Research On Optimization Of Multi-objective Production Ore Blending For Open Pit Mine

Mineral resources are an important material basis for social development and progress.Nowadays,with the gradual shortage of mineral resources,rational utilization of mineral resources has become an urgent problem.Scientific and reasonable ore blending is conducive to improving the utilization rate of low-grade ore and prolonging the mining life of the mine.The quality of production and ore blending links directly affects the recovery rate of mineral processing,production profit and sustainable development of mining enterprises.Open-pit ore blending is an important part of mine production management.In order to promote the development of ore blending towards scientific,refined and efficient,this paper focuses on multi-objective optimization of ore blending in polymetallic open-pit mines.(1)The current situation of ore blending research at home and abroad and related theories are reviewed in detail.The principle of ore blending,the main mathematical models and methods of ore blending are briefly introduced.At the same time,the basic concepts and solving methods of multi-objective optimization problems are summarized,and the advantages and disadvantages of different solving methods are analyzed.It establishes a theoretical basis for the multi-objective optimization of ore blending in polymetallic open pit mines.(2)According to the actual situation of open-pit production and ore blending,the characteristics and principles of ore blending are analyzed.At the same time,the existing representative open-pit ore blending optimization model is systematically analyzed.The objective of this paper is to construct an optimum model of ore blending for open pit mines which is in good agreement with the actual production situation.The maximum ore yield,the minimum deviation between ore blending grade and target grade and the minimum transportation work are selected as objective functions.The production capacity,stockpile explosion reserves and production tasks of ore blending related equipment are constraints.The optimization model of ore blending is constructed to meet the requirements of multiple metals participating in ore blending and multiple objectives.At the same time,the characteristics and solving methods of the above models are systematically analyzed.Because of the limitations of traditional multi-objective solving methods and single optimization algorithm,a hybrid algorithm is selected to solve the above models.Based on the analysis of the applicability,advantages and disadvantages of particle swarm optimization(PSO)and pigeon swarm optimization(PIO),the two algorithms are selected for hybrid research.(3)A multi-objective particle swarm optimization algorithm(MOPSO-PIO)is proposed to solve the multi-objective ore blending optimization problem by combining particle swarm optimization(PSO)with pigeon swarm optimization(PSO-PIO).Firstly,particle swarm optimization and pigeon swarm optimization are improved,and the improved algorithm is fused to form a two-stage hybrid algorithm.At the same time,a diversity function is proposed to monitor the population diversity in real time.When the population diversity drops to a certain threshold,it is the demarcation point of the two stages of the algorithm.Then three multi-objective strategies are introduced to form MOPSO-PIO algorithm for multi-objective ore blending optimization problem.(4)The MOPSO-PIO algorithm-based multi-objective optimization method of ore blending in a polymetallic open-pit mine is applied to the production of ore blending in an open-pit mine.Based on the actual ore blending data of a shift,the ore blending optimization is carried out.By comparing and analyzing the results of ore blending plan,ore output,grade and transportation work after ore blending with those of actual production,the practicability and efficiency of the proposed ore blending method are proved.Based on the theory of ore quality balance,multi-objective optimization and multi-objective optimization algorithm,a multi-objective optimization model of open-pit ore blending is constructed,and a new multi-objective hybrid optimization algorithm is designed,which provides a scientific and reasonable optimization method for open-pit ore blending.