电炉渣热态改质对其铁组分回收与胶凝活性影响的研究

发布时间：2018-04-02 14:23

本文选题：电炉渣　切入点：热态改质　出处：《北京科技大学》2017年博士论文

【摘要】：目前,直接利用各种钢渣的难度很大,必须经过改变成分(改质)、矿相结构、活性等,才能进行高附加值应用。本文在国家"十二五" 863项目子课题"万吨级液态钢渣在线改质示范工程"(编号2011AA06A105)的资助下,开展了对山东莱芜钢铁集团电炉渣热态改质的研究,通过降低碱度以改变电炉渣的矿物组成与微观结构,进而提高改质渣铁尖晶石的析出量以提高其铁回收率,同时改质渣磁选后尾渣的胶凝活性也得到提高,提高了电炉渣资源化利用的附加值。本研究为电炉渣源头热态改质提供理论与技术指导,实现电炉渣"铁"、"渣"、"热"三利用。本研究以河沙为改质剂,研究了热态改质过程中电炉渣显热熔化改质剂的能力。为了热态改质不增加额外能量,计算了电炉渣热态改质的热平衡过程,得到了最大改质冷料的加入量。熔渣改质河沙掺量的理论最佳区间为11%～24%,此时,改质渣的碱度为1.62～1.19,熔渣显热的利用效率高,改质效果好。河沙掺量接近11%时,改质熔渣的流动性较好;河沙掺量接近24%时,改质熔渣的碱度较低。本研究以河沙为改质剂,研究了电炉渣热态改质过程的固相反应热力学过程,为改质过程所生成的矿物提供了理论指导。系统研究了渣碱度对改质渣的铁回收率、矿物组成与微观结构影响的规律,探讨了改质渣铁回收率与矿物组成的关系,研究表明空冷与水冷改质渣的碱度分别为1.3与1.42时,改质渣的铁尖晶石含量大,而其它矿物含量较低,改质渣的铁回收最大。研究了冷却制度对改质渣铁回收率、矿物组成与微观结构影响的规律,另外,采用高温共聚焦激光显微镜,分析了改质熔渣冷却的析晶路线与TTT图,研究表明铁尖晶石在高温阶段析出,高于其它矿物的析出温度。提出了电炉渣热态改质的优化工艺参数:改质渣在1500℃保温60 min后,以20℃/min的速率,降温到1375℃,并保温30 min,然后直接进行水淬。本研究以尾矿、粉煤灰、煤矸石与化学纯Al2O3为改质剂,通过熔融还原法以消除Fe含量对改质渣的胶凝活性的影响,利用DSC图谱的放热峰面积,判断改质渣玻璃相含量,采用拉曼光谱计算玻璃相的网络聚合度,以判断其活性。系统研究了碱度与冷却制度对改质渣的胶凝活性、矿物组成、玻璃相含量及其活性的影响,研究表明空冷与水冷改质渣的碱度分别为0.9与1.5时,其玻璃相含量大,矿物活性高,改质渣的胶凝活性最大。研究了胶凝活性与其矿物组成、玻璃相含量及其活性的关系,当改质渣玻璃相含量较大,反应活性高时,改质渣的胶凝活性较高,当玻璃相析出高活性的矿物时,改质渣的胶凝活性进一步加大,为进一步开发出高附加值产品提供理论基础。在山东莱芜钢铁集团100t电炉厂对电炉渣进行热态改质的中间试验,开发出了中试改质工艺流程,优化了改质剂原料和用量,中试结果理想地验证了实验室试验结果。
[Abstract]:At present, the direct use of all kinds of steel slag is very difficult, must pass through the changing composition (modified), mineral phase structure, activity, to high value-added applications. In 12th Five-Year the national "863 project" million tons of steel slag modified online demonstration project "(No. 2011AA06A105) under the support of carry out research on Shandong Laiwu iron and steel group electric furnace slag thermal modification, by reducing the alkalinity to change the mineral composition and microstructure of electric furnace slag, and then improve the precipitation of modified slag and iron spinel to increase the recovery rate of iron, and modified slag after magnetic separation tailings cementitious activity is also improved, improve the added value of furnace slag utilization. This research provides theoretical and technical guidance for the source of thermal electric furnace slag modification, realize the electric furnace slag iron," slag "," hot three ". In this study, using sand as the modifier, the modified thermal electric slag quality process Sensible heat melting agent. In order to change the ability of thermal modification without extra energy, the heat balance process furnace slag thermal modification of the calculation, got the maximum amount of modified cold material. The best theoretical interval slag modified river sand content ranged from 11% to 24%, at the same time, alkalinity modification the slag is 1.62 ~ 1.19, the sensible heat of slag with high efficiency and good effect. The modified river sand content is close to 11%, the liquidity of modified slag is better; sand content is close to 24%, the basicity of slag modification is low. In this study, the river sand as the modifier, solid phase the thermodynamic process of furnace slag thermal modification process, provides a theoretical guidance for the modified process generated. Mineral slag basicity on iron recovery rate of modified slag was studied, the effects of mineral composition and microstructure of modified slag and iron recovery rate and mineral composition are discussed research shows that air cooling and water cooling, change Alkalinity matter slag were 1.3 and 1.42, the content of modified iron spinel slag, and other mineral content is low, the modified slag was studied. The maximum recovery of iron cooling system on the modified slag and iron recovery rate, influence of the mineral composition and microstructure of the law, in addition, the Jiao Jiguang temperature copolymerization microscope. Analysis of the modified slag cooling crystallization route and TTT diagram, studies show that iron spinel precipitated at high temperature stage, precipitation temperature is higher than that of other minerals. The optimization of furnace slag thermal modification: modification of slag at 1500 DEG C for 60 min, at a rate of 20 DEG /min, down to 1375 C, and the insulation of 30 min, then direct the water quenched. In this study, tailings, fly ash, coal gangue and pure chemical Al2O3 as modifying agent, in order to eliminate the influence of Fe content on the cementitious activity of modified slag by smelting reduction method using heat peak area map DSC, modified judgment Slag glass phase content, the calculation of degree of polymerization of network of glass phase by Raman spectroscopy, to determine the activity of basicity and cooling system. The system of modified slag cementitious activity, mineral composition, effect of glass phase content and activity, studies show that the basicity of air cooling and water cooling, the modified slag were 0.9 and 1.5 when the glass phase content, mineral activity and high cementitious activity of modified slag. The cementitious activity and mineral composition of glass phase, relationship between content and activity, when the modified slag glass phase content is large, high reaction activity, high cementitious activity of modified slag, when the glass phase precipitation the high activity of minerals, the cementitious activity of modified slag was further increased, for the further development of high value-added products and provide a theoretical basis. The middle test thermal modification of electric furnace slag in Shandong Laiwu iron and Steel Group 100t electric furnace factory, has developed a pilot modification The raw material and dosage of the modifier are optimized in the process flow. The results of the laboratory test are ideally verified by the results of the pilot test.

【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X757

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