Overview
The Cozamin mill processes copper-zinc ores from the San Rafael and MNFWZ deposits, with increasing throughput since 2018. The circuit has been optimized to handle projected throughput requirements through 2030, including harder ores from the San Jose extension. The plant features parallel grinding lines, differential flotation circuits for copper and zinc, and is transitioning to filtered tailings disposal.
Key Process Stages
- Crushing Plant: Three-stage crushing circuit (jaw + cone + HP4) with 230 tph capacity. Recent upgrades include high-efficiency tertiary screens and bypass systems for underground ore.
- Grinding: Two parallel ball mills (3.65m x 4.27m) operating at P80 of 230 µm, with cyclone classification and increased power draw capacity up to 1,500 HP.
- Flotation: Differential Cu/Zn flotation with tank cells for copper roughers, two-stage cleaning, and zinc regrind circuit with column cell for final cleaning.
- Concentrate Handling: Larox pressure filters for copper (10% moisture), disc filters for zinc, and drum filters for future lead production.
- Tailings: Transitioning from slurry deposition (40-42% solids) to filtered tailings system in 2023.
Critical Data
| Parameter | Value | Units |
|---|---|---|
| Average Throughput | 3,780 | dry tpd |
| Mill Availability | 90.0 | % |
| Bond Work Index | 18.5 | BWi @212 µm |
| Mill Feed Size | 6,300 | µm |
| Mill Product Size | 230 | µm |
| Copper Concentrate Grade | 25 | %Cu |
| Water Consumption | 0.82 | m³/t |
Circuit Upgrades
Key modifications implemented to sustain increased throughput:
- Installation of high-efficiency tertiary screens (Oct 2020)
- Mill discharge modifications for higher power draw (2021)
- Addition of column cell to zinc cleaning circuit
- Planned grizzly installation at primary crusher
- Transition to filtered tailings system (2023)
