用铜渣制备无机胶凝材料及其高温性能研究

发布时间：2018-09-07 20:59

【摘要】：在高温环境作用中,混凝土会发生一系列的物理和化学变化,从而使得建筑结构出现破损,甚至坍塌,因此混凝土材料的耐高温性能直接影响着建筑结构的安全。有研究早已表明混凝土中胶凝材料的高温劣化是引起混凝土高温损伤的重要因素之一。因此对传统混凝土胶凝材料进行改性或开发新型胶凝材料,提高其耐高温性能,能够减小混凝土高温损伤,从而可以提高建筑结构在高温环境下的安全性。工业固体废弃物是在工业生产时产生的副产品,若处理不当,将会对生态环境造成非常不利的影响,所以如何处理这些工业固废物并提高其综合利用率便成为日益迫切需要解决的问题。目前,就有不少学者进行利用工业固体废弃物制备无机胶凝材料的研究,并发现此类无机胶凝材料有着不同于普通硅酸盐水泥胶凝材料的特性,其中就有研究表明粉煤灰、耐火砖粉、硅粉和矿渣粉等工业固体废弃物可以提高胶凝材料的耐高温性能。铜渣作为一种产量较大的工业固体废弃物,由于综合利用率很低,导致堆存量巨大,尤其像铜矿产资源丰富的云南省,随着铜冶炼工业的生产,带来了大量铜渣的排放。鉴于铜渣与粉煤灰、矿渣等工业废渣有着同样的高温生产环境和相似的化学成分,故也可能有着相似的胶凝特性,因此铜渣制备的无机胶凝材料也可能具有较好的耐高温性能。基于以上情况,本文利用工业固废物铜渣制备了铜渣水泥复合胶凝材料体系(CSC)和碱激发铜渣胶凝材料体系(CSA),运用了材料万能试验机系统、X射线衍射仪、热重分析仪、扫描电镜等试验分析设备,研究了高温后铜渣胶凝材料力学性能随温升变化规律、水化产物变化以及微观形貌演化等内容。研究结果表明:(1)与普通硅酸盐水泥胶凝材料相比,掺入铜渣对胶凝材料的性能没有不利影响且高温力学性能变化规律一致;(2)不同于水泥胶凝材料,碱激发铜渣胶凝体系(CSA)抗压强度随温升而提高;(3)CSC体系和CSA体系的物相组分有所不同,CSC体系主要的物相组分为C-S-H和CH且会在高温下分解,CSA体系主要的物相组分为Fe2SiO4和Fe3O4且会在高温下生成耐高温物质Fe2O3和FeO;(4)CSC体系和CSA体系在高温作用下的微观形貌和结构有所不同,CSC体系在高温下由于水化产物分解使得微观结构变得松散,CSA体系在氋温下由于生成耐高温物质使得微观形貌和结构更加密实从而力学性能得到恢复并提升。铜渣用于制备无机胶凝材料,有利于铜渣的资源化利用,且碱激发铜渣胶凝材料有较好的耐高温性能,在提高强度后可应用于冶炼、石油开采等高温环境中的工业建筑结构以及面临火灾威胁的民用建筑结构。本论文结果对耐高温混凝土胶凝材料的开发提供理论依据,同时期望在提高铜渣以及其他工业固体废弃物的资源化利用方面有参考意义。
[Abstract]:In the high temperature environment, a series of physical and chemical changes will take place in the concrete, which will lead to the breakage or even collapse of the building structure. Therefore, the high temperature resistance of the concrete material will directly affect the safety of the building structure. It has been shown that high temperature deterioration of cement material in concrete is one of the important factors causing high temperature damage of concrete. Therefore, the modification of traditional concrete cementing materials or the development of new cementitious materials can improve the high temperature resistance of concrete, reduce the damage of concrete at high temperature, and improve the safety of building structures in high temperature environment. Industrial solid waste is a by-product produced in industrial production. If it is not properly treated, it will have a very negative impact on the ecological environment. Therefore, how to deal with these industrial solid wastes and improve their comprehensive utilization becomes an increasingly urgent problem to be solved. At present, many scholars have studied the preparation of inorganic cementitious materials from industrial solid waste, and found that this kind of inorganic cementitious materials have different characteristics from ordinary silicate cement cementitious materials. Refractory brick powder, silicon powder, slag powder and other industrial solid wastes can improve the high temperature resistance of cementitious materials. Copper slag, as a kind of industrial solid waste with large output, has a huge heap stock due to its low comprehensive utilization ratio, especially in Yunnan Province, where copper mineral resources are abundant. With the production of copper smelting industry, a large amount of copper slag is discharged. In view of the fact that copper slag has the same high temperature production environment and similar chemical composition as fly ash and slag, the inorganic cementitious material prepared by copper slag may also have similar cementitious property, so the inorganic cementitious material prepared by copper slag may also have good high temperature resistance. Based on the above situation, the copper-slag cement composite cementitious material system (CSC) and the alkali excited copper-slag cementitious material system (CSA), were prepared from industrial solid waste copper slag. The material universal testing machine system, X-ray diffractometer and thermogravimetric analyzer were used. The changes of mechanical properties of copper slag cementing materials with temperature rise, the changes of hydration products and the evolution of microstructure were studied by means of scanning electron microscope and other experimental analysis equipment. The results show that: (1) the addition of copper slag has no adverse effect on the properties of the cementing materials compared with the ordinary Portland cement cementitious materials, and the change of mechanical properties at high temperature is consistent; (2) it is different from the cement cementitious materials. The compressive strength of (CSA) increased with the increase of temperature, (3) the main phase components of CSC system and CSA system are different. The main phase components of CSC system are C-S-H and CH, and the main phase components of CSC system are Fe2SiO4 at high temperature. The microstructure and microstructure of Fe2O3 and FeO; (4) CSC system and CSA system under high temperature are different from those of Fe3O4 system at high temperature due to the decomposition of hydration products. Due to the formation of high temperature resistant materials at high temperature, the microstructure and microstructure are more dense and the mechanical properties are recovered and improved. The application of copper slag to the preparation of inorganic cementitious material is beneficial to the utilization of copper slag, and the alkali activated copper slag cementitious material has good high temperature resistance, and can be used in smelting after increasing the strength of the cementitious material. Industrial structures in high temperature environment, such as oil exploitation, and civil structures which are threatened by fire. The results of this paper provide a theoretical basis for the development of high-temperature resistant concrete cementing materials and are expected to be of reference significance in improving the utilization of copper slag and other industrial solid wastes.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU526

【参考文献】