Corrosion Resistance Mechanism of Magnesia Zirconia Brick to RH Furnace Slag

Magnesia zirconia brick containing 11 wt% zirconia was prepared with magnesia and monoclinic zirconia as starting materials in order to replace the chrome-containing materials for Rtt furnace. The corrosion resistance of magnesia zirconia brick and fused rebonded magnesia chrome brick （short for magnesia chrome brick） to high, and low basicity slag of RH fitrnace was comparatively researched by rotary slag method and their slag resistance mechanisms were analyzed. The results show that： （1） because the reaction layer containing CaZrO3 forms in magnesia zirconia brick, it has better corrosion resistance to high basicity slag than magnesia chrome brick, however, it has worse corrosion resistance to low basicity slag than magnesia chrome brick; （2） ZrO2 in the magnesia zirconia brick can absorb CaO in the slag, which decrea- ses the basicity of slag and inereases the viscosity of slag, so the degree of slag penetration in magnesia zircon.ia brick decreases ; （ 3 ） there is little zirconia in the slag layer of residual nutgnesia zirconia brick;from working face to original brick layer, the residual magnesia zirconia brick shows three layers： obviotasly deteriorative layer, slightly deteriorative layer, and original brick layer, but the residual magnesia chrome brick only shows two layers ： obviously deteriorative layer and original brick layer; the SiO2 content of residual magnesia zirconia brick is the highest in the slightly deteriorative layer, however, the SiO2 content of residual magnesia chrome brick gradually decreases front working face to original brick layer.

Research on Alkali Resistance of Alumina-rich MgAl2O4 Spinel for Alkali Recovery Furnace

Chrame containing refractories are a kind of traditional material for the lining of alkali recovery furnaces, but the formation of hexavalent chrome compounds will give rise to detrimental effect on environment and human＇s health. With the gradual awakening of people＇s comciousness about environment protection, it is urgent to prepare environmental-friendly materials for alkali recovery jurnaces with high quality and long life. In this paper, alumina-rich MgAl2O4 spinel （ AR90 ） was used to replace chromite. The physical properties of dried （110 ℃ for 24 h） or fired （1 300 ℃ for 3 h） AR90 and chromite were studied, respectively. The alkali vapor method was used to determine the alkali resistance of the two materials. The results show that： （1） after drying at 110 ℃ for 24 h, AR90 specimens show higher apparent porosity and slightly lower bulk density than chromite specimens; after firing at 1 300 ℃ for 3 h, AR90 has significantly higher apparent porosity as well as higher bulk density; （2） after the alkali attack, the AR90 specimens sintered at 1 300 ℃ exhibit smaller strength change and much higher compressive strength than the chromite specimens; meanwhile, the permeability degree of alkali salt in chromite specimens is more serious than that in AR90 specimens, which indicates that AR90 possesses better alkali resistance.

Abrasion Resistance of Cement Paste with Granulated Blast Furnace Slag and Its Relations to Microhardness and Microstructure

The abrasion resistance of cement pastes with 30 wt%,40 wt%and 50 wt%granulated blast furnace slag(GBFS),and its relations to microhardness and microstructure like hydration products and pore structure were studied.Results indicated that GBFS decreased the abrasion resistance of paste,and among the pastes with GBFS,the paste with 40 wt%GBFS showed the highest abrasion resistance.The microhardness of GBFS was lower than that of the cement,and the microhardness of the hydration products in paste with GBFS was also lower than that of the hydration products in paste without GBFS,so that the abrasion resistance of paste decreased when GBFS was incorporated.The reason for the decrease of microhardness of pastes with GBFS was that the contents of Ca(OH)_(2)in pastes with GBFS was significantly lower than that in the paste without GBFS,while large amounts of calcium aluminate hydrates and hydrotalcite-like phases(HT)in pastes with GBFS were generated.Furthermore,among the pastes with GBFS,the paste with 40 wt%GBFS showed the lowest porosity which was the main reason for its highest abrasion resistance.

Preparation and Properties of SiC Assembled Large Block for Blast Furnace Tuyeres

A SiC assembled large block for blast furnace tuyeres was prepared using silicon carbide particles(3-1 and 1-0.088 mm)and fine powder(<0.088 mm),silicon powder(<0.088 mm),industrial carbon black(N990),microsilica,ρ-Al_(2)O_(3) powder,etc.as raw materials.The developed block was compared with a silicon nitride bonded silicon carbide brick,a self-bonded silicon carbide brick and an imported self-bonded silicon carbide block to analyze and evaluate their service performance.The results show that:(1)in the 0-100 mm zone,the SiC large block mainly consists ofβ-SiC and nitrides such as O'-SiAlON,β-SiAlON,α-Si_(3)N_(4),and Si_(2)N_(2)O,the bulk density is 2.68-2.70 g·cm^(-3),the apparent porosity is 14%-15%,and the material structure is uniform;(2)in the 0-100 mm zone,β-SiC nano-whiskers intercalate with nitrides;with the depth increasing,the number of flocculentβ-SiC nano-whiskers increases,while the number of nitrides decreases;when the depth reaches 150 mm or more,the main bonding phases areβ-SiC and mullite;(3)compared with the reference products,the developed SiC large block has a good basic performance,and after alkali corrosion,the mass change rate is-0.1%,which is obviously superior to the imported self-bonded silicon carbide and the homemade silicon nitride bonded silicon carbide materials.

Designing for Long Campaign Life Blast Furnace (1)──The Mathematical Model of Temperature Field for Blast Furnace Lining and Cooling Apparatus and New Concept of Long Campaignship Blast Furnace Cooler Design

The physical and mathematical model of temperature field for blast furnace stave coolers was established. The computation results show that the heat resistance of 2-6 mm water scale within the cooling pipe is about 7%-20% of the total heat resistance of cooling stave body, as for drilling duct type, the heat resistance of 2-6 mm water scale is about 88%-98% of the total heat resistance. Using drilling duct or full cast pipe can eliminate gas clearance and coating layer between pipes and cast iron body and reduce the heat resistance of the cooler sharply and improve the coefficient of heat transfer to a great extent. The water velocity within coolers can be kept at the 1evel of 0.5- 1 .5 m/s, the higher water velocity can not decrease the hot surface temperature, but can increase energy consumption for cooling water.

Simulation on the Conductivity of Charging Stock with Percolation Structure in the Submerged Arc Furnace

Based on the fractal geometry, a new way for selecting material burden ratio and size distribution, named physical design of burden, which is different from stoichiometric weight of carbon burden, would play a more important role in the operation of submerged arc furnace process. Cold simulation investigation was carried out to find how the fraction and size of metal balls affects the specific conductivity of charge mixture, by applying the percolation structure theory. A parameter equation, s/s=A(F-Fc)v, was suggested to calculate the specific conductivity of the charge mixture.

Analysis of the Parameters of the Ore RestorationFurnaces for Equal Power on the Shelf-Baking andGraphitized Electrodes

Results of calculation of the power indicators of the ore restoration arc furnaces with the set power of 10.5 MVA workingon are given as on the self-baking also on the graphitized electrodes. It is established that despite high cost of the graphitizedelectrodes in comparison with the self-baking electrodes, power parameters much more improve. Besides, the natural power factorincreases, melting time decreases and that the most important the furnace turns out compact, convenient for service, building of thegraphitized electrodes is carried out for a small period, and also the number of service personnel is reduced. We propose a newdesign scheme of low-voltage circuit for the arc furnace according to the scheme ＂a triangle on the electrodes＂ designed in athree-bifilar version, in which more complete symmetry is gained by means of the crosspieces forming a triangle directly at theelectrode arms. In the proposed scheme, the current-carrying tubes that have different polarity are located on the same arm that leadsto further reduction in low-voltage circuit inductance. The application of this scheme allows for reducing reactive and activeresistances of low-voltage circuits by 2.5-3 times and 15-20%, respectively, as well as for shortening the heat, reducing specificenergy consumption and increasing the installation power factor.

Molybdenum Electrodes Applied in Electric Melting Furnace

The conditions and points for attentions of molybdenum electrode, which used in glass melting furnace, are introduced. Problems in corrosion of molybdenum electrodes are analyzed through the glass components, temperature and current density, and how to eliminate bubble formation on the process. At last, the specific requests of the applications of molybdenum electrode in glass industry are presented.

炉腹煤气量指数和透气阻力系数在马钢2号高炉的应用

对炉腹煤气量指数X_(BG)和透气阻力系数K在马钢2号高炉的应用进行了总结。通过对2号高炉1年多的生产数据跟踪分析,结果表明:X_(BG)控制在63~64m/min,对应炉腹煤气量V_(BG)控制在6300~6400m^(3)/min时,高炉稳定顺行,燃料比较为稳定;针对2号高炉炉腹渣皮厚、炉腹温度整体偏低现象,风压控制在靠上限水平,K值实际控制在4.25~4.75为宜,高炉运行状态良好。认为炉腹煤气量指数和透气阻力系数都是综合操作参数,在高炉日常操作中,可以用此来判断炉况,衡量强化程度,使炉况保持稳定顺行,技术经济指标改善。

基于热阻及成本分析的高炉冷却壁多目标优化

本文建立了高炉冷却壁热阻模型,冷却壁热阻包括火积耗散热阻和对流热阻,分别表征其导热性能和换热表面的对流换热性能。分析冷却壁运行过程中的各项成本,包括冷却壁材料成本、运行耗水成本、运行能耗成本以及冷却壁厚度减薄时产生的额外收益。应用遗传算法以冷却壁热阻和成本为目标函数,以冷却壁各结构参数为决策变量,对冷却壁进行多目标优化,获得了Pareto最优解集。优化后的冷却壁与初始冷却壁相比,可在传热性能相当的前提下成本下降79.9%,或在冷却成本相当的前提下,热阻下降27.3%。

基于ARM的电阻炉炉温控制系统设计

在科学技术突飞猛进发展的背景下,现代工业生产中的电压、电流、开关量等都是重要的被控参数,在冶金制造业中,温度是器件生产过程中非常重要的物理参数,需要对各种加热炉的温度进行严格控制,对其温度变化进行实时监测,确保炉内温度满足制造器件的需求。电阻炉在金属热处理中具有较为广泛的应用,是进行金属锻压加热、烧结的重要工业设备。电阻炉温度控制多采用自动化控制系统,实现智能化管理,保证炉温的均匀度以及零件温度的均匀性,提高生产的可靠性和稳定性。从电阻炉温度控制的难点入手分析,结合电阻炉温度控制系统的设计原则,提出一种基于ARM处理器的电阻炉炉温控制系统设计方案,能够提高电阻炉温度控制的精度,保证工业生产的稳定性。

耐火材料的抗碱侵蚀性研究进展

碱侵蚀是高炉、回转窑、匣钵等高温装置重要部位损毁的主要原因,不同于熔渣导致的溶解侵蚀和物理冲刷导致的蚀损,碱侵蚀有着其特殊的作用机制。本文首先介绍了碱的物理性质并计算了其与耐火氧化物反应的吉布斯自由能和体积效应,以此为出发点综述了碱对典型高温装置关键部位的侵蚀过程及机制,并概述了碱性耐火材料、铝硅系耐火材料、非氧化物耐火材料、新型合成材料抗碱侵蚀的研究与应用新进展,同时对比了几种国内外抗碱侵蚀标准或方法,最后对耐火材料抗碱侵蚀性研究提出了几点建议。

蒸汽转化管内壁瘤状物组成与形成机制研究

在一根天然气制甲醇蒸汽转化炉管内壁某位置发现瘤状物,不仅突出于内壁还向炉管内部生长,导致炉管性能受到严重影响。针对此罕见现象,文章采用光学显微镜,扫描电子显微镜和能谱仪等手段对该瘤状物的组织和成分进行观察分析。结果表明:瘤状物的本质为Cr与Fe的氧化物,与基体之间存在不同于常规氧化物的过渡区,且在瘤状物内部观察到许多富碳的疏松结构。推测瘤状物的形成机制与还原-氧化相互共同作用有关。

粒化高炉矿渣粉沥青混合料路用性能研究

为了拓宽废弃粒化高炉矿渣的利用途径,文中采用不同比例的粒化高炉矿渣粉代替矿粉后,进行AC-13C沥青混合料配合比设计,并对其高温稳定性、水稳定性和低温抗裂性等路用性能进行对比分析。结果表明,将粒化高炉矿渣粉作为填料应用于沥青混合料中,提高了沥青混合料的高温稳定性和高温水稳定性,但降低了其低温水稳定性。当粒化高炉矿渣粉替代率不超过50%时,沥青混合料的低温抗裂性可以得到提高,而当粒化高炉矿渣粉替代率超过75%时,沥青混合料的低温抗裂性降低。综合分析结论得出,AC-13C沥青混合料的粒化高炉矿渣粉替代率不超过50%。

智能控制的电阻炉炉温控制系统研究

电阻炉是一种常用于工业生产中的热处理设备,广泛应用于金属加工、材料烧结、玻璃制造等领域。炉温控制是电阻炉运行过程中的关键问题,对于保证产品质量、提高生产效率至关重要。智能控制是具有智能信息处理、智能信息反馈及智能控制决策的控制方式,用来解决那些传统方法难以解决的复杂控制问题。智能控制技术和现代传感器技术的不断发展将推动电阻炉控制技术的进步。在分析电阻炉控制技术现状以及发展趋势的基础上,对智能控制的电阻炉炉温控制系统设计进行了全方位的探讨,最后介绍了电阻炉炉温控制系统测试仿真环境与调试方法,帮助调整电阻炉的加热功率和工作模式,通过精确控制温度和优化能量利用,可以降低能源成本和生产成本,提高能源利用效率。

武钢废钢全流程一体化协同管控系统的建设

随着国家大力推进智慧制造,借助数字化转型来推动钢铁企业废钢管理升级优化,是钢铁企业降低生产成本、实现绿色低碳发展的必然选择。建立了武钢废钢全流程一体化协同管控系统,支撑废钢全流程管控精细化,实现物流、质检、库区岗位操作智能化,建立废钢计划需求及区间配送调度模型,全流程全要素可视化,实现管理岗位决策智慧化。

基于单片机的电阻炉温度控制系统研究

电阻炉温度控制系统在现代工业生产以及实验室研究中的重要性不容忽视,它是实现高精度温度控制的核心技术之一。在信息技术快速发展的背景下,电阻炉温度控制系统的设计和优化已成为众多研究和应用领域的热点。电阻炉温度控制系统主要由加热元件、温度传感器、控制器和执行机构等组成。其中,加热元件主要负责提供热能,通过传感器对温度进行监测,结合温度传感器的反馈,由控制器对热元件进行控制,确保加热炉温度控制在目标值附近。执行机构则负责执行控制器的指令,对加热元件进行开关或调节。在介绍电阻炉温度控制系统研究现状的基础上,分析单片机应用于电阻炉温度控制系统的价值,结合控制原理、硬件设计以及软件设计进行系统构建分析,以望能够推动基于单片机的温度控制系统在工业实践中的广泛应用,促进相关领域的技术进步和发展。

电炉冶炼复杂物料高温电阻测量方法的研究

电炉作为清洁能源装备,用于工业固废冶炼处理,实现复杂物料高附加值利用。然而工业固废物料成分较为复杂,物料在高温冶炼过程中涉及化学反应、温度场、电场、磁场等相互耦合作用,电阻等基本物理参数极其复杂、不稳定。以钛渣电炉为研究对象,研究电炉冶炼钛渣高温电阻测量方法,动态监测电炉实际冶炼过程中高温炉渣在不同冶炼阶段、不同工况情况下的电流、电压,通过对测量数据进行统计分析和理论计算,分析计算出高温钛渣在不同冶炼阶段、不同工况下的热态阻值,从而归纳总结出电炉冶炼反应合理用电参数,为电炉供电制度优化、电气参数设计提供基础数据理论支撑。

基于Matlab的电阻炉温度控制系统仿真

电阻炉作为重要的工业加热设备对部件进行热处理,是一种利用电流通过电阻材料发生热能的加热炉,电阻炉在机械领域主要用于金属的锻压前加热、粉末冶金烧结、玻璃陶瓷焙烧及退火、熔点低金属熔化等。电阻炉与火焰炉相比具有结构简单、炉温均匀、加热质量好、便于控制、无噪声等优点。作为重要的热处理设备,电阻炉的温度控制直接关系到生产产品部件的质量和精度。但电阻炉的温度变化具有较强的时滞性以及惯性,因此建立有效的温度控制系统提升电阻炉的温度控制水平具有重要的意义。先分析了模糊PID算法的原理,然后基于SX-10-12型号箱式电阻炉介绍了温度控制系统的整体设计方案、硬件设计以及软件设计,并在Matlab仿真环境下对温度控制系统的运行情况进行论述,旨在提升电阻炉温度控制的自动化水平。

电阻炉温度控制系统优化

电阻炉是一种广泛应用于各种工业和实验室应用的设备,它通过电流加热炉内的金属电阻丝来产生热量。电阻炉具有加热均匀、温度控制精确、热效率高、使用寿命长等优点,因此在许多领域中得到了广泛应用。电阻炉温度受到多种因素的影响,包括负载变化、环境变化和传热特性等,极大的影响了系统的快速响应以及调节能力。电阻炉温度控制是一个涉及多个方面的复杂过程。通过合理的目标设置、有效的控制系统、以及适当的温度均匀性和过热防护措施,可以实现电阻炉的高效、安全和稳定运行。基于传统电阻炉温度控制系统存在的问题进行分析,分析进行优化控制的意义,分析电阻炉的物理特性以及温度响应,构建电阻炉温度模型,并提出基于模糊自适应PID算法的温度控制优化算法,以提升电阻炉的实际工作能力。