双电极直流电熔镁埋弧电弧炉

介绍了一种新型的双电极扁圆形直流电熔镁埋弧电弧炉·通过实验研究了该种炉型的运行特点,并对炉子的能耗指标及实验样品的质量与交流电熔镁埋弧电弧炉的生产状况进行了对比分析·结果表明:采用双电极直流供电技术,可减少电弧闪烁,噪音小,生产稳定,电能消耗降低,电极消耗降低约50%;扁圆形炉型有利于MgO的结晶,结晶颗粒大,质量分数为98%以上的MgO收得率提高了约15%·     

电弧炉通风除尘设计与监理

介绍了10t电弧炉通风除尘的特点,设计中应注意的几个问题以及施工监理中重点控制的几个方面.     

电弧炉电极升降控制系统的设计

针对纯模拟器件自耗电极真空电弧炉电极升降控制系统故障率高、维护量大等一系列问题．设计出了由PLC和模拟调速器组成的电极升降控制系统．介绍了系统主要硬件配置、S7-300PLC程序结构、操作面板OP27组态画面．该系统控制算法采用PID算法，且根据现场工艺要求实现了从手动到自动的无扰切换功能．现场运行数据表明，基于PID控制规律的电弧炉电极升降PLC控制系统运行稳定可靠，操作方便，维护量小，对同行业的生产进步将起到示范和推动作用．     

现代电弧炉冶炼周期综合控制理论及应用

在分析40年来国内外现代电弧炉炼钢技术发展特点的基础上,指出现代电弧炉炼钢技术是围绕缩短冶炼周期以满足高效连铸节奏要求这一核心发展起来的,提出了现代电弧炉冶炼周期的综合控制理论.简要地介绍了这一理论以及在这一理论指导下开发的包括电炉加铁水冶炼等一系列高效化电弧炉炼钢技术和在中国电炉钢生产中的应用效果.这一理论指导和推动了钢铁冶金及我国电炉钢生产的发展.     

直流电弧炉炉内熔体温度场及流场

通过将麦克斯韦方程、纳维-斯托克斯方程及能量平衡方程相结合,提出了一个描述单电极直流电弧炉炉内熔体温度场及流场的数学模型。通过实验室规模的直流电孤炉的温度实测和模型计算表明,熔体内的温度分布是均匀的,电弧附近的一定区域除外;熔体的流动是高度紊流的;操作电流为0.8～1.2kA时,热浮力是控制熔体流动的主导力量。     

LA-ICP-MS zircon U-Pb dating for high-pressure basic granulite from North Qinling and its geological significance

Inrecentyears,discoveriesofhightoultrahighpressuremetamorphicrocksatthenorthandsouthsidesoftheQinlingGroupinthenorthernpartoftheQinlingMountains(hereafterNorthQinling)haveattractedfocusattentionofgeologistsworldwide.Thenorthhigh-pressure(HP)metamorphicbelt,distributedintheareafromGuanpotoShuanghuaishunorthwardtoShizipin,LushCountyinHenanProvince,consistsmainlyofeclogiteoutcroppedaslenticularmassesofdifferentsizesinthegneissesoftheQinlingGroupclosetothesouthsideofZhuyangguan-Xiaguanfault…     

70T高阻抗电弧炉的全自动化泡沫渣管理系统

介绍了70T高阻抗交流电弧炉全自动泡沫渣管理系统;用西门子PLC集成FOX公司泡沫渣管理器与KOLL公司喷碳装置,实现了电炉炼钢全过程全自动化的泡沫渣分析与管理;以FOX300泡沫渣管理器作为泡沫渣的控制核心,阐述了泡沫渣指数的算法、碳量确定及喷碳装置在PWM方式下的控制过程;使用西门子PLC的系统功能块实现数据通信;WinCC人机界面实现系统的实时监测与控制;使用FOX300软件优化系统参数;通过电炉炼钢全过程全自动化的泡沫渣管理,有效提高了电弧的传热效率,缩短了冶炼时间,降低了电能消耗,大幅度地提高了生产率。     

电弧炉炼钢用四元炉料的冶炼过程物耗和能耗分析

天津钢管集团股份有限公司150t电弧炉炼钢长期使用四元炉料,其平均炉料配入比为46.2%废钢、9.1%生铁、26.4%热铁水、18.3%DRI,通过物料衡算和能量衡算分析了电弧炉冶炼过程的物耗和能量状况.论文研究得出了单位炉料对物耗和能耗的影响,以及四元炉料结构变化对吨钢电功率输入的需求范围为153～744kW.对大量生产数据进行逐步回归分析,结果表明:直接还原铁配入比RDRI的影响最为显著,每增加1.0%,吨钢电耗大约增加1.4kWh;其次是铁水配入比RHM,其每增加1.0%,吨钢电耗大约降低2.0kWh.     

Some new ideas about the deep subduction of continental crust

The discovery of coesite in metasedimentary rocks not only implies that the materials of continental crust with low density could subduct down to mantle depth, but also initiates a series of studies on continent-deep-sub-duction. Could continental crust be subducted down to the depth of more than 300 km? Water played a role in ultra-high-pressure (UHP) metamorphism although limited. Was the fluid really limited within meter-scale, as the authors suggested, at mantle depth? Erosion and extension could remove the overburden of the UHP rocks, while squeezing and buoyancy could lift up the UHP rocks through the overburden. What, however, is the main process and mechanism with which the UHP rocks have exhumed from mantle depth? All progress of these studies will eventually form and complete a new paradigm of geodynamics.     

Mesozoic basin development and its indication of collisional orogeny in the Dabie orogen

The Dabie orogen underwent deep continental subduction, rapid exhumation, and the huge amount of erosion during the Mesozoic. Its tectonic evolution, especially how its evolution was recorded by sedimentary basins at the flanks of the Dabie orogen is one of the most important issues of the world’s attention. These years, newly studies of basin sedimentology, combined with structural geology, have shown a fundamental progress. The overall distribution of different basin types in the orogen indicates that shortening and thrusting at the margins of the orogen from the Late Triassic to the Early Cretaceous controlled the foreland basins, and extension, doming and rifting were initiated in the core of the orogen from the Jurassic to the Early Cretaceous and were expanded to the whole orogen after the Late Cretaceous. Therefore, The Dabie orogen records gradual transition from overall shortening and thrusting to dominantly extension and rift basin formation expanded from its core to its margins, although these shortening and extension overlapped in time from the Jurassic through Early Cretaceous at crustal levels. The unroofing ages of the ultra-high pressure (UHP) metamorphic rocks in the Dabie orogen change from Early Jurassic to Late Jurassic westward. The depth of exhumation increases eastwards. The sediment sources for the Hefei basin are mostly composed of the deeply exhumed, axial Dabie metamorphic complex, and the sediment sources for the Middle Yangtze basin are mostly from cover strata in the southern orogen and related strata with subjacent (i.e. subsequently overthrusted) Mianlue suture belt. Geodynamic analysis represents that continental collision between the North China Block and the South China Block along the Shangdan and Mianlue sutures, subsequently northwestward progradation of the Jiangnan fold and thrust belt, and the underthrusting of the North China Block along the Northern Boundary Fault of Qinling Range led to crustal thickening, gravitational spreading and balanced rebound of the resultant thick crustal welt, and multi-episodic exhumation of the HP/UHP metamorphic rocks. The future studies by the methods of tracing the Dabie orogeny through deposition in the marginal basins should focus on eastward extension of the Mianlue suture, thrust and overlap of the Dabie HP/UHP metamorphic block on different lithotectonic zones and basins along the northern South China Block, the structural framework of the source area of the basins in the syn-depositional stage, the basin lateral extension, huge amount of erosion and sediment transportation from the Dabie blanket and basement rocks, and recovery of subducted and re- moved structural units within the Dabie orogen, etc.