The project, which began in February 2016, consisted of the rehabilitation and improvement of the extraction capability of shaft #3 as well as improvement of infrastructure, security and preparation of prospective mining areas at levels 2 to 4 of the mine.
Alain Lambert, chairman and CEO of Cyprium, commented: “Over the last three months we have replaced almost 1.5km of railway tracks at level 0 and at level 4. This includes the installation of railway tracks between an existing raise from the level 4 proposed initial mining area to shaft #3 as well as the installation of railway tracks in the level 4 mining area where much of our near-term mining activities will take place. New air and water tubing has been installed and we have rehabilitated existing equipment including two air-loaders and a small electric locomotive. Once we have re-assembled the air compressor which was brought down into the mine last week, we will turn our focus on cleaning up old stopes in level 2, 3 and 4, retrieving existing mineralised material from past mining operations and initiating drilling and blasting.”
The rehabilitation of shaft #3 will allow materials, services and equipment to be brought into the area around the shaft for near term exploration and mine development. The shaft will also allow for the removal of mineralised material from underground development at levels 2 to 4 of the mine. Shaft #3 has a mechanical daily extraction capability of 100t. However the company noted that it has no resources or reserves at the Potosi mine and any such production would be from unmeasured mineralised material.
Mineralised material extracted through shaft #3 will be processed at the company’s Aldama plant. The Aldama plant is located 42km from the Potosi mine. Under an agreement which expires in May 2019, the company has the exclusive right to use the Aldama plant which has a capacity of 100t/d. The company is responsible for the supervision of all metallurgic processes at the Aldama plant, including quantitative chemical analysis, assaying of samples, determining feed grades and the sale of concentrates.
Work at the Potosi mine in the near term will continue to focus on the area around the #3 shaft as access is easier and rehabilitation of the hoist is now complete. Exploration using longholes with jacklegs and drifting by drilling and blasting are expected to be used to further explore these mineralised areas.
To date, widely spaced sampling on levels 3-4 in the area of the Potosi #3 shaft and levels 6 and 9-11 in the area of the Potosi #1 shaft has shown that mineralised material of interesting grades is exposed at the margins old stopes and adjacent areas and this work will continue in order to evaluate the potential for defining resources. As data compilation proceeds, exploration to expand known stopes or to encounter new mineralisation, possibly by diamond drilling, will be planned. Work completed by the company at the Potosi mine has been successful in demonstrating potential for encountering mineralised material by exploration.
Visible mineralisation on levels 2 to 4 along with relatively easy access and near term installation of services make this area ideal to focus exploration and development activities. Construction of some underground workings will probably be necessary, but the amount of this work is not known as final survey information is not yet available. Surveying work of the old workings to provide a 3-D framework for planning and determining the volume of material already extracted is ongoing. The sampling density will also be increased. Some of this work is already in progress in the level 4 stope and will be extended to other visibly mineralised areas surrounding Potosi shaft #3.
