Study On Rational Cutoff Grade At Malanzhuang Iron Mine

The determination of cutoff grade in mining operation is an important decision-making problem. On one hand, it directly affects the economic benefits of a mine. On the other hand, it has a great impact on the efficient utilization of mineral resource in a whole nation. The determination of cutoff grade involves complicated analysis and calculations, and it also has close relations with the knowledge of geology, mining, mineral processing, applied mathematics, economics and management. Combining the actual conditions in Shaheshan Stope, Malanzhuang Mine with the constructed optimizing model and ore-blending model achieved system optimization.First, the evolution of the theories and models of cutoff grade both in China and abroad is described, historical period is determined according to their analytical method. The technological and economic factors relating to the cutoff grade analysis are studied, providing the basis for the inter-variable relations analysis in optimization modeling.Aiming at the real actuality of Malanzhuang iron mine, by utilizing many kinds of decision theories of cost control in Management Economics, and use the optimizing model to confirm if it is economical to reduce the current cutoff grade furtthermore. And every year's optimal cutoff grade in the life of the mine for the different discount rates are worked out.It also confirms the lower limit of the cutoff grade of every year. At the same time,use the model of price and cost fluctuation, the optimal cutoff grade for the variational market is worked out. They are especially applicable for the economic analysis of the utilization of low-grade ores in Malanzhuang iron mine. As well, this model is applicable to other single metal open-pit mines.Finally,on the basis of above analyzing the production plan and expenditure disposition, the model of linear programming ore blending is set up. With this established model, the scheme of optimal exploitation is put forward. And also it can be adjusted constantly according to actual situation.