First production ore from Black Rock Cave comes online

The first production ore from the Black Rock Cave has come online following the development of the mining levels, with the underground ore body expected to yield around 1.8 million tonnes of copper ore from 2020 to 2024.

Glencore commenced development on the Black Rock ore body in May 2018 to access and extract ore around and below the historic Black Rock Open Cut.

The Black Rock Cave project further develops the existing copper resource at Mount Isa Mines, and will use sub-level caving to improve the economic viability of extracting ore from the existing ore body.

General Manager Mount Isa Mining Simon Pope says ore from the Black Rock Cave project will be extracted from a series of sub-levels downward through the ore body in a highly efficient pattern, using loaders and trucks to transfer ore to the surface.

"Glencore's Ernest Henry Mining, located outside of Cloncurry, successfully converted from open pit operations to sub-level cave mining in 2011, but this will be quite a different application of this highly efficient mining method given the rock is less competent in the Black Rock ore body," says Simon.

"The underground decline and development of the mining levels is nearing completion by PYBAR Mining Services and we are pleased to report that the first production ore is now coming online."

To implement this mining method, the Black Rock Cave project will involve the progressive relocation of a number of surface assets, infrastructure and personnel in and around the area known as R62, including the recent demolition of the original change house which was later repurposed as a core shed.

The R62 shaft will remain in operation throughout the Black Rock Cave project, however, a new change house facility will be built at X41 with workers transported on lease to R62 in the near future.

The project is progressing well says Simon with current focus being the removal of the crude ore bins and conveyors from R62 as well as the process water tanks. Demolition works on the No. 2 Ore Shaft headframe will start shortly, with the R60 building to follow.

"We are undertaking some major works to progress the Black Rock Cave project and both residents and workers alike will be noticing some changes to the Mount Isa Mines skyline and site as part of work on the Black Rock Cave project," Simon says.

"We are currently demolishing six crude ore bins that sit nestled to the southern side of the Lead Smelter Stack on the Mount Isa Mines lease which are visible from the Mount Isa city centre."

"Each of these massive crude ore bins once served as a monument to the hard work of the miners, holding thousands of tonnes of crude ore they worked extremely hard for."

The ore bins were constructed in the early 1960s around the same time as the commissioning of the R62 shaft (then known as K57 before the grid moved from imperial to metric) and No. 2 Concentrator expansion project.