Heat Affected Coal Spontaneous Combustion Propensity. Grosvenor Mining Inquiry Findings already Ordained?
We have heard much over the last 2 weeks at the Grosvenor Inquiry about the theory of the Ignition on the LW 104 production face came from
A small intense spontaneous combustion event that no one detected prior to the event suddenly flares to over the ignition temperature of methane from around 150C to over 540C in seconds.
More this heating is within metres of the back of the longwall chocks in the immediate area of around 100 chock
This will no doubt lead the Grosvenor Inquiry to include in their Main Findings words along the lines of
We will ban the use of that particular brand of PUR/Grout.
SIMTARS and RESEARCHERS will be given millions of dollars to research strata binding agents.
Further Millions in research for a method of safely injecting fly ash or something similar into the goaf to cut gas flow paths.
Lots of Research Papers will be delivered at various conferences around the world that no one at the actual coal face ever gets to read.
We will run industry wide training programs for Mine Managers, Ventilation Officers, ERZC’s and maybe even poor old face worker (or as sometimes referred to “Coal Face Cannon Fodder” might get some.
Mining will continue as normal until we blow up another mine, this time with much more fatal consequences.
This has been blatantly obvious from the time the Mines Inspectorate released their Safety Alert over PUR on the 21st of February 2021, some 3 weeks before the Grosvenor Inquiry Recommenced Hearings.
It has been no surprise to me that this was expounded on from the Opening Statement on March 9th from Counsel Assisting where the whole Inquiry was heading
Since then we have had a Conga line of Inspectors and Consultants each having their two bob’s worth.
All leading to official Findings for the Inquiry
Most Likely Cause of the face Ignition at Grosvenor was
A small intense spontaneous combustion event that no one detected prior to the event suddenly flares to over the ignition temperature of methane from around 150C to over 540C in seconds.
More this heating is within metres of the back of the longwall chocks in the immediate area of around 100 chock
RECOMMENDATIONS
We will ban the use of that particular brand of PUR/Grout.
SIMTARS and RESEARCHERS will be given millions of dollars to research strata binding agents.
Further Millions in research for a method of safely injecting fly ash or something similar into the goaf to cut gas flow paths.
Lots of Research Papers will be delivered at various conferences around the world that no one at the actual coal face ever gets to read.
We will run industry wide training programs for Mine Managers, Ventilation Officers, ERZC’s and maybe even poor old face worker (or as sometimes referred to “Coal Face Cannon Fodder” might get some.
Mining will continue as normal until we blow up another mine, this time with much more fatal consequences.
I still avow
No Ethylene is ever mentioned as being detected prior to first methane explosion and not detected it seems during any of the time frames either mentioned by the Inspectors so far in either their statements or sworn evidence while attending the mine as part of the Investigation.
We know from centuries of hard learned tragedy and a bit of scientific research that CO, Hydrogen and Ethylene evolves before visible “smoke” from coal heating.
Ethylene evolves when Coal reaches approximately 150C
The presence of Ethylene we have learned means the Mine is in the “Last Chance Saloon”.
It obviously was not able to be identified via gas monitoring when the Re-Entry Risk Assessment process was completed, or during the week or so of investigation.
There is also no mention of elevated levels of hydrogen, carbon monoxide in either fixed gas monitoring points or the goafstream when able to be inspected in the weeks following the explosion
There has also been no mention of strange smells or odours.
On what we know so far I can easily accept that there is little likelihood that Grosvenor was effectively ever able to monitor spontaneous combustion, given the trouble they have even monitoring methane.
Let alone the unmonitored cut-throughs and C hdg they have in their LW104 Ventilation arrangement
There are a few basic questions that in my view cannot be explained by this theory.
No matter which way you look at it, there are certain pre-requisites that have to be met to ignite methane.
We know from centuries of hard learned tragedy and a bit of scientific research that CO, Hydrogen, Ethane and Ethylene evolves before visible “smoke” from coal heating.
The presence of Ethylene we have learned means the Mine is in the “Last Chance Saloon”.
How on earth can a short duration compression wave (overpressure event) cause a supposed heating right at the back/roof of the chocks around # 111 to flare into open flame above 537C and then after it has ignited the methane, disappears totally?
The fact is, it cannot
