1. Designing Effective
Store-release Covers for the Long-term Containment of Mine Waste
INAP funded this project designed to address one of the major information
gaps related to models used for store and release covers: the
lack of readily available data on the transpiration characteristics
of plants. The water uptake processes of different vegetation
communities, which are being (or could be) used on store and release
covers in Australia – or other parts of the world- will
be quantified and modelled. The Australian Centre for Mining Environmental
Research (ACMER) lead the project with the University
of Western Australia and the University of Queensland. Other sponsors
were the Commonwealth Government through the ARC Linkage Program,
MERIWA, and individual mine sites.
2. Workbook on
the Application of Geo-chemical Models to Acid Drainage
This workbook was developed as part of an ADTI Metal Mining
Sector series to provide state-of-the-art information on environmentally
sound mine waste management designed for federal and state agencies.
A literature survey of existing geo-chemical models for acid drainage
systems has been compiled into a guide including activity coefficients
and speciation theory, geo-chemical codes, as well as applications
and case histories. Kirk Nordstrom undertook the project
under ADTI management.
3. Workbook on
Pit Lake Characterization, Modeling, and Remediation Approaches
This workbook was developed as part of an ADTI Metal Mining
Sector series to provide state-of-the-art information on environmentally
sound mine waste management designed for federal and state agencies.
The workbook will aim to compile all of the facets of pit lakes
into a manageable format. The document is meant to be a resource
on published research pertinent to a range of pit lake circumstances.
Jim Jonas from CDM compiled the workbook under ADTI management.
4. A study to improve our ability to accurately predict
the long-term performance of dry covers.
Dry cover systems are one of the most common
preventative measures used to control acid drainage. Accurately
predicting the long-term performance of covers is a vital part
of minimising the mining industry’s AD legacy issues. With
this objective a study on the long-term stability of dry covers
was commissioned to O’Kane Consultants Inc.
The study:
- Identified and defined factors that affect
long-term performance.
- Evaluated state-of-the-art tools for modelling
dry cover systems.
- Provided recommendations for improving
and validating existing models.
Click
here for the final report (1674 KB).
5. A characterization study of the geo-chemical and hydrological
nature of 2 waste rock dumps that were being dismantled by member
companies.
In 2000, waste rock dumps from the Rio Tinto Kennecott Ridgeway
Mine and the Inco Whistle Mine needed to be relocated. The opportunity
was seized to study the geochemical and hydrological nature of
the waste rock dumps and the extent of oxidation zones within
them. The project generated much interest and was jointly funded
by INAP, NSERC, and R&D Start Funds. Dr. Ward Wilson from
UBC, Maree and Stuart Miller from EGi, and David Williams from
the University of Queensland lead the study.
The findings from the work link the hydrological and geo-chemical
nature of the dumps, which contain complex hydrological pathways
that dictate the geo-chemistry of the released drainage. There
is an indication that many of the layers within the dumps contain
large amounts of stored oxidation products and soluble metals.
The layers may not have an adequate degree of saturation to allow
water to flow through them, thus reducing final drainage concentrations.
Click
here for the final report (806 KB).
6. A review of sulphate treatment practices and a discussion
of legislation trends "Treatment of Sulphate in Mine Effluents".
Very little research has been undertaken on the treatment of sulphate
in mine effluents. INAP members saw the need to fund a literature
review of state-of-the-art sulphate treatment processes including
regulations and guidelines from governments and agencies around
the world. Lorax Environmental (the consultant) carried out the
study, which describes methods for removing sulphate and metals
from mine effluents and associated operating costs. Case studies
of successful operations are also documented.
Click
here for the final report (3416 KB).
7. A case study on the deteriorating performance of the
18 year-old Rum Jungle dry cover system in Northern Territory,
Australia.
The 18 year old cover Rum Jungle in Northern
Territory, Australia is one of the oldest cover systems for which
the design, construction, and continuous monitoring date are well
documented. Water infiltration through the covers increased significantly
in the last few years and this project was designed to use the
data history to understand the reasons for the deterioration performance.
The Australian Nuclear Science and Technology Organisation (ANSTO)
and the Commonwealth Scientific and Industrial Research Organisation
(CSIRO) were contracted to undertake the work. The study found
that the cover materials no longer met the original design specifications
–particularly for permeability which increased by several
orders of magnitude. Findings from the study indicated that the
increased permeability may be attributed to:
- A shortage of cover material during
construction resulting in bare patches;
- A combination of biological and physical
process - galleries formed by termites and ants, root growth
from
- the pasture grasses and the few
volunteer trees, and an extensive system of shrinkage/dessication
cracks.
Click
here for the final report (2224 KB).
8. A study to use Diffusive Gradient in Thin-films (DGT)
technology (or gel samplers), which allows for in situ determinations
of free-ion activity of metals in mine water and provides a more
accurate representation of biological impacts than measurements
of total or dissolved metal concentrations.
Conventional water quality analysis is
restricted to measuring total and dissolved metals in discrete
water samples. Lorax (the consultant) was commissioned to undertake
a study on the use of diffusive gradients in thin-films (DGT)
- or gel samplers as this technology can provide a more accurate
estimation of metal toxicity in water.
The project findings indicated that the use of DGT provides a
measure of metal bioavilability, and hence a more representative
measure of metal toxicity in water. This is mainly due to the
fact that DGT detect free or weakly complexed metal species without
measuring constituents that are not bio-available. The use of
DGT also has the advantage of being an in-situ measure and can
provide a time-integrated estimation over a deployment interval.
This is especially beneficial when dealing with highly variable
water quality, as is usually the case when measuring mining effluents
discharged into natural watercourses. The use of DGT is, however,
limited to a certain pH range (5-9 for most metals, 2-11 for Cu)
and is not effective in waters of very low cation concentration.
The study concluded that the DGT technique can be applied to various
aspects of environmental chemistry, however more work is required
to validate the use of DGT in mining-impacted waters.
Click
here for the final report (1587 KB).
9. A review of the potential use of co-disposed waste rock
and tailings for the construction of covers on mine waste dumps
as a practical, low cost AD prevention method.
Following a literature review on the application
of co-disposed tailings and waste rock to construct covers, this
project was designed to examine the stability and hydraulic conductivity
of a number of co-mixtures with varying ratios of tailings, waste
rock and slag. Klohn Crippen in association with Dr. Wilson from
the University of British Columbia, were commissioned to undertake
the study. The findings of the work can be summarized briefly
as follows:
The International Network for Acid Prevention
