Otjikoto goes underground to reach Wolfshag – first gold expected in January 2022
B2Gold’s development of the Wolfshag deposit adjacent to the company’s open pit Otjikoto mine marks a first for Namibia as it is the only local mine where access to the new deposit will be by underground tunnel leading from the sidewall of the existing open pit.
The portal to this tunnel was constituted last week Friday, 30 October when blasters cut the first square out of the rockwall to start the further blasting and excavation of the access tunnel. This tunnel will be a declining shaft up to the point where it intersects the ore body.
Mining the Wolfshag deposit in an underground mine was approved by the B2Gold board in December 2019, following an internal trade-off study between open pit and underground mining. The development tender issued earlier this year to source the skills of an experienced underground miner for the initial phase of the declining tunnel attracted global attention and was eventually awarded to South Africa’s Murray & Roberts Cementation in joint venture with Lewcor Namibia.
The total project development cost, including contractor costs, amounts to nearly one billion Namibia Dollar.
While the rest of the country was still in lockdown, the contractor started moving equipment and material to the site of B2Gold’s Otjikoto mine halfway between Otjiwarongo and Otavi. Recruitment of construction workers began immediately as well as construction of the contractor’s camp. Preference was given to local candidates from the Otjozondjupa region.
Before the first blast could be done, the rockwall of the mined-out open pit of the mine’s second phase had to be stabilised and secured for safety.
The new tunnel will eventually reach 1.3 km in length and descend to some 275 metres below surface. Construction of the tunnel is expected to be completed in just over a year at which point extraction of the gold-bearing ore can begin. The mine will be ventilated through a vertical 4-metre wide shaft close to the main ore body. The shaft will double as an emergency escape route for underground workers.
The Wolfshag ore body is estimated to contain 210,000 ounces of gold in 1.2 million tonnes of ore grading at 5.57g/t gold and will be extracted over a period of four years from January 2022 to August 2025. During this period, it is expected that the project will realise revenue of US$403 million at a gold price of US$1500 per ounce.
The new project is expected to create between 300 and 400 direct and indirect jobs.
The first gold production from Wolfshag’s ore is expected around January 2022.
After much preparation to ensure the safety of the site, the combined Murray & Roberts Lewcor blasting team last week cut the first square out of the open pit mine’s rockwall to start the tunnel that will eventually reach the Wolfshag deposit about 1.3 kilometre away. The safety netting and stabilising pegs can be seen against the rockwall.