Overview
The Rainy River Mine processing plant is a conventional gold and silver recovery facility that began operations in September 2017. The plant achieved commercial production in October 2017 and processed 8.99 million tonnes in 2024, averaging 24,563 tonnes per day (tpd) with metallurgical recoveries of 91.8% gold and 61.1% silver. The circuit features crushing, grinding, gravity concentration, leaching, carbon adsorption, and electrowinning.
Key Process Stages
- Crushing: Primary crushing via a 1,400 × 2,100 mm gyratory crusher (600 kW) with a P80 product size of 120 mm. Ore is stockpiled in an 85,690-tonne coarse ore stockpile.
- Grinding: SAG mill (11.0 m × 6.1 m, 15,000 kW) with pebble crushing (Raptor L500 cone crusher, 447 kW). Ball mill (7.9 m × 12.3 m, 15,000 kW) targets a P80 of 80 µm.
- Gravity Concentration: Two 48-inch Knelson concentrators (600 tph combined) recover free gold, with concentrate processed in an Acacia intensive cyanide leach circuit.
- Leaching & CIP: Eight 18 m-diameter leach tanks (24-hour retention) and seven 7 m-diameter CIP tanks (1.5-hour retention) for gold adsorption.
- Carbon Stripping: Zadra process (high-pressure, high-temperature) with two 10-tonne stripping vessels. Reactivation in a 750°C rotary kiln.
- Electrowinning: Three parallel trains (two cells each) recover gold/silver sludge, which is smelted into doré bars.
- Tailings: Cyanide destruction (SO₂/lime) before pumping to the Tailings Management Area (TMA) via 550 kW centrifugal pumps.
Critical Data
| Parameter | Value |
|---|---|
| Throughput (2024) | 8.99 Mt (24,563 tpd) |
| Gold Recovery | 91.8% |
| Silver Recovery | 61.1% |
| SAG Mill Energy | 8.8 kWh/t |
| Ball Mill Energy | 13 kWh/t |
| Total Site Energy | 34.5 kWh/t |
| Reagent Consumption (kg/t) | Sodium Cyanide: 0.21, Lime: 0.72, Activated Carbon: 0.027 |
| Water Storage (TMA) | 11.6 million m³ |
Based on filing data from 2024-2025.
