12 / 72
10
MODERN MINING
August 2015
MINING News
In its latest trading update, LSE-listed Petra
Diamonds says that the bulk earthworks
for its new R1,65 billion processing plant
at the Cullinan mine near Pretoria have
started and all long-lead items have been
ordered.
The plant is scheduled to be fully
operational by the end of FY2017. MDM
Engineering has been contracted to
deliver the plant. The project has an IRR
of 25 % and a payback period of approxi-
mately three years.
The new 6 Mt/a ROM capacity plant
will utilise gentler processing methods
(comminution via attrition) instead of
extensive crushing, which is expected to
reduce diamond breakage and increase
revenue from larger/exceptional dia-
monds. This will be achieved through the
use of AG (Autogenous) milling (a method
The existing processing plant at Cullinan, which was commissioned over 60 years ago. The new plant will be much more efficient, feature AG milling and have
a very compact footprint (photo: Petra Diamonds).
Simplified flowsheet of the new Cullinan processing plant.
Bulk earthworks underway for new Cullinan plant
of comminution using attrition to enable
self-grinding of ore) and high pressure
grinding rolls (HPGR) technology, the lat-
ter representing a move away from high
impact cone crushing.
The new plant will feature enhanced
utilisation of XRF X-ray technology to
replace conventional DMS processing
when treating coarser +12 mm material.
Petra says the new facility will result in