NORTH GOONYELLA MINE FIRE SYPTOM OF SAFETY CANCER IN QUEENSLAND MINING

The current Crisis in Mining Safety and Health is deep seated.

Events such as the North Goonyella Mine Fire and Sealing at the Surface are an obvious example of the Cancer eating away the Industry.

The most serious Spontaneous Combustion event since Moura No 4.

Two years on what do Mine Workers and the General Public know about this.

Nothing because the Mines Inspectorate claim that the Investigation is still ongoing.

Lets have a look at a few MRE’s from the 3rd to 5th of September 2018

MRE – North Goonyella – 03.09.2018

MRE – North Goonyella – 04.09.2018

MRE – North Goonyella – 05.09.2018

 

3^rd September

DNRME Les Marlborough

NGC Marek Romanski UMM; Dennis Black VO; Nev Impson CO (Compliance Officer), NO ISHR

1. 1 Fan closed down in Planned Ventilation Change at 6pm on 2^nd September
2. Modelled to reduce face ventilation to 20m3/s with only 2m3/s reporting to TG hatch. Unable to be confirmed as workers not allowed underground
3. TUBE BUNDLE 24 LW 9N TG Goaf Edge CO drops to 155 ppm at 7:55pm, then peaked at 767 ppm at 2:00am.
4. TB 24 at 8:00 am. CO 558ppm, Ethylene 2.5ppm, CH4 10.52%, O2 dropping from 8pm 2/9/18 from 17.7%
5. Larger Floxal Unit (250 l/sec) due on site 12:00 Noon
6. Power shut off to the Underground as per Inspector Marlborough Suggestion (No time)

Bag Sample Results

8:am CO drops to 558; Ethylene > to 3.7ppm at 2:00am < to 2.5ppm at 8:00am

CO Make TG Regulator 154 l/min (6pm 2/9/18) drops to 106 l/min at 8:00 am

Grahams Ratio approx. 1 and falling

Injecting 300 l/sec CH4 down Drainage Hole 2470 (89m from face opposite TG Chute road)

 

MINE 24 HR PLAN

1            Set up the large Floxal unit onto a gas riser (hole 1991) located 134 behind the TG end of the face.

2            Run a second 6″ pipe to connect to a second gas riser on the South Side to increase the Methane being put into the goaf at hole 2470 to approximately 1 ,000 Ifs.

 

MARLBOROUGH RECOMMENDATIONS

Turn Power off to Underground Time Unknown

1. A mine plan showing current ventilation set up with quantities, monitoring points, inertisation points and points where Methane was being injected into the goaf;
2. Establish a detailed timeline of events. This to commence when the Longwall was approximately 50 m from its finish point. The timeline to detail the following as a minimum;

• Milestone events such as roof falls, ventilation changes, bolting runs etc;
• Gas readings, CO Make etc at key points before and after milestone events;
• Air quantities (could be taken from ERZ Controllers’ stat reports);
• Changes in monitoring locations;
• Any other details to assist in the determination of what had caused the heating in the goaf.

 

4^th SEPTEMBER

DNRME Les Marlborough

NGC John Anger SSE, Marek Romanski UMM; Dennis Black VO, Gavin Shields Safety Manager, Robin Hall Continuous Improvement Manager, NO ISHR

TB 24 LW 9N TG Goaf Edge

• CH4 risen from 12.6% to 14.02%
• CO dropped from 486 ppm to 447 ppm
• 02 dropped from 9.95% to 8.96%
• C02 increased from 1.9% to 3.19%.
• Graham’s Ratio falling.
• CO/H2 Ratio rising.

 

Romanski: The TARP allowed re-entry following 4 consecutive samples below Level 3,

 

MARLBOROUGH RECOMMENDATIONS

 

I advised that the re-entry plan needs to address the critical work required to be completed to manage the situation in 9 North and to ensure the safety of the Mine. Mr Anger agreed that was the approach the Mine was taking. I explained that the actions to date were managing the Oxygen but not addressing the heating.

 

MARLBOROUGH OBSERVATIONS

 

1.The Mine had commenced preparing a timeline to assist in determining the events leading up to the incident. This would assist in determining the cause of the incident and help with the investigation to develop actions to prevent a recurrence.

2.The Mine have commenced spreadsheets to show gas results to make interpretation and trending easier.

3.The situation is being managed using the Mine’s Emergency Management system, which is proving beneficial in achieving control of the issues.

4.An incident action plan has been developed.

5.The Mine is continuing to provide regular updates to crews (3 times per shift for day shift and twice per shift for night shift).

6.There was good discussion concerning the may forward, The Mine intends, once re-entry commences that they will limit entry underground to essential personnel only. A risk assessment would be undertaken prior to re-entry.

 

Activities during the Previous 24 hours;

• Verified that all surface boreholes over the 9 North goaf were capped or sealed;
• Floxal running into borehole 1991. Started around 6:00 PM on 3-Sep, approx. 250 1/s;
• Second methane line hooked up to hole 2470. Initially supplying 700 1/s methane but overnight this has dropped to 400 1/s. Believed that the water traps underground require emptying;
• Commenced coupling 2nd Floxal to the methane line feeding into hole 2470;
• Started developing re-entry plan.

 

The plan for the next 24 hours; 

• Complete re-entry plan;
• Conduct risk assessment on re-entry;
• Complete connecting 2nd Floxal unit;
• Mine was sourcing a third Floxal unit;
• After re-entry – plan would be to connect Floxal range to TG seal, bag off seal and inject Floxal in through TG seal. This will, in conjunction with the Floxal injecting down borehole 1991 completely inert the TG end of the face and purge the CO out through the TG Chute Road. It is believed that this would achieve the goal of treating the Spon Com area.
• Mine to source foam generator used at Carborough Downs and Narrabri when injecting Floxal gas. Seeking advice as to whether this application would be beneficial in the North Goonyella situation.

 

 

5^th SEPTEMBER

 

DNRME Les Marlborough

NGC John Anger SSE, Marek Romanski UMM; Gavin Shields Safety Manager, Robin Hall Continuous Improvement Manager, Chris Markowski Tech Services Manager, Chris Lily (Peabody Senior Director of Engineering, Mine Carter SSE Millenium Mine, NO ISHR, No Dennis Black VO

 

Gas levels were reviewed from Tube 24 at 8am

CH4 17.6%

CO 487 ppm

02 8.03%

C02 3.07%

Graham’s Ratio 0.46

 

Marlborough Observations

The Mine supplied a copy of the gas results spreadsheet for tube 24 and tube 28.

Gas behaving as expected and situation continuing to improve.

Had a discussion regarding the gas results.

It is clear that the barometer is having an effect on the gas readings at the TG end.

The Oxygen dropped right down to 4.14% at 16:00 hours the previous day following the Diurnal low. The gas levels and other indicators appear to be fairly stable and consistent.

 

Next 24 Hr Plan

Plan for the next 24 hours

A discussion was held regarding the best course of action. It was agreed that it would be beneficial to be able to bag off the TG hatch and introduce Floxal gas through the TG seal. This would flush all gas from the TG end and, with the Floxal gas going in at hole 1991 would serve to flood the whole TG end of the goaf with Floxal gas. This would actually treat the heating. A risk would be held and Mr Romanski, accompanied by a Shift Supervisor and two ERZ Controllers would proceed underground to complete the work. Mr Romanski explained that there was already a Driftrunner loaded with the required equipment ready to go. He explained that, apart from travel time, there would be approximately 30-60 minutes work to couple this inertisation line up to the TG seal. While underground these people would drain the water trap from the Methane Drainage Riser that was showing signs of the water trap being full. I asked that the Mine notify me when the work was completed.

Other activities for next 24 hours;-

Third Floxal arriving from Millennium approx. 2:00 pm. Will set up on existing holes to add more Nitrogen to the underground; o Identifying the best location to put a borehole from the surface closer to the potential source of the heating. It was agreed to place this as close as possible to a position mid-way between the TG Chute Road and the TG, about 50 m behind the face;    Mobilising two Floxal units from NSW.