基于大型铁矿石熔滴检测设备的综合炉料性能

铁矿石的高温软熔滴落性能影响高炉内软熔带的形状及位置,进而影响高炉操作的稳定顺行。国内外传统的铁矿石熔滴检测设备存在坩埚尺寸小,试样量少等问题,导致无法客观地模拟高炉实际生产中复杂的炉料结构,同时试验结果波动较大,重现性差。使用大型铁矿石熔滴检测设备,测定了不同炉料结构下含铁炉料的高温软熔滴落特性,同时对比了传统小型熔滴检测设备,结果表明,随着块矿使用比例的增加,大型铁矿石熔滴检测设备测定的炉料的滴落温度td值随之减低,熔滴特征值S值呈相反规律;试验过程中料层出现的压差ΔP值达到峰值后呈现一定幅度的动态变化,初渣试样主要成分为黄长石类矿物及硅酸二钙(C2S)等,且料层的收缩率ΔH值明显增大,符合炉内铁矿石还原过程的生产实际。     

高炉下部炉料运动与渣铁排放的研究

通过模型试验,测定了在不同条件下,死料柱形状的变化,确定了软熔带的形状及位置与死料柱形状的函数关系,同时,在有浮力的作用下,测定模型内炉料的压力和风压的变化,探讨渣铁浮力对炉料运动及高炉操作的影响,论述了连续出铁的实际意义。     

脉冲熔融-热导法测定硅铁中氮

硅铁中氮的测定没有标准方法和相应的参考物质,本文通过以屑状钢中低氮参考物质建立氮校准曲线,采用镍箔助熔自动分析模式测定,建立了脉冲熔融热导法测定硅铁中氮的方法。对比了直接投样手动分析模式、添加石墨粉手动分析模式和镍箔助熔自动分析模式3种分析模式对氮的测定影响,结果表明,采用镍箔助熔自动分析模式测定硅铁中氮,氮释放完全、测试结果稳定。本方法的测定下限为0000 37%,用于2种硅铁样品中氮的测定,测定结果的相对标准偏差分别为10%和9%（n=4）。     

不同料柱模式下高炉内煤气流分布的模拟

高炉炼铁广泛使用高铝炉料，冶炼过程中需要控制渣成分以满足炼铁需求，这会导致渣比增加和软熔带位置改变，进而影响高炉煤气流的分布。为此，基于Flunt数值模拟手段，研究了不同料柱模式下高炉内煤气流的分布情况。结果表明，不同料柱模式主要影响软熔带附近煤气流分布，对炉身上部煤气流分布情况影响较小。倒V形软熔带的料柱模式下，随着软熔带的高度升高、厚度增加，高炉内中心处11.1 m到13.0 m高度平均煤气流速由0.76 m/s减弱到0.69 m/s,边缘处8.6 m到11.1 m高度平均煤气流速增加了0.05 m/s。W形软熔带的料柱模式下软熔带下部的煤气流速高于倒V形软熔带料柱模式下的流速。研究结果可为指导高炉大渣量冶炼提供理论依据。     

无钟炉顶高炉"漏斗形"料面建立与维护方法的探讨

高炉解剖研究成果表明,软熔带一般是倒“V”形,软熔带中的“焦窗”起“透气”作用“。平坦形”和“馒头形”料面均影响高炉透气性,不利于高炉顺行,分析溜槽布料与料面形状的关系也表明“漏斗形”料面是炉况稳定的合理料面。并提出通过使用附加焦或正常料焦批等建立与维“护漏斗形”料面的简易方法。     

高比例酸性炉料对高炉操作的影响及应对措施

随着环境保护压力的增加,中国钢铁公司的高炉炉料结构中酸性料(球团和块矿)配比显著提高,尤其在冬季取暖季的时候。但是,各钢铁公司的资源条件不同,采用高比例酸性炉料冶炼时,有的钢铁企业获得较好的生产指标,但也有钢铁企业操作指标不佳或难以实现高比例酸性料操作。基于此,以提高高炉酸性料比例和降低生产成本为目的,分析了高比例酸性料所带来的问题,并提出了应对高比例酸性炉料的技术措施。高比例酸性料对高炉冶炼的影响主要体现在块状带和软熔带。对块状带的影响主要有,粒度的差异导致空隙率降低;堆积性能的差异导致料面难以控制;还原产生的粉末影响高炉块状带的透气性。对软熔带的影响主要有,酸性料自身软熔温度较低;还原度较低导致矿石进入软熔带前FeO含量高,使得软熔带位置上移且变宽;软熔带焦窗长度变长,增加整个焦窗的压力损失。应对高比例酸性炉料的具体措施有,合理选择优质酸性炉料;制备碱性镁质球团;采用合理的布料制度尽量克服球团矿对料面的不利影响;高炉精细化用焦,充分发挥大块焦与小焦丁的特点与功能。能够改善块状带和软熔带透气性的技术措施都可以缓解高比例酸性料对高炉冶炼的不利影响,各生产企业可结合自身的资源情况和炉型特...     

真空熔烧工艺参数对Co基合金—碳化钨复合涂层组织结构和性能的影响

选用钴基合金—25 vol％WC复合料作为试验材料,并用真空熔烧方法在45号钢表面制得复合涂层。用金相显微镜、扫描电子显微镜和X射线衍射仪观察和分析复合涂层的组织结构。在石腊基础油润滑条件下,应用MHK—500环—块滑动磨损试验机进行滑动磨损试验。测定真空熔烧工艺参数对复合涂层组织结构、强度、硬度和摩擦磨损性能的影响。在综合分析的基础上,给出了钴基合金—25 vol％WE复合涂层最佳的真空熔烧工艺参数为:熔烧温度为1180℃,保温时间为2min。     

高炉软熔带的形成及其对煤气流分布的影响

本研究选用与铁矿石软熔性能相似的模拟物料在动态热模型中研究软熔带的形成过程及其对煤气流分布和传热的影响,以探索高炉软熔带的规律。通过建立的流体流动-综合传热模型,在“银河”计算机上所进行的数值解析,得到了气流在料层中的流函数、速度矢量、压力以及气体和固体温度的分布等。热态试验和数模计算结果与鞍钢7号高炉活体测定数据相一致。     

矿石还原软化透气性测定

目前,如何强化包钢高炉冶炼已成关键问题。为查明影响包钢高炉强化的基因和解决的途径,我们对包钢、首钢、鞍钢烧结矿的还原软化透气性进行了测定,初步查清了包头矿软熔透气性与首钢、鞍钢烧结矿的差别及其特性,并对现行的高炉配料和配加公益明矿以取代白云块矿进行了测定比较,结果表明,包钢烧结矿配加公益明矿是降低料层压损、提高料柱透气性的有效措施。     

陶瓷坩埚感应熔炼法制备LaNi_5化合物研究

本文采用差热分析法对6种预选坩埚材料进行了热分析比较,选用6种不同材料的坩埚做了熔料试验;叙述了采用3种致密型陶瓷坩埚感应熔炼LaNi_5化合物的熔炼工艺,对熔锭进行了化学分析与x射线衍射检测。结果指出:致密型Al_2O_3、MgO和ZrO_2坩埚用于感应熔炼LaNi_5化合物时成分均匀,由坩埚带入的杂质含量<0.08%,经x射线衍射检测熔锭为LaNi_5结构,存有微量La_2Ni_7相。     

On the relation between optical basicity and phosphorus capacity of complex slags

In this work, the coexistence of monomer and dimer phosphate ions is considered and their relative proportions, as related to the slag phosphorus content, is used to accurately calculate the slag capacity of phosphorus as monomer and dimer phosphate ions respectively. The slag capacity of phosphorus as monomer phosphate ions is discussed to clarify the applicability of different scales of optical basicity. It is found that the theoretical optical basicity is an excellent measure of slag phosphorus capacity for a wide range of slags and seems not to be restricted to certain components or compositional limits. As a result, excellent relationship is displayed between phosphorus capacity, temperature and theoretical optical basicity. The influence of slag composition on equilibrium oxygen distribution is also considered and it is found that the oxygen concentration in liquid iron can be closely related to temperature and theoretical optical basicity.     

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RH oxygen top- blowing for raising temperature should be avoided to improve the cleaniness of IF steel as far as possible, which made the end point temperature of converter higher and then dephosphorization in converter became difficult. Thermodynamics and dynamics of dephosphorization process in converter were calculated to study the relationship of phosphate partition ratio to compositions of molten steel, slag, temperature in molten steel based on slag- remaining and double slag process. Through changing the first deslagging time and the composition of slag,then serial sampling from molten steel and slag in industrial production experiments, the behavior of phosphorus in molten steel was studied and then the main measures obtaining higher phosphate partition ratio in slag- remaining and double slag process are: small- sized scrap or thin steel sheet should be used to increase FeO content in slag and prevent molten steel temperature increase when oxygen blowing in converter begins. Slag with high phosphorus content should be poured when amount of oxygen blowing reachs 40% of the total; FeO content in slag should be increased to assure the mobility of slag and then reduce rephosphorization from slag to steel when amount of oxygen blowing is greater than 40% and less than 80% of the toal; the end- point slag with 4. 0 basicity and 18 mass%-20 mass% FeO content and molten steel temperature should be controlled.     

Contribution to phosphorus behaviour in steelmaking with sponge iron

Experiments were conducted in a 70 t UHP electric arc furnace to study the phosphorus behaviour in steelmaking with sponge iron. The proportion of sponge iron in the metallic feed was varied from 52 to 95.4 wt.%. The results are used to show the effect of the sponge iron proportion in the charge on the phosphorus content of the bath. They are also utilized to illustrate the effects of the composition, temperature and theoretical optical basicity of the slag on the phosphate capacity and to investigate the kinetics of dephosphorization. It is found that both initial and final phosphorus contents of the bath decrease almost linearly with increasing sponge iron proportion in the charge. Using regression analysis, linear equations were obtained which show the change of the phosphate capacity of a slag, at a given temperature, with the total lime content as well as with the theoretical optical basicity. Based on these equations, a functional relationship was derived which shows the effect of simultaneous variation of total lime content and temperature of a slag on its phosphate capacity. A similar equation is given for the influence of simultaneous change of theoretical optical basicity and temperature on the phosphate capacity of a slag. The effect of the compositions of the slag and metal on the phosphorus distribution ratio is expressed by an equation. The kinetics of dephosphorization are investigated, assuming that the mass transfer of phosphorus in the metal is the rate controlling step. In the present investigation the activation energy of dephosphorization is equal to 38 kJ/mol and the mass transfer coefficient of phosphorus at 1600°C is 0.0135 cm/s.     

钢渣中磷分离及回收的研究现状和发展趋势

 中国的钢渣产量巨大,但是钢渣的综合利用率较低,造成了严重的资源浪费和环境负担。钢渣中磷的分离与回收是实现钢渣高效资源化利用的关键所在,对开发新的磷资源和建立“无废渣”炼钢流程具有重要意义。首先分析了钢渣中磷的分布状态,总结了目前提出的从钢渣中分离和回收磷的主要方法及其技术特点,并着重介绍了利用选择性浸出从钢渣中直接提取磷酸盐产品的新技术及其研究进展,分析了选择性浸出的原理和实现钢渣循环利用的冶金工艺流程,讨论了其优缺点,最后对未来钢渣资源化利用的发展提出了建议和展望。     

Methodological Aspects of Using Blast Furnace Slag for Wastewater Phosphorus Removal

Blast furnace (BF) slag is a by-product of steel plants. The objective of this study was to evaluate experimental methods to determine the phosphorus sorption capacity of BF slag. The handling of BF slag, before usage and clogging were also considered, as well as estimating the phosphorus retention capacity. Agitation and pilot-scale experiments were performed using both wastewater and phosphate solutions. This investigation showed that sorption capacities derived by wastewater experiments were considerably lower compared to those by phosphate solutions. Fresh BF slag briefly exposed to rainfall had a higher phosphorus sorption than weathered BF slag, indicating the importance of handling the slag carefully before usage. The risk for leakage of sulfuric compounds is considerable, especially during the initial operation phase of BF slag filters. Locations of BF slag filter beds for wastewater treatment must be carefully chosen from an environmental point of view.     

Study on phosphate and sulphide capacities of CaO-CaCl2 slags

Experiments were carried out at 1175–1350°C to study the phosphate capacity of CaO-CaCl₂ slags and the sulphide capacity was calculated according to the correlation between the two capacities. At 1200°C the logarithm of the phosphate capacity increased from 24.5 to 26.5 with increasing CaO mole fraction from 0 to 0.22 in the slags and it decreased with increasing temperature. Sulphide capacity increased both with increasing CaO mole fraction and temperature. A good linear correlation was found between slag carbonate capacity and phosphate capacity as well as sulphide capacity. Optical basicity was used to evaluate the property of the CaO-CaCl₂ slag in the present study. The value of optical basicity of CaCl₂ is established as 0.63. The correlations of optical basicity with above mentioned three capacities were found to be linear.     

Distribution of Phosphorus between CaO-CaF2 Slag and Fe-C-P Melt

SymbolList　　a(i) ———Activityofconstituentiinslag ;　　CP———Phosphatecapacityofslag ;　　eji———Interactioncoefficientofconstituentjtoconstituenti;　　f[i] ———Activitycoefficientofconstituentiinmelt;　　Km———Equilibriumconstantofreactionm ;     

钢渣还原脱磷技术研究现状及展望

分析了磷在钢渣中的赋存状态,介绍了目前关于钢渣中磷的脱除技术现状。通过采用热力学分析,在加入部分锰铁矿的基础上,提出了钢渣作为烧结原料于烧结过程脱磷的技术构想。该技术对钢渣在烧结过程中大规模应用具有重要参考价值。     

钢铁厂磷素流的路径分析及探讨

针对钢渣尚未有效资源化利用的情况，以磷元素为中心对钢铁厂磷素流从矿选、烧结（球团）、炼铁、炼钢工艺上进行了全生命周期的梳理，重点分析了首钢京唐公司生产过程中磷素流路径，利用平衡的手段，研究了磷元素的分配规律和富集规律，并对生产过程磷素流的优化进行了探讨。认为可通过生产流程整体优化来降低铁水磷含量，实现钢渣的减量化，并利用冶金技术将富磷的钢渣和矿选尾矿等制备成矿渣、铁水和磷酸铁等产品来实现钢渣资源化利用。