帘线钢用长寿命中间包挡渣墙的研究

发布时间：2018-07-07 23:30

本文选题：挡渣墙 + ρ-Al_2O_3-水泥复合结合　；参考：《武汉科技大学》2015年硕士论文

【摘要】：本文首先通过挡渣墙损毁分析，确定损毁原因，然后分别从材料的颗粒级配、不同粒度的尖晶石的选择、结合体系以及分散剂的确定和添加物对材料显微结构的影响等方面入手，对刚玉-尖晶石质中间包挡渣墙进行了系统的研究： (1)基于武钢目前所使用的挡渣墙的基本情况，通过实验室分析了其各项物理指标，并对用后挡渣墙进行了损毁原因的分析。结果表明：目前武钢所使用挡渣墙显气孔率较高，常温强度较低，热处理过后体积膨胀较大，对于材料的抗渣性能非常不利。显微结构分析也验证了其损毁的主要原因是渣的侵蚀和渗透，挡渣墙的渣线部位损毁非常严重，熔渣与材料发生化学侵蚀，产生大量液相，高温下液相的破坏作用非常大，不断向材料内部溶解侵蚀。在钢水的不断冲刷下导致结构剥落，最终坍塌。 (2)通过分析目前挡渣墙所存在的缺陷，本文首先以高铝质材料体系入手，通过q值的变化，研究了不同粒度组成对浇注料各项常规性能的影响。研究结果表明：当q为0.27时，浇注料流动值最高，材料达到最紧密堆积，拥有较高的体积密度和常温强度，以及较低的显气孔率。 (3)以q值为0.27的高铝质材料体系为基础，研究了添加不同粒度的尖晶石对材料常规物理性能、热震稳定性以及抗渣性能的影响。研究表明：添加尖晶石对于材料的常规物理性能影响不大，对热震稳定性和抗渣性能的改善是有利的。当骨料：细粉=15：5时，拥有较好的热震稳定性和抗渣性。通过建立熔渣/耐火材料侵蚀热力学模型，发现刚玉-尖晶石材料高温下主要通过在骨料表面与熔渣中的MgO发生反应形成镁铝尖晶石隔离层，阻止熔渣对材料的进一步溶解。而对骨料：细粉=15：5的试样静态抗渣试验后，观察其显微结构也同样验证了热力学模拟的情况。 (4)通过引入ρ-Al2O3使材料体系“纯净化”，大大改善了材料的高温强度和抗渣侵蚀性能；但ρ-Al2O3结合的试样早期强度较低，不利于挡渣墙吊挂和安装，因此在ρ-Al2O3加入量为3%的基础上，引入较低含量的水泥来改善挡渣墙的常温强度，并与单纯以ρ-Al2O3作为结合剂的试样进行对比，发现当ρ-Al2O3加入量为3%，水泥加入量为1.5%时，，材料不仅具有较高的常温强度和较低的显气孔率，而且其抗渣性能和高温强度也并未下降；通过XRD和抗渣试验后显微结构分析发现，少量水泥的引入并没有在材料内部产生过多的液相，相反在加入到一定量时生成CA6高熔点相，对材料高温强度和抗渣性能的改善是有利的。在确定了ρ-Al2O3-水泥复合结合的结合体系之后，研究了三种分散剂对浇注料基质浆体流变行为的影响。结果表明：聚羧酸醚类减水剂(以下简称FS60)通过静电斥力和空间位阻的协同作用，大大降低了浆体的粘度，随着FS60加入量增加，浆体的粘度基本没有变化，因此减水剂的加入量有一个合适的范围。实验表明当加入量为0.1%时，对浆体的分散效果较好，满足施工要求。 (5)热力学模拟计算及XRD分析表明，随着镁锆共晶材料(以下简称MZ)加入量增加，生成的尖晶石含量增加，由此造成高温处理后线变化率和显气孔率随之升高，常温强度和体积密度降低；当加入量过大的时候，抗渣渗透性能有所下降。同时，由于ZrO2的存在，通过其马氏体相变增韧改善了材料的热震稳定性，但加入量一旦过大，反而热震稳定性有所下降。由此可见，适当的引入MZ可以改善材料的热震稳定性和抗渣侵蚀渗透性，综合各项性能来看当MZ加入量为1%时较为合适。 (6)通过热力学软件模拟计算可知：在刚玉-尖晶石质挡渣墙中引入Y2O3，而不添加SiO2，高温下体系中主要存在的物相为尖晶石相和刚玉相，经热力学计算Y2O3与A2O3在1500℃下极易生成Y3Al5O12(钇铝石榴石),钇铝石榴石具备优良的物理化学性能，对于提高材料的高温抗折强度是有利的。与此同时，Y2O3颗粒细小活性较大，在材料基质内分布均匀，促进材料的烧结，提高材料的致密度，同时Y2O3与熔渣中的Al2O3反应生成Y3Al5O12，Y3Al5O12为高熔点相，这些高熔点相随着液相向试样内部扩散，液相中的固含量逐渐升高，粘度逐步增大，熔渣与墙体间的润湿程度降低，从而抑制渣的进一步渗透。综合各项性能，本文选用Y2O3加入量为2%较为合适。
[Abstract]:In this paper, through the analysis of the damage of the retaining wall, the cause of the damage is determined. Then, a systematic study of the corundum spinel middle bag retaining wall is carried out from the aspects of the particle size distribution of the material, the selection of the spinel with different granularity, the binding system, the determination of the dispersant and the effect of the additives on the microstructure of the material.
(1) based on the basic situation of the slag retaining wall used at present in Wuhan Iron and Steel Group, the physical indexes of the retaining wall are analyzed in the laboratory and the cause of the damage of the slag retaining wall is analyzed. The results show that at present, the slag retaining wall has high apparent porosity, low strength at normal temperature, large volume expansion after heat treatment, and the slag resistance to material. The microstructure analysis also proves that the main cause of the damage is the erosion and penetration of the slag, the damage of the slag line in the slag retaining wall is very serious, the chemical erosion of the slag and the material, the production of a large amount of liquid phase, and the great damage to the liquid phase at high temperature, and the continuous dissolution and erosion of the material inside the material. Under the continuous scour of steel water, it is caused by the continuous erosion of steel. The structure exfoliate and eventually collapses.
(2) by analyzing the defects existing in the current slag retaining wall, the influence of different particle size composition on the conventional properties of the castable is studied by the change of Q value. The results show that when the Q is 0.27, the flow value of the castable is the highest, the material reaches the closest accumulation, and has a higher volume density and a higher volume density. The normal temperature strength and the lower apparent porosity.
(3) based on the high alumina material system with a Q value of 0.27, the effects of spinel with different grain sizes on the physical properties, thermal shock stability and slag resistance of the materials were studied. The results showed that the addition of spinel to the physical properties of the material was not significant, and it was beneficial to the thermal shock stability and the improvement of slag resistance. Material: fine powder =15:5 has good thermal shock stability and slag resistance. By establishing a thermodynamic model of slag / refractory erosion, it is found that the corundum spinel materials mainly react with the MgO in the slag to form the magnesia aluminum spinel isolation layer at high temperature, and prevent the further dissolution of the slag to the material. After the static slag resistance test of the fine powder =15:5, the microstructure of the sample is also verified by thermodynamic simulation.
(4) the material system is "pure purification" by introducing Rho -Al2O3, which greatly improves the high temperature strength and slag resistance of the material. However, the early strength of the sample combined with Rho -Al2O3 is low, which is not conducive to the hanging and installation of the slag retaining wall, so the low content of cement is introduced to improve the normal temperature strength of the slag retaining wall on the basis of the addition of P -Al2O3. And compared with the sample with P -Al2O3 as a binder, it was found that when the amount of P -Al2O3 added to 3% and the cement added to 1.5%, the material not only had higher normal temperature strength and lower apparent porosity, but also the slag resistance and high temperature strength did not decrease. A small amount of water was found by the microstructure analysis after XRD and slag resistance test. The introduction of mud does not produce too much liquid in the material. On the contrary, it is beneficial to improve the high temperature strength and slag resistance of the material when it is added to a certain amount of CA6. The influence of the three kinds of dispersants on the rheological behavior of the matrix slurry is studied after determining the combination system of the combination of P -Al2O3- cement. The results show that polycarboxylate water reducing agent (hereinafter referred to as FS60) greatly reduces the viscosity of the slurry by the synergistic effect of electrostatic repulsion and space steric resistance. As the amount of FS60 increases, the viscosity of the slurry is basically unchanged. Therefore, the amount of water reducing agent has a suitable range. The experiment shows that when the amount of addition is 0.1%, the slurry is divided. Good dispersion effect, meet the construction requirements.
(5) the thermodynamic simulation calculation and XRD analysis show that with the increase of magnesium zirconium eutectic (hereinafter referred to as MZ) addition, the content of the spinel increases, resulting in the increase of the line change rate and the apparent porosity after high temperature treatment, and the decrease of the strength and volume density of the normal temperature, and the slag penetration performance decreases when the addition amount is too large. Due to the existence of ZrO2, the thermal shock stability of the material is improved by toughening of the martensitic phase, but the thermal shock stability of the material decreases as once the amount of addition is too large. Thus, the proper introduction of MZ can improve the thermal shock stability and the penetration resistance of the slag, and the comprehensive performance will be more suitable when the amount of MZ is 1%.
(6) through the simulation of thermodynamic software, it is found that Y2O3 is introduced into the corundum spinel retaining wall without adding SiO2. The main phase in the system at high temperature is spinel and corundum. By thermodynamic calculation, Y3Al5O12 (yttrium aluminum garnet) is easily generated by Y2O3 and A2O3 at 1500, and yttrium aluminum garnet has excellent physical and chemical properties. It is beneficial to improve the flexural strength of the material at high temperature. At the same time, the fine activity of the Y2O3 particles is larger, the distribution of the material is uniform in the material matrix, the sintering of the material is promoted and the density of the material is increased. At the same time, the reaction of the Al2O3 in the Y2O3 and the slag is generated by the reaction, and the Y3Al5O12 is a high melting point phase. These high melting points follow the liquid phase to the sample. In dispersion, the solid content in the liquid phase increases gradually, the viscosity increases gradually, and the wetting degree between the slag and the wall is reduced, thereby inhibiting the further infiltration of the slag. In this paper, the selection of Y2O3 is 2% suitable for the comprehensive performance.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ175.1

【参考文献】