Single Particle Crushing under Slow Rate of Loading

An experimental study of the single particle crushing under a slow (constant) rate of loading was carried out by using specimens shaped into sphere made of quartz glass, borosilicate glass and six kinds of minerals. The diameters of sphere ranged from 0.5 to 3.0 cm and the rate of loading was fixed at 3 ton/min for the quartz glass and borosilicate glass specimens and 0.3 ton/min for the six kinds of minerals, respectively. A summary of experimental results is as follows : 1) compressive strength of specimens was increased with the decrease of their volumes ; 2) the status of fracture was mainly transcrystalline type ; 3) in the case of hard material, experimental values of strain energy agreed fairly well with the theoretical values ; 4) the strain energy was proportional to (1-5/3m) power of volume of specimen, where "m" is the Weibull\u27s coefficient of uniformity ; 5) in coarse size range, the energy rule of single particle crushing was followed approximately by the Rittinger\u27s law ; 6) the reciprocal of size modulus of fractured products was proportional to (5/3) power of the compressive strength of specimen ; 7) after obtaining the required energy where the crushing is made by a mill of industrial scale by applying the values of work index, the percentage of the strain energy at the time of fracture of a single spherical particle to the required energy was found 2.71 to 42.0 percent