金川镍渣烧结试验探讨

为了提高镍渣利用效率,进行了金川镍渣3种配比(全镍渣,镍渣:红土矿为7∶3,镍渣:红土矿为5∶5)的烧结杯试验,并对试验结果进行了分析。试验表明:采用全镍渣进行烧结,控制适宜条件,即焦粉配比为8%左右,混合料水分质量分数为3.5%~4.5%,烧结矿可满足要求;配入红土矿可进一步提高烧结矿各项指标;且随着红土矿配比的增加,应增大配炭量和混合料水分。     

配加高品位印度粉矿的烧结试验

用印度粉矿替代澳大利亚粉矿,烧结机利用系数降低,烧结矿强度下降,返矿率上升,影响了烧结生产的技术经济指标。为此进行了在现有原料条件下配加高品位印度矿的烧结试验。实验室试验结果表明,用8%高品位印度粉矿替代8%澳大利亚粉矿,钢渣配比由4%增加到6%,烧结矿中<5mm的粉末含量下降,烧结机利用系数、转鼓指数均有较大的提高。     

MgO含量对低硅烧结成矿性能的影响

利用实验室烧结杯实验,研究了MgO含量对低硅烧结的影响,控制烧结矿碱度为1.9,配碳量为4.5%,通过利用白云石调节烧结混合料中的MgO含量,并对烧结成矿进行冶金性能分析。试验结果表明:MgO含量由1.2%升高到1.6%时,烧结矿的强度得到改善,MgO含量由2.0%升高到2.8%时,烧结矿的强度逐渐变差;随着烧结矿MgO含量的升高,烧结矿的低温还原粉化性能和还原性能逐渐变差,荷重软化开始温度和终了温度升高,软化区间变宽。因此,在低硅烧结工艺中应尽量降低烧结混合料的MgO含量。     

高铁三水铝石型铝土矿的烧结特性

以Al2O3含量为26.35%,总Fe含量为31.22%,铝硅比为3.17的某高铁三水铝石型铝土矿为原料,研究了碱度、焦粉用量、混合料水分等对烧结矿质量指标的影响。结果表明:烧结矿碱度增加时,其转鼓强度和成品率下降,烧结矿自粉化程度加重;焦粉用量增加时,烧结矿转鼓强度和成品率提高;当混合料水分为9.0%、焦粉用量为8.0%、烧结矿碱度为4时,烧结矿转鼓强度为69.1%,成品率为81.2%,垂直烧结速度为30 mm/min,利用系数为1.2 t/(h.m2);烧结矿碱度为4时,样品存放2天粉化率为5%,烧结矿平均粒度由22.2 mm减小到21.9 mm,延长存放时间,烧结矿自粉化率增大,平均粒度显著减小。该烧结矿的冶金性能能基本满足高炉冶炼的要求。     

降低烧结矿煤耗

料层厚度、燃料粒度、混合料水分、混合料温度、高炉灰配比等因素对本钢炼铁厂一烧烧结矿煤耗产生影响。在本钢目前的原料条件下,通过对烧结过程各参数的控制及配料过程的优化,找出影响本钢烧结矿煤耗的因素,在生产过程中对主要影响因素进行了一系列的改进,并研究应对措施,改造烧结工艺和技术,有效地克服烧结过程中所出现的难题,生产出优质、低耗的烧结矿,从而达到降低生产成本的目的,为钢铁企业创造良好的经济效益。     

南非富矿粉配矿烧结矿相结构分析

为了充分利用南非富矿粉,对南非富矿粉(坦巴津比、PMC尾矿、PMC0.044 mm)和巴卡矿粉配矿烧结矿相的微观结构进行了分析。研究结果表明,随着PMC0.044 mm精粉配比的增加,烧结矿的交织熔蚀结构变得更加均匀,孔隙率减少,针状铁酸钙的含量增加且分布趋于均匀;随着坦巴津比矿粉配比的增加,针状铁酸钙的分布由均匀变得集中再到均匀,烧结矿的强度先略微降低后升高;随着巴卡矿配比的增加,铁酸钙含量先减少后增多,烧结矿强度先升高后降低,铁酸钙的形态先由集中分布的柱状转变为均匀的交织熔蚀结构,后又转变为分布较为集中的柱状。当配比巴卡∶坦巴津比∶PMC尾矿∶PMC 0.044 mm为10∶70∶20∶0时,烧结矿的冷强度及矿相结构最理想。     

单种添加剂对钒钛烧结矿的影响

为了改善承钢钒钛烧结矿的质量和冶金性能,针对4种添加剂对烧结矿的影响进行了烧结试验研究。试验结果表明:选择的4种添加剂中,方案5~#钒钛矿烧结质量最优,即添加B_2O_3能够显著提高烧结矿质量和冶金性能,其利用系数为1.34 t/(m~2·h),转鼓指数为63.76%,RI、RDI_(+3.15)分别为74.92%和53.78%。     

烧结配矿优化及高炉生产应对实践

烧结配矿技术是在全面掌握铁矿粉的常温特性和高温特性的基础上，应用互补性原理和方法进行合理的配矿设计。本文在工业试验中通过增加进口加拿大精粉的配比，迅速提高烧结转鼓强度，改善烧结矿质量。同时对降低高炉渣中氧化镁进行技术攻关，获得了显著效果。     

优化生产工艺降低安钢400m~2烧结内循环返矿率实践

烧结生产过程中烧结矿(饼)经过破碎、筛分会产生一定量的内循环返矿,烧结内循环返矿配比水平的高低直接影响烧结矿的产量及能耗,降低并稳定烧结返矿率是提升烧结矿产量、减少烧结生产能耗的主要方向之一。在现有工艺、原料条件下,根据安钢400 m2烧结工艺和烧结矿质量要求,通过加强工艺控制、操作及管理,合理工序控制参数,降低400 m2烧结生产内循环返矿率,实现烧结矿产量提升。     

济钢低硅烧结矿的冶金性能试验研究

以低硅烧结矿为试验样品,进行了微型烧结试验和烧结杯试验,并对试样的冶金性能进行了研究。研究结果表明,在烧结温度1 240℃、w(Si O2)为4%、碱度2.5、w(Mg O)为1.6%条件下,低硅烧结矿的平均转鼓强度(82.13%)最高,平均返矿平衡系数(1.09)最低,粘结相强度最高,表明该烧结条件是最佳工艺条件。     

在线测水技术在烧结混合料上的应用研究

简要介绍了三种在线式测水方法的特点,并结合烧结混合料在线测水需要注意的问题对三种测水方法进行了分析。相对于其他两种测量方法,微波测水技术更适用于烧结混合料实时水分测量,具有应用推广价值。     

Co-reduction of Copper Smelting Slag and Nickel Laterite to Prepare Fe-Ni-Cu Alloy for Weathering Steel

In this study, a new technique was proposed for the economical and environmentally friendly recovery of valuable metals from copper smelting slag while simultaneously upgrading nickel laterite through a co-reduction followed by wet magnetic separation process. Copper slag with a high FeO content can decrease the liquidus temperature of the SiO₂-Al₂O₃-CaO-MgO system and facilitate formation of liquid phase in a co-reduction process with nickel laterite, which is beneficial for metallic particle growth. As a result, the recovery of Ni, Cu, and Fe was notably increased. A crude Fe-Ni-Cu alloy with 2.5% Ni, 1.1% Cu, and 87.9% Fe was produced, which can replace part of scrap steel, electrolytic copper, and nickel as the burden in the production of weathering steel by an electric arc furnace. The study further found that an appropriate proportion of copper slag and nickel laterite in the mixture is essential to enhance the reduction, acquire appropriate amounts of the liquid phase, and improve the growth of the metallic alloy grains. As a result, the liberation of alloy particles in the grinding process was effectively promoted and the metal recovery was increased significantly in the subsequent magnetic separation process.     

Efficient enrichment of nickel and iron in laterite nickel ore by deep reduction and magnetic separation

The process of deep reduction and magnetic separation was proposed to enrich nickel and iron from laterite nickel ores. Results show that nickel–iron concentrates with nickel grade of 6.96%, nickel recovery of 94.06%, iron grade of 34.74%, and iron recovery of 80.44% could be obtained after magnetic separation under the conditions of reduction temperature of 1275 °C, reduction time of 50 min, slag basicity of 1.0, carbon-containing coefficient of 2.5, and magnetic field strength of 72 kA/m. Reduction temperature and time affected the possibility of deep reduction and reaction progress. Slag basicity affected the composition of slag in burden and the spilling and enriching rate of nickel–iron from a matrix to form nickel–iron particles. Nickel–iron particles were generated, aggregated, and grew gradually in the reduction process. Nickel–iron particles can be effectively separated from gangue minerals by magnetic separation.     

Effect of Sinter Mix Composition and Additives on the Quality of Blast Furnace Sinter

Effect of variations in sinter feed composition on sinter strength, bulk density, re-ducibility, chemical composition, and microstructure were determined by sintering experimental samples on a production sintering machine. Increasing amounts of roll scale, ore fines, return fines, and blast furnace slag were most beneficial to feed permeability, sinter bulk density, and strength. Burnt lime additions improved feed permeability but were not beneficial to sinter strength or bulk density. Sinter reducibility was adversely affected by all additives.     

高炉增加高铝铁矿冶炼的可行性探讨

介绍了Al2O3对高炉炉渣和烧结矿的影响作用,分析认为,高炉终渣中Al2O3含量增至175,高炉冶炼仍是可行的。合理配料,改进工艺,可克服原料中Al2O3的提高对烧结带来的负面效应。     

Efficient Utilization of Nickel Laterite to Produce Master Alloy

To lower the smelting temperature associated with the carbothermic reduction processing of laterite, the optimization of slag and alloy systems was investigated to enable the reduction of laterite ore in the molten state at 1723 K. The master Fe-Ni-Mo alloy was successfully produced at a lower temperature (1723 K). The liquidus of the slag decreased with the addition of oxide flux (Fe₂O₃ and CaO) and that of the ferronickel alloy decreased with the addition of Mo/MoO₃. More effective metal–slag separation was achieved at 1723 K, which reduces the smelting temperature by 100 K compared with the current electric furnace process. A small addition of Mo/MoO₃ not only decreased the melting point of ferronickel alloys but also served as a collector to aggregate the ferronickel sponges allowing them to grow larger. The FeO concentration in the slag and the nickel grade of the alloy decreased with increasing graphite reductant addition.     

低品位红土镍矿深度还原机理

采用扫描电子显微镜和EDS能谱研究低品位红土镍矿深度还原过程中金属颗粒的生长行为,并在此基础上分析其还原机理。结果表明,金属铁和镍逐渐聚集生长为Fe—Ni颗粒,并且颗粒粒度随着还原温度的升高和还原时间的延长而明显增大。还原后,红土镍矿明显变为Fe—Ni金属颗粒和渣相基体两部分。铁镁橄榄石的还原与其晶体化学特性密切相关。铁和镍的氧化物被还原剂还原为金属铁和镍,同时,橄榄石的晶格结构被破坏。红土镍矿深度还原包含金属氧化物还原和金属相生长两个过程。     

BLAST FURNACE SMELTING WITH HIGH MgO SLAG

高炉在用18.5％MgO的炉渣进行冶炼时,炉子比较顺行,炉温比较稳定。但由于炉渣的脱破能力较弱,必须提高炉渣的总碱度((CaO+MgO)/SiO_2)。 本文着重地分析了高MgO渣冶炼时焦比升高的原因。理论计算证明将白云石直接装入高炉时由于带入炉中的CO_2量(每吨铁)增加了15％,导致了高炉的直接还元率以及因此的焦比的升高。应将白云石作为烧结原料。