落锤作用下磁铁矿石冲击破碎特征的能比效应  

Energy Ratio Effect of Impact Crushing Characteristics of Magnetite Ores under the Action of Drop Ammer

作　　者：甘德清 于泽皞[1,2,3,4] 刘志义 孙海宽 GAN Deqing;YU Zehao;LIU Zhiyi;SUN Haikuan(School of Mining Engineering,North China University of Science and Technology,Tangshan 063210,China;Collaborative Innovation Center of Green Development and Ecological Restoration of Mineral Resources,Tangshan 063210,China;Hebei Key Laboratory of Mining Development and Security Technology,Tangshan 063210,China;Hebei Province Green Intelligent Mining Technology Innovation Center,Tangshan 063210,China)

机构地区：[1]华北理工大学矿业工程学院,河北唐山063210 [2]矿产资源绿色开发与生态修复协同创新中心,河北唐山063210 [3]河北省矿业开发与安全技术实验室,河北唐山063210 [4]河北省矿山绿色智能开采技术创新中心,河北唐山063210

出　　处：《金属矿山》2025年第2期48-55,共8页Metal Mine

基　　金：国家自然科学基金项目(编号:52074124)。

摘　　要：为了确定利于磁铁矿石破碎的加载能量,确保破碎粒度达标的同时提高有效能量占比,从而提高矿山破碎作业中的能量利用率。通过改变落锤冲击高度,探究了不同冲击能比下磁铁矿石的强度特征、破碎能量变化规律以及破碎粒度分布特点。研究表明:磁铁矿石的冲击力时程曲线分为冲击力急速提升、平稳作用、回落、回升与震荡四个阶段,平稳作用阶段持续时间最长,可达9~10 ms,试件所受冲击强度随冲击能比增加线性升高;随冲击能比增加,磁铁矿石吸能效率先增后减,再增再减,存在吸能效率较高的能比范围,矿石吸收能、吸收能密度均呈线性趋势增加,使得矿石起裂时的裂纹由单一张拉裂纹转为拉伸剪切交织裂纹,破碎方式也由拉伸破坏逐渐转向压缩剪切破坏,磁铁矿石的破碎程度逐渐加剧;冲击能比增加降低了破碎产品的大块率,使得破碎产品粒度更加均匀,粒度分形维数线性增加,碎块平均粒径呈指数趋势减小,破碎产品细度t_(10)以缓—急—缓的趋势增加。研究结果对优化矿山破碎机械参数、提高磁铁矿石破碎效率具有一定的指导意义。In order to determine the loading energy conducive to the crushing of magnet ore,to ensure that the crushing particle size meets the standard and improve the effective energy proportion,so as to improve the energy utilization rate in the crushing operation of mine.By changing the impact height of the drop hammer,the strength characteristics,the change law of crushing energy and the distribution characteristics of crushing particle size of the magnet ore under different impact energy ratio are investigated.The results show that the impact time-history curve of magnet ore is divided into four stages:rapid impact rise,steady action,fall,rise and shock.The steady action stage lasts the longest,up to 9~10 ms.The impact strength of the specimen increases linearly with the increase of impact energy ratio.With the increase of impact energy ratio,the energy absorption efficiency of magnet ore increases first and then decreases,and then increases and decreases again.There is an energy ratio range with high energy absorption efficiency.The energy absorption and energy density of ore show a linear trend of increase,which makes the crack of ore cracking from a single tensile crack to a tensile shear interwoven crack,and the crushing mode gradually shifts from tensile failure to compressive shear failure.The crushing degree of magnet ore is gradually intensified.The increase of impact energy ratio reduces the bulk percentage of the broken product,makes the particle size of the broken product more uniform,the fractal dimension of the particle size increases linearly,the average particle size of the broken product decreases exponentially,and the fineness of the broken product t10 increases in a slow-rapid-slow trend.The research results have certain guiding significance to optimize the parameters of mine crushing machinery and improve the crushing efficiency of magnet ore.

关 键 词：磁铁矿石 冲击能比 强度变化 能量特性 破碎特征 

分 类 号：TD231[矿业工程—矿井建设]