JOHANNESBURG (miningweekly.com) – JSE-listed DiamondCorp has started commissioning its newly installed 400 t/h underground conveyor belt ahead of the ramp-up in production from the Upper K4 (UK4) mining block at the Lace diamond mine, in the Free State.

The Southern Africa-focused diamond mining, development and exploration company aimed to complete commissioning by the end of October in what DiamondCorp CEO Paul Loudon described as a significant milestone in the construction of the Lace mine.

The new conveyor belt would replace the company’s fleet of dump trucks for the hauling of future kimberlite and development waste mined at Lace, which would reduce the cost per tonne to load and haul rock.

The dump trucks would still be used to transport the kimberlite from the UK4 production level to the conveyor belt at a planned rate of up to 30 000 t a month.

“While mining of the UK4 progresses, the conveyor belt will be progressively extended down to the first block cave level. Development waste from the deeper levels will be loaded directly onto the conveyor belt by underground loaders without the use of trucks,” DiamondCorp said.

The company procured a conveyor belt with double the capacity of the current front-end capacity of the processing plant to ensure it could continue to transport sufficient ore to surface to enable a future increase of the underground mining rate.

Investec commented that it expected to see imminent cash flows, with the Lace mine set to ramp up now that the conveyor belt was in place.

"We also hope to see success at reducing water consumption that could support increased production, thereby adding value," it added.

DIAMOND SALE DELAY
Meanwhile, DiamondCorp has placed the sale of 4 250 ct of recovered diamonds on hold owing to the weaker prices attracted for diamond parcels of less than 10 000 ct and the fewer recoveries on the back of the slower-than-scheduled development rate in the UK4.

“Management has decided to wait until more diamonds have been accumulated before commencing sales,” the company said.

However, despite the recoveries, to date, being less than half of one month’s production, they had proved sufficient for an independent valuation of what the diamonds were expected to fetch in commercial volumes.

Excluding the occurrence of larger high-value stones, DiamondCorp expected to achieve prices of $140/ct to $160/ct at a 1 mm bottom screen size cutoff and between $160/ct and $200/ct at a 1.25 mm bottom screen size cutoff.