聚丙烯纤维对膏体充填料流动性影响的分析

Analysis on the Influence of Polypropylene Fiber on the Flowability of Paste Slurry

掺入聚丙烯纤维的膏体中能有效改善充填体的抗压强度及峰后韧性,但由于聚丙烯纤维膏体的流动性与材料特性之间关系复杂,在一定程度上严重影响了膏体的管输阻力。以某矿山全尾砂和棒磨砂为试验材料,研究聚丙烯纤维掺量及长度对膏体流变性能的影响规律,建立不同纤维掺量及长度下的膏体塌落度及扩展度回归模型,并在此基础上计算出聚丙烯纤维膏体的经济成本。研究结果表明:塌落度及扩展度随聚丙烯纤维长度和掺量的增加而减小,聚丙烯纤维长度和掺量基本与塌落度呈负线性关系,聚丙烯纤维掺量与扩展度基本呈负指数函数关系;影响塌落度及扩展度的顺序由大到小依次为纤维掺量、纤维长度,且扩展度受聚丙烯纤维长度和掺量的影响大于塌落度;与未掺聚丙烯纤维相比,掺入纤维的膏体塌落度降低了0.77%~5.02%,扩展度降低了3.70%~36.54%,膏体成本增加了2.95%~15.61%。最后,建立了关于纤维掺量及长度的流动性回归模型,回归效果显著。

The paste mixed with polypropylene fiber can effectively improve the compressive strength and post-peak toughness of the filling body.However,due to the complex relationship between paste fluidity and material properties,the pipeline resistance of the paste is seriously affected to a certain extent.The influences of fiber content and fiber length on the rheological properties of paste were studied by using total tailings and rod mill sand of a mine as test materials.The regression models of slump and expansion degree of paste under different fiber contents and fiber lengths were established,and the economic cost of polypropylene fiber paste was calculated on this basis.The results show that the slump and expansion degree decrease with the increase of fiber length and fiber content.The relationships between fiber length and fiber content with slump are negative linear,and the relationship between fiber content and expansion degree is negative exponential function.The influencing order of slump and expansion degree from large to small is fiber content and fiber length,and the influences of fiber length and fiber content on expansion degree are greater than that on slump.Compared with the paste without polypropylene fiber,the slump of slurry with fiber is reduced by 0.77%~5.02%,the expansion degree is decreased by 3.70%~36.54%,and the paste cost is increased by 2.95%~15.61%.Finally,the flow regression model of fiber content and fiber length was established,with a remarkable regression effect.