加载速率对不规则钼矿石破坏特性的影响研究

Research on the Influence of Loading Rate on the Failure Characteristics of Irregular Molybdenum Ores

  • 摘要: 加载速率是影响矿石破碎特性的关键因素之一。为探究加载速率对不规则钼矿石破坏特性的影响,开展了不规则钼矿石在不同加载速率下的单轴压缩实验,系统研究了加载速率对钼矿石的破坏形态、载荷峰值、位移变化、断裂能、破碎强度及Weibull分布模型的影响。实验结果表明:随着加载速率增大,不规则钼矿石破坏程度愈剧烈,其载荷峰值呈现增大趋势,且在高加载速率下增加幅度更为显著,峰值位移(峰值强度对应位移)逐步减小;断裂能在低加载速率(0.1 mm/min和0.5 mm/min)时变化不显著,高加载速率(10 mm/min)时断裂能增加幅度较为显著;随着加载速率增加,不规则钼矿石的破碎强度表现为先急剧增大、后缓慢增加的变化趋势,近似满足幂函数关系;两参数Weibull分布模型可以较好地描述不规则钼矿石破碎强度分布,其中Weibull分布模量m为常数,与加载速率无关,特征强度σ0随着加载速率的增大呈现增大趋势。本论文研究结果进一步丰富和扩展了不规则矿石破碎的理论与方法。

     

    Abstract: Loading rate is one of the key factors affecting the crushing characteristics of ore. In order to explore the influence of loading rate on the failure characteristics of irregular molybdenum ore, uniaxial compression experiments of irregular molybdenum ore at different loading rates were carried out. The effects of loading rate on the failure mode, peak load, displacement change, fracture energy, crushing strength and Weibull distribution model of molybdenum ore were systematically studied. The experimental results show that with the increase of loading rate, the damage degree of irregular molybdenum ore is more severe, the peak load shows an increasing trend, and the increase is more significant at high loading rate, and the peak displacement ( peak strength corresponding displacement ) gradually decreases. The fracture energy does not change significantly at low loading rates (0.1 mm/min and 0.5 mm/min), and the fracture energy increases significantly at high loading rates (10 mm/min). With the increase of loading rate, the crushing strength of irregular molybdenum ore increases sharply at first and then increases slowly, which approximately satisfies the power function relationship. The two-parameter Weibull distribution model can better describe the crushing strength distribution of irregular molybdenum ore. The modulus m of Weibull distribution is constant and has nothing to do with the loading rate. The characteristic strength σ0 increases with the increase of loading rate.The research results of this paper further enrich and expand the theory and method of irregular ore crushing.

     

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