The mine site is located at Ada Tepe hill, approximately 3km south of the town of Krumovgrad in south-eastern Bulgaria. It is an open-pit mining operation comprising of a process plant, which employs conventional crushing, grinding and flotation processing for gold extraction, and the disposal of thickened tailings, together with mine rock waste, in an integrated mine waste facility (“IMWF”).

The plant is designed to treat up to a maximum of 840,000 tonnes of ore per annum over an eight-year mine life. Two (2) main styles of mineralization are recognised at Ada Tepe: Wall zone occurring within shallow north dipping zone of brecciated vein material and variably silicified sedimentary breccia; and Upper zone predominantly occurring within east-west striking, steep dipping veins.

Challenges

Ore loss, dilution and misclassification due to difficulty in visually identifying ore boundaries

• Variable thickness of ore polygons with little/no visual controls in Upper Zone mineralization
• Highly variable horizontal blast movement of between 0.7 m – 2.8 m meant that ore blocks were no longer in their original position post-blast

Results

In one flitch of one blast alone, Ada Tepe Mine recovered an additional 668 t of ore valued at USD $465,246 that otherwise would have been sent to the waste pile had blast movement not been accounted for

• Measured horizontal movement ranged from 0.7 m to 2.8 m
• Recovered an additional 668 t of ore valued at USD $ 465,246

“Lack of visual controls in the upper zone mineralization coupled with variable ore thickness ranging from 2 m to 30 m would have been difficult to accurately locate after blasting without BMT” ~ Samuel Amoh, Corporate Senior Mining Engineer

State assumptions
• Grade of Waste material = 0 g/t
• Gold price = USD $1250 / oz
• Density of rock = 2.44 t/m3
• Mill Recovery = 90%