摘要
为探究胶东地区黄金矿山细尾砂充填可行性,分析了细尾砂粒级和矿物特征,使用新型胶凝材料制备了细尾砂充填料,通过开展流变和管路输送性能试验,研究了充填料流动性,分析了充填体强度及其形成机理。结果表明:(1)比表面积大和黏土矿物含量高是造成细尾砂充填料流动阻力大和强度低的内因;(2)细尾砂料浆更易出现层流,且层流—紊流临界流速随浓度的增加先缓慢增长再快速增长,结合流变建立的层流—紊流临界流速模型结果可指导控制管路输送流速;(3)随着钙矾石(AFt)和水化硅铝酸钙(C-AS-H)的生成,细尾砂料浆自由水转化成结合水,同时充填体结构在水化产物的填充和包裹作用下不断致密,二者促进了充填体强度的增长。该研究证明通过确定合适浓度和使用新型胶凝材料能够获得满足矿山需求的细尾砂充填体强度。
The tailings yield of gold mines is typically high leading to the utilization of a small amount of binder in dense tailings slurry for the preparation of backfilling materials used in underground goaf filling.This practice facilitates the resource utilization of tailings and goaf treatment.However,the particle size of tailings used for backfilling is becoming finer and finer,and the high transport resistance of fine tailings and the low strength of cemented fine tailings backfill are the problems that hinder its application.In order to solve this problem,the fine tailings backfilling in gold mine in Jiaodong area was taken as the engineering background in this paper,and the grain size and mineral composition of fine tailings were analyzed.The slag based binder proposed in the previous study was used to prepare the fine tailings backfilling material.The pipeline conveying performance of fillers was analyzed by rheological test and L-tube test.The internal microstructure of the backfill was characterized by scanning electron microscopy,uniaxial compressive strength test was carried out,and the strength formation and growth mechanism of the fine tailings backfill was analyzed.The results show that,in addition to the large specific surface area of fine tailings,the high proportion of low hardness minerals(Mohs hardness less than 3)such as clay minerals is another internal reason for the high flow resistance of fine tailings backfilling slurry and the decrease of strength of backfill.The larger viscosity is conducive to the formation of laminar flow of fine tailings.The laminar-turbulent critical velocity of fine tailings slurry first increases slowly and then rapidly with the increase of concentration.The critical velocity of fine tailings slurry can be determined by the improved laminar-turbulent critical velocity model,so as to control the slurry velocity.The fine tailings slurry has a reasonable filling concentration of 64%,the slurry of this concentration is laminar flow and can achieve full pipe state,and the strength of the fine tailings filling body can meet the mine demand.The slag-based binder is suitable for fine tailings backfilling.With the hydration of the binder,most of the free water in the slurry becomes the binding water of the hydration product ettringite(AFt)and the hydrated calcium silicaluminate(C-A-S-H).Moreover,the inner structure of the backfill increases in density through the continuous filling of hydration products,which promotes the increase of strength.The research conclusion proves that the strength of fine tailings backfill that meet mining demand can be obtained by determining the suitable concentration of backfill slurry and using the new binder,and the feasibility of fine tailings backfill in gold mines was demonstrated.
作者
胡松涛
朱庚杰
张军童
徐世群
寇云鹏
HU Songtao;ZHU Gengjie;ZHANG Juntong;XU Shiqun;KOU Yunpeng(Shandong Gold Group Co.,Ltd.,Jinan 250000,Shandong,China;Shandong Gold Mining Technology Co.,Ltd.,Jinan 250101,Shandong,China;Shandong Gold Heavy Industry Co.,Ltd.,Laizhou 261400,Shandong,China)
出处
《黄金科学技术》
CSCD
北大核心
2024年第3期425-436,共12页
Gold Science and Technology
基金
山东省重大科技创新工程项目“金属矿深部开采环境精细探测技术与工程风险分析方法”(编号:2019SDZY05)资助。
关键词
细尾砂
物化性质
矿渣基胶凝材料
管输性能
水化产物
微观结构
强度
fine tailings
physicochemical properties
slag based binder
pipeline transport performance
hydration products
microstructure
strength
