【作者】 唐卫军；

【导师】 陈鸿汉；

【作者基本信息】 中国地质大学（北京） ， 环境工程， 2009， 博士

【摘要】 我国是钢铁生产大国,目前我国粗钢产量已经达到5亿吨,产量位居世界第一。根据计算,我国每年产生矿渣大约1.5亿吨和钢渣大约6500万吨。如何充分利用好这些冶金固体废弃物事关我国循环经济发展水平和环境保护事业。本文在对钢渣和矿渣理化性能分析的基础上,采用不同钢渣掺量和钢渣细度的钢渣矿渣复合微粉替代50%的水泥进行水泥胶砂实验,研究机械激发对复合微粉活性指数和流动度比的影响。研究发现,等量替代部分水泥时,复合微粉中钢渣微粉的掺量增加,浆体需水量呈下降趋势,复合微粉活性指数呈下降趋势,并且28天活性指数下降较7天活性指数下降明显。比表面积在400～505m2/kg的钢渣微粉等量取代水泥时需水量相差不明显。钢渣细度增加,复合微粉流动度比略有提高。本文采用三种不同类型的激发剂对复合微粉活性进行化学激发,研究不同类型激发剂对复合微粉活性指数和流动度比的影响。研究表明,经激发剂激发后的矿渣钢渣复合微粉的浆体标准稠度用水量较未激发的复合微粉明显增大。碱性激发剂对复合微粉的活性激发效果优于酸性激发剂。本文在水泥胶砂实验的基础上,进行了不同掺量和不同钢渣微粉比例的复合微粉替代水泥的混凝土实验,研究复合微粉对混凝土强度和耐久性的影响。研究表明:掺加20%~80%的复合微粉混凝土实测强度,经过KYH-10激发剂激发后,混凝土的早期抗压强度可显著提高。在要求的坍落度范围内,复合微粉配制的混凝土具有良好的和易性,均能达到设计强度的要求。大掺量复合微粉混凝土在抗渗性、干缩、抗冻性和抗氯离子渗透性等方面的性能良好。本文在实验室研究的基础上,采用钢渣掺量为60%的复合微粉替代50%的水泥,配制C30混凝土,进行了工业应用试验。试验表明:钢渣矿渣复合微粉替代部分水泥配制C30混凝土,在规定坍落度条件下各项指标能够满足工程施工的要求。本文还对钢渣进行了稳定化改性研究,考察不同钢渣温度条件下,水蒸气和二氧化碳对钢渣中f-CaO含量的影响。研究表明液态水的存在有利于钢渣中的f-CaO发生反应,通入水蒸气和二氧化碳后生成的主要产物为氢氧化镁、氢氧化钙和碳酸钙;只有气态水存在时,即使有二氧化碳,也很难生成碳酸钙,只有氢氧化镁和氢氧化钙产生。更多还原

【Abstract】 Presently, China is a country with the largest crude steel output of 5 billion tons in the whole world. According to calculation, our country produces 1.5 billion tons blast furnace slag and 0.65 billion tons steel slag annually. How to utilize the metallurgical solid wastes is related to the economy development and circular economy level of our country.Based on the physical and chemical properties of steel slag and blast furnace slag, cement mortar experiments were conducted with different proportions of micro-powder mixture substituting for 50% cement. Effect of mechanical activation of the micro-powder mixture on the mortar activity index and fluidity ratio was investigated. Results showed that when equivalent substitution for cement occurred, the slurry water demand decreased with the increasing dosage of steel slag micro-powder in mixture. In addition, 28-day activity index of the micro-powder mixture decreased more significantly than 7-day activity index However, when steel slag micro-powder with different size fraction and a specific surface area ranging among 400～505m2/kg substituted for cement equivalently, no significant difference in water demand was found. In addition, the fluidity ratio of the micro-powder mixture increased slightly with the increasing of steel slag size.Three different kinds of active agents were used in this study to chemically activate the micro-powder mixture. Influences of the active agents on the activity index and fluidity ratio of the mixture were investigated. Results showed that the chemically activated mixture presented a much larger water content of pastes at standard consistency than the non-activated mixture. The alkaline active agent exhibited better activation effect on micro-powder mixture than the acidic active agent. However, the active agents contributed little to the enhancement of fluidity ratio of the mixture.Based on the cement mortar experiments, concrete experiments were performed using micro-powder mixture with different dosage and different steel slag micro-powder proportions to substitute for cement. Effect of micro-powder mixture on the concrete strength and durability was investigated. Results indicated that when concrete dosed 20%-80% micro-powder mixture was activated by KYH-10 active agent, its early compressive strength was increased significantly. Furthermore, the concrete exhibited good workability within the required slump range to meet the design strength requirement. Concrete mixed with large amounts of micro-powder mixture presented such good impermeability, drying shrinkage, frost resistance and resistance to chloride ion permeability that it can be used widely in concrete construction such as in ocean engineering.According to the laboratory studies, C30 concrete was prepared dosed micro-powder mixture with 60% steel slag to substitute for 50% cement and the concrete was used in industrial application test. Results showed that C30 concrete prepared by micro-powder mixture substituting for cement can meet the engineering construction requirements within the the required slump range.Moreover, the stabilization of steel slag was also studied. Especially, effect of steam and carbon dioxide on the content of f-CaO in steel slag was mainly investigated at different steel slag temperatures. Results indicated that the presence of liquid water was helpful to the reaction of f-CaO in steel slag. When steam and carbon dioxide were pumped in, the main reaction products were magnesium hydroxide, calcium hydroxide and calcium carbonate; however, when only steam was present but liquid water was absent, even if there existed carbon dioxide, it was difficult to produce calcium carbonate but magnesium hydroxide and calcium hydroxide.更多还原