微波养护对石墨尾矿砂浆早期性能的影响

EFFECTIVENESS OF ACTIVATED GRAPHITE TAILINGS AND MICROWAVE CURING ON EARLY PROPERTIES OF MORTARS

为探究微波养护对石墨尾矿砂浆早期性能的影响,文中通过机械研磨和高温煅烧对石墨尾矿进行活化,测试了掺活化石墨尾矿砂浆的早期力学性能。对砂浆试件进行微波养护,建立了多物理场数值模型以探究养护过程中的电场、磁场和温度场等分布特征,测试了微波养护试件的强度和电阻率发展。结果表明750℃煅烧后的石墨尾矿活性最高。砂浆的早期抗压强度随着活化温度的提升总体呈现先提高后下降的趋势,并随着石墨尾矿掺量的增加而下降。微波养护对早期性能影响显著,随着龄期增长,电阻率在微波养护后发展迅速,此后在14d龄期内稳定增长。为石墨尾矿砂浆的微波加热养护方法研究提供理论和模型基础。

To investigate the effectiveness of microwave curing on the early performance of graphite tailings mortar,graphite tailings are activated by mechanical grinding and high-temperature calcination,the mechanical properties of which are measured.Microwave curing is carried out on the mortar specimens,and a numerical model with multi-physical field is established to investigate the distribution characteristics of electric,magnetic,and tempera⁃ture fields during the curing process.The strength and resistivity development of the microwave cured specimens are measured,showing that the graphite tailings after calcination at 750℃had the highest activity.The early compres⁃sive strength of the mortar is affected by the activation temperature and dosage of graphite tailings,with an overall tendency of increasing then decreasing with the increase of temperature,which decreases with the increase of graph⁃ite tailings dosage.With the age growth,the microwaves curing has a significant effectiveness on the early perfor⁃mance.The electrical resistivity rapidly develops after microwave curing,and then steadily increases during the 14 day age period.The paper may provide theoretical and model basis for the study of microwave heating curing method for graphite tailings mortar.