter mineralogy and sinter properties with dolomite. Microstructural examination of dolomite sinter revealed that hematite and calcium ferrite phases decreased whereas magnetite phase increased with increase in MgO percentage in sinter. From the laboratory pot grate sintering results it was found that sinter reduction degradation index improved whereas tumbler index and reducibility decreased with increase in MgO%.     

MgO对烧结工艺及烧结矿冶金性能的影响

研究了MgO对烧结工艺及烧结矿冶金性能的影响.研究结果表明,在烧结过程中不加或少加MgO,可提高烧结生产效率,获得冷态强度高、软熔带温度区间窄的烧结矿,从而提高高炉软熔带的透气性、降低料柱全压差.为保证高炉渣对MgO含量的要求,以及确保烧结矿低的低温还原粉化率,提出了合理添加MgO的新工艺.     

配加高镁粉的烧结试验及生产

介绍了在安钢原料条件下配用高镁粉的烧结试验及生产情况。实验室试验和工业生产结果表明，高镁粉MgO含量高，在烧结过程中用其替代白云石，其用量只需1％即可满足要求，且对烧结生产技术质量指标影响小或没有影响，是烧结生产过程中比较理想的MgO添加剂。     

MgO对钒钛烧结矿矿物组成及冶金性能影响的研究

 针对攀钢烧结生产的情况,在实验室进行了MgO对钒钛烧结矿矿物组成及冶金性能影响的试验研究。结果表明：MgO对钒钛烧结矿矿物组成和结构有较大的影响;在MgO的质量分数为2.5%～3.7%时,随着MgO含量的增加,烧结矿中温还原度略有下降,低温还原粉化率降低,软熔滴落性能改善。     

MgO对高碱度高铝烧结矿的影响

 随着钢铁企业高铝铁矿粉使用比例的提高,带来了高炉炉渣黏度增大、渣铁分离困难等一系列问题。采用烧结杯试验,研究了MgO含量增加对高碱度高铝烧结矿经济技术指标、冷强度和冶金性能的影响,采用Nova400 NanoSEM型场发射扫描电子显微镜分析了烧结矿微观结构。试验结果表明,高碱度高铝烧结矿中MgO质量分数从1.72%提高到2.49%时,垂直烧结速度降低4.38 mm/min,利用系数降低0.51 t/(m2·h),低温还原粉化指数增加6.7%;当烧结矿中MgO质量分数为2.11%时,转鼓指数和还原度最高,分别达到61.93%和86.39%;Mg2+主要固溶在磁铁矿晶格中并替代Fe2+,替代的质量分数最高达3.64%,生成的含镁磁铁矿抑制烧结矿降温过程中由Fe₃O₄→Fe₂O₃氧化过程的相变,减少了二次赤铁矿的生成,有利于改善烧结矿的低温还原粉化性能。研究结果可以为改善高碱度高铝烧结矿性能和提高炉渣流动性提供理论指导和参考依据。     

改善鞍钢球团矿冶金性能的研究

对带式机酸性球团矿添加含MgO添加剂的造球、焙烧和冶金性能研究表明,在带式机目前焙烧工艺制度条件下,MgO／SiO2比值在0．45～0．6时,球团矿抗压强度高于2500N／个,还原膨胀率大幅度降低;随着MgO／SiO2比值的升高,低温还原粉化率RDI＋3.15、RDI＋6.3提高;900℃还原度提高。当MgO／SiO2比值为0．45时,球团矿的综合冶金性能较好。     

配加高镁粉的烧结生产工艺研究

对添加高镁粉的烧结生产工艺进行了研究,结果表明,在烧结生产中添加质量分数为1．0％～1．5％的高镁粉,可使烧结矿MgO增加。为提高烧结矿MgO含量采取合理组织原料进料系统、改进配料电子秤和除尘系统等措施,改善了烧结矿的冶炼性能和高炉的透气性和炉渣的流动性,提高了炉渣脱硫能力。     

Influence of magnesia on sintering characteristics of iron ore

Abstract

The MgO in blast furnace slag provides an optimum condition in terms of both good flowability and desulphurisation. The mode of its addition to the blast furnace changed from, initially, as raw flux in the form of dolomite, to via sinter, with the argument that raw flux demands energy for its decomposition inside the blast furnace. Thus, the decomposition reaction was diverted from the blast furnace to the sintering bed, and the energy source for decomposition was changed from costly blast furnace coke to a relatively cheap coke breeze. Now olivine/dunite/serpentine is being used as a source of MgO, where energy for decomposition is not required; this also provides a source of SiO₂, which eliminates need for the addition of quartzite. The effect of MgO on blast furnace slag is fairly well established, but its effect on sintering and sinter quality is unclear. Operating results of the sinter plants show that, with an increase of MgO, the sintering rate, the fuel rate, and sinter strength and reducibility deteriorate; however, high temperature properties such as the reduction degradation index and the softening-melting characteristics of the sinter improve. The present work attempts to establish this influence on the sintermaking process and sinter quality with the help of operating plant data.     

不同MgO含量对烧结矿质量的影响

依据石钢原料条件,研究了MgO含量对烧结矿常温强度及冶金性能的影响.结果表明,MgO含量对烧结矿有着双重的影响,其中在2.3%为最佳.随着MgO的增加,烧结矿的冶金性能、低温还原粉化指标改善.当MgO含量达到2.3%时,烧结矿强度,性能指标达到最佳.随后,随MgO含量增加烧结矿强度及冶金性能明显降低.     

不同氧化镁含量烧结矿粒度分布的分形研究

通过对不同MgO含量烧结矿破碎体的筛上、筛下物分布规律的研究,计算得出了烧结矿粒度分布的分形维数,线性相关系数均大于0.97,说明使用分形维数定量表征烧结矿在不同MgO含量条件下的粒度组成是可行的.结果表明:分形维数随着MgO含量的增加而增加,在一定程度上可以定量估测烧结矿中MgO含量的范围,并结合微观结构,合理解释了转鼓强度、成品率和分形维数之间的关系.为更加深入表达不同MgO含量的烧结矿的有关数值模型提供了新的理论依据和研究方法.     

高铁低硅烧结技术研究

高铁低硅烧结矿固结机理与普通高碱度烧结矿不同,它是铁酸钙液相固结与铁氧化物再结晶或重结晶固相固结并存.采用一整套与高铁低硅烧结矿相适应的技术,如理想的碱度制度、合理的料层高度、较低的配碳量、添加优质活性石灰及调整烧结矿中的MgO和Al2O3等,在保证利用系数的情况下,获得了高强度、高还原性的烧结矿.     

富矿粉烧结中配加蛇纹石与白云石的对比研究

采用微型烧结法 ,在实验室条件下研究了富矿粉烧结时配加蛇纹石与白云石对烧结矿矿物结构和物理性能的不同影响 ,分析了它们在烧结矿中的作用和赋存状态 ,并通过烧结杯试验验证了机理研究的结果。     

Sintering Characteristics of Indian Chrome Ore Fines

Chrome ore concentrate consists of high-temperature melting oxides such as Cr₂O₃, MgO, and Al₂O₃. The presence of these refractory constituents makes the ore a very high melting mineral. Hence, it is difficult to produce sinter from chrome ore by a pyrometallurgical route. Currently, chrome ore is ground to below 75 μm, pelletized, heat hardened through carbothermic reaction at 1300 °C to 1400 °C, and then charged into a submerged electric arc furnace (EAF), along with lumpy ore for ferrochrome/charge-chrome production. Electricity is a major cost element in this extraction process. This work explores the sinterability of chrome ore. The objective of this study was to: (1) determine whether chrome ore is sinterable and, if so, (2) ascertain ways of achieving satisfactory properties at a low temperature of sintering. Sintering of the raw material feed could be a way to reduce electricity consumption, because during sintering a partial reduction of minerals is expected along with agglomeration. Studies carried out by the authors show that it is possible to agglomerate chrome ore fines through sintering. The chrome ore sinter thus produced was found to be inferior in strength, comparable to that of an iron ore sinter, but strength requirements may not be the same for both. Because the heat generation during chrome ore sintering is high owing to some exothermic reactions, compared with iron ore, and because chrome ore contains a high amount of fines, shallow-bed-depth sinter cake production was attempted in the laboratory-scale pot-sintering machine. The sintered product was found to be a good conductor of electricity because of the presence of phases such as magnetite and maghemite. This characteristic of the chrome ore sinter will subsequently have a favorable impact in terms of power consumption during the production of ferrochrome in a submerged EAF. The sinter made was melted in the arc furnace and it was found that the specific melting energy is comparable to that of heat-hardened chrome ore pellets but lower than briquettes and lump ore.     

普矿配加对钒钛烧结矿质量的影响

 通过烧结杯制备了全钒钛以及配加一定量印粉（YD）、马粉(MF)及自产普粉(ZF)的钒钛烧结矿,并对其烧结速度、烧损率、成品率、转鼓强度、RDI>3. 15 mm以及软化性质进行了测定及分析。试验结果表明：全钒钛烧结矿质量较差,尤其是RDI>3. 15 mm过低,产率较低,需配加普矿提高其质量及产量。选择普粉时应兼顾其制粒性以及化学成分等,应保证烧结矿中一定量的SiO2、MgO以及Al2O3不宜过高。配加3种普粉均有利于提高烧结速度及提高软化区间,配加自产粉有利于提高钒钛烧结矿的转鼓强度(64. 25%)以及RDI>3. 15 mm ,但降低了成品率;配加印粉有利于提高转鼓强度、成品率,但是降低了RDI>3. 15 mm;配加马粉有利于提高强度和RDI>3. 15 mm ,但是其铁品位低、烧损大。配加13%（印粉+马粉+自产）钒钛烧结矿的指标优于配加6. 5%（印粉+马粉+自产）的钒钛烧结矿。     

低品位复杂矿烧结碱度优化试验

 为了合理利用新疆区域的贫矿资源,优化高炉炉料结构,开展优化烧结矿碱度的试验研究。利用50 kg烧结杯,针对新疆复杂矿做了7组碱度为1.65～2.00的烧结杯试验。通过对烧结矿机械强度、冶金性能及矿物组成分析,得出碱度为1.80～1.85时,烧结矿中铁酸钙质量分数明显增加,烧结矿的ISO转鼓强度较高,成品率最高达到78%,还原度和低温还原粉化指数均得到改善,软熔区间最窄,为最优的烧结碱度区间;而碱度为1.65～1.75时,转鼓强度降低、熔滴性能变差,处于烧结矿的粉化区间,配加新疆区域复杂矿烧结生产时应避开此碱度区间。     

原料结构变化对烧结生产的影响及对策

随着进口矿的大量使用,原料结构的变化引起混合料中SiO2、MgO的含量降低,导致烧结矿强度变差,MgO含量急剧下降,烧结矿低温还原粉化率大幅上升.为了应对原料结构的变化对生产的影响,烧结厂采取了一系列工艺改造和添加MgO熔剂、烧结矿喷洒CaCl2溶液、低硅烧结技术和褐铁矿烧结技术等措施,不断提高烧结矿的质量,满足高炉冶炼的要求.     

Improvement in Blast-Furnace Performance by Using a New Form of Iron Ore

The effective blast-furnace smelting of iron requires the use of uniform fluxed iron ore in sintered form—local cakes produced by the production of pellets with a high content of iron and residual carbon, minimal content of silica, high cold strength, and high strength in the blast furnace. The proposed new material combines the best metallurgical properties of sinter and pellets.     

w(MgO)和w(Al2O3)对混合炉料软熔性能的影响

 改善高w（Al2O3）矿石冶炼的常用方法是增加烧结矿w（MgO），则高碱度烧结矿中w（MgO）和w（Al2O3）均升高且w（MgO）/w（Al2O3）改变。为降低冶炼成本，需合理调控高炉综合炉料的w（MgO）和w（Al2O3）。以现场烧结矿和天然块矿为试验原料，考察了烧结矿中w（MgO）和w（Al2O3）均增加的条件下混合炉料软熔性能的变化规律，结合相图和X射线衍射分析w（MgO）和w（Al2O3）的影响机制。结果表明，随着烧结矿中w（MgO）和w（Al2O3）增加，混合炉料软化特征温度降低；渣相熔化温度和黏度下降引起混合炉料的熔化特征温度降低，添加MgO能改善高Al2O3炉料的软熔性能，达到适宜的 w（MgO）/w（Al2O3）即可。     

Briquets for washing blast furnaces

Periodic washing of the hearth of a blast furnace by charging hard-to-reduce iron-bearing materials helps form fluid iron-bearing slags whose iron is reduced mainly by coke fines in the coke column. Lump iron ore, specially prepared washing sinters, or welding slag are usually used for this purpose. The washing sinter contains up to 50% ferrous oxide. One alternative to the washing sinter might be briquets made from mill scale. Washing briquets made from mill scale with a cement binder (8–10% Portland cement M500) are made by vibrational compaction. These briquets have good cold strength, remain intact when heated in a reducing atmosphere to 1200°C at a rate of 500°C/h (which corresponds to the rate of heating of the blast-furnace charge), and have low reducibility. Inside the fusion zone, they form primary slags based on iron-calcium olivines with an FeO content on the order of 50%. __________ Translated from Metallurg, No. 5, pp. 46–50, May, 2007.