A guide to leading practice sustainable development in mining

PCBs from transformers. Australia’s PCB Management Plan (1996) has been
taken up in State and Territory regulations. As a result of earlier efforts to
remove PCBs from service, many transformer oils are actually dilute solutions
of PCB in paraffin. Where the PCB content is 50 mg/kg (50 ppm) or greater,
the material must be treated to destroy PCBs and reduce the level to 2 ppm
or less. Although complete phase-out may still be some years away, most
PCB-containing oil has been removed from service, and treated as required.
Asbestos from various on-site plants including AC (Asbestos cement)
sheets on old buildings. Asbestos lagging is seldom employed on pipework
these days but some old plants may still contain this material. State and
Territory regulations place restrictions on its removal and disposal.
Surplus paints, pesticides and laboratory chemicals. Stored oil-based paints
are fire hazards, while pesticides and laboratory chemicals may have human
health and/or environmental impacts, or both. Chemical containers may contain
residual chemicals that pose risks to human health and the environment.
They should be disposed of safely. Clean containers may not be hazardous,
and collection and recycling options may be available under the DrumMuster
program for plastic and metal containers in which pesticides had been supplied.
Solvents used in extraction plants. Hydrocarbon solvents such
as kerosene are used in solvent extraction plants for separating
complexed metal ions. As with the petroleum products described
above, there are flammability hazards and also security risks.
Managing Acid Mine Drainage
Although acid mine drainage is usually associated with hard rock metalliferous mines
it can also manifest itself in coal mines and, in mineral sand mines. The Cloverdale
mine is one of several mineral sand mines operated by Iluka Resources Limited (Iluka)
in the south-west of Western Australia. The mines occur in deep sandy soils formed
by marine regression and transgression events 1.5-2.3mya. AMD is a potential risk at
these sites and is typically associated with fine-grained framboidal pyritic material in
the pit walls, ore and overburden material.
In the early stages of mine planning at Cloverdale, a detailed survey was undertaken
to map the extent of acid generating materials within the orebody and adjacent
areas. The survey data and 3D model of acid generating materials assisted mine
management to better understand the possible extent of AMD issues at the
Cloverdale site. Mine planners have utilised this information during development of
the mining schedule, to minimise the impact of AMD associated with pit dewatering,
mining and handling of acid generating materials. The information has also been
used to estimate AMD management (e.g. treatment) costs during operations, and
the overall economic impact of AMD on the project. An AMD Management Plan was
also developed for the site, to provide a basis for day to day management of acid
generating materials throughout the mine life (see LP AMD p.41).
A GUIDE TO LEADING PRACTICE SUSTAINABLE DEVELOPMENT IN MINING 109