This paper investigates erosion behaviors of Al2O3-SiC-SiO2-C (ASSC) castable refractory in a 2650 m3 blast furnace hearth. Post-service residual thickness measurements, conducted via 3D laser scanning and manual gauging across multiple hearth orientations with radial sampling at 8.7 m and 6.7 m elevations, revealed critical erosion zones at the "elephant foot" region (1.5-2 m below taphole centerline) and furnace bottom. Minimum residual thicknesses were recorded at 300 mm (sidewall) and 160 mm (bottom), with erosion rates reaching 81.99 % (314.6 mm/yr) and 84.00 % (168.0 mm/yr), respectively. The 3D erosion profile exhibited a distinctive "shallow pot-bottom" morphology, where measured thicknesses exceeded theoretical predictions by approximately 50 mm. Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) analysis elucidated erosion mechanisms: The taphole area exhibited tri-layered degradation from molten iron, slag, and harmful elemental penetration, while the elephant foot region showed predominant iron and elemental infiltration. Design recommendations include increasing ASSC layer thickness in taphole and elephant foot zones, along with thermocouple integration for realtime monitoring. Operational strategies to prolong refractory lifespan involve maintaining saturated carbon/silicon content in hot metal, controlling charge impurities, and implementing regular alkali removal protocols. These findings provide mechanistic insights for optimizing hearth design and operational practices in large-scale blast furnaces.

An autopsy of a 2650 m(3) Al2O3-SiC-SiO2-C type castable blast furnace was conducted in this study, where castable samples from various heights after service were obtained through manual sampling. The phase composition and micromorphology of the post-service castable samples were analyzed using X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). The research revealed that the erosion of the castable in the region above the taphole centerline on the side wall of the hearth exhibited characteristics of hot-face slag erosion and cold-face harmful element erosion. Below the taphole centerline, the castable demonstrated a combination of hot-face slag-iron erosion and cold-face harmful element erosion. In the region above the taphole centerline, high-melting-point slag phases such as magnesium aluminum spinel, anorthite, and calcium aluminosilicate formed and adhered to the hot face of the castable, preventing further erosion by molten iron and harmful elements. In the region below the taphole centerline, the castable reacted with high-temperature molten iron, causing the reaction products to dissolve into the molten iron, which led to structural damage of the castable. Harmful elements such as K, Na, and Zn diffused into the cold end in the form of vapor along the damaged areas, condensed, and then reacted with the castable to form potassium-sodium feldspar, garnet, as well as zinc oxide and zinc sulfide. The volume expansion resulting from these reactions caused damage to the cold face of the castable.

The brittle layer of carbon brick in a Chinese 4000 m 3 blast furnace hearth is investigated in detail, and its formation mechanism is proposed correspondingly. The occurrence form of the brittle layer in carbon brick is characterized by chemical analysis, X‐ray diffraction, and scanning electron microscopy–energy dispersive spectroscopy. The results show that obvious harmful element (K, Na, and Zn) erosion on the sidewall of the blast furnace hearth is observed, in which Zn erosion is dominant. The K 2 O, Na 2 O, and KCl produced in the carbon brick by K and Na are the inducement of the brittle layer formation, and the ZnO formed by Zn is the main reason for the brittle layer formation. The thermal stress caused by temperature gradients in carbon brick is greater than its bending strength, which will increase the microcracks in carbon brick. The brittle layer has a lower thermal conductivity due to higher porosity, resulting in a large temperature difference. The resulting thermal stress will aggravate the embrittlement degree.

介绍了鱼雷罐罐体侵蚀监测系统红外成像与温度检测技术,通过鱼雷罐罐体内部耐材侵蚀仿真模型及评估系统,将鱼雷罐罐体内耐材侵蚀划分为不同的报警级别,当出现危险级别时,自动进行报警,防止烧穿泄漏造成经济损失和安全事故.

对首钢股份1号高炉炉底长寿应用效果进行了分析.重点从高炉炉底结构、生产操作及维护、炉底损调查结果等方面进行了探讨,认为1号高炉采用的炉底结构及刚玉莫来石质陶瓷垫,能够满足工作年限达到15年以上,一代炉役单位炉容产铁量大于1万t/m3的长寿要求.建议今后可以通过提高陶瓷垫的密度,降低气孔率和气孔直径等方法,来抑制铁水对陶瓷垫的渗透.

对首钢股份1号高炉炉缸炭砖、炉底陶瓷垫和富钛保护层进行了取样分析研究,探讨了富钛保护层的形成过程.Ti(C,N)晶粒最初从铁水中析出,然后通过晶界迁移在炉渣中长大,最后Ti(C,N)晶粒与熔渣和铁水一起凝结形成保护层.此外,还用酸蚀法观察了Ti(C,N)析出相的微观形貌,发现Ti(C,N)晶粒主要以环形层状结构存在,Ti(C,N)晶粒内部并不致密.

The three-dimensional (3D) model of erosion state of blast furnace (BF) hearth was obtained by using 3D laser scanning method. The thickness of refractory lining can be measured anywhere and the erosion curves were extracted both in the circumferential and height directions to analyze the erosion characteristics. The results show that the most eroded positions located below 20# tuyere with an elevation of 7700 mm and below 24#–25# tuyere with an elevation of 8100 mm, the residual thickness here is only 295 mm. In the circumferential directions, the serious eroded areas located between every two tapholes while the taphole areas were protected well by the bonding material. In the height directions, the severe erosion areas located between the elevation of 7600 mm to 8200 mm. According to the calculation, the minimum depth to ensure the deadman floats in the hearth is 2581 mm, corresponding to the elevation of 7619 mm. It can be considered that during the blast furnace production process, the deadman has been sinking to the bottom of BF hearth and the erosion areas gradually formed at the root of deadman.

在首钢股份1号高炉停炉及炉缸浇注修复过程中,重点在保护性凉炉技术、浇注烘烤技术、铁口孔道修复技术和炉皮排水技术等方面进行了技术攻关,开炉前期的铁口喷溅治理取得了明显成效.1号高炉开炉时,铁口未喷溅,铁水直接进鱼雷罐,大大减轻了炉前工作量,开炉第15天日产量达到6 400 t/d以上,炉缸二段热电偶温度和冷却壁水温差稳定.

遥感图像中城市区域的自动分析解译是遥感对地观测领域重要的应用方向,针对自动高效城区检测的迫切需求,提出了一种基于遥感图像的城区区域快速检测算法.首先通过智能去雾处理降低薄雾气象条件对检测的干扰,然后通过快速的关键点搜寻进行城区特征位置初选,并以全局与局部约束相结合的策略筛选出高置信度的城区特征位置,最后通过高斯渲染加权的方法整合城区特征位置,并在获得的城区高斯加权图上自适应分割出最终的城区.本算法使用Google提供的卫星图像进行算法验证测试,可得到准确的检测结果.本检测算法可满足遥感图像城区检测自动化、实时化的需求,大大减小了人工判图的工作量,能够广泛应用于机载或星载平台.

Automatic ship detection from SAR remote sensing imagery is very important, with a wide array of applications in areas such as national marine safety, vessel traffic services, and naval warfare. However, SAR remote sensing images with the high inhomogeneity of sea clutter and complex scene result in a large number of false alarms. This paper focuses on the problem of false alarm removal and coverts it as a classification problem with respect to ship targets and false alarms. However, in real application: (1) Compared to false alarms the number of ships is much smaller, and (2) false alarms with diverse categories and no uniform characteristics are difficult to be distinguished from ships. To solve the problems above, we present a new method based on one-class SVM (OCSVM) combined with grid optimization that only use the data of ships to train classifier in the absence of false alarms. First, 2P-CFAR is adopted to extract ship candidates and 14 features mainly focusing on ship targets are selected. Second, grid optimization is exploited to obtain parameters for OC-SVM training, where it is a compromise between the probability of false alarm and detection rate. Experimental results of OC-SVM on a large SAR image set demonstrate that in comparison with other state-of-the-art methods like SVM, BP neural network, our approach can achieve higher detection accuracy.

A case study of University of Michigan at Ann Arbor is conducted to explore the spatial structure of a research university.This study first reviews UM's facility construction practices during the past decade in a theoretical framework developed by Spatial Sociology.Then,spatial analysis techniques(specifically,Kernel density,mean center and standard deviation ellipse) are applied to visualize and reveal the spatial distribution patterns of the whole campus as well as four categories of disciplines: liberal arts,engineering,medicine and other professional schools.The result shows that Ann Arbor campus has multiple cores with medical school in the spatial center.

论文以QuickBird数据为例,基于高空间分辨率卫星影像,开展了内蒙古额济纳胡杨林树冠信息提取方法的研究。在数据融合的基础上,采用面向对象的多层次图像分割方法,提取了影像中的树冠信息。结果表明,稀疏胡杨林样区的整体用户精度为87.63%,生产者精行快速定位。