矿石粉体在各个领域都有着重要的应用价值，是一种具有广阔发展前景的新型材料，但现有矿石粉化技术及设备存在能耗高、流程长、成本高等问题。随着科技的进步和市场的需求，要求不断创新和完善矿石粉体的制备技术和设备。因此，开展岩石破碎行为和力学特性的研究，优化岩石破碎粉化方法、降低粉体制备的能耗，提高粉体制备的效率和质量，不仅具有理论研究价值，更有丰富的工业生产研究价值。本文通过室内实验和理论分析，探究了岩石在高孔压及高速冲击共同作用下的破碎粉化规律和力学特性。主要具体研究内容和结论如下：

（1）通过高孔压及冲击作用下岩石破碎粉化实验，对多种岩石进行粉化实验，研究岩石破碎颗粒的粒度分布特征。研究发现，尽管岩石种类不同、实验中气体压力不同，但粉化实验得到的粒度分布曲线均符合Weibull分布形态，利用修正的Rosin-Rammler分布函数（MR-R）可以非常好得拟合粒径累积通过率曲线，并将这个分布函数用于对实验得到的破碎颗粒的粒度分布特征进行统计描述。通过量纲分析，获得了一系列可以影响分布函数中统计参量的关键物理量。

（2）结合量纲分析结果，对包括实验气体压力以及岩石自身特性在内的多项参量进行敏感性分析。研究结果表明：实验过程中的气体压力（包括料仓中的气体初始压力以及气仓中的气体推动压力）是影响岩石破碎粉化效果的重要因素，两种压力均对破碎粉化效果起到正向促进作用，即压力越高，岩石的破碎粉化效果越好；岩石的块体尺寸并不会对破碎效果造成明显影响；而岩石的孔隙率越高，破碎效果会越好。

（3）设计不同类型压力组合下的岩石粉化实验，包括气体初压与气体推压同时变化、单独变化气体初压、单独变化气体推压，探究MR-R分布函数中统计参量与两种气体压力的关系。研究发现，均匀性参量k不受实验压力变化影响，而与材料自身属性有关；特征粒径参量λ受实验压力变化影响明显，λ值与两种气体压力均呈负相关，单个压力变化时，线性影响λ值，两个压力同时变化时，非线性影响λ值。

（4）基于应变强度分布准则，借助岩石粉化实验的统计结果直接表征岩石破坏过程中的破裂度，完善了一种可描述岩石材料渐近破坏行为的三维应变强度分布本构模型。该模型中不仅考虑了岩石材料的非均匀性，而且模型中的各参量可以通过本文提出的高孔压及冲击作用下岩石破碎粉化实验直接获得，通过将破裂度与岩石的渐近破裂演化过程建立联系，模型的应力-应变曲线直观地刻画出岩石宏观非线性、软化等力学行为。对本构模型中的两个参量λ和k进行敏感性分析，研究发现，参量λ值的变化对应力-应变曲线的形状没有明显影响，而会改变曲线峰值，反映了岩石材料的宏观平均强度；参量k值的变化会改变应力-应变曲线的陡峭程度，反映了岩石材料破坏的的宏观脆性程度。

Ore powder is a new type of material with broad development prospects and important application value in various fields. However, the existing ore powder technology and equipment have problems such as high energy consumption, long process, and high cost. With the advancement of technology and the demand of the market, it is required to continuously innovate and improve the preparation technology and equipment of ore powder. Therefore, conducting research on rock crushing behavior and mechanical properties, optimizing rock crushing and pulverization methods, reducing the energy consumption of powder preparation, and improving the efficiency and quality of powder preparation not only has theoretical research value but also has rich industrial production research value. This article explores the fragmentation and pulverization laws and mechanical properties of rocks under the combined action of high pore pressure and high-speed impact through indoor experiments and theoretical analysis. The main specific research content and conclusions are as follows:

(1) By conducting rock fragmentation experiments through high pore pressure and impact, experiments were conducted on various rocks to study the particle size distribution characteristics of rock fragmentation. It was found that although different types of rocks and different gas pressures were used in the experiments, the particle size distribution curves obtained from the fragmentation experiments all conform to the Weibull distribution shape. The modified Rosin-Rammler distribution function (MR-R) can be used to fit the cumulative particle size distribution curve very well, and this distribution function can be used for the statistical description of the particle size distribution characteristics of the fragmented particles obtained from the experiment. A series of key physical quantities that can affect the statistical parameters in the distribution function were obtained by dimensional analysis.

(2) Combining dimensional analysis results, this paper conducts sensitivity analysis on multiple parameters including experimental gas pressure and rock properties. The research shows that the gas pressure during the experiment (including the initial gas pressure in the silo and the gas propulsion pressure in the gas chamber) is an important factor affecting rock fragmentation and powdering effects, and both pressures have a positive promoting effect on fragmentation and powdering effects. That is, the higher the pressure, the better the fragmentation and powdering effects of rocks. The block size of rocks does not have a significant impact on fragmentation effects; however, higher porosity of rocks leads to better fragmentation effects.

(3) Design rock fragmentation experiments under different types of pressure combinations, including simultaneous changes in initial gas pressure and gas push pressure, changes in initial gas pressure alone, and changes in gas push pressure alone, to explore the relationship between statistical parameters in MR-R distribution function and two types of gas pressures. It was found that the uniformity parameter k was not affected by changes in experimental pressure, but was related to the material’s properties; the characteristic particle size parameter λ was significantly affected by changes in experimental pressure, and λ values were negatively correlated with both types of gas pressures. When a single pressure changed, it linearly affected λ value; when both pressures changed simultaneously, it nonlinearly affected λ value.

(4) Based on the strain strength distribution criterion, this paper proposes a three-dimensional strain strength distribution constitutive model that can describe the asymptotic failure behavior of rock materials. The model considers not only the heterogeneity of rock materials but also the fact that various parameters in the model can be directly obtained through high-pore pressure and impact-induced rock fragmentation experiments. By establishing a relationship between fracture degree and asymptotic fracture evolution process, the stress-strain curve of rock materials can be intuitively characterized by macroscopic nonlinear and softening mechanical behaviors. Sensitivity analysis of two parameters λ and k in the constitutive model shows that changes in λ have no significant effect on the shape of the stress-strain curve but will change the peak value of the curve, reflecting the macroscopic average strength of rock materials; changes in k will change the steepness of the stress-strain curve, reflecting the macroscopic brittleness degree of rock materials.