Design and Application of Intelligent Control System for Molten Iron Transportation Based on 5G Technology

Molten transport is an important link in the iron and steel enterprise production,involves many complex factors,artificial management is difficult.Therefore,puts forward a kind of molten iron transport wisdom control system based on 5G technology,which mainly contains the intelligent identification tracking system,equipment status collection information acquisition system,locomotive vehicle terminal system,etc.Combined with the analysis of the actual application situation,the system could integrate all the processes and elements of molten iron produc-tion and transportation,realize the integration of operation and management,and also promote the improvement of the turnover efficiency of molten iron tank,reduce the demand for personnel,and reduce the labor cost.

Production of low-silicon molten iron from high-silica hematite using biochar

A new method of utilizing high-silica hematite to produce low-silicon molten iron was proposed.In this method,FASTMELT,which comprised direct reduction and melt separation processes,was applied,with highly reactive biochar as the reductant in the direct reduction stage.The proposed method was experimentally investigated and the results show that the method is feasible.In the direct reduction stage,ore-char briquette could achieve a metallization rate of 84%-88% and residual carbon of 0.27-0.89mass% at temperature of 1373 K,biochar mixing ratio of 0.8-0.9,and reduction time of 15 min.Some silica particles remained embedded in the iron phase after the reduction.In the melting separation stage,molten iron with a carbon content of 0.02-0.03mass% and silicon content of 0.02-0.18mass%could be obtained from the metallic briquettes under the above-mentioned conditions;the iron recovery rate was83%-91% and impurities in the obtained metal were negligible.

Properties of a reaction-bonded β-SiAlON ceramic doped with an FeMo alloy for application to molten aluminum environments

An FeMo-alloy-doped β-SiA1ON （FeMo/β-SiA1ON） composite was fabricated via a reaction-bonding method using raw materials of Si, Al2O3, A1N, FeMo, and Sm2O3. The effects of FeMo on the microstructure and mechanical properties of the composite were investi- gated. Some properties of the composite, including its bending strength at 700℃ and after oxidization at 700℃ for 24 h in air, thermal shock resistance and corrosion resistance to molten aluminum, were also evaluated. The results show that the density, toughness, bending strength, and thermal shock resistance of the composite are obviously improved with the addition of an FeMo alloy. In addition, other properties of the composite such as its high-temperature strength and oxidized strength are also improved by the addition of FeMo alloy, and its corrosion re- sistance to molten aluminum is maintained. These findings indicate that the developed FeMo/β-SiA1ON composite exhibits strong potential for application to molten aluminum environments.

Effect of titanium content on the precipitation behavior of carbon-saturated molten pig iron

The use of iron ores bearing titanium as a raw material is an effective measure to prevent hearth erosion and prolong the life of a blast furnace. In this research, the effect of titanium content on the precipitation behaviors of high-melting phases of carbon-saturated molten pig iron were studied by confocal scanning laser microscopy. The results showed that, when the titanium content was less than 0.25 wt%,Fe_3C was precipitated as a single phase from the molten carbon-saturated iron. The growth rate of the precipitated Fe_3C crystals was very high, reaching 7387 μm^2/s. When the titanium content in the molten pig iron was greater than 0.47 wt%, TiC crystals precipitated first. The shape and size of the precipitated TiC crystals did not obviously change. After TiC was precipitated, the fluidity of the molten pig iron worsened. With a decrease in temperature, Fe_3C was also precipitated but the growth rate of Fe_3C was limited by the presence of the first precipitated TiC phase. The crystal size of the precipitated Fe_3C was much smaller than that of pure Fe_3C.

Study on Foaming Behaviour of Molten Slag during Smelting Reduction with Iron Bath

The molten slag in smelting reduction with iron bath has peculiar behaviour for its high FeO concentration. Slag foaming is effected by the concentration and reduction rate of FeO, basicity of slag and temperature. Addition of granulated coke can greatly decrease slag foaming extent in the process of smelting reduction with iron bath. The anti-foaming capacity of granulated coke is the best when the ratio of coke used for coke layer to total coke used in smelting reduction is controlled at about 20%.

STUDY ON THE MECHANISM OF GRAPHITIZATION IN MOLTEN CAST IRON PROMOTED BY ELECTROPULSE DISCHARGE

From the points of both molten cast iron structure and the appearing ratio of electrons in outer-layer of different atoms, analysis on enhancement mechanism of graphitization ability after processing of the iron by pulse electric discharge has been made, and the theory has been proofed by corresponding experiments. The results show that when the molten cast iron is being processed by pulse electric discharge, both the size of crystal embryos that composed by Fe and C atoms as well as the number of clusters can be reduced, even be separated by such discharging; consequently results in the segre- gation of C atoms in the molten cast iron near the cathode of discharging. The nucleation of graphite in these areas of the iron has been promoted at the discharging temperature; even though such degree has not been reached, the most favorable nucleation conditions of graphite can be at least created. Under the preconditions of not breaking up the graphite crystal embryos, with proper adjustment of discharging frequency, the stronger of the electric field and the longer of the pulsation treatment time are, the more graphitization ability of the molten cast iron is. The theoretical analysis on the above rules consists well with experimental results.

KINETICS OF REDUCTION IRON OXIDE IN CaO-SiO_2-Al_2O_3-Fe_tO SLAGS WITH CARBON SATURATED IN MOLTEN IRON

The rate of reducing Fet O in CaO-SiO2-Al2O3-Fet O slags with carbon saturated in molten iron has been determined in a graphite crucible in the temperature range of 1673-1773K. The effects of temperature, slag basicity and FetO content on the reduction rate have also been discussed. Test results show that the reduction rate increases with increasing temperature or FEtO concentration in slags, and the reduction rate has a parabolic relation with the simple basicity or optical basicity of slag, the maximum reduction rate being observed at around CaO/SiO2=1.5 of molten slags. The reduction reaction order is 1. 73 or 1.80, and the reduction activation energy is 299.9 or 295.9 kJ/mol in regard to Fet O weight content or Fet O activity calculated by using regular solution model, respectively. The reduction rate of CaO-SiO2-Al2 O3-Fet O slags with carbon saturated in molten iron is in the range of 0.32-3.48 mol-O/cm2·s.

Development of Magnesium Aluminate Spinel Castable for Roof of EAF with High Molten Iron Charging Ratio

Specimens of magnesium aluminate spinel castable and calcium aluminate cement bonded bauxite based castable were prepared using special bauxite （particle size ≤8 mm ） and sintered magnesia as aggregates, SiO2 micropowder, α-alumina micropowder and calcium aluminate cement as binders, drying, firing at 1 350 ℃ and 1 500 ℃ for 3 h, respectively. The bulk density, cold modulus of rupture, cold crushing strength, permanent change in dimensions on heating, thermal shock resistance and slag resistanee were determined. The results show that compared with calcium aluminate cement bonded bauxite based castable, the magnesium aluminate spinel castable has higher cold crushing strength after drying, better slag resistance but worse thermal shock resistance. Magnesium aluminate spinel based roof of EAF with high molten iron charging ratio has a longer service life.

Research on the AOD molten iron manufacture of ferritic stainless steel

Based on the existing technology and equipment for stainless steel production, the smelting process of ferritic stainless steel in the argon-oxygen decarburization （AOD） furnace using blast furnace （BF）molten iron （after dephosphorization） and ferrochrome alloy is studied and discussed. In the new process,phosphorus and other harmful elements are reduced to a lower level （P≤0. 020% ） when smelting ferritic stainless steel. With this process,both production flexibility and efficiency are enhanced. As no electric furnace is used in the smelting, the production cost is lowered with a great deal of electric power saved, while the total yield of chromium is increased.

Wetting between molten iron and prereduced ilmenite with carbon

An interfacial study between molten iron and the prereduced ilmenite with carbon was conducted at different melting temperatures by the sessile droplet method.The wetting characteristics between molten iron and the prereduced ilmenites with carbon were investigated by measuring contact angle of the droplet of molten iron on the prereduced ilmenite substrate.The images of the interface were also examined by the optical microscope and SEM equipped with EDS.The volume of molten iron increased with the melting temperature increasing when titania or high-content titania slag was used as the substrate.The contact angle decreased with the melting temperature increasing and it was independent on time at constant temperature.The contact angle was positively correlated with the reduction degree of the ilmenite,but the work of adhesion was negatively correlated with it.Higher smelting temperature was beneficial to the separation of iron and Ti oxides.The permeability of molten iron into the prereduced ilmenite with carbon was more obvious with reduction degree increasing owing to the high porosity of prereduced ilmenite.

莱钢降低铁水温降关键技术研究与应用

为降低铁钢界面铁水温降,莱钢自2020年开始,通过开发“一罐到底”组织模式、铁水罐型统一、铁水运输选用汽车运输、配罐模式优化以及铁水罐加盖和高效脱硫工艺等,使莱钢运输效率明显提升,转炉入炉铁水温度持续提高,为进一步降低铁钢比、稳定转炉操作,提供了有利条件。通过各项技术研究与应用,莱钢铁水温降由230℃逐步降低到156℃,其中汽运铁水温降达到85℃,达到国内先进水平,为国内各大钢厂降低铁水温降提供了宝贵经验。

新钢高炉提高块矿用量降本生产实践

块矿相对烧结、球矿等熟料具有先天成本上的优势,但其物化、冶金性能劣于熟料,大比例直接入高炉冶炼会对炉料的熔化性能带来不利影响。于是新钢对几种块矿质量情况进行了对比,着重介绍了在较高比例配用块矿时的原料管理与生产操作调整模式。结合新钢铁前工序、装备水平,按照普惠指数测算使用块矿与烧结矿、球团矿的性价比,并通过精细管理、精心操作,实现炉料结构动态优化,保持铁水成本最优。

基于炼钢过程钢包折铁的研究与实践

通过对现有炼钢工艺过程研究,介绍了顶底复吹转炉出钢后铁水再兑入的实践应用。生产流程通过对转炉出钢成分、温度及出钢量的提前控制,根据转炉来铁的铁水成分及温度,计算铁水再兑入量,以保证钢液的化学成分及温度达标,同时满足现场生产节奏。实践结果表明,利用转炉出钢后铁水再兑入的方式,可有效利用铁水中的热量、各元素含量高等优势条件,实现炼钢钢种目标成分达成及降低物料消耗,有明显的经济效益。

铁钢界面铁水成分差异分析

成分是钢铁制造流程铁钢界面物质流运行的关键参数之一,目前钢铁企业普遍存在炼铁和炼钢工序测得的铁水成分存在差异的问题,并由此导致脱硫站脱硫剂消耗量大、处理周期长、生产成本高。针对首钢京唐铁钢界面“一包到底”技术应用过程中铁水成分存在差异的问题,结合实际生产数据,统计了铁水成分差异的现状,并从生产工艺、检测方法等方面分析了差异形成的原因。结果表明,高炉与脱硫站测得的铁水Si含量绝对偏差平均为0.06%,S含量绝对偏差平均为0.024%,炼铁测得的铁水成分对脱硫和炼钢的参考性有限;铁水包装入多个铁次的铁水、高炉出铁过程铁水取样方法不科学、铁水转运过程部分元素与空气发生氧化反应及个别铁水样品中夹杂有炉渣,是造成铁钢界面铁水成分差异的主要原因。指出,钢铁企业应通过优化高炉出铁操作制度、改进铁水取样方法、加强铁水包管理、加强取样探头质量管理和建设沿途铁水快速取样装置等措施,解决铁钢界面铁水成分差异问题。

铁水成分对成品氮含量影响的分析

从铁水各成分元素着手,深入探讨对成品氮含量的控制。通过对现场数据进行统计分析,得出控制成品氮含量的有效控制方向,并从脱氧、造渣等方面提出了改进措施。

基于机器人应用技术及视觉识别技术的自动折铁系统改进

针对炼钢生产倒罐工序引进基于机器人应用技术及视觉识别技术的自动折铁系统在试运行中,存在机器人插接成功率低,机器人本体抓手检测元件不适用于现场生产环境,自动折铁模型在网络硬件发生故障时可能引发重大设备事故等问题,采取了优化鱼雷罐插座定位销尺寸和结构,增加机器人对鱼雷罐的跟踪检测功能,优化自动折铁模型作业程序等措施后,大大提高了自动折铁系统的智能化程度,提高了作业安全系数,保证了生产的顺行。

高炉炉缸铁水流场影响因素的数值模拟研究

对高炉炉缸铁水流场影响因素开展数值模拟研究。结果表明:铁水剪切应力较高区域主要集中在炉缸出铁口下方;提高高炉利用系数会增大炉缸壁面上的剪切应力;在高炉正常生产情况下,死料柱孔隙率和铁口直径变化对炉缸侧壁铁水剪切应力影响较小;增加铁口深度和减小铁口倾角可以有效降低铁水对炉缸侧壁的剪切应力。实际生产中,保持良好原燃料条件,适度增加铁口深度,采取小铁口倾角出铁有利于减缓铁水对炉缸内衬的冲刷,从而实现炉缸长寿的目标。

高炉长期休风快速达产研究及应用

针对120 t炼钢转炉更换炉衬、煤气公共管道检修,会导致系统全停、影响产能的问题,采取了相应措施:休风前1#、2#高炉调节,包括渣、铁及产量调节;休风期焦炭、炉温、炉渣二元碱度及上休风料调节;复风前准备,1#、2#高炉复风及恢复炉况等操作。采取措施释放产能后3 d内恢复至检修前水平,实现炉况稳定及快速达产目标。

大型冲天炉-电炉双联熔炼生产高强度灰铸铁过程控制

介绍了铸造二期冲天炉-电炉双联熔炼工艺,要获得优质铁液,首先需控制原辅材料质量,质量稳定可控的炉料是获得优质铁液的先决条件;其次是熔炼工艺,标准化、严格的过程控制才能保证持续提供合格铁液。得益于从炉料到熔炼过程完善且不断优化的全流程管控,自投产以来累计熔化优质铁液100万t。通过严格的原铁液质量控制,配合适当的孕育与合金化处理,可生产高强度灰铸铁。

水钢1350 m^(3)高炉入炉钒冶炼规律的探讨与控制

根据水钢1350 m^(3)高炉铁水钒含量低且不稳定的特点,结合钒氧化物还原的冶炼特征、影响[V]含量因素的探讨,对高炉现有控制参数与铁水[V]含量进行关联性统计分析,总结影响[V]含量的关键因素以明确控制方向,采取强化生产过程管控、优化操作制度等措施,含钒铁水的合格率提高了27.2%,钒的回收率提高了7.67%,为今后高炉操作制度的调整提供了重要的技术支撑。