Economical Assessment of Block Cave Method Respect to the Processing Factory Constraints

Production planning defines the drawpoint extraction percentage in order to a deterministic destination (processing factory) according to scheduling objectives. One of the main problems in such planning is related to the lack of integration designing factors. So, there is a need to develop a model for mine scheduling using all factors influencing the strategic plan. In the current study, the Mixed Integer Linear Programming (MILP) has been developed according to metallurgical constraints. The maximum and minimum cut of grade as well as relative grade constraints are used to produce a real production from drawpoints according to the dilution control. The CPLEX software is used as a MILP solving framework, and also MATLAB to develop mathematical models. The application of the models based on metallurgical constraints was validated using 85 drawpoints over 12 periods. The results showed that in usual condition, the reduction of NPV was only 9% with the proportional non-distribution of average grade 24% of the maximum grade in the drawpoints, while by applying the metallurgical constraint this was reduced to 4%. Finally applying the metallurgical constraints with other operational constraints presented the real production planning.