NEW EQUIPMENT
One of the TOMRA XRT sorting machines installed at Lucara’s Karowe Mine in Botswana.
operations, as they reduce the number
of machines required, and therefore
also decrease capital and operating
expenditure.
The unit boasts a highly selective
ejection system, using data processing
in combination with precise control of
the pneumatic valves, which eject the
selected material from the stream. Driving
this system is TOMRA’s proprietary data
processing pipeline that links sensors,
image processing, and the valve control
boards.
The performance of this ore sorting
technology has been proven at Ma’aden
Phosphates’ new USD560-million
processing plant at the Umm Wu’Al
project in Saudi Arabia, one of the largest
integrated phosphate fertiliser facilities in
the world.
The objective of the sorters is to reduce
the milling and flotation of silica in the
www.plantonline.co.za
plant process, using a dry technology
at a low cost per ton. The TOMRA units
achieve this by removing more than 90%
of the chert in the +9mm fraction, which
makes up half of the plant feed, before
the phosphates are fed to the milling and
flotation circuit. This leads to the removal
of over 1.2 million tons a year of SiO 2 ,
which therefore does not have to be
crushed, ground, and floated.
This installation considerably
improved the mill performance by
reducing the consumption of energy,
water, and chemicals per ton of final
product, which was all achieved with
a smaller sorting plant footprint. The
resultant saving in flotation reagents
alone amounts to almost USD8-million
a year.
In Botswana, TOMRA Sorting
Solutions has installed two TOMRA
COM XRT 2.0 /1200 sorters in the
mega-diamond recovery (MDR) circuit
of Lucara Diamonds’ Karowe Mine.
Located directly after the primary
crusher and ahead of the process plant,
the MDR circuit treats material in the
size range between 50mm and 120mm.
It maximises the upfront recovery of
exceptional diamonds before the ore
reaches the comminution processes,
where diamond damage may occur.
“The machine has proven itself through
its high availability throughout its first year
of operation there,” Hartwig says.
TOMRA Sorting Solutions also has
several smaller units in portable and
containerised configurations in many
different countries, where they must
operate in a variety of climatic conditions
from arctic to tropical. These machines
sort minerals ranging from copper, iron
ore, and coal to industrial minerals,
chrome, and diamonds. ■
NOVEMBER 2018
27