Tag Archives: Tarkwa

Gold Fields installs CAS safety solution at Tarkwa gold mine

Gold Fields is upping the safety stakes at its Tarkwa gold mine in Ghana, employing a collision avoidance system (CAS) that should reduce the number of vehicle-to-vehicle and vehicle-to-personnel interactions at the open-pit operation.

Having installed a fatigue management system back in 2012-2013 – which saw equipment interactions and accidents decrease – the company has now purchased the HxGN MineProtect Collision Avoidance System Pro as part of a “discrete, dedicated project”, a company spokesperson confirmed to IM.

Hexagon says the CAS Pro system protects all mining vehicles, assets and vehicle operators within 500 m of the installed cab-based unit in open-pit mines.

The solution provides 360° awareness for surrounding vehicles and selected assets, as well as a collision avoidance function based on path prediction, the company explained.

Using GNSS and RF technologies, the solution enjoys high operator adoption because of minimal nuisance alarms and enhanced safety for all mine and vehicle types, according to Hexagon.

The Gold Fields spokesperson said CAS Pro was being used in line with Earth Moving Equipment Safety Roundtable (EMESRT) guidelines. The solution includes operator awareness and advisory controls, the spokesperson added.

As part of the project, Gold Fields has issued 150 personal tags to employees working near operating equipment, including spotters and samplers. The operating equipment to benefit from the new solution includes 84 dump trucks, 21 excavators, 65 pieces of ancillary fleet (including loaders, dozers and service trucks) and 100 light vehicles (50 with fixed CAS units and 50 with removable units).

While the CAS solution does not include anti-braking functionality, it does have a range of other intervention procedures, according to the spokesperson.

“Stopping a plus-200 t haul truck in milliseconds in an open-pit environment may create other hazards,” the spokesperson explained.

Gold Fields to trial Caterpillar dual-fuel solution on haul trucks at Tarkwa mine

Gold Fields plans to test the use of LNG to power haul trucks in a trial at its Tarkwa open-pit gold mine in Ghana, CEO Nick Holland told attendees of the IMARC Online event this week.

Speaking on a panel reviewing progress of the Innovation for Cleaner, Safer Vehicles (ICSV) initiative – a supply chain collaboration between the International Council on Mining and Metals (ICMM) and original equipment manufacturers (OEMs) – Holland said the trial would involve a mix of LNG and diesel fuel at the operation, and four trucks would initially be tested with the fuel combination in 2021.

Gold Fields later confirmed to IM that the trial would take place in the second half of 2021 and involve the use of Caterpillar’s dual-fuel LNG Dynamic Gas Blending (DGB) retrofit system on four of the mine’s Cat 785C 146 t payload dump trucks.

The DGB conversion kits, available on Cat 785C and 793D haul trucks, are a dual-fuel technology that enables miners to substitute diesel fuel with LNG, according to Cat. The use of LNG has been proven to reduce emissions by up to 30%, as well as lower costs by up to 30%, Cat says.

DGB vaporises liquid fuel into natural gas, then replaces diesel fuel with LNG when possible. On average, DGB replaces about 60-65% of diesel with LNG, according to Cat.

Tarkwa, which is 90% owned by Gold Fields, produced 519,000 oz of gold in 2019, 1% lower than the 525,000 oz produced in 2018. It employs Engineers & Planners Co Ltd as mining contractor.

While this trial will potentially lower the company’s carbon emissions – as will Gold Fields’ plan to fit “diesel filters” on all its machines underground in the next 12-18 months – Holland pointed to a much loftier long-term goal during the ICSV panel.

“The challenge to our teams and OEMs is to move away from diesel completely,” he said.

Such a move could see the company employ both battery-powered and hydrogen-powered solutions at its underground mines, he added.

Mercury Free Mining’s GOLDROP tech to be tested in Ghana

The non-profit organisation, Mercury Free Mining (MFM), has been given a chance to test out its GOLDROP separation process in Ghana, potentially providing artisanal miners with a mercury-free alternative to traditional gold panning.

MFM has been invited by the Ghana National Artisanal and Small-Scale Miners Association to coordinate scientific testing of GOLDROP with the University of Mines and Technology in Tarkwa, Ghana.

North American gold miners, in discussions with MFM, have said GOLDROP equipment is significantly more efficient than traditional gold panning, which often uses mercury to separate gold from other heavy minerals, according to MFM.

MFM Executive Director, Toby Pomeroy, will travel to Ghana on January 8 to begin ten days of scientific field testing of the GOLDROP technology. He said: “MFM is thrilled to be leading the scientific tests of this gold processing system in Ghana, West Africa. We may be witnessing the beginning of the end of toxic mercury use in gold mining.”