The transition from cut and fill mining to bulk mining in the same orebody while maintaining production
Mr Steven Townend (Chief Mine Engineer - Vale)
The selection of a mining method for a particular orebody determines many of the capabilities and requirements needed to safely and efficiently mine that orebody. When there is a need to significantly change the mining methodology for the same orebody many new challenges are raised that need to be overcome. These challenges need to be overcome so mining can continue at similar rates or at rates acceptable to meet long term plans so as to generate required revenues.Coleman Mine, a Nickel/Copper producing mine for Vale in the Sudbury mining district, is a mature mine that has been in continuous production since 1991. This maturity is reflected in the amount of ore that has been mined from several major ore zones and the number of associated sill pillars, many of which are still in production. In the main nickel orebody one sill pillar is almost completely mined out and two more have just started to be mined. Prior to mining these sill pillars the mining method was post pillar cut and fill, however the resulting stress conditions necessitated that a bulk mining method be used to safely mine the sill pillars. This paper describes the challenges encountered and the opportunities offered in the transition from post pillar cut and fill mining to slot/slash blasthole mining.