Timeline prediction for Appin mine recovery with reference to 2022 Appin outburst incident: 3-4 months

Appin Colliery Incident – Recovery Timeline Prediction

Incident Overview:

On April 6, 2025, a suspected underground pressure explosion at Appin Colliery resulted in injuries to four miners and a partial roof collapse at approximately 500m depth. Operations have been suspended pending investigation.

Reference Case:

The 2022 outburst event at Appin (IIR22-05) involved a series of gas-related disruptions during remote mining. While it caused no injuries, it triggered significant ventilation and geological responses that inform the current recovery outlook.

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Predicted Recovery Phases

1. Immediate Response (0–3 days)

Site secured, miners evacuated and treated.

Initial inspections initiated by NSW Resources Regulator.

Scene locked down for investigation.

2. Stabilization & Risk Zoning (1–2 weeks)

Re-establishment of ventilation and structural support.

Roof integrity and outburst zone mapping.

High-risk zones likely cordoned off; degassing commenced if needed.

3. Geological & Gas Assessment (2–6 weeks)

Fault mapping, gas content testing, and possible borehole drilling.

Historical issues with gas drainage may necessitate re-design of boreholes.

Delays likely if high methane/CO₂ levels persist.

4. Safety & Operational Revisions (1–2 months)

Revised Authority to Mine (ATM) for affected sections.

Updates to ROS (Remote Operating Station) functionality and emergency systems.

Enhanced controls for methane exceedance and ventilation modeling.

5. Mining Resumption (2–4 months)

Unaffected headings may resume under strict controls within 2 months.

Full restart in affected zone contingent on regulator clearance and successful risk mitigation.

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Total Estimated Recovery Time

3 to 4 months, assuming no further complications.

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Key Risks to Timeline:

Confirmed “pressure bump” could lead to extended shutdown.

Injuries elevate scrutiny and regulatory involvement.

Potential need for redesign of mine plan or exclusion of high-risk headings.