Name of the Mine
Ada-Tepe mine.

Location  
About 3 km south of Krumovgrad, in south-eastern Bulgaria.

Mine Owner/s
Dundee Precious Metals.

Brief Description  
Ada-Tepe is one of the highest-grade openpit gold mines in the world.

Brief History  
Construction works started on the site of operations in the fourth quarter of 2016. First concentrate production started in March 2019, with commercial production achieved in June 2019.

Primary Metals/Minerals  
Gold.

Secondary Metals/Minerals  
Silver.

Geology/Mineralisation  
Dundee describes Ada-Tepe as a low-sulphidation, epithermal gold/silver deposit.

The mineralisation is hosted near the base of a fairly young sequence of Paleogene sedimentary rocks that range from breccias and conglomerates to marls. These rocks are separated from the lower and older metamorphic basement rocks, known as the Kessebir-Kardamos core complex, by a shallow fault, frequently referred to as a detachment fault, which dips about 15° to the north. This fault forms the lower bounding surface of the deposit.

The mineralisation at Ada-Tepe is divided into Wall Zone and Upper Zone mineralisation.

Wall Zone mineralisation forms a massive siliceous body of up to 5 m thick that is situated immediately above the detachment fault.

The Upper Zone mineralisation is a series of predominantly steeply dipping east–west trending veins that extend upwards from the Wall Zone into the sedimentary rocks.

Gold is present as electrum, and the highest gold grades are associated with typical epithermal veins with colloform-banded and lattice-bladed veins and hydrothermal breccias.

The surrounding prospects, referred to as satellite orebodies, include Surnak, Skalak, Synap, Kuklitsa and Kupel.

Reserves  
Total proven and probable reserves in the Ada-Tepe Wall Zone are estimated at 1.4-million tonnes grading 3.44 g/t gold and 2.34 g/t silver.

Total proven and probable reserves in the Ada-Tepe Upper Zone are estimated at 1.3-million tonnes grading 6.35 g/t gold and 4.14 g/t silver.

Total proven and probable reserves in the Ada-Tepe stockpiles are estimated at 300 000 t grading 2.37 g/t gold and 1.58 g/t silver.

Resources  
No values for measured and indicated resources are given for the Ada-Tepe mine.

The Ada-Tepe Upper Zone has inferred resources of 200 000 t grading 1.63 g/t gold and 1.32 g/t silver.

Mining Method  
Conventional excavator and truck methods.

Major Infrastructure/Equipment  
Ore is processed by crushing the mined ore in the primary jaw crushing circuit, grinding in a semiautogenous grinding milling circuit followed by a further secondary grind in a vertimill circuit. Tailings and waste rock material from the mine are placed in an integrated mine waste facility

Prospects  
An estimated 20 000 m of drilling is planned, of which almost half is dedicated to near-mine target delineation and drilling within the mining concession and the surrounding Krumovitza exploration licence.

Contact Details
Dundee Precious Metals
Tel +1 416 365 5191
Email pr@dundeeprecious.com
Website https://www.dundeeprecious.com

Sources
Dundee Precious Metals. NI 43-101 Technical Report – Mineral Reserve and Mineral Resource Update for the Ada Tepe Mine, Krumovgrad, Bulgaria (November 20, 2020).
Dundee Precious Metals. Annual information form (March 31, 2022).
Dundee Precious Metals. NI 43-101 Technical Report : Mineral resource and mineral reserve update – Chelopech mine (March 31, 2022).
Dundee Precious Metals. Website : https://www.dundeeprecious.com [accessed October 10, 2022].