镁钙材料抗精炼渣性能研究进展

本文综述了炉渣碱度,炉渣中氧化铝、氟化钙、氧化镁含量,镁钙材料中氧化钙含量与抗水化添加剂对镁钙材料抗渣性的影响。总结了提高镁钙材料抗渣性的方法。提出了镁钙材料抗渣性研究的方向。     

烧成镁钙砖生产过程防水化措施的探讨

镁钙系耐火材料是耐火材料的重要组成部分,其中镁钙砖是以MgO和CaO为主要化学成分的镁质复合耐火材料,其主要矿物组成为方镁石和方钙石。方钙石具有良好的高温塑性,能减缓砖内部高温产生的热应力;且方钙石与熔渣中的SiO2反应,生成高熔点矿物C2S和C3S,提高了熔渣的黏度,减轻了熔渣对砖的渗透,使砖具有良好抗剥落性能;对于钢水中的S、P和Al2O3等非金属夹杂物等,方钙石具有吸附作用,起到了净化钢水的效果。因此,镁钙砖具有良好的热震稳定性、良好的抗结构剥落性能和抗熔渣的渗透性能,还具有净化钢水的独特性能。在钢铁冶炼中得到广泛应用,镁钙砖性能如此优良,却有一个致命的缺点,因为其中含有游离CaO,易水化现象无法避免,造成产品不易保存,非常易损坏,所以在生产过程中采取何种抗水化措施是提高其性能的重要技术问题。     

不烧镁钙砖的抗精炼炉渣侵蚀性能

为了适应精炼钢包对镁钙材料日益增长的需求，通过感应炉抗渣实验研究了不同精炼渣系(CaO-SiO2和CaO-Al2O3)对不同组成的树脂结合不烧镁钙(MgO-CaO)砖侵蚀的影响，并借助显微镜和电子探针对熔渣熔蚀、渗透进行了研究。结果表明：对于CaO-SiO2渣，随着砖中Ca0含量的增加，砖的抗渣蚀能力增强，而CaO-Al2O3渣却恰好相反；无论对哪一种渣，熔渣的渗透深度都随着砖中CaO含量的增加而减小。     

氧化铝、氧化铬对方镁石-尖晶石材料抗钢水侵蚀性的影响

以电熔镁砂和高纯尖晶石作为主体原料,研究氧化铝、氧化铬两种添加剂对方镁石-尖晶石材料抗钢水侵蚀性的影响。首先针对原料性质对试样进行高压成形、高温烧成处理,烧后试样利用感应炉炼钢机理进行抗钢水侵蚀性试验。利用反光显微镜对侵蚀后试样进行显微观察,结果发现：加入Al2O3与Cr2O3有利于方镁石-尖晶石材料基质中镁铝尖晶石和...     

矿物原料及冶金产品中铝、钙、镁的容量分析法简述

钒、钛、锰、铬等元素,对EDTA容量法测定铝、钙、镁,都有不同程度的干扰。高镁低钙、高钙低镁及低钙镁试样,由于待测元素之间含量悬殊较大,对测定会引起干扰。因此,弄清各类试样的干扰情况,是选择分离干扰元素方法及拟定测定方法的基础。 一、干扰元素对测定铝、 钙、镁的影响 钛和铝在一定条件下同时和EDTA络合,又同时被氟盐释放,因而,钛定量干扰铝的测定。当PH=10,用EDTA滴定镁时,微克量的钛就能使铬黑T指示剂封闭。当钛含量高时,由于水解产生的沉淀吸附钙离子而使结果偏低。五价钒与PAN或二甲酚橙指示剂生成红色络合物,当V_2O_5高于0.5毫克时,终点难于判断。     

稀土金属氧化物对MgO晶粒生长动力学影响研究

制备了添加稀土金属氧化物的高钙镁钙材料试样,研究了添加稀土金属氧化物对MgO晶粒在不同温度下的生长速率的影响,计算得出合成高性能抗水化的高钙镁钙砂在不同合成温度下晶粒生长的活化能。结果表明:无添加剂时,QMgO为1104.02kJ/mol;添加质量分数为1%Y2O3时,QMgO为937.06kJ/mol;添加质量分数为2%Y2O3时,QMgO为922.70kJ/mol。当Y2O3加入量在1%时,氧化钇在1650℃下全部固溶到氧化钙晶格中,导致氧化钙晶格畸变,促进了高钙镁钙材料的烧结,提高了该材料的抗水化能力。这对降低高性能抗水化的高钙镁钙合成原料的能源消耗具有理论指导意义。     

镁阿隆-钛酸铝复合材料抗Al2O3附着的研究

利用镁阿隆—钛酸铝复合材料与熔渣和钢水润湿性较小的性能 ,并与Al2 O3 -C和CaO·ZrO2 -C材料作对比试验 ,研究镁阿隆—钛酸铝复合材料抗Al2 O3 的附着作用。结果表明 :镁阿隆—钛酸铝复合材料具有很好的抗侵蚀性和抗Al2 O3 附着性 ,是理想的防堵塞和非污染浸入式水口的内衬材料。     

镁碳砖静态热侵蚀试验研究

为研究低碱度条件下镁碳砖侵蚀过程中石墨氧化以及镁砂溶解与钢渣氧化性、碱度的关系,设计了两组静态热侵蚀试验。试验结果表明:1)在氧化性钢渣碱度为1.0时,钢渣能快速氧化砖体中的石墨,使其抗渣润湿性变差,导致砖体结构疏松,与镁砂接触后,加快了侵蚀速度;2)在非氧化性钢渣碱度为1.0时,钢渣可与镁砂形成大量低熔点相(钙镁橄榄石),使其具有很强的侵蚀能力;当碱度为0.8和1.2时,钢渣的侵蚀能力减小。     

脱硅氧化锆对MgO—CaO—ZrO2材料性能的影响

为提高精炼炉用镁钙砖的抗侵蚀性,系统地对烧成温度及加入量进行探索,通过实验数据的对比,得出5%脱硅氧化锆加人量,1650.C x2h烧成,是合成MgO-CaO-ZrO2材料的最佳生产工艺参数.     

高碱度高 Al2O3 炉渣下合金钢液中非金属夹杂物的行为

通过MgO坩埚硅钼电阻炉研究了(%):43～47CAO-5～10SiO2-46～54Al2O3高碱度炉渣下合金钢液(%:0.42C、1.14Cr、0.23Mo)中夹杂物的成分和组织形貌.结果得出,高碱度高Al2O3炉渣和钢液反应90 min后,钢中主要生成低熔点钙镁铝硅酸盐夹杂,该夹杂大部分上浮去除,留在钢中的为球形夹杂,有利于提高钢材的抗疲劳性能.当炉渣碱度约为9时,有利于生成钙镁铝硅酸盐夹杂.     

Inclusion evolution in 50CrVA spring steel by optimization of refining slag

In order to control the CaO-Al2O3 -SiO 2 -MgO system inclusions in 50CrVA spring steel in a lower melting temperature region, high temperature equilibrium experiments between steel and slag were performed in the laboratory, under the conditions of the initial slag basicity within 3-7 and the con-tent of Al2O3 between 18-35 mass%, to investigate the formation and evolution of this type of in-clusion.The results indicate that the total oxygen content in the steel decreases with the increase of slag basicity and the decrease of Al2O3 content in slags, and CaO-Al2O3 -SiO 2 -MgO inclusions tend to deviate from the low melting point region with the increase of Al2O3 content in slags.The most fa-vorable composition for the refining slag is composed of 51-56 mass% CaO, 9-13 mass% SiO2 , 20-25 mass% Al2O3 and 6 mass% MgO.In this case, the inclusions in 50CrVA spring steel are mostly in the low melting point regions, in which their plasticities are expected to improve during steel roll-ing.The MgO-based inclusions were observed in the steel matrix and the formation mechanism was theoretically and schematically revealed.It is also found that adding around 11 mass% of MgO into the refining slags is beneficial to reducing the refractory corrosion.Further work should be carried out focusing on the evolution rates of MgO-based inclusions.     

Corrosion behavior of high alumina and low silicon CaO Al2O3 slags on corundum/calcium hexaaluminate based castables

Due to the corrosion of CaO-Al2O3 based slags on refractory materials is related to the safe smelting of low-density and high-strength steel with high aluminum, the reaction experiment of calcium hexaaluminate castables with high-alumina and low-silicon CaO-Al2O3 based slag was carried out by introducing calcium hexaaluminate into corundum castables, and it was compared with that of alumina magnesia castable. The experimental results agreed with that of thermodynamic simulation and show that corundum calcium hexaaluminate castable has excellent slag resistance. Because the corundum calcium hexaaluminate castable reacted with the CaO Al2O3 based slag and produced high melting point phase CA2, which consumed a large amount of CaO in the slag and increased the viscosity of the slag, and CA2 filled the pores and blocked the penetration of slag. The wear mechanism of the calcium hexaaluminate castable is slag infiltration due to the higher porosity. Therefore, the combination of corundum aggregates and calcium hexaaluminate matrix is expected to be a candidate refractory material for ladle lining of low density and high strength steel smelting.     

高铝低硅CaO-Al2O3系熔渣对刚玉/六铝酸钙质浇注料的作用行为

摘要：由于高铝低硅CaO-Al2O3系熔渣对耐火材料的侵蚀损毁影响高铝含量低密度高强钢的安全冶炼生产,为此通过在刚玉质浇注料中引入六铝酸钙,开展六铝酸钙质浇注料与高铝低硅CaO-Al2O3系熔渣反应实验,并与铝镁浇注料进行对比研究了其作用行为。实验结果表明：刚玉 六铝酸钙浇注料具有优异抗渣性能。这主要是由于熔渣中大量的CaO被消耗,间接提高了熔渣黏度,并与刚玉 六铝酸钙浇注料反应生成的高熔点相CA2填充了气孔,阻挡了熔渣的渗透,实验结果与热力学模拟计算结果相吻合。六铝酸钙浇注料自身气孔率高,熔渣主要以渗透形式对六铝酸钙耐火材料造成破坏。因此,将刚玉骨料与六铝酸钙基质组合是有望成为低密度高强钢冶炼用钢包内衬候选耐火材料。     

不同碱度低氧化铝精炼渣对弹簧钢夹杂物成分的影响

为了优化55SiCrA弹簧钢中夹杂物的组成和形态,采用热力学软件Factsage分别研究了CaO、SiO_2含量对CaO-SiO_2-Al_2O_3-MgO与CaO-SiO_2-Al_2O_3-MnO系相图低熔点区域面积的影响,研究结果表明:随着CaO和SiO_2含量的增加,CaO-SiO_2-Al_2O_3-MnO系相图低熔点区域面积分数逐步增大;在CaO-SiO_2-Al_2O_3-MgO系中,当CaO的质量分数为40%,SiO_2的质量分数为50%时,对应相图的低熔点区域面积最大。同时,研究了不同碱度的精炼渣对钢样中夹杂物的影响,结果表明:当精炼渣的Al_2O_3含量相同时,随着精炼渣碱度的增大,夹杂物中Al_2O_3的含量不断增加,其成分逐渐偏离低熔点区域。当精炼渣中Al_2O_3的质量分数为8%,碱度为1.2时,可得到低熔点的塑性夹杂物,形貌多为球形,尺寸在5μm以下。     

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In order to effectively protect the hearth lining of the blast furnace by using materials containing titanium, the corrosion behavior of slags containing TiO2 to Al2O3 ceramic cup was experimentally investigated through slag resistance test in static crucible and calculation of slag quantity by mass conservation of CaO. The effect of temperature, reaction time and slag binary basicity on the corrosion behavior was studied, and the corrosion mechanism was discussed. The results show that increasing temperature and prolonging reaction time can lead to an increase of corrosion of Al2O3 ceramic cup by the slags with TiO2, whereas the corrosion shows a decrease trend with the increase of slag binary basicity. The corrosion mechanism can be summarized as that: CaO and SiO2 in slag will react with Al2O3 from ceramic cup to form CA6, C2AS and CAS2; the formed CA6, C2AS and CAS2 will dissolve into slags?? some high-melting-point minerals such as MA and CA2 near the original brick layer of ceramic cup will be formed to make slag more viscous.     

Viscosities Behavior of CaO-SiO2-MgO-Al2O3 Slag With Low Mass Ratio of CaO to SiO2 and Wide Range of Al2O3 Content

 The present paper is aimed at recycling of coal ash and blast furnace slag to produce mineral wool. Considering the mineralogical constitutions of coal ash and blast furnace slag, the primary quaternary slag compositions of CaO-SiO2-MgO-Al2O3 with basicity (mass ratio of CaO to SiO2) ranging from 05 to 09 and alumina ranging from 5% to 20% were investigated through a rotating cylinder method. The experimental results indicated that the viscosities decreased with increasing basicity above the liquidus temperature, and increased with increasing alumina content, and the maximum values were reached and as the alumina content was 20%, followed by the decrease with further increasing alumina content due to its amphoteric behavior. The amphoteric behavior of Al2O3 also performed in the relationship between viscosity and non-bridging oxygen per tetrahedrally-coordinated atom (NBO/T), and the viscosities decreased with increasing the NBO/T except the slag with a basicity 05 and Al2O3 20% which have a low NBO/T value and a low viscosity than others.-     

低硅CaO-Al2O3渣对铝镁质浇注料的侵蚀

低密度高强化是钢铁材料的重要发展方向.由于低密度高强钢冶炼用低硅CaO-Al2O3系炉渣会不可避免地与现行铝镁质耐火材料发生反应,严重影响钢的安全高效熔炼及其品质提升.针对这一问题,采用静态坩埚法开展铝镁质浇注料的抗低硅CaO-Al2O3渣蚀实验,探究Al2O3含量变化对耐火材料渣蚀的影响规律,得到以下结论:低硅CaO...     

顶渣对帘线钢中夹杂物塑性化的控制

以某钢厂生产的帘线钢铸坯试样为原料,使用硅钼棒炉对其进行顶渣熔炼实验,研究顶渣成分对CaO-Al2O3-SiO2 类夹杂物塑性化的影响。结果表明, 在顶渣碱度为0.8～1.2时,随着顶渣中Al2O3 质量分数的增加夹杂物中的Al2O3 质量分数也随之增加。当顶渣中Al2O3质量分数低于10%时,CaO-Al2O3-SiO2 类夹杂物的成分在塑性区范围,对应的此时钢液中的w［Al］s低于8×10-6。通过控制顶渣的成分可以把CaO-Al2O3-SiO2 类夹杂物的成分控制在塑性区内。