Petra Diamonds is making steady progress on finishing the 5.7 ha C-Cut phase 1 expansion project that will at the outset prolong its Cullinan diamond mine’s life span by 15 years, according to media reports.
Mining Weekly quoted Petra chief executive Johan Dippenaar as saying that the project would consolidate the areas it was mining from eight to three, a move that would help the company reduce Cullinan’s production costs to R200/t over the next two to three years from between R280/t and R290/t.
He said Cullinan’s old mining areas had become “contaminated” with waste rock, resulting in the dilution of the ore grade and lowering of the mine’s earnings for each ton of ore treated.
Dippenaar said that the C-Cut development would result in the mine’s run-of-mine (RoM) grade increasing to between 38 carats per hundred tons (cpht) and 40 cpht in the 2017 financial year.
The RoM grade was projected to further improve between 49 cpht and 51 cpht by the 2019 financial year, when the C-Cut was set to reach full production.
The group wants to increase the mine’s production from 729 496 ct to 2.2-million carats by the 2019 financial year.