复吹转炉炼钢过程脱碳模型

通过分析复吹转炉脱碳过程的冶金机理,应用冶金热力学、动力学和传输理论,建立描述转炉脱碳过程的动力学模型,确定了模型的有关参数.模型的关键在于正确计算并比较钢液中[C]和[O]的传质速度,找到转炉冶炼脱碳过程的限制环节,并通过一系列热力学计算得到进入钢液的氧在各元素间的分配比例,从而得到转炉中脱碳反应的速度方程.将模型应用于本钢150 t转炉冶炼过程,模型在不同时刻的计算结果与现场实测值吻合较好.     

复吹转炉炼钢过程数学模拟:动力学模型

在对复吹转炉冶炼过程的机理分析的基础上,应用冶金热力学、动力学、传输原理和反应工程学理论,建立了描述冶炼过程的动力学模型,确定了模型的有关参数.作为模型的关键,根据钢中各元素竞争氧化反应的Gibbs自由能估算了吹入熔池中的氧参与各元素氧化反应的分配比率.     

竖炉焙烧转炉污泥生产铁酸钙球团的试验与探讨

1.前言转炉炼钢周期短(约40分钟一炉钢),冶炼速度快,氧化反应激烈。传统的造渣剂化渣速度慢,跟不上转炉冶炼速度和氧化速度,限制了转炉质量、产量的提高和品种的多样化。因此转炉炼钢迫切需要快速脱磷脱硫的     

转炉冶炼脱磷过程数学模型

在对复吹转炉脱磷过程的机理分析的基础上,应用冶金热力学、动力学、传输原理和反应工程学理论,建立了转炉冶炼脱磷过程数学模型,确定了模型的有关参数.模型的     

利用数学模型分析复吹转炉吹炼工艺

在冶金热力学和动力学及反应工程学原理的基础上，建立了模拟复吹转炉冶炼过程的数学模型．在用梅钢150t复吹转炉工业试验的结果对模型加以验证之后，利用模型对具有中高磷铁水特点的梅钢转炉吹炼工艺进行了分析讨论．     

VD过程脱硫速度控制模型及应用

通过对影响脱硫反应的限制环节分析，导出了脱硫反应的速度式，并通过处理现场实验数据，建立了ＶＤ过程脱硫反应动力学模型。使用本模型所进行的实际预测结果与生产实践吻合良好。     

转炉炼钢过程的动态模型控制

介绍了唐钢第一炼钢厂150t转炉炼钢过程控制动态模型的组成和功能。以转炉冶炼过程的物料平衡、热量平衡关系以及炼钢反应的理化原理为依据，该模型完成了转炉冶炼从备料到钢水处理各阶段的下料计算。     

利用数学模型分析复吹转炉吹炼工艺

在冶金热力学和动力学及反应工程学原理的基础上,建立了模拟复吹转炉冶炼过程的数学模型.在用梅钢150 t复吹转炉工业试验的结果对模型加以验证之后,利用模型对具有中高磷铁水特点的梅钢转炉吹炼工艺进行了分析讨论.     

转炉吹炼过程中耗氧比模型

通过对转炉冶炼过程中耗氧比模型的比较及Mn,Si,P氧化机理的分析,应用冶金热力学和动力学建立了耗氧比模型,并根据生产数据的检验结果与模型预测结果的一致性,得出如下结论:供氧强度决定Mn,Si,P的氧化速率;Mn,Si,P在熔池中扩散系数和初始含量的大小将决定各自耗氧比的起始大小;温度通过反应平衡常数影响耗氧比.     

采用周期性改变氧耗的方法向转炉熔池吹氧

为了改善钢的质量和提高生产率,必须完善转炉冶炼的控制,特别是从顶部向钢水吹氧的动力控制。 本文研究了第二喷吹期碳氧化的动力学。在新利佩茨克钢铁公司的二号车间研究了转炉熔池中碳氧化过程的动力学特性。 研究表明,最初碳的氧化速度迅速上升;稳定时间和转换过程的时间分别为12—18s和24—30s。当氧耗减少时,碳氧化速度的下降趋于平缓,稳定时间和转换     

Kinetics of Oxidation Reaction for Magnetite Pellets

An experiment for the oxidation process of single magnetite pellet and theoretical analysis based on modified unreacted core shrinking (MUCS) model were carried out, and the controlling mechanisms of the initial and developing reactions were examined, respectively. From the study of the initial reaction, it was found that the chemical reaction of surface is the controlling step of the overall reaction when the temperature is up to about 750 K, while the mass transfer through the gaseous boundary layer dominates the reaction rate when the temperature is above 750 K. As the reaction developing within the pellet, the mass transfer through the produced layer becomes the controlling step. In addition, the effects of reaction conditions (such as oxygen concentration, temperature) on the fractional oxidation of magnetite pellet were determined.     

Mechanisms and kinetics underlying the oxidation of magnetite in the induration of iron ore pellets

The chemical and transport phenomena that may participate in controlling the oxidation rate of magnetite pellets were examined. Reaction rates were measured under a varying range of conditions including temperature, oxygen partial pressure, and porosity of the pellet. Models based on the initial as well as developing reaction rates were used to explain the experimental findings. In contrast with many experimentally-made agglomerates, all pellet samples were made with a uniform internal structure. Such a condition was a prerequisite to obtaining a meaningful correlation of the experimental data with the theoretical base. A study of the initial reaction rates revealed that two mechanisms were operative in the first stages of pellet oxidation. Up to about 420°C a surface type of chemical reaction was the controlling step, while above 420°C mass transfer through the gaseous boundary layer was the controlling step and dominated the reaction rate. As the reaction developed within the pellet, mass transfer through the gaseous boundary layer as well as that through the product layer became the controlling steps. These mechanisms were studied in the temperature range of from 1000° to 1200°C and the role played by each was found to be a function of the amount of oxidation which had taken place. Formerly with the International Nickel Company, Formerly with the International Nickel Company,     

基于Gamma粒度分布的电炉渣钙浸出动力学模型

 为了研究电炉渣吸收CO2时电炉渣粒度分布对钙浸出率及过程控速的影响,以平均颗粒尺寸为20 μm,不同偏离系数(CV)的电炉渣为研究对象,建立了电炉渣在0.05 mol/L醋酸溶液中的浸出动力学模型,并利用Mathematica8.0对模型进行了求解,并通过试验验证了模型的准确性。仿真结果表明,电炉渣在浸出70 min时,钙浸出率基本稳定,在浸出前70 min,浸出反应速率随着偏离系数的增大而增大,70 min后则随着偏离系数的增大而减小。随着电炉渣偏离系数的增大,电炉渣浸出过程受到化学反应控速越来越弱,而受到扩散控速先变强后变弱,在[CV＝0.7]时扩散控速最强。通过试验数据与仿真结果对比,证明所建立的基于Gamma粒度分布的电炉渣钙浸出率动力学模型能较好的反映电炉渣在醋酸溶液中的浸出过程。     

Theoretical Foundation of Carbonation Pellet Process for Ferrous Sludge Recycling

 For the recycling of ferrous sludge from steel industry, the carbonation pellet process should be considered as a “green” process, since no impurities are added as well as CO2 can be sequestrated and consumed. Through the thermodynamic calculation, the carbonation reaction can occur spontaneously and is an exothermic reaction. Based on the kinetic analysis through unreacted core model, the interfacial chemical reaction was the rate controlling step in the initial fast stage of carbonation, and the CO2 diffusion through the CaCO3 product layer was the rate controlling step in the following extremely slow stage. For the carbonation bonded mechanism, the pellet strength was gained by the formation and growing of CaCO3 product layer. Since the interfacial chemical reaction was the critical stage of the entire carbonation process, the emphasizes should be focused on the improvement of sorbent activity and the optimization of process parameters, such as pore structure, pore surface area, and total pressure, CO2 partial pressure, reaction temperature, etc to accelerate the reaction rate and to improve the quality of carbonation pellets.     

Dynamic Model of Basic Oxygen Steelmaking Process Based on Multizone Reaction Kinetics: Modeling of Manganese Removal

In the earlier study, a dynamic model for the BOF process based on the multizone reaction kinetics has been developed. In the preceding part, the mechanism of manganese transfer in three reactive zones of the converter has been analyzed. The study predicts that temperature at the slag–metal reaction interface plays a major role in the Mn reaction kinetics. Further, mathematical treatments to simulate the transient rate parameters associated with each reaction interface have been developed. The model calculations of Mn removal rate obtained from different zones of the converter predicts that the first stage of the blow is dominated by the oxidation of Mn at the jet impact zone, albeit some additional Mn refining has been observed as a result of the oxidation of metal droplets in emulsion phase. The simulation result shows that the reversion of Mn from slag to metal primarily takes place at the metal droplet in the emulsion due to an increase in slag–metal interface temperature during the middle stage of blowing. In the final stage of the blow, the competition between simultaneous reactions in jet impact and emulsion zone controls the direction of mass flow of manganese. Further, the model prediction shows that the Mn refining in the emulsion is a strong function of droplet diameter and the residence time. Smaller sized droplets approach equilibrium quickly and thus contribute to a significant Mn conversion between slag and metal compared to the larger sized ones. The overall model prediction for Mn in the hot metal has been found to be in good agreement with two data sets obtained from different size converters reported in the literature.     

基于熔池混匀度的转炉烟气分析定碳模型

转炉冶炼终点碳曲线拟合模型避开了熔池初始碳含量难以精准确定的问题,假设吹炼后期脱碳速率与熔池碳含量具有一定的函数关系,通过这种函数关系预报钢水终点碳含量.终点碳的三次方模型和指数模型预报精度在±0.02%之间的命中率分别为85.9%和81.2%.运用熔渣分子理论,基于冶炼热轧板材(SPHC)的渣组元成分,计算得出渣中FeO的活度为0.241.出钢温度为1686℃时,C和Fe元素选择性氧化的临界碳质量分数为0.033%.本文在传统指数模型的基础上,充分考虑了枪位、顶吹流量、底吹流量等操作参数对熔池脱碳速率的影响,建立了基于熔池混匀度的指数模型.基于熔池混匀度的指数模型与其他烟气分析碳曲线拟合模型相比,命中率有所提高.以新钢生产热轧板材(目标碳质量分数为0.06%)时的烟气数据为研究对象建模,终点碳质量分数预报误差在±0.02%之间的有75炉次,占验证数据量的88.2%.      

Kinetics of decarburization of iron-chromium melts in highly oxidizing atmosphere

The kinetics of decarburization in Fe-Cr-C melts were studied to determine the rate con-trolling step for the process. The experiments were carried out under nitrogen-oxygen at-mosphere in a resistance-heated vertical-tube furnace. The liquid melt was held in a freshly prepared magnesite crucible. Sampling and chemical analysis of the metal phase led to time-carbon concentration curves for the system. An iron oxide layer just below the impinging are a and a general boil were observed. Results obtained by varying param-eters such as temperature, partial pressure of oxygen, flowrate of the oxidizing gas and amount of melt determined the limiting reaction mechanism. The rate has been found to be almost independent of flow rate and partial pressure of oxygen (between 1.0 to 2.0 l/min. and 0.5 to 1.0 atm of oxygen). The amount of melt and temperature have a marked effect on the reaction rate. The apparent activation energy has been found to be 48.0 ± 5.4 K cal/mol. The carbon oxidation reaction has been proposed to occur predominantly at CO bubble/metal interface. On the basis of the experimental results and discussions reaction involving reduction of oxides by carbon has been proposed to be the rate controlling step. Formerly a graduate student of IIT, Kharagpur     

减少转炉提钒过程碳烧损

摘要：为了有效减少了转炉提钒过程的碳烧损量,在硅钼炉内进行氧化性炉渣与铁水在不同温度下的渣金反应实验,发现炉渣与铁水的反应速率随温度的升高而加快;温度越高铁红(Fe2O3)将钒氧化到极值的速度越快,但达到极值后钒会被还原回铁水中,且还原速度也随温度的升高而提高;温度越高钒渣中的钒被铁水中碳还原的量越大。根据实验结果对转炉提钒工艺进行了优化,吹炼温度为1340～1350℃时加入冷却剂,控制较低的终点温度,在钒氧化率不降低的情况下,碳烧损率从19.39%降到17.91%、碳烧损量从0.82%减少到0.76%,有效减少了转炉提钒过程的碳烧损。     

基于函数型数字孪生模型的转炉炼钢终点碳控制技术

由于转炉冶炼过程中的热力学和动力学反应复杂,副枪控制模型和传统的烟气分析模型存在很大的局限性,导致了转炉冶炼终点碳含量的预测精度偏低,是实现智能炼钢的主要技术瓶颈. 针对上述问题,提出了基于烟气分析的炼钢过程函数型数字孪生模型. 首先,利用烟气分析得到连续监测的实时数据,以此来实时监控转炉熔池内钢水的碳氧反应状态; 然后,根据熔池反应所处的不同阶段,利用函数型数据分析方法建立吹炼前期和吹炼后期的函数型预测模型; 在此基础上,按照吹炼前期和吹炼后期这两个阶段来分别自动修正模型中的系数函数,从而能在复杂的实际工况条件下完成对熔池碳含量的准确预测. 通过260 t氧气转炉的工业应用实例,证实函数型数字孪生模型具有良好的自学习和自适应能力,对异常冶炼状态具有良好的鲁棒性,可以实现全过程的熔池碳含量动态预测,终点碳质量分数在± 0. 02% 范围内的命中率为95%. 利用函数型数字孪生模型在拉碳阶段对钢水中碳含量的预测值来控制终吹点. 更为重要的是,在保证入炉原料成分、温度、质量等参数稳定的前提下,采用该模型可以有望取消基于副枪的停吹取样步骤,从而降低生产成本,提高产品质量和生产效率,具有广泛的工业应用前景.