基于正交试验的细尾砂-分级尾砂充填体强度研究

Study on the Strength of Fine Tailings-graded Tailings Packing Body Based on Orthogonal Test

为解决某矿山细尾砂充填体流动性差、强度低的问题,通过正交试验和胶结充填试验,探究尾砂料浆浓度、胶凝材料掺量、外加剂掺量和细尾砂掺加比例对充填体强度的影响,得出了各因素影响充填体强度的重要性顺序。通过多元回归分析确定推荐配比参数,并结合试验结果和SEM分析,对充填体微观结构进行进一步的探究。结果表明:各因素影响充填体强度的重要性顺序依次为胶凝材料掺量、料浆浓度、外加剂掺量和细尾砂掺加比例。通过控制变量,可得充填体强度的增长规律,即增大料浆浓度和胶凝材料掺量,均可提高充填体强度;在合适的掺量范围内,充填体强度随外加剂掺量的增加而提高;细尾砂掺量对充填体强度产生较复杂的影响。实际矿房充填推荐配比参数如下:料浆浓度为70%,胶凝材料掺量为20%,外加剂(减水剂)掺量为1‰,细尾砂掺量为30%。掺加外加剂可使充填体水化反应更充分,有助于提高其强度。研究表明,细尾砂充填体强度和流动性可以满足矿山实际矿房充填的要求。

With the development of economy and society,the national environmental protection policy has become increasingly strict.According to the requirements of relevant departments,the mine tailings pond is facing a gradual and comprehensive withdrawal.At present,the utilization and disposal of the tailings dumped in the tailing pond has become a practical problem that has to be solved.Considering the actual situation of the mine studied,the tailings stored in the tailings pond are all fine tailings with small particle size.If used this fine tailings as filling,there are problems such as poor fluidity and low strength of filling body.The chemical composition and particle size of the tailings was determine by X-ray fluorescence spectroscopy and laser particle size analysis.Orthogonal experiments and cement filling experiments were conducted to explore the influence of tailings slurry concentration,cementitious material content,the amount of admixture,and the proportion of fine tailings on the strength and diffusion of the backfill.By using range analysis and variance analysis,the order of importance of the influence of each factor was obtained,and the recommended ratio parameters were determined through multiple regression analysis.Finally,the microstructure of the filling body was further explored through the test results and SEM analysis.The results show that the order of importance of the factors affecting the strength of the filling body is the cementing material content,slurry concentration,admixture content,and the proportion of fine tailings.The order of importance of the factors affecting the diffusion is as follows:The proportion of fine tailings,the amount of additives,the slurry concentration and the amount of cementitious materials.The control variables can obtain the strength growth law of the filling body:Increasing the slurry concentration and the amount of cementitious material can increase the strength of the filling body;Within the appropriate amount,the strength of the filling body increases with the increase of the admixture;The content of tailings will have a more complex impact on the strength of the backfill.According to the regression formula,the recommended ratio parameters for the actual ore house filling are 70%slurry concentration,20%cementitious material content,1‰admixture content,and 30%fine tailings content.Adding admixtures can make the hydration reaction more fully,thereby increasing its strength.The results show that the strength and fluidity of the fine tailings filling body can meet the requirements of the actual chamber filling.