Dundee Precious Metals' 2021 prefeasibility study for the Timok gold project near Žagubica, Serbia, stacks 19.2 Mt over an eight-year mine life on a two-phase valley fill pad. The overall discounted gold recovery is 82.6%.
The NI 43-101 Technical Report, Timok Project Pre-Feasibility Study, Zagubica, Serbia, was prepared by DRA Americas and others for Dundee Precious Metals, with an effective date of February 23, 2021. Oxide and transitional ores from the Bigar Hill (BH), Korkan (KO) and Korkan West (KW) deposits are processed by conventional heap leaching on a heap leach fill (HLF) design. The plant crushes and stacks 2.5 Mtpa at an average gold grade of 1.07 g/t. Discounted gold recoveries are 84.9% for oxide and 71.8% for transitional ore. The pad is built in two phases, holding 9.9 Mt in Phase 1 and a further 9.3 Mt in Phase 2. The QP states that the testwork to date supports the flowsheet and recovery factors.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Report effective date | February 23, 2021 | Not applicable | DRA Americas for Dundee Precious Metals |
| Throughput | 2.5 | Mtpa | 19.2 Mt over 8 years |
| Gold head grade | 1.07 (oxide 1.08, transitional 1.04) | g/t Au | Weighted average design |
| Discounted gold recovery | 82.6 overall | % | 84.9 oxide, 71.8 transitional |
| Crush size | P80 17 mm, P100 25 mm | Not applicable | Three-stage crushing |
| Crushing availability | 75 (6,570 h/a) | % | 18 h/d |
| Leach and ADR availability | 95 (8,322 h/a) | % | 22.8 h/d |
| Crushing work index | 14.4 | kWh/t | Design |
| Irrigation | 467 m³/h BLS, PLS 423 m³/h | Not applicable | Single-stage drip irrigation |
| Pad | 146,000 m² footprint, 1.65 t/m³ stacked | Not applicable | Composite liner |
| Adsorption | Single 6-stage VCIC column, 3.8 m x 10.4 m | Not applicable | 4.5 t carbon per stage |
| Elution | Split-AARL, 4.5 t columns | Not applicable | Eight strips a week |
| Reagents | NaCN 0.14, quicklime 0.32 | kg/t | Weighted averages; cement only for agglomeration |
Overview
Run-of-mine ore is crushed in three stages: a jaw crusher, a secondary cone and a tertiary cone with screens. It is conveyed to an ore storage bin and loaded into trucks. When high-clay ore is processed, crushed ore is diverted to an agglomeration drum and mixed with lime, cement and cyanide. Crushed ore is truck-dumped on the pad, spread by bulldozer and ripped. Agglomerated ore is placed with a front-end loader, mobile conveyor and radial stacker. Barren leach solution is applied through drip emitters. Pregnant solution collects in an in-heap pond at the toe of the pad and is pumped to a vertical carbon-in-column (VCIC) adsorption unit. Loaded carbon is acid washed and stripped by split-AARL, and gold is electrowon and smelted to doré.
Key Process Stages
Crushing. A rock breaker, apron feeder and vibrating grizzly feed the jaw crusher. Secondary and tertiary cone crushers with vibrating screens bring the ore to P80 17 mm.
Agglomeration and stacking. The agglomeration drum runs only as needed for high-clay ore. The solution application flux is 1.64 t of solution per t of ore.
Heap leach pad. The composite liner has a low-permeability underliner beneath a geomembrane. A perforated collection pipe network sits on the geomembrane in a free-draining granular overliner. During Phase 2, the pad footprint is expanded and more lifts are added. The integrated PLS pond is double lined with HDPE and has a leak detection system between the liners. A downstream event pond catches overflow during upsets, such as a 24-hour power outage.
Adsorption. Pregnant solution enters the bottom of a single counter-current VCIC column. The column has six stages separated by bubble cap plates, each holding 4.5 t of 6–12 mesh carbon. Upward flow fluidizes the carbon, and a recessed-impeller pump advances it down the column. Barren solution overflows to a carbon safety screen and the BLS tank, where cyanide, water and antiscalant are added.
Desorption and refining. Loaded carbon is acid washed in a 1.27 m by 8.25 m column with dilute hydrochloric acid and rinsed. It is then eluted by split-AARL in a column of the same size. Gold is electrowon, and the sludge is filtered and smelted to doré in a furnace. Carbon is regenerated in a kiln.
Additional Interesting Data and Summary
Discounted recoveries by deposit range from 83.4% to 86.2% for oxide ore and from 68.8% to 81.0% for transitional ore. Phasing the pad's earthworks, construction and lining reduces the initial capital. The only product leaving the heap leach facility is doré.
In summary, the 2021 Timok prefeasibility study is a small 2.5 Mtpa crushed-ore heap leach on a phased valley fill pad, with intermittent agglomeration for clay-rich ore. Gold is recovered in a single six-stage VCIC column and a split-AARL ADR plant.
Key Processes
- Three-stage crushing to P80 17 mm
- Intermittent drum agglomeration with lime, cement and cyanide
- Truck and radial-stacker placement on a lined valley fill pad
- Drip-irrigated cyanide heap leaching
- Vertical carbon-in-column adsorption
- Acid wash, split-AARL elution, electrowinning and smelting to doré
- Kiln carbon regeneration
Source: NI 43-101 Technical Report, Timok Project Pre-Feasibility Study, Zagubica, Serbia, prepared by DRA Americas Inc. and others for Dundee Precious Metals, effective date February 23, 2021.
Technical report and processing history
The following archived source profiles have been consolidated here to preserve the project’s processing history and study context.
Timok Gold Project — 2018 Mineral Resource Estimate Update
Timok Gold Project — 2018 Mineral Resource Estimate Update
| Company | Dundee Precious Metals |
| Mine | Timok Gold Project |
| Date | 2018 |
| Region | Serbia |
| Commodities | Gold |
Executive Summary
This report presents an updated Mineral Resource Estimate for the Timok Gold Project in Serbia, commissioned by Dundee Precious Metals. The technical report documentation indicates that there are currently no Mineral Reserves defined for the property.
As of the date of this report, the project is not considered an Advanced Property, as there is no current Preliminary Economic Assessment (PEA), prefeasibility study, or feasibility study to support the potential economic viability of the identified Mineral Resources. Consequently, technical details regarding operational throughput, mining methods, and recovery processes are not applicable at this stage of development.
Website: https://dpmmetals.com/assets/exploration/timok-gold-project/
Report Date: 2018
Region: Serbia
Commodity: Gold
Timok Gold Project — 2021 PFS Technical Report
Timok Gold Project — 2021 PFS Technical Report
| Company | Timok Gold Project |
| Date | 2021 |
| Region | Timok |
| Commodities | Gold, Silver |
Executive Summary
This Pre-Feasibility Study (PFS) Technical Report outlines the proposed processing methods for the Timok Gold Project, focusing on the recovery of gold and silver from oxide and transitional ore deposits. The project design utilizes conventional heap leach technology with a Heap Leach Fill (HLF) configuration, targeting a throughput of 2.5 million tonnes per annum (Mtpa). The ore is sourced from the Bigar Hill (BH), Korkan (KO), and Korkan West (KW) deposits, with an average gold grade of 1.07 g/t and an overall discounted gold recovery of 82.6% for the combined oxide and transitional ore types.
The processing facility is designed for an 8-year mine life, with the heap leach pad constructed in two phases totaling 19.2 million tonnes of ore. The flowsheet includes a three-stage crushing circuit, an agglomeration circuit for high-clay ores, and a solution recovery system comprising an Adsorption, Desorption, and Recovery (ADR) plant. The ADR plant utilizes Vertical Carbon-In-Column (VCIC) technology to recover gold and silver from the Pregnant Leach Solution (PLS), followed by electrowinning and smelting to produce doré bars.
The report confirms that the metallurgical testwork supports the selected process flowsheet and associated recovery factors. Key design criteria include a crush size of 100% passing 25 mm, a leach cycle time of 90 days, and specific reagent consumption rates for sodium cyanide, cement, and lime. The plant layout ensures constructability, operability, and maintainability, with the QP opinion supporting the project evaluation based on the mineral resource and reserve estimates.
Reports
Website: https://dpmmetals.com/news-media/news-releases/dundee-precious-metals-announces-positive-pre-feasibility-study-and-encouraging-new-exploration-results-for-the-timok-gold/
Report Date: 2021
Region: Timok
Project Status:
Commodity: Gold, Silver
Throughput:
Mine Life:
Mine Type:
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NI 43-101 Technical Report – Timok Copper-Gold Project, Serbia: UZ PFS and Resource Estimate for the LZ
NI 43-101 Technical Report – Timok Copper-Gold Project, Serbia: UZ PFS and Resource Estimate for the LZ
| Company | Timok Copper |
| Date | 2018 |
| Region | Serbia |
| Commodities | Copper, Gold |
Executive Summary
This report details the Pre-Feasibility Study (PFS) for the Upper Zone of the Timok Copper-Gold Project in Serbia. The recovery methods focus on a single bulk concentrate flowsheet designed to treat sulphide ore containing covellite and enargite. The plant is designed to produce a single bulk concentrate with a capacity of 3,250,000 tonnes per annum.
The process plant design includes primary crushing located underground, followed by an overland conveyor to the mill. The grinding circuit utilizes a SAB (SAG and Ball mill) configuration. Copper recovery is achieved through a flotation circuit comprising rougher, regrind, and two-stage cleaner flotation cells. The concentrate is then thickened and filtered before storage and load out.
Key design criteria include a flotation feed size of 75 µm P80 and operating availability of 92% for grinding and flotation. The plant also includes effluent treatment to manage acidic water from the tailings impoundment. Reagents such as lime, copper collector, and frother are stored and dosed on-site to optimize recovery.
Processing Methods
Website:
Report Date: 2018
Region: Serbia
Project Status:
Commodity: Copper, Gold
Throughput:
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Mine Type:
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Timok Project — 2018 Technical Report
Timok Project — 2018 Technical Report
| Company | Timok |
| Date | 2018 |
| Region | Serbia |
| Commodities | Copper |
| Mine Type | Underground |
| Status | Development |
Executive Summary
This Pre-Feasibility Study outlines the recovery methods for the Timok Project in Serbia, focusing on a copper sulphide ore body containing covellite and enargite. The process plant is designed to treat 8,900 tonnes per day of ore, producing a single bulk copper concentrate. The flowsheet was optimized to handle arsenic content variations, though the current design focuses on a simplified bulk concentrate production strategy.
The processing circuit begins with primary crushing located underground using a jaw crusher, followed by overland conveyance to the surface plant. The grinding circuit utilizes a Semi-Autogenous Grinding (SAG) mill in combination with a ball mill operating in closed circuit. Copper recovery is achieved through a flotation circuit comprising rougher, regrind, and two-stage cleaner flotation cells, followed by thickening and pressure filtration of the final concentrate.
Processing Profile
- Crushing: Primary Jaw Crusher
- Milling: SAG Mill, Ball Mill
- Flotation: Rougher, Regrind, Two-Stage Cleaner
- Dewatering: Thickeners, Pressure Filters
Website: https://dpmmetals.com/assets/exploration/timok-gold-project/
Report Date: 2018
Region: Serbia
Project Status: Development
Commodity: Copper
Throughput:
Mine Life:
Mine Type: Underground
Ore type:
