(1. 中國礦業(yè)大學（北京） 能源與礦業(yè)學院，北京 100083；
2. 華能煤炭技術研究有限公司，北京 100070)
摘 要: 將充填技術引入高寒地區(qū)可有效減少采礦對環(huán)境的破壞。針對低溫下尾砂膠結充填體力學性能和固結機理研究的不足，開展5 ℃養(yǎng)護下充填體試塊的單軸抗壓、XRD分析、熱分析和SEM觀測試驗研究，根據定性和定量分析結果探討低溫下尾砂膠結充填體的強度演化規(guī)律與固結機制。結果表明：低溫對尾砂膠結充填體早期強度影響較大，其中各主要因素的影響程度由大到小依次為灰砂比、養(yǎng)護齡期、質量濃度；低溫下的水泥凈漿的AFt、C-S-H主特征峰均低于常溫下的水泥凈漿，7 d齡期無外加劑的水泥凈漿未出現AFt衍射特征主峰，而7 d齡期摻外加劑的水泥凈漿出現了AFt衍射特征主峰，有利于早期充填體強度的提高；無論低溫下的水泥凈漿是否摻外加劑，兩者的TG-DSC、DTG曲線類似，存在5個吸熱峰和4個失重峰；7 d齡期摻外加劑的水泥凈漿的TG曲線位于無外加劑水泥凈漿的TG曲線下方，其失重峰也高于無外加劑水泥凈漿，有利于早期充填體生成更多水化產物；低溫環(huán)境下，添加Na2CO3、NaOH可明顯提高充填體早期強度，但不利于中后期強度增長。
關鍵字: 膠結充填體；高寒地區(qū)；固結；水化產物；外加劑
（1. School of Energy and Mining Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China;
2. Huaneng Coal Technology Research Co., Ltd., Beijing 100070, China）
Abstract:The introduction of filling technology into alpine regions can effectively reduce mining damage to the environment. Aiming at the lack of research on the mechanical properties and consolidation mechanism of the tailings cemented backfill at low temperature, the experiments of uniaxial compression, XRD analysis, thermal analysis and SEM observation were carried out to study the filling body specimens under curing at 5 ℃, the strength evolution law and consolidation mechanism of cemented filling body in low temperature environment were analyzed and discussed from characterization and quantification. The results show that low temperature has a greater impact on the early strength of tailings cemented filling body, among which the main factors are in descending order: cement-tailings ratio, curing age, mass concentration. The main diffraction characteristic peaks of AFt and CSH of cement paste at low temperature are lower than those at room temperature. There is no main diffraction characteristic peak of AFt for cement paste without admixtures at 7 d age, the diffraction characteristic main peak of AFt for cement paste with admixtures at 7 d age appears, which is conducive to the improvement of the early strength of the filling body. At low temperature, the TG-DSC and DTG curves of cement paste with or without admixtures are similar, with 5 endothermic peaks and 4 weight loss peaks. At 7 d age, the TG curve of cement paste with admixtures is below the TG curve of cement paste without admixtures. The weight loss peaks of cement paste with admixtures are also greater than those of the cement paste without admixtures, which is conducive to the early generation of more hydration products in the filling body. In a low temperature environment, the additions of Na2CO3 and NaOH can significantly increase the early strength of the filling body, but it is not conducive to the mid-to-late strength growth.
Key words: cemented filling body; alpine regions; consolidation; hydration product; admixture
