Energy and power factors of selective destruction of ores
The aim of the work is to assess the factors that determine the effectiveness of devices used at different stages of ore processing. The nature of the destruction at each stage is determined by different parameters, therefore, it is so important to search for information factors that allow evaluating the response of mineral raw materials to external influences at the stages of ore preparation. The research methodology is based on the analysis of energy and power factors, which can be correlated both with the loading device and with the body being destroyed. Force factors characterize the response of a material to damaging effects, for example, the limiting amount of resistance to deformation is estimated by the force at which the destruction occurred. The results of the analysis of the role of energy and power factors are given on the example of a selfgrinding mill, a centrifugal crusher, and others. The effectiveness of the self-grinding mill is determined by the ratio of energy and power parameters in the processes of ore lumps kinetic energy conversion into the energy of elastic and breaking strains of the crushable (and crushing) material. It is shown that the efficiency of centrifugal crushers is ensured by the high intensity of collisions of a multitude of particles, which initially possess excess kinetic energy. In devices such as a roller-press or a cone inertial crusher, the final phase of destruction is associated with volumetric deformation of the layer. This means that the final stages of destruction are completely determined by the structural and strength characteristics of the feedstock and its particle size distribution. The field of application of the presented results are technologies in which the liberation of minerals during ore destruction is considered as a process of structure transformation based on the principles of rational ore preparation. The properties of ores, energy and force factors are important informational parameters of the analysis and selection of methods of destruction during the liberation of minerals. Examples of successful and unsuccessful use of a roller press as a device for reducing the energy consumption for ore preparation are explained within the framework of ideas about the relationship between energy and power factors.