毕业论文-镍渣改性及其做水泥缓凝剂的应用研究.doc

Southwest university of science and technology 本科毕业设计（论文） 学院名称 材料科学与工程 专业名称 材料科学与工程 学生姓名 学号 指导教师 二〇一五年 摘 要 镍渣是冶炼金属镍时产生的工业废弃物，经分析表明本次实验采用的镍渣成分和天然石膏极为相似，理论上完全可以用其代替天然石膏做水泥缓凝剂但因为镍渣本身杂质的存在，给镍渣的大量应用造成困难。本课题主要对1）用未经处理的镍渣全部或部分代替石膏做水泥缓凝剂；（2）用改性后的镍渣部分代替石膏做水泥缓凝剂。 实验结果表明，未经处理的镍渣和经过改性的镍渣复合粉体用做水泥缓凝剂时，对水泥的凝结时间和强度影响不同。掺镍渣水泥的强度在石膏：镍渣=1:2时强度初凝和终凝时间变化不大；当镍渣及改性后的镍渣全部或部分代替天然石膏作为水泥缓凝剂时，对水泥性能并没有很大的不良影响。掺改性镍渣的水泥和掺天然石膏的水泥相比，强度和凝结时间略有减少；和没有经过改性的镍渣相比，强度下降了1MPa左右，凝结时间缩短了40分钟左右。Study on nickle slag modification and Utilization of it for Cement Retarder Abstract： Nickle slag is industrial waste which the process smelt the metal nickle.The analysis shows that the chemical composition of nickle slag used in this experiment is mostly similar to the natural gypsum.Theoretically,nickle slag can replace the natural gypsum as cement retarder totally.But it is difficult to use nickle slag widely because of the existence of impurities.This work investigates the use of nickle slag and modified nickle slag as cement retarder :（1）the use of untreated raw nickle slag replace gypsum totally or partly as cement retarder （2）the use of modified nickle slag as cement retarder . Obviously，the effect of setting time and strength of cement are different when untreated raw nickle slag and modified nickle slag are used as cement retarder. .For the untreated raw nickle slag,the early strength of cement reaches the maximum value which is similar to natural gypsum when gypsum：nickle slag=1：2 the initial and final setting time remain the same when the proportion of it increases;Stability qualified?.The result shows that the untreated raw nickle slag and modified nickle slag don’t have a negative effect as retarder agent instead of the natural gypsum.The setting time and strength of cement which added the modified nickle slag is similar to cement which added the the natural gypsum.Compared to the untreated raw nickle slag,the strength which added modified nickle slag decreased by 1MPa and the sett