瓦斯抽采钻孔磁性密封浆液配合比试验研究

Experimental study on mix proportion of magnetic sealing slurry for gas drainage borehole

为探究一种具有磁性特性的瓦斯抽采钻孔密封浆液配合比,选取微米粒度(3μm)下的羰基铁粉和纳米粒度(200 nm)下的四氧化三铁(Fe3O4)为磁性粒子,以一定比例聚乙烯醇和水作为密封浆液主要基液,按照磁性粒子在浆液中不同质量分数、不同磁性粒子种类以及不同磁性粒子粒度,进行多水平多因素下的浆液配合比试验,并借助三维磁性成像系统作相似材料模拟,验证浆液的磁性示踪效果。结果表明:在以羰基铁粉为主要溶质的浆液中加入一定量Fe3O4,可大幅度降低密封浆液沉降率;在相似材料密封胶结后,浆液中的磁性粒子可较好地表征出相似材料内密封浆液的填充胶结位置,且在相似材料中,磁性强度越大的区域,内部破裂越明显。

In order to explore the mix proportion of sealing slurry with the character of magnet for gas drainage borehole,carbonyl iron powder with micron size(3μm)and ferro-ferric oxide(Fe3O4)with nanoparticle size(200 nm)were selected as magnetic particles,and polyvinyl alcohol and water in a certain proportion were taken as the main base liquor of sealing slurry.Then the slurry mixing ratio experiments under multi-level and multi-factor conditions were carried out according to different mass fractions of magnetic particles in the slurry and different types and particle sizes of magnetic particles.Similar material simulation experiments were conducted by means of three-dimensional magnetic imaging system.Magnetic tracking effect of the slurry was verified.The results show that adding a certain amount of Fe3O4 into the slurry with carbonyl iron powder as the main solute can greatly reduce the sedimentation rate of the sealing slurry,that after the sealing of similar materials,the magnetic properties in the slurry can better characterize the filling and bonding cementing position of the sealing slurry in similar materials,and that in similar materials,the internal cracking will be more obvious in areas with larger magnetic strength.