摘要
针对石灰岩开采中剥离而未利用的覆盖层和夹层,提出以其剥离尾矿为原料,将其进行煅烧活化处理并作为辅助胶凝材料。结合力学性能、基础性能(流动度、标准稠度用水量、凝结时间及安定性)的测试和同步热分析、X射线衍射(XRD)等测试方法。结果表明:石灰石矿山剥离尾矿质软,其化学组成和矿物组成近于硅铝质黏土矿物。煅烧过程中,剥离尾矿中碳酸盐分解、矿物失水活化,800℃煅烧温度下得到的活化剥离尾矿活性最高,28 d活性指数为73%,且所形成的水泥基材料经压汞(MIP)测试发现,在800℃活化后的孔隙率较小,整体较为致密,因而显示出宏观强度较高,为尾矿利用提供了新思路。
In view of the unused overburden and interlayer in limestone mining,it is proposed that the stripping tailings should be calcined and activated as supplementary cementitious materials.Combined with mechanical properties,basic properties(fluidity,water consumption for standard consistency,setting time and stability),synchronous thermal analysis and X-ray diffraction(XRD)tests,the results show that the stripping tailings of limestone mines are soft,and their chemical composition and mineral composition are close to those of silica-alumina clay minerals.During the calcination process,carbonate decomposition and mineral dehydration activation are found in the stripping tailings,which is certain pozzolanic activity.The highest activity of the stripping tailings is obtained at 800℃,with an activity index of 73% for 28 days.The cement-based materials are characterized by mercury injection(MIP).It is found that the porosity of the cement-based materials activated at 800℃,is smaller and the whole density is more compact,thus showing a higher macro-strength,which provided a new idea for the utilization of tailings.
作者
赖航
吕淑珍
卢忠远
李军
李文超
LAI Hang;LYU Shuzhen;LU Zhongyuan;LI Jun;LI Wenchao(School of Materials Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China;State Key Laboratory of Environment-Friendly Energy Materials,Southwest University of Science and Technology,Mianyang 621010,China)
出处
《中国矿业》
北大核心
2020年第2期172-178,共7页
China Mining Magazine
基金
国家重点研发计划项目资助(编号：2016YFC0701004)
国家自然科学基金项目资助(编号：51402246)
关键词
剥离尾矿
活化
辅助胶凝材料
stripping tailing
activation
supplementary cementitious material
