Integrated Mine-to-Mill Optimization of Toromocho Operation at Minera Chinalco Peru

Abstract

Minera Chinalco (Chinalco), the owner of the Toromocho copper mining complex in Peru, has conducted an integrated Mine-to-Mill optimization project with the aim to maximize the throughput of the Phase 1 SABC grinding circuit (Line 1), using the existing assets while maintaining the product size specifications. Following a typical Mine-to-Mill approach, improvement in the drill and blast operation resulted in significantly finer Run-of-Mine (ROM) fragmentation and, therefore, finer SAG feed size. In 2020, Hatch Consulting & Technology was engaged to identify and quantify comminution circuit optimization opportunities for Phase 1 leveraging the full benefits of the fine SAG feed, and develop a throughput forecast model for the medium and long term.

The project identified various opportunities to increase throughput in Phase 1 by up to 14%, with 10% of the increase attributed to the SAG mill discharge system, despite the very fine SAG feed size. Chinalco is currently implementing the recommendations to capitalize on all benefits and extending the study for the Phase 2 SABC grinding circuit (Line 2), which has a different installed capacity. This will ensure that the Mine-to-Mill approach is applied to the complete comminution circuit.