17.3 Multidisciplinary Integration, Interfaces & Independent Review
Key Takeaways
- A feasibility study requires accountable contributions from mining, geology, metallurgy, geotechnics, hydrology, tailings, environment, social, infrastructure, execution, market, finance, tax, and legal specialists.
- An interface register defines the data exchanged, units, version, owner, receiver, due date, acceptance check, and consequence of change.
- Design criteria and a single controlled project model prevent disciplines from optimizing incompatible assumptions in isolation.
- Independent review tests evidence, methods, interfaces, and material risk without taking over authorship or management accountability.
- A change-control process evaluates technical, cost, schedule, safety, environmental, social, permit, and reserve effects before accepting a design change.
No single discipline can establish mine feasibility. Geology defines the deposit; mining determines extraction; metallurgy establishes response; geotechnical, water and tailings teams control physical risks; environment and social teams establish impact and obligations; infrastructure and execution teams determine deliverability; market, finance, tax and legal teams convert the plan into commercial and legal consequences. Integration is a designed process, not a final editing exercise.
Clear Roles
Each workstream needs a scope, accountable lead, competent contributors, reviewer, deliverables, assumptions, schedule, and interfaces. The project manager owns integration but does not replace professional accountability. The Competent Person owns applicable public resource or reserve conclusions; legal counsel interprets material legal issues; engineers own their designs within competence.
Design Criteria
A controlled design-criteria document states common inputs:
- coordinate system and survey datum;
- units, currency, base date, inflation and exchange;
- resource and reserve model version;
- production rates, operating calendar, availability and utilization;
- geotechnical domains and acceptance criteria;
- metallurgical ore types, throughput and recovery basis;
- design storms, seismic parameters and water quality;
- safety, environmental, social and closure criteria;
- estimate and schedule conventions; and
- study data cut-off.
Changes are issued formally so every model uses the same basis.
Interface Register
| Provider -> receiver | Interface | Acceptance check | Consequence if wrong |
|---|---|---|---|
| Geology -> mine planning | Block model, classification, density | Version/hash, totals, coordinate check | Tonnes, grade, schedule |
| Mine -> process | Feed tonnes, grade, hardness, mineralogy by period | Reconcile schedule and ore types | Throughput/recovery |
| Process -> tailings/water | Tailings rate, PSD, chemistry, water return | Mass/water balance closure | Facility size and discharge |
| Geotech -> mine | Slope/stope domains and controls | Design review and field criteria | Safety, recovery, dilution |
| Environment/social -> layout | Exclusions, receptors, commitments | GIS and permit-condition check | Approval and redesign |
| Execution -> finance | Capital schedule and ramp-up | Critical-path and cash-flow tie | NPV and funding |
The receiver should confirm fitness; transmitting a file is not interface acceptance.
Integrated Model Checks
Maintain one controlled production and financial case. Reconcile annual and life-of-mine tonnes, grades, recoveries, products, waste, tailings, water, power, labor, capital, operating cost, closure and cash. Run balance checks automatically and investigate differences rather than forcing totals.
Grind-Size Example
Metallurgy proposes reducing product P80 from 100 to 75 micrometres to gain two recovery percentage points. The integrated decision asks:
- Does ore hardness permit throughput at the finer grind?
- What additional grinding energy and mill capacity are required?
- Does finer material alter flotation, thickening, filtration, water recovery, or tailings behavior?
- Does added metal revenue exceed energy, reagent, capital, maintenance, and tailings cost?
- Do water, power, emissions, permit, and schedule constraints remain acceptable?
Optimizing recovery alone can reduce total project value or create a tailings risk.
Independent Review
Reviewers need sufficient independence from the original work and access to source data. They should test material assumptions, reproduce selected calculations, inspect interfaces, visit the site when necessary, and classify findings by consequence. Review does not transfer responsibility away from authors or management. Close findings with evidence and record accepted residual risk.
Change Control
A proposed change states reason, baseline, alternatives, technical effect, cost, schedule, safety, environmental and social impacts, permit consequences, resource/reserve effect, risk, implementation plan, and approvals. Emergency field changes may be needed to control danger, but they are documented and reconciled afterward.
Beware gradual scope drift. Ten small unreviewed changes can invalidate a plant mass balance or environmental assessment even when none seemed material alone. Periodic configuration audits compare constructed or current design with approved basis.
Decision Meetings
Provide decision papers before meetings, distinguish information from approval, record dissent, and assign conditions. The loudest discipline should not dominate. Where evidence remains uncertain, identify the test that would change the choice.
Exam Approach
When a scenario spans disciplines, draw the interface chain. A harder ore changes grinding throughput, power, production schedule, revenue, and possibly reserve economics. A new waste location changes haulage, drainage, land access, environment, community and closure. The correct answer usually integrates downstream consequences before approval.
Interface Acceptance Test
Do not mark an interface complete when a file is sent. The receiver checks coordinate system, units, dry or wet basis, effective date, scenario, naming, totals and uncertainty, then confirms acceptance. Reconcile a few source records and control totals across the transfer. For every material change, identify downstream models and reports, rerun affected checks, and record which prior conclusions remain valid. This turns coordination into testable engineering control rather than meeting attendance.
Metallurgical testing suggests a finer grind would improve recovery. What should the feasibility team do before adopting it?