The Hugo North Extension is a rich coppergold porphyry deposit in southern Mongolia and forms the northern-most extension of the Oyu Tolgoi mining complex. The property is managed by Oyu Tolgoi LLC (OTLLC), a subsidiary of Turquoise Hill Resources and the Government of Mongolia. Sandstorm acquired gold, silver and copper streams over the Hugo North Extension from Entrée Resources Ltd. Entrée has a 20% joint venture interest with OTLLC on the Hugo North Extension property.
Four deposits have been identified in the mineral resources at Oyu Tolgoi: Oyut, Hugo North, Hugo South, and Heruga. In the initial years of production the main source of ore has been from the Oyut open pit and while the pit is being mined, underground infrastructure and block cave mine development is ongoing at Hugo North. Conventional crushing, grinding, and flotation circuits process the ore and the concentrates produced are sent to smelters in China.
Entrée Resources published the results of a Feasibility Study based on the mineral reserves attributable to the Lift 1 underground block cave at the Hugo North Extension. It is estimated that 223 Mlbs of copper, 102 kozs of gold and 730 kozs of silver will be mined as part of Lift 1 operations. Initial block cave production is expected to start in 2026.
The Hugo North Extension has a January 2018 Probable Mineral Reserve of 35 Mt at grades of 1.59% copper, 0.6 g/t gold and 3.7 g/t silver and an Indicated Mineral Resource (inclusive of Reserves) of 122 Mt grading 1.68% copper, 0.6 g/t gold and 4.2 g/t silver (0.37% CuEq cut-off).
Turquoise Hill reported that underground development progressed by 2.4 km during the second quarter. During 2018, underground development is expected to advance by approximately 10.0 kilometres.
The results of a Feasibility Study based on the Mineral Reserves attributable to the Entrée/ Oyu Tolgoi JV from Lift 1 of the Hugo North Ext. underground block cave were released.