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The new vibrating grizzly building with the BATEMAN - Brandt bag filter
on it's right and the existing gyratory crusher in the background.
The new primary (front) and secondary (rear) ball mills. The former at
6,7 m by 8,1 m is probably the largest in Southern Africa and the latter
is 5 m in diameter and 6, 1 m long.
The concentrator plant.
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Amplats Potgietersrust platinum concentrator
expansion
This EPCM project by Bateman Minerals for Amplats Management Services
increased the processing capacity of the concentrator at the Potgietersrust
Platinum Mine, Northern Province, RSA, from 270000 to 425000 tonne/month.
The new circular stockpile, coarse and fine ore silos,
new pebble fotation building and the pipe rack.
Key features of the project included:
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increasing the tonnage through the existing autogenous mills and
processing the throughput in a dedicated milling and fotation plant
after in-circuit crushing. This overcame previous process inefficiencies
and improved recoveries from 84 % to above 90 %;
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an automated pressure filter system to reduce the moisture content
of the concentrate from 15 % to12%. This reduced operating costs
and labour input;
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attribition scrubbers (30 by 20 m³ cells - the largest in
such an application worldwide) which agitate the slurry to polish
the particles and assist in the recovery of platinum;
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new engineering design techniques which contributed to the successful
design arrangement of the new fotation tank cell and attrition scrubbers;
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and interfacing brown and green fields components in the same project,
with a high degree of planning and organisation to minimise production
down-time. The original feasibility study for this expansion was
carried out by BATEMAN.
The process upgrade
Avibrating grizzly screen separates the coarse (+150 mm) and fine (-150
mm) material from the primary crusher. The former is stored in a new
15 000 tonne conical stockpile and the latter in the existing storage
facility. New 1 500 tonne coarse and fine ore silos control the feed
blend to the autogenous mills.
Prior to primary ball milling, two existing 900 tonne silos store the
product obtained by in-circuit crushing of near sized pebbles from the
autogenous mills.
In the new milling circuit, the primary and secondary ball mills operate
in closed circuit using hydrocyclones. Primary cyclone overflow reports
to the new rougher circuit and rougher tailings are reground in the
secondary mill to produce a product for the new scavenger circuit. Concentrates
from these circuits are upgraded in the new complex cleaning circuit.
Concentrates from the pebble treatment plant and autogenous mills are
stored in the existing concentrate thickeners. The concentrate is filtered
using a new high pressure filter. A bulk reagent store, water and air
reticulation systems and a sewage water treatment plant were
installed.
Modifications to the existing concentrator plant included the upgrading
of the feed hoppers to the autogenous mills, an attrition scrubbing
plant, additional primary rougher flotation cells and a new scavenger
flotation plant.
E-mail pgm@batemanengineering.com
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