Paste thickeners for Liqhobong and ASSMANG
In less than two years since Bateman Engineering acquired the
rights to market WesTech Inc's paste thickening technology, it has
secured a number of contracts to supply these systems throughout Southern
Africa.
A Bateman-WesTech Paste Thickener was supplied to the Liqhobong Diamond
Mine project located in the Maluti Mountains of Lesotho. The contract
covered the design, fabrication, procurement, transportation and installation
on site of an 8 m diameter paste thickener unit, complete with tankage,
mechanism, drive, bed pressure detection, level control and electrical
panel. Commissioning was done under a separate contract.
The thickener, which was installed to maximise water recovery, was
sized based on the rheological properties of paste produced by testwork
on samples provided by the client. Installation of the unit was complex
due both to the accessibility of the site at an altitude of 2,550
m ASL, as well as the extreme temperature fluctuations (including
snow in Winter) and the high rainfall and wind.
The open-pit Liqhobong Diamond Mine, which commenced production in
September 2005 mining a 1.6 ha diamondiferous kimberlite pipe, is
owned by European Diamonds (75 % shareholding) and the government
of Lesotho. Its recently completed diamond-recovery plant processes
around 420,000 t/yr of ore.
In a contract through Apic Toll Treatment (Pty) Ltd (Atoll), a Bateman-WesTech
Paste Thickener has been commissioned at the Associated Manganese
(ASSMANG) ferrochrome plant in Machadodorp, South Africa.
The plant is operated on a toll treatment basis by Atoll and the thickener
was installed to effectively dispose of the slimes with minimal water
content. The thickened tailings, in the form of high-density paste
with limited free water, are pumped to a pond where they are left
to dry and then removed with front-end loaders and dump trucks. This
not only limits the size of the deposited tailings stack, but also
reduces the amount of water lost from the plant.
The 8 m diameter unit treats approximately 15 t/h of slag at a flow
rate of 160 m³/h, resulting in an underflow density of 1.6 to
1.7 t/m³ or above 60 % solids. Pilot-scale testwork was conducted
at SA Chrome on ferrochrome slag to determine the rheological properties
of the paste and for the purposes of sizing the unit.
As with the Lighobong contract, Bateman Engineering was responsible
for the design through to site installation. Hot commissioning of
the unit has been completed, as well as an extremely successful 24-hour
performance run.
Bateman Engineering has the right to use WesTech Inc., USA's paste-thickening
systems in its projects, both in Africa and globally, and has a further
agreement with PasteThick™& Associates to provide the sales
and marketing services for Bateman-WesTech Paste Thickeners.
For further information, contact Craig Gilbert, Manager, Processing
Technologies, on +27-11-201-2300 or email engtech@BatemanEngineering.com.
