Full Mine-to-Mill Optimization & Continuous Improvement of Lundin Mining's Chapada Operation in Brazil

Abstract

Chapada’s open pit copper-gold mine and processing plant commenced operation in 2007. As mining has progressed deeper the ore hardness has increased, adversely impacting plant throughput. Therefore, Lundin, Hatch and Enaex conducted a Mine-to-Mill optimization project to maximise throughput with existing equipment while maintaining comminution product size. The comminution circuit consists of two primary crushing lines followed by an SABC grinding circuit.

The project encompassed review of ore characterisation data, definition of ore domains, review of drill and blast and comminution operating practices, analysis of historical operating data, drill and blast audit, measurement of blast fragmentation, comminution circuit survey, and development of site-specific mathematical models for blasting and comminution. Integrated simulations and analysis were used to determine optimized strategies to maximise production for the overall operation (Mine-to-Mill). This included development of blasting guidelines tailored for each domain to improve blast fragmentation and recommendations to improve comminution performance leveraging the finer feed. This involved changes to operating conditions (crushers, SAG and ball mills, and cyclones), liner design, and grinding media size and level.