As open-cast mining operations face the inevitable shift to underground due to depleted shallow deposits, increasing surface environmental requirements, and an increased call for minerals to support the transition to low-carbon energy, United Mining Services Group has equipped its operations in preparation for the surge in demand for specialist underground mining skills.

The company is concentrating its efforts on making underground mining as cost effective for clients as possible while increasing productivity, as quickly and safely as possible.

Murray Macnab, Group Executive Technical Director for UMS, says that as a multi-disciplinary specialist underground mining and metallurgical processing services company, with 60 years of institutional knowledge and extensive front-end expertise, UMS is capitalising on its experience, intellectual resources and equipment to get the best economical solution for its clients. By combining the extensive engineering and consulting ability of the UMS engineering as well as the UMS contracting businesses, UMS can complement clients’ technical teams’ short and long-term requirements.

“Traditionally, Tier 1 mining houses would start planning for an underground mine five to ten years in advance and commission feasibility studies five years ahead of time,” says Macnab. “Through the engineering and consulting arms of our business, we have the capability to do feasibility studies for our clients within one year, as well as complete early engineering and procurement concurrently to ensure reduced timelines on long-lead time items.

“Furthermore, shaft sinking requires a lot of expensive equipment. Besides the capital cost of hundreds of millions of dollars for the equipment alone, it can take in excess of 24 months to manufacture a new winder for example, a minimum of two of which are typically needed for a new underground mine. These timeframes are no longer feasible in current times and with varying mine owners, this is where UMS can assist by decreasing timeframes and costs.

“UMS Group has recently invested substantially in mining equipment which we can use during a project, and it can then be made available to the client afterwards if it fits their long-term requirements,” says Macnab.

He explains that UMS has been purchasing equipment, including many winders, from various sources including the heritage shaft sinking businesses and local mining houses. The equipment will be refurbished with the latest electrical technology to make the machines fit for the specific application. The replacement value of this equipment runs into multiple billion rands.

“We have specialist expertise in mining equipment and winders, and have an internal winder division that specifies what needs to be done to the winders so that they can be modified accordingly. These teams are also available to consult and audit mine winders and mining equipment.

“Our clients are realising the benefits of using refurbished machines, as it can be much more cost effective and can save them up to two years on the lead time for equipment,” says Macnab. “For example, for our client in Brazil, we already owned the Kibble winder, amongst other equipment required to sink the shaft, and have shipped it there where it is now being used to sink the shaft. It will then be converted to the permanent man winder to save the client money and schedule.”

Macnab emphasises that the best way to save clients time and money is to increase efficiency and productivity, but never at the expense of safety. “In the ‘70s and ‘80s, South Africa was setting shaft sinking advances and competing for world records. Everyone was trying to sink over 100 metres a month, and safety was a casualty of this competition. The world has changed for the better, and safety has been prioritised. However, eliminating risks resulted in some sinking rates reducing across all sinking companies, in some cases, by to up to 30 metres a month.

“Safety imperatives have resulted in a significant rethink about the viability of certain mining ventures. At UMS, safety is part of everything that we do. We are constantly exploring innovative ways to improve productivity while making sure safety is never compromised. We’re now achieving monthly sinking advances again that are starting to be on par with sinking advances of the '80s, recently achieving 105 metres in a month at one of our sites and looking to increase this,” says Macnab.

“We’re also rethinking and re-engineering innovations of the past and seeing how we can upgrade or modify them to increase productivity and save money, while still prioritising safety. For example, we have rigorously changed the way cactus grabs are used to comply with and increase on modern safety regulations. Cactus grabs are the most efficient machines to load rock, but we changed the sinking method to make it safer by, amongst others, completely removing people from the shaft bottom when loading.”

Macnab provides a further example of adapting old technology by putting a modern spec on a mobile escape winder that was initially only suitable for shallow mines, modifying it to reach a depth of 1 500m. He says that UMS is using one of these units at their Botswana project as an emergency escape winder. It will eventually be used in the ventilation shaft for this purpose to 800 m below the surface, saving the client from having to build a headgear on an emergency escape shaft.

“We are constantly innovating within UMS. We’re much more than a sinking contractor, and have the right people and equipment to offer competitive and smart solutions to our clients. This puts us in a strong position to undertake several more long-term underground projects in the future, safely, expeditiously and cost effectively,” concludes Macnab.