Ivanhoe Electric Inc.

Source: Worley, 2026

Ore produced from the underground mine will be processed using a heap leach and solvent extraction and electrowinning flowsheet to produce London Metal Exchange (“LME”) grade copper cathode. The heap leaching process will take place on an on/off pad. Spent ore will be removed from the leach pad and processed for paste backfill or stacked on a spent ore pile. Approximately 50% of the spent ore will be processed for use in paste backfill. Operations will be conducted 24 hours per day, 365 days per year for approximately 26 years at a design stacking rate of up to 22,000 t/d.

Run of mine (“ROM”) ore will be delivered to surface at a diameter of less than 254 mm via the conveyor. Ore from underground will be conveyed to the coarse ore stockpile for further 2-stage crushing. Fine ore (undersize from the crushing circuit) will be trucked to the agglomeration drums where sulfuric acid and sodium chloride can be added to facilitate agglomeration and leaching.

Crushed and agglomerated ore will be delivered to the leach pad via a combination of overland conveying and stacking equipment. The final mobile conveyor will feed two self-propelled indexing conveyors in series, which in turn will feed the self-propelled mobile radial stacker. The cells will be ‘retreat’ stacked by the radial stacker in a 65.5 meter-wide (half-cell) half moon shape.

The on/off heap leach pad will be divided into seven cells, each approximately 130 x 730 meters. The cells will be separated by divider berms located near their base so that solution flow from each cell can be segregated for collection. The liner for the leach pad is comprised of a high-density polyethylene geomembrane overlaying a geosynthetic clay liner overlaying prepared native foundation materials or grading fill.

Ore will be stacked at up to 22,000 t/d, while unloading will consider a constant rate of 22,000 t/d; based on a typical interior half-cell strip (i.e., not the end cell strips on the north or south sides of the pad), it will take approximately 25 days to stack each half-cell strip at the design production rate. Each of the cells (and more specifically, each of the half-cell strips) will cycle through the following processes in sequence with an entire cell cycle, under the design production rates and idealized cell sizing, taking approximately 320 days.

The cycles are as follows:

The cells will be irrigated with raffinate (depleted pregnant leach solution from the solution extraction process) or secondary leach solution (“SLS”) produced from leaching. Leach solution will report to the solution collection ponds. At the end of the leach cycle, spent ore will be removed to the spent ore stockpile or the paste plant using dozers, loaders, grasshopper / link conveyors and trucks (see figure below).