Emerald producer Grizzly Mining has invested in 20 B50E articulated dump trucks (ADTs), manufactured by South African mining and construction equipment manufacturer Bell Equipment, for its operation that is located 48 km south-west of Kitwe, in Zambia.

The Bell B50E 45 t ADTs will reduce mining costs by optimising economies of scale and consequently serve to ramp up the mine’s production capabilities.

“We were mining nine-million tonnes of waste a year with plans to scale up to 15-million tonnes at the beginning of this year, once the full fleet of B50E ADTs arrives,” says Grizzly Mining mine manager Langson Mukuma.

Grizzly Mining, which was founded in 1997 by company chairperson Abdoulaye Ndiaye, started as a small-scale artisanal mine and has grown into a large-scale, fully mechanised mine involved in the mining, processing, grading, marketing and supply of Grade-A emeralds.

Maintaining the highest standards in the production and supply of its gems has been critical to the success of Grizzly Mining.

The company’s long relationship with Bell Equipment dates to when the mine was commissioned and Bell has played a valuable role in achieving production targets ever since.

At that time, four Bell B25Cs were used to haul large amounts of overburden covering the gem deposits, the latter being carefully removed by hand owing their preciousness.

After about 16 000 hours of service, two of these machines were traded in on larger Bell B30Ds, before the mine ordered three Bell B35Ds, which are loaded with material by a fleet of Bell excavators.

Currently, the Bell ADT fleet numbers 26 at the mine, including three B35Ds, eight B40Ds purchased in 2017, five B40Es bought in 2018, and the ten new B50Es.

Seven trucks were delivered in September and October 2023, while the remainder will be delivered this year.

Bell all the Way

According to Mukuma, Grizzly Mining has remained loyal to the Bell brand owing to the “unmatched” reliability of the Bell D-series ADTs, with the B35Ds and B40Ds having reached about 33 000 hours of production, while still “going strong”.

The first tranche of ten B50Es was delivered in June 2022 and the oldest units have already clocked over 6 500 hours of operation, which should be understood in the context of Grizzly Mining conducting 24/7 operations.

The fleet works three eight-hour shifts a day with the average haul cycle taking 24 minutes.

Describing the underfoot conditions of the haul route, Mukuma explains that the ramps are only muddy in a few areas during the rainy season and gradients are gentle, averaging 11%, with the steepest being 15% in a few sections.

He adds that this makes the Bell ADTs well suited to Grizzly’s operation, especially when manoeuvring in tight spaces and in the rainy season when the extra traction afforded by the ADT’s 6 x 6 drivetrain is required.

The B50Es come standard with Bell Fleetm@tic during the warranty period, and Grizzly Mining can access basic productivity information such as the number of hours operated, the vehicle’s tonnages hauled on an hourly basis and fuel consumption.

Thus far, Grizzly Mining reports that it has been impressed with the productivity of the B50Es. “They are very productive, largely due to their larger size compared to the 40-tonners,” says Mukuma.

He explains the B50Es each work an average of 560 hours a month, moving 800 t during an eight-hour shift, and consume an average of 31 ℓ/h of fuel. By comparison, the B40Ds return average fuel figures of 23.1 ℓ/h, while the B40E’s return 24.35 ℓ/h.

Mukuma states that Grizzly Mining has been impressed by the ergonomics, high productivity and powerful engine of the B50Es, which are providing decent mechanical availability of 87%.

Grizzly Mining has also ordered four construction machinery manufacturer Kobelco SK850LC-8 excavators to expand its loading tool fleet, the first of which was commissioned in early August 2023.

Chosen as an ideal loader to match the B50Es, Grizzly Mining has excavators from a few other original-equipment manufacturers in its fleet and thought it would be prudent to try Kobelco excavators to compare their performance in both soft and hard rock applications.

Appreciating that “strong reliable machines need strong reliable support”, Grizzly Mining’s older machines are all serviced by their qualified in-house technicians, and the new Kobelco excavators and B50Es will be serviced by Bell Zambia during the warranty period.

“The support we receive from Bell Zambia is very good, and their technical team responds on time and, while there is still room for improvement, availability of parts is reasonable,” concludes Makuma.