Aveng Moolmans and Lucara Diamond Corp have agreed to cut short a six-year mining contract at the Karowe mine, in Botswana, following equipment availability issues and difficulties with waste mining, the diamond miner said.

Moolman Mining Botswana, an Aveng subisidiary, was awarded the contract to deliver the full suite of mining services at the Karowe mine, including all drill, blast, load and haul functions for both ore and waste, in January 2017.

In Lucara’s June quarter results, it said the two companies had continued to work to “find a solution” to the problems experienced during the March quarter of 2018 and, following extensive discussions in May and June, both parties had agreed to terminate the contract at the end of 2018.

In the March quarter, ore mined volumes and carats recovered were as expected, but waste mining was lower than forecast at just under 4 Mt.

Lucara said performance stepped up “considerably” during the June quarter – with 4.4 Mt of waste mined – and continued through the month of July, the first full month of transition between Moolmans and new contractor Trollope Mining Services.

As a result of this, waste mining was still expected to be within guidance (13-16 Mt) for the year, while diamonds recovered were expected to total 270,000-290,000 ct.

Lucara said of the contractor transition: “The addendum provides for a transition period of up to six months to allow for a new mining contractor, Trollope, to gradually assume responsibility for both ore and waste mining from Moolmans, with full responsibility for all mining activities to be the responsibility of Trollope as of January 1, 2019.”

Trollope, based in Johannesburg, South Africa, has previously worked with companies such as Exxaro, Anglo American, Harmony Gold and BHP.

Aveng Moolmans took over from former contractor Eqstra Botswana in 2017, which also had its contract cut short.