While steps are being taken to provide additional water resources
to parched Potgietersrust Platinum, engineers are studying
dry-tailing-deposition technology as a means of maximising water
recovery.
“Lack of water is the governing constraint at Potgietersrust
Platinum right now,” Anglo American Platinum Corporation
(Amplats) divisional director mines Mike Smith discloses, despite
last month’s 22 mm of rain breaking a two-year drought.
Potgietersrust Platinum requires some nine megalitres a day.
The local authority, which igermany used stone crushers meant to supply up to five megalitres
of effluent a day to the operation, has been unable to do so since
May, owing to some of its own wellfields drying up, Smith tells
Mining Weekly.
Severe water restrictions have been imposed in the town and Amplatcrushing squeezing in a bowls
has stepped up its search for more water, carrying out an extensive
airborne electromagnetic survey north of the mine.
Existing wellfields, introduced as supplementary sources, have had
to be drawn down faster than intended owing to the cessation of
crushing performance vs ore typeeffluent supply.
Meanwhile, electromagnetically-surveyed target sites are being set
out for the sinking of an additional number of boreholes, and
tenders have been invited for the building of a new pipeline to
supply additional water from Doorndraai tojawa crusher price in pakistan Potgietersrust by the
end of 2000.
Amplats will be compensated for financing the pipeline by reduced
water tariffs.
With water used very sparingly in the open-pit mine, most is needed
for platinum group metals processing in the concentrator plancone crusher shan bawat,
where the ore mined is crushed, screened, classified, milled,
floated and dried to produce a concentrate for trucking to the
smelter in Rustenburg.
In addition, the Potgietersrust operation has received temporary
Water Affairs Department sanction to draw up to 1,5 megalitres of
water a day from Samancor’s Grass Valley chrome mine
nearby.
The Grass Valley water is trucked to Potgietersrust’s
effluent ponds for pumping, with the rest of the water, to the
concentrator. Water balances have been undertaken by Steffen
Robertson & Kirsten in order to minimise water use in the
concentrator.
In theory, water from tailings is meant to flow gravitationally to
a penstock for repumping to the concentrator, but in dry
conditions, the water generally evaporates before reaching the
penstock, resulting in negligible recovery.
Amplats engineers and consultants are thus considering
dry-tailings-deposition technology, involving the use of multiple
presses to filter water out of the slime prior to dumping.
This would increase the rate of water recovery to about 85% from
the current 45%, with the 15% tailings moisture content being
regarded as the minimum practical level.