Project Tasks |
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Workpackage 0: Project
Management |
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- Administrative and scientific coordination of the project including
reporting and maintaining internal communication
- Construction and maintenance of a parameter spreadsheet/database
framework for defining and tracking common parameters across all workpackages
- Promotion and coordination of general dissemination activities
- Organisation and servicing of panel of expert industry advisers
to inform, critique and validate project directions, work and outputs
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Workpackage 1: Definitions
- Technologies and Parameters |
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Technology and procedures definition and review; standard parameters
identification and ranges. Review of the following issues:
- Existing mineral processing methods, with special emphasis on tailings
production and water management
- Existing slurry handling, treatment and transport techniques, including
dewatering and paste technologies
- Existing tailings placement and lagoon and dam design and formation
practices
- Existing authorisation, management, monitoring and inspection practices
From these data and experiences the relevant parameters governing the
safety of tailings facilities will be extracted, defined and evaluated
regarding their significance. The normal ranges of these parameters
will be noted and compiled into the parameter spreadsheet format. |
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Workpackage 2: Analysis
- Risks and Reliability |
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Evaluation of impact, risk, instability and failure mechanisms; critical
parameter levels and sensitivities. Mechanisms leading to reduced or
non-existing safety margins for tailings facilities will be surveyed.
Consideration will be given to the impacts of such facilities onto environmental
and human safety, the risks posed by unsafe facilities, unstable conditions
in existing tailings dams, and relevant failure mechanisms (e.g., overtopping,
dam breaches). The critical parameters will be quantitatively described
and their sensitivity indicated. Review covering the following issues:
- Operational or disused tailings facilities interacting 'normally'
or 'as intended' with their environment (excluding mechanisms of catastrophic
failure)
- Operational or disused tailings facilities impaired by adverse factors,
natural or human (including mechanisms of catastrophic failure)
- Bodies of fine material, with particular attention to their moisture
content, structural stability, flow-deformation behaviour, and liquefaction
- Bodies of such material containing toxic and/or hazardous substances,
with particular attention to the release of contaminants
For parameters where sufficient data do not exist or are not available,
data collection by means of field measurements or sampling and analysing
will be conducted, where practicable. |
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Workpackage 3: Intervention
Actions |
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Identification of intervention action options for dangerous or impaired
tailings facilities plus parameters relevant to their choice/implementation.
The following aspects are addressed in subworkpackages:
- Evacuation of tailings pond content, in whole or part, by digging,
dredging, pumping, breaching: Ranges of equipment/methods available,
including for access, and typical parameters of materials they can
deal with.
- Treatment of tailings pond content in situ, including dewatering,
by chemical or other means: Dewatering by e.g. colloid addition, vegetation,
and chemical or biological treatments to immobilise or ameliorate
contaminants, and typical parameters of materials they can deal with.
- Strengthening of tailings impoundment by conventional engineering
methods: Methods of strengthening by muckshift, rock facing, sheet
piling, drainage works, grouting, sandbagging, geosynthetical structures
etc, and typical parameters for impoundments where they may be applicable.
- Strengthening of tailings impoundment by less conventional methods:
More novel approaches involving injection of clogging agents upstream,
use of geotextiles, floating booms, cable anchorage, etc.
The workpackage reflects the intent of the project to focus on parameter
measurement relating to risk reduction, and a concern to ensure that
it addresses risk reduction not in an abstract way but by reference
to practical intervention options. |
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Workpackage 4: Prevention
and Remediation |
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To assist the implementation and improvement of the full range of
prevention, mitigation, or amelioration measures by establishing associated
parameter trigger/target levels and sampling location and frequency
requirements. Risk reduction needs to be seen not only in relation to
the remediation of dangerous or impaired facilities, but to preventing
their construction or damage in the first place. The workpackage includes
the following subworkpackages:
- Implementation and improvement of design and authorisation procedures
for proposed tailings facilities. Parameter sampling and levels which
could prevent the need for intervention if addressed in design and
authorisation.
- Implementation and improvement of water management and paste technology
for reducing tailings facility hazards. In order to increase tailings
facility safety, physical parameters (slurry consistency, grain size
distribution, particle surface properties etc.) will be suitably influenced
with the aim of establishing an optimum set of transport parameters
and maximising stability of tailings dams and ponds. Management of
water balance, including advances in paste technology will be the
focus of interest, to reduce water quantities and costs, pond size
and depth, and instability and pollution risks.
- Implementation and improvement of closure and restoration plans
for disused tailings facilities. Parameter sampling and levels which
could prevent the need for intervention if addressed in closure and
restoration plans.
- Implementation and improvement of risk reduction actions for substandard
or impaired tailings facilities. Parameter sampling and trigger/target
levels for undertaking actions described in WP 3. Once deficiencies
and potential intervention actions have been identified, a systematic
approach is needed to tailor and undertake such actions. This workpackage
will consider what general preparations may be possible to help ensure
that sound routines are followed (albeit imaginatively) to support
the rapid, safe and practical on-site development of such solutions.
- Improvement of management and inspection procedures and harmonisation
of regulation and enforcement standards and criteria. Parameter sampling
and levels which could prevent the need for intervention if addressed
in management and inspection procedures. The emphasis here will be
upon relating all the parameter evaluation work to the adoption of
well defined and practical standards and criteria in the formal regulations
and codes of practice which cover such procedures.
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Workpackage 5: Investigation
and Monitoring |
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Review and development of measurement methods for investigating,
monitoring and evaluating parameters critical to the safety and risk
reduction of tailings facilities; stochastic modelling of sediment profiles,
analysis of reliability and risk of tailings dams. The following subworkpackages
are included:
- Basic mineralogical analysis, soil mechanics and contaminant survey
of bodies of tailings. Sampling of dam and sludge material from model
sites and mineralogical, geochemical and geotechnical analysis. Characterisation
of the flow-deformation behaviour of fine hydraulically placed non-plastic
materials. Collecting analogue data of other sites from reports and
compiling them into a review database. Evaluation of own data in context
of the review database, and integration of relevant data into the
spreadsheet/parameter framework.
- Structural stability, simulation, modelling, reliability analysis
of bodies of tailings and of tailing dams. Develop methods to deal
with uncertain and random data which will be used to calculate the
structural risk and the reliability. Implementation of the vectors
in a GIS to get knowledge about the representativeness and statistics
of data. Quantitative assessment of uncertainty and randomness of
the data. Identification of limit state conditions and correlation
of the several effects. Stability analysis with deterministic methods
using the stochastic field of data in circular and wedged mechanisms
of failure. Testing the methods of risk analysis originated in aerospace
and nuclear industry for geotechnical issues of structural stability
of tailings dams.
- Minimally intrusive methods (including geophysical) for the investigation
and monitoring of tailings impoundments. Review, evaluation and development
of geophysical, minimally intrusive and non-destructive (NDT) methods
(surface based) for structural analysis and monitoring of tailings
ponds dams as input for stability analysis and remediation/intervention
planning. Development of geophysical and NDT methods for structure
assessment of tailing pond dams. Development of geophysical and NDT
methods for mapping and monitoring water and contaminant flow inside
and off tailing ponds. Assessment of available NDT/geophysical monitoring
technologies for relevance, reliability and cost effectiveness vis-à-vis
critical ranges/frequencies of vital parameters
- Probes, sensors, instrumentation and integrated data evaluation
for the investigation and monitoring of tailings impoundments. Review
and adaptation of equipment (probes, sensors and instruments) for
investigation and monitoring of tailings facilities. Where cost-effective
solutions are not readily available, the work under this project will
be limited to the specification of equipment or systems to do the
job.
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Workpackage 6: Field
Experiments - Refinement and Testing |
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Refinement and testing of suite of measurement methods, via case
study applications at actual and model tailings facilities. The following
subworkpackages are included in this workpackage:
- Choice and characterisation of case study sites on basis of critical
parameters identified previously as set out in the spreadsheet framework.
Site characterisation criteria based on the requirements of the technology
developing workpackages. Test site selection according to the needs
of the project partners for technology testing. Basic site characterisation
and description on the base of available data. Additional characterisation
by conventional methods to get calibration data for the new techniques.
Preparation of test sites for technology testing (legal and technical
issues).
- Trialling and refinement of improved measurement and evaluation
methods at the case study sites. Adaptation/demonstration of proven
technologies in tailings facility case situations. Testing of new
investigation and monitoring techniques. Recommendations for stabilisation,
remediation, technology changes and risk management for the test sites
will be derived.
- Trialling and refinement of improved measurement and evaluation
methods at a model tailings facility including simulated failure,
subject to available funding and permissions. Design and construction
of a pilot-scale tailings facility, equipping the dam with appropriate
instruments enabling measurement and monitoring of all parameters.
Artificially creating conditions leading to failure and 'performing'
a controlled dam failure. The experimental tailings facility may be
a model within a real one.
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Workpackage 7: Application
- Framework and Dissemination |
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Explanation and dissemination to end users by offering and demonstrating
a 'TAILSAFE' risk reduction framework. Development of the spreadsheet/database
framework into a practical risk reduction tool for tailings facilities.
Concluding dissemination of project results. The following subworkpackages
are included:
- By drawing on successive outputs of previous workpackages, gradual
conversion of the project's spreadsheet parameter framework into a
characterisation, risk assessment, and risk reduction framework for
tailings facilities.
- Integration into that risk reduction framework of standards and
criteria, plus improved measurement and evaluation methods, for the
harmonisation and enforcement of regulations for tailings facilities
across the EU.
- Adaptation of that 'TAILSAFE' framework into a working tool with
user guidelines, and its dissemination among industrial end users
and regulators. The framework will be presented as a series of modules,
through which a user can cycle, in checking out a particular problem
situation or procedure. The objective is to produce a workable Mark
I version, which attracts positive user feedback.
- By comparing final risk reduction framework with initial parameters
framework, evaluation, with aid of expert advisory panel, of contribution
of project itself to improvement of tailings facility safety. This
comparison, by a panel independent of the project team, will enable
verification of the degree to which the project has met its technological
objectives.
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The TAILSAFE Parameter
Framework |
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The quantified parameters resulting throughout the project will be
incorporated into the TAILSAFE parameter framework. There the parameters
will be tracked, refined and elaborated throughout the project and
additions, changes, adaptations or adjustments made as appropriate.
Attention will be given to the acquisition and organisation of metadata,
both to aid proper data management within the TAILSAFE project, and
to facilitate its use to others. Construction of a meaningful framework
will not be so simple in practice. For instance, criticality is likely
to be a dynamic attribute, with the critical parameters varying with
problem situation and solution stage. The TAILSAFE framework intends
to offer a systematic means of organising data from this targeted research,
alongside data from elsewhere, in a way which relates them not only
to assessing, but also to monitoring and reducing risk.
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The TAILSAFE Expert Advisory
Panel |
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The project is accompanied by an independent panel to inform, critique
and validate project directions, work and outputs, and guide the team
in tackling issues of real innovation, practical importance and viability.
The TAILSAFE Expert Advisory Panel is a group of independent individuals
having a wealth of experience in the field, plus additional representatives
from the minerals industry. The panel is UK-based for cost-effectiveness.
The group will evaluate the project by comparing the final risk reduction
framework with the initial parameter framework and by assessing the
contribution of the project itself in terms of its capability for the
improvement of tailings facilities safety.
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The
TAILSAFE shell has been created and is maintained by Federal Institute
for Materials Research and Testing (BAM) |