Download Full Deposit Nickel Electrowinning at Rustenburg Base Metal Refiners

Full Deposit Nickel Electrowinning at Rustenburg Base Metal Refiners
J. Hagemann,1 L.R. Nelson,1 L.J. Bryson,2 M.W. Gilmore,1 K. Hines,1 B. Peyper,1 R. Varty1 and
T. Sepoloane.1
1
Anglo American Platinum, 2Anglo American
ABSTRACT
As part of Anglo American Platinum’s Rustenburg Base Metals Refinery (RBMR) expansion, a new
Nickel Electrowinning Tank House, with a nameplate capacity of 32 400 tons per annum, was constructed.
Commissioning of the new electrowinning technology, which involved world first full deposit plating,
commenced in 2011.
The old nickel electrowinning process at the RBMR used starter sheets which, along with a divided cell
configuration, was very labour intensive and exposed operators to high levels of aerosols that contained
both nickel and acid. To overcome this problem two key design intents of the new technology are aerosol
abatement and minimising labour in the electrowinning cell environment, with a design target to reduce the
nickel occupational exposure limit (OEL) to half the legislated limit of 0.1 mg.Nm-3.
Commissioning of the new technologies adopted to achieve mist abatement is described, together with a
review of technical and operational challenges relating to the titanium blank edge strips, blank roughness
and sandblasting optimisation, blank quality control, electrode spacing, polyconcrete cell dimensional
stability and cell top furniture. The impact of these on process performance is presented and the
development of fault checking and rectification methods, to maintain high process performance, is
explained.
KEYWORDS
RBMR, base metals, nickel, electrowinning, aerosols, occupational exposure limit, OEL.