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08.13
South Deep’s return water dam.
ing the growing trend towards retreatment of tailings
in the gold and platinum sectors through the consoli-
dation of smaller tailings dams into single tailings
facilities in order to better manage reprocessing and
rehabilitation.
Fraser Alexander operates and manages 200 tail-
ings dams in precious metals, base metals and coal
industries internationally and undertakes re-mining
projects through hydro-sluicing of about 7 Mt/month.
“I’m seeing a change in mine solutions with min-
ing houses such as AngloGold Ashanti consolidating
the plethora of tailings dams into single construc-
tions with more accommodating footprints. The
quantities of commodities recovered from these tail-
ings can amount to only fractions per ton of material
treated and therefore the volumes being processed
are extremely high. This is driving the need for bigger
tailings dams, coupled with the need to implement
designs and operational methodologies that make re-
habilitation easier.”
He says Fraser Alexander is already running four
hydraulic recovery mining projects in the Rusten-
burg region while another project is in the study
phase. He adds that the company has developed
and patented remote controlled, track-mounted
hydro-sluicing units which “have revolutionised
the tailings re-mining industry via safety advan-
tages and high production capability.”
He continues: “Retreatment of existing surface re-
sources will grow in the platinum sector since the
mines need to keep their treatment plants operating.
Issues such as underground mining becoming uneco-
nomic and a fractious labour force are likely to accel-
erate the drive towards the reprocessing of millions of
tons of tailings and dump material. Mines often run
separate streams into the main process plants and in
some cases dedicated retreatment tailings plants are
in operation.”
Turning to challenges surrounding the consolida-
tion of small tailings dams into a single large dam,
Gotz says self-propelled cyclone units (SPCUs) have
been designed and patented by Fraser Alexander
Tailings to address the issues associated with high
tonnage tailings dams. Twelve cyclone units are han-
dling about 1,8 Mt of tailings per month at a tailings
dam in Stilfontein with the same volume of tailings
material being placed into another tailings dam by 12
units in Brakpan.
“Cycloning presents mines with an opportunity to
manage three important tailings dam criteria – foot-
print, tonnage and rehabilitation,” he says. “We con-
verted DRDGold’s Withok tailings dam on the East
Rand to a SPCU cyclone operation to successfully
overcome various operational limitations.
“Cycloning permits the separation of coarse and
fine material, with coarse material being placed on
the outer wall where it builds a protective barrier as
the material consolidates quicker as a result of more
tailings
