某多金属矿新型充填胶凝材料性能及微观结构研究

Study on Properties and Microstructure of a New Filling Cementing Material in a Polymetallic Mine

采用矿渣新型胶凝材料为胶结剂,细尾砂为骨料,开展充填料浆流动度、泌水率和充填配比试验,研究浓度、灰砂比对料浆流动性、泌水率、充填体抗压强度的影响,以及不同养护龄期下充填体抗压强度的发展规律。结果表明:充填浓度对料浆流动度、泌水率的影响较大,随着浓度的提高,料浆流动度和泌水率显著降低;灰砂比的影响相对较小,随着灰砂比的降低,料浆流动度、泌水率略有提高;充填体抗压强度随浓度的增加而提高,随灰砂比的减小而降低,新型胶凝材料充填体在养护早期3 d强度发展较为缓慢,7 d后强度开始明显提高,28 d后强度仍能持续增长,且养护60 d强度相比28 d提高约20%;矿渣微粉在水泥、石膏等激发作用下生成纤维状C-S-H、针棒状钙矾石等水化产物是充填体产生强度的主要原因。

By using slag new cementing material as cementing agent and fine tailing sand as aggre⁃gate,tests on fluidity,bleeding rate and filling ratio of filling slurry were carried out to study the effects of concentration,lime sand ratio on slurry fluidity,bleeding rate and compressive strength of backfill,as well as the development law of compressive strength of backfill under different curing ages.The results show that filling concentration has great influence on slurry flow and bleeding rate,and with the increase of concentra⁃tion,slurry flow and bleeding rate decrease significantly.The influence of lime sand ratio is relatively small.With the decrease of lime sand ratio,slurry fluidity and bleeding rate increase slightly.The compressive strength of the backfill increases with the increase of the concentration and decreases with the decrease of the ratio of lime to sand.The strength of the new cementified material backfill develops slowly at the early stage of curing for 3 d,the strength begins to increase significantly after 7 d,and the strength continues to increase after 28 d,and the strength at 60 d of curing is increased by about 20%compared with 28 d.The hydration products such as fibrous C-S-H and needle-rod ettringite formed by the slag fine powder under the excitation of cement and gypsum are the main reasons for the strength of the backfill.