A Case Study of Ventilation Modeling of A Large Block Caving Operation

This paper describes a ventilation study carried out to establish the basic ventilation model for the expansion of the San Manuel mine to include the Lower Kalamazoo orebody at a depth of 1050-1140 m (3400-3700 ft). The increased depth and projected size of the mine workings necessitated a new design of the ventilation and cooling systems, and the use of a ventilation network model to consider different options. The model is based on a partial ventilation survey of the Lower Kalamazoo portion of the mine to obtain values of representative friction factors and resistances for typical airways and ventilation boreholes. Since all the main fans at the mine are located underground and the new levels are connected to the upper part of the mine, upper levels of the mine were included in the model as single branches with representative level resistances. The model has been used to consider different alternate scenarios every time changes need to be made, either to optimize the ventilation system, or because of physical changes as development progresses. This paper discusses the methods used to conduct this comprehensive study, changes that the model has undergone, some of the scenarios investigated and the resulting changes in the ventilation system.