Supplier of industrial gases and equipment Air Products South
Africa recently commissioned a new air-separation unit (ASU) at the
Impala Platinum refinery, in Spjaw crusher pef 250 400 pricerings, as a means of ensuring the
supply of oxygen and nitrogen to the plant.
The R90-million ASU facility supplies 80 t of high-purity oxygen
and 50 t of high-purity nitrogen daily to Impala’s
base-metals refinery (BMR) operations. While the oxygen is
primarily used in the BMR process to assist the dissolution of
nickel, cobalt and other metals in leach autoclaves, nitrogen is
used, in combination with hydrogen, for the creation of controlled
reducing atmospheres in furnaces. It is also used for the inerting
and purging of equipment.
Speaking at the opening of the new facility, Impala manager of the
BMR Tim Spandiel said that the company did not initiate the project
as a savings mechanism, but rather as a means to ensure reliability
of supply.
Prior to the construction of the facility, liquid oxygen and liquid
nitrogen were trucked to the plant. This constituted a considerable
risk to Impala since potential strikes in the transport sector
could result in the shutdown of the refinery. Spandiel pointed out
that the nature of the refinery means that “it does not have
the luxury of long shutdown periods, making over-the-fence supply
very important.” The new ASU is designed with sufficient
capacity to support the refining of some 2,5-million ounces of
platinum yearly and can accommodate Impala’s anticipated
long-term growth strategy.
Spandiel hinted, however, that this growth stra-tegy may be
exceeded and could potentially require modifications to the
facility to tackle this.
Nevertheless, the ASU includes five days worth of on-site storage
capacity backup in the event that the plant needs to be shut down.
“In terms of disruption, we are covered and our risks have
been reduced,” enthused Spandiel.
He added that establishing the plant on-site has had the added
benefit of lessening traffic entering the refinery area and with it
the potential security risks.
Recipient of the tender for the project, Air Products, has
designed, supplied, constructed and commissioned the facility,
which it will own and operate to supply the needs of Impala on an
‘over-the-fence’ basis.
The ASU plant takes in atmospheric air, removes the moisture and
carbon dioxide and finally separates the nitrogen and oxygen at
temperatures of about –175