The Mount Isa Open Pit (MIOP) project is located to the west of the Mount Isa Township in northwest Queensland and is operated by Xstrata Mount Isa Mines (XMIM). Klohn Crippen Berger Ltd (KCB) was commissioned by XMIM to conduct a geochemical characterisation program, including predictive modelling, for waste rock and tailings materials for the proposed project.
The objective of the geochemical characterisation program was to identify the potential for acid and metalliferous drainage generation (AMD) from the Waste Rock Dump (WRD), Tailings Storage Facility (TSF) and Pit Wall. Three conceptual geochemical models were generated for the proposed WRD, the proposed tailings and the associated mine water quality as part of the MIOP operations. The predictive water quality model was based on results from static and kinetic laboratory tests, together with available water quality data.
Aspects of this project included:
- Development and implementation of a geochemical testing program (static and kinetic testwork), including sampling guidelines to assist with the identification of AMD producing geologic units.
- Evaluation of results to classify MIOP waste rock, wall rock and tailings.
- Development of a conceptual model to assess waste rock and tailings geochemical behavior, and the changing conditions of waste materials that contribute to surface water and groundwater quality. This includes a single waste rock dump (WRD) hydrogeochemical model, a water quality model for both tailings storage facilities (TSF), and a pit water quality model for pit wall run-off.