The Turmalina plant processes ore through three-stage crushing, grinding, cyanide leaching, and carbon-in-pulp recovery, with tailings treated for detoxification and used for underground paste backfill or dry stack storage.
Report context
The Technical Report is dated February 2, 2024, with SLR Project No. 233.03852.00001, and addresses the Turmalina Mining Complex, including ore from the Turmalina mine and the Faina deposit. During 2021, the Turmalina Plant processed approximately 409,700 t at an average grade of 3.12 g/t Au with overall plant recovery of 88.6%. The plant has a nominal processing capacity of 2,000 tpd (720,000 tpa), providing approximately 18% excess capacity at the planned peak production rate of about 600,000 tonnes per year (1,644 tonnes per day) in 2025 and 2026. Since inception, annual overall recoveries have ranged between 87% and 92%.
Processing route
Crushing and Screening
Ore from the Turmalina and Faina mines is transported to the processing plant and dumped onto run-of-mine stockpiles. The primary jaw crusher operates in open circuit at a nominal rate of 140 tonnes per hour. Material is fed via a vibrating grizzly feeder; grizzly oversize enters the primary crusher while grizzly undersize combines with crushed product on the primary screen feed conveyor. Secondary and tertiary cone crushers operate in closed circuit with their associated vibrating screens. The final crushed product is minus 9.5 mm and is stored in a crushed ore storage bin that provides grinding plant surge capacity and allows the crushing plant to operate at a higher rate for routine maintenance.
Grinding, Classification and Thickening
Since 2017, the plant has operated using Mill #3, one of three installed ball mills, to conserve energy and reduce costs. Mill #3 has a capacity of 70 tph (1,545 tpd at 92% operating availability) and is 4 m in diameter by 6.6 m equivalent grinding length, driven by a 1,491 kW (2,000 HP) motor. Mill #1 is 3.2 m by 4.7 m EGL with a 745 kW motor and maximum capacity of 25 tph. Mill #2 is 3.8 m by 5.5 m EGL with a 1,342 kW motor and maximum capacity of 60 tph. Combined grinding capacity of all three mills is 3,400 tpd at 92% operating time. A second mill may be required in 2025 when production increases to 1,644 tpd.
Lead nitrate (Pb(NO₃)₂) is added in the grinding mill feed at 50 g/t to prevent excessive NaCN consumption. Grinding mill slurry discharges into a cyclone feed pump box and is pumped to hydrocyclones for particle size separation. Cyclone overflow contains the P₈₀ 74 µm product size; cyclone underflow returns to the ball mill for reprocessing. Overflow slurry passes through a trash screen then enters a 30.5 m diameter leach feed thickener, where flocculants are added. Thickener underflow is pumped at 53% solids by weight to the CIP plant pulp conditioning system. The thickener is instrumented to maintain pulp density at approximately 48% to 50% solids by weight.
Leaching Circuit
The leaching circuit consists of seven agitated tanks operating in series. Lime and NaCN are added to the first tank to adjust pH and commence leaching. If required, the first tank can be used for sulphide preoxidation with oxygen or air and lime, with NaCN added in the second tank. Compressed air is injected at the bottom of all tanks at 0.94 m³/s and 3.5 kg/cm². Residence time in the leaching circuit is approximately 25 hours.
Adsorption Circuit
The carbon-in-pulp adsorption circuit comprises five agitated tanks arranged in series. Activated carbon (2.4 mm to 1.19 mm size range) is added at a minimum pulp concentration of 20 g/L to the last tank and is pumped counter-current to slurry flow. The adsorption cycle is approximately ten hours. Loaded carbon, containing approximately 1.5 kg of gold per tonne of carbon, is pumped from the first tank to the elution and electrowinning circuit.
Elution and Electrowinning
Loaded carbon is screened on a 28 mesh screen; undersize returns to adsorption and oversize feeds the elution circuit comprising four columns operating in batch mode. Each column is 1.25 m in diameter and 6.25 m high, with an estimated carbon load of approximately 2.7 t. Loaded carbon is eluted using 1% w/w caustic soda solution plus 200 L of ethyl alcohol per batch, heated to 95°C and pumped from bottom to top. Rich eluant feeds the electrowinning circuit of six cathodes and seven anodes, energized with 360 A at 3.5 V to 4.0 V. Gold precipitates onto cathodes forming a precious metal sludge that is cleaned, filtered, dried, and smelted to produce doré ingots. Jaguar ships the electrowinning sludge to a third party for smelting and refining.
Acid Washing
Activated carbon undergoes stripping in elution columns with 1% NaOH solution at 95°C. Carbon is then conveyed to a surge tank via an ejector directed to a 28 mesh screen for fines removal. Oversize goes to an 8 m³ fibreglass acid washing tank. Acid washing uses 10% HCl solution to remove carbonates and base metals. The acid washing time is approximately 16 hours. After acid washing, the carbon is neutralized with 1% NaOH solution for one to two hours, then washed with water for two hours. A furnace is not employed for carbon regeneration as expected performance was not successfully achieved.
Detoxification Plant
CIP adsorption tank tailings (86 tph at 42% solids) flow by gravity to a belt screen to avoid carbon loss, then to the tailings pulp treatment plant where Caro’s acid is used for cyanide destruction.
Filter and Paste Fill Plant
Treated tailings at 42% solids are pumped by rubber lined centrifugal pumps to the filter and paste fill plant approximately one kilometre away. Slurry is received in a pulp storage tank, pumped to a hydrocyclone cluster, with overflow feeding a thickener. Cyclone underflow and thickener underflow feed three drum filters (3.0 m diameter by 4.9 m). The filtration process produces a cake at approximately 30% moisture and a filtrate. The filtrate, less than 3% of total tailings as ultra-fines, is pumped to the tailings dam. The filter cake is either conveyed to the paste fill circuit or trucked to a dry stack filtered tailings storage facility.
Filter cake for paste fill is conveyed to a cake preconditioning hopper, then to a weigh hopper where Portland cement or “Fosbinder” is added. The paste fill plant uses a batch process for better control of paste characteristics for underground backfill.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Plant nominal capacity | 2,000 tpd (720,000 tpa) | Design |
| 2021 plant throughput | 409,700 t | Actual operating data |
| 2021 average feed grade | 3.12 g/t Au | Actual operating data |
| 2021 overall plant recovery | 88.6% | Actual operating data |
| Historical annual recovery range | 87% – 92% | Historical operating data |
| Peak LOM production (2025-2026) | ~600,000 t/yr (1,644 tpd) | Proposed design |
| Crushing product size | Minus 9.5 mm | Design |
| Grinding product size | P₈₀ 74 µm | Design |
| Mill #3 capacity | 70 tph (1,545 tpd at 92% availability) | Design |
| Combined mill capacity | 3,400 tpd at 92% availability | Design |
| Leach residence time | ~25 hours | Design |
| Adsorption cycle time | ~10 hours | Design |
| Gold load on carbon | ~1.5 kg Au/t carbon | Design |
| Thickener underflow solids | 53% by weight | Design |
| Tailings flow to Detox | 86 tph at 42% solids | Design |
| Filter cake moisture | ~30% | Design |
| Annual energy consumption | ~51,200 MWh | Historical operating data |
| Annual water consumption | 1.94 million m³ | Historical operating data |
Project website: https://www.jaguarmining.com/assets/turmalina-gold-mine
Technical qualifications
This article is based solely on Section 17.0 (Recovery Methods) of the Technical Report. No flowsheet details, performance data, economic analysis, ownership information, current operating status, or external links beyond what is explicitly stated in the provided section are included. The report does not provide testwork data for proposed design parameters; values described as design or proposed are from the life-of-mine plan and process design descriptions. Historical operating data is from 2021 only. The simplified process flowsheet (Figure 17-1) and mine site plan (Figure 18-1) mentioned in the report are not reproduced here.
Source: Turmalina Mining Complex , 2024 Technical Report, Sections 17.0 through 17.11, dated February 2, 2024.
