Construction of Botswana-based diamond mining company Debswana’s Letlhakane mine tailings resource treatment plant project (LMTRTP), near Orapa, is currently 80% complete, with final project completion expected by 2017.

“The plant will undergo C5 commissioning and attain full production from the third quarter of 2017,” Debswana corporate affairs manager Naledi Dikgomo-Goulden tells Mining Weekly.

With Debswana following the industry CI to C5 commissioning process, various project components are undergoing different levels of commissioning.

C4 commissioning, which involves the introduction of feed to the modular tailings treatment plant, is planned for the second quarter of 2017.

The project

was approved in 2014, with construction of the plant having started in the first quarter of 2015.

The objective of the project, which remains within budget, is to deliver sustained and profitable operations at Letlhakane beyond the end-of-life of openpit mining, according to Debswana. The LMTRTP is expected to achieve a yearly production of 800 000 ct of diamonds and will provide specifically designed mining and treatment solutions to ensure optimal economic recovery of the coarse tailings mineral resource, thereby extending the life-of-mine by 25 years.

The LMTRTP scope comprises construction of the modular tailings treatment plant at the Letlhakane mine, the upgrade of facilities at the contractor’s village in Orapa, as well as new mining offices, including an operators’ mess, training offices, change rooms and ablution blocks. To ensure reliable power supply to the plant, the project will also deliver a 40 MVA 220/33 kV transformer and the construction of a 66 kV overhead power line and its associated works (covering 45 km from Orapa to the mine). The construction of switchyards at both Orapa and the mine is also part of the project scope.

Completed parts of the project include the upgrade of the contractors’ camp and associated services – with all the facilities functional and occupied – civil works, the tailings starter ramp, the procurement of main plant components, the relocation of services and bulk earthworks. The retaining wall and haul road have also been constructed at the tailings resource and were constructed with rock-filled gabions at the tip area.

Construction of the two slimes dams, with four cells each measuring 300 m × 300 m, has also been completed.

The structural, mechanical, platework and piping work is progressing well, while ongoing work includes mechanical installation at the dense-media separation, scrubbing, screening and crushing area, says Dikgomo-Goulden.

She highlights that electrical and instrumentation work for the plant has started, with ongoing work that includes the installation of cable racks and the pulling of electrical cables.

The 66 kV overhead power line construction is also nearing completion. Ongoing work includes termination at the Damtshaa and Francistown road crossing, Dikgomo-Goulden says, noting that the project is due for completion in the fourth quarter of 2016.

Other project successes to date include the achievement of more than two-million lost-time injury-free working hours. “This demonstrates the team’s dedication and commitment towards safety, which is in line with Debswana’s aspiration of zero harm,” she highlights.

To date, the LMTRTP has engaged more than 25 different contractors and has a current peak of 884 personnel on site.