石灰石粉对胶结膏体充填材料性能的影响

Influence of Limestone Powder on the Properties of Cemented Paste Backfill

为满足矿山对质优价廉、不同粒度分级尾砂胶结充填材料的需求，以粗、细两种分级尾砂胶结充填材料为对象，研究了外掺粗、细、超细石灰石粉对胶结充填材料性能的影响。结果表明：固体质量浓度为65％的细粒尾砂胶结充填料和固体质量浓度为75％的粗粒尾砂胶结充填料外掺15％的超细石灰石粉，均可制成胶结膏体充填材料，其充填料的坍落度均超过200mm、脱水率均低于2％、28d硬化体的抗压强度在0．3～1．2MPa、28d硬化体沉缩率均低于2％；继续增加超细石灰石粉的掺量，充填料的坍落度和脱水率下降，28d硬化体的抗压强度略有提升、沉缩率进一步下降。如何提高28d硬化体的抗压强度是今后研究的重点。

In order to meet the mine demand of cemented paste backfill for different size classification with high quality and low price, the effect of admixture of coarse, fine and ultra-fine limestone powder on the properties of cemented paste back- fill was researched using the course and fine classified tailings cemented paste backfill as research objects. The test results showed that cemented paste backfill （CPB） would be formulated by the solid concentration of 65% fine classified tailings and solid concentration of 75% coarse classified tailings with the admixture 15% of ultra-fine limestone powder,by which slumps are all higher than 200 ram,water removal percentages are all lower than 2% and the 28 d unconfined compressive strengths （UCS） are O. 3 - 1.2 MPa and the 28 d sedimentation rates are lower than 2%. With the continuous increasing of ultra-fine limestone powder content, the slumps and water removal percentages decline, but the 28 d UCS slightly increase, and the sedi- mentation further decrease. How to increase the 28 d UCS of CPB would be the focus of the research in future.