HomeFeatures & AnalysisEssakane study confirms feasibility from transition from CIL to heap leach

Essakane study confirms feasibility from transition from CIL to heap leach

TSX-listed IAMGOLD Corporation’s feasibility study at its Burkina Faso-based Essakane operation supports an increase in current hard rock carbon-in-leach plant capacity and outlines an economically viable heap leach facility at the end of CIL operations.

Feasibility highlights

  • Indicated resources of 4.878 Moz grading 0.98 g/t gold, inclusive of reserves on the Essakane mining concession, based on a new resource model;
  • Proven and probable reserves of 3.985 Moz grading 0.96 g/t gold;
  • Mine life of 12 years (2020-2031), with mill throughput of 11.7 Mtpa hard rock equivalent capacity, up from current design of 10.8 Mtpa at 100% hard rock (2020-2026); and heap leach throughput of 8.5 Mtpa (2027-2031);
  • Robust average annual production of 433 000 oz during CIL operations, representing a 4% increase above CIL output from the previous study, including peak year production exceeding 530 000 oz using CIL;
  • Annual production of 73 000 oz per year of HL production at end of CIL production; achieving an annual gold output from HL similar to previous study, but with 15% lower throughput;
  • Minimal capital investment of $9 million required for CIL optimisation, with commissioning targeted for Q3, 2020;
  • Reduction, and deferral, of total HL capital expenditures by $40 million to $115 million (2025-2026) from the previous study, while maintaining the same HL production profile;
  • After-tax NPV@6% of $874 million, life of mine direct cash costs of $778/oz and all-in sustaining costs of $949/oz;
  • Significant increase in HL recoveries to 67% (from 55%) through the use of high pressure grinding rolls (HPGR) edges recycling in closed circuit including agglomeration step and extended leach time;
  • 5% increase in average diluted grade of CIL material to 1.24 g/t;
  • Future option retained to process the HL material either through the HL development scenario as described in the feasibility study or, if prevailing metal prices are supportive, through the CIL for improved recoveries and forgo the capital investment in the HL facility.


The capital cost of the HL facility was reduced by $40 million, for the new scenario, by re-using existing CIL plant equipment (primary & secondary crushing circuits) at the end of CIL life and by optimising the heap leach pad footprint.

The optimisation of the heap leach pad footprint allows for the HL infrastructure to remain within the current industrial complex of the mine, versus the PFS scenario which would have required additional land outside of the current complex, thus avoiding impact to communities and farmland.

Steve Letwin, President and CEO of IAMGOLD, commented:

“With our self-funding lens in place, the IAMGOLD team reviewed the CIL/HL feasibility study and produced a robust, low cost plan with optionality in the future. I would like to thank our COO Gord Stothart, his project team and our consultants for their excellent work in defining the future plan for Essakane.”

The FS was completed by IAMGOLD, with inputs from technical studies completed by other consultants, and has an effective date of 6 November 2019.

The FS represents a comprehensive study of the technical and economic viability of a mineral project that has advanced to a stage where a preferred mining method has been established and an effective method of mineral processing has been determined.

IAMGOLD is using the FS to support a $9 million investment in the current plant to improve its capacity to 11.7 Mtpa (at 100% hard rock equivalent capacity) and plan for a heap leach facility to be deployed in 2027.