Matsui A. Methodological foundations of energy efficient invariant control of ore grinding-classification based on indirect predictive assessment of characteristics of raw materials and equipment

The aim of the work is to increase the efficiency of the control of the technological process of ore preparation in the first stage using a new developed methodology. It is based on the implementation of progressive ideas of invariant control, new mathematical models and established dependencies for raw materials and equipment, methods and systems of automatic control, approaches and means for assessing the main technological parameters. Methods for indirect predictive estimation of the optimal ball loading of the mill, the mass and number of worn out balls in the process of grinding ore, the number of balls of different sizes that need to be loaded into the technological unit to replace worn ones are proposed. A method has been developed for the automatic assessment of the weighted average size of the classifier sands and the unloading of the mill, built on the basis of a magnetoelectric system by ensuring invariance to the solid content in the measurement zone, the speed of material movement and the content of magnetic iron in the solid, which reduced the measurement error to ±2,91%. A new criterion for assessing the circulating load is proposed, which consists in the fact that according to the found height of the sands in between the coiled space of the classifier spiral, an indirect predictive determination of the parameter follows from the obtained mathematical models, due to which it is possible to significantly increase the accuracy of identification of the mass flow rate of pulp sands in the sand trough. An invariant approach to managing the energy efficiency of ore destruction is proposed, where the criterion for assessing energy efficiency is not the concentration of solid in the control zone, but its weighted average size at the inlet of a ball mill, which made it possible to implement an automated control system with a mass consumption of ore into the mill with the highest energy efficiency of its grinding. A method for indirect predictive assessment of the missing water flow rate in the classifier to ensure the separation of material for a given size is proposed, due to which a new automated control system for the technological process has been developed. The developed theoretical provisions made it possible to determine the principles of improving the methods of automated control of the cycle taking into account the disturbing factors and to create a complex of automatic systems for targeted purposes. It provides an increase in productivity for the finished product by 13,2%, an increase in classification efficiency by 19,4%.