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Post by John on Jul 12, 2015 16:49:28 GMT -5
I was reading on other sites discussions on aluminium in coal mining. I remember the problems occurred because magnesium was used to harden the soft metal. I remember my first day at Cotgrave, stopped by the canteen before I got changed and picked up a pack of Wrigleys, proceeded through the baths and followed someone through to deployment, I was walking to pit top when I pulled out my packet of Wrigleys, holy crap, you'd better not take those underground or you'll lose your job someone said...I took all the gum out of their wrappers and disposed of them.
One thing always puzzled me, all the "rams heads" were aluminium, how did we get away with them??
Although aluminium was banned in NSW mines, there was an exemption, we had small compressors, and they had their motor frames made out of aluminium, but it had to be coated in a skin of epoxy of a certain thickness.
When I was at Clifton Colliery, there was a pump in a back road off of 15's centre gate, it was powered by an old GEB, it didn't have an NCB plant number, so was never signed for, just checked, it had an aluminium case. I doubt any Inspector ever went down that way.
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rob52
Shotfirer.
Posts: 199
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Post by rob52 on Jul 15, 2015 7:17:56 GMT -5
Bad idea J, aluminium alloys on rusty steel objects cause an incendive spark ACARP Al & Rusty Steel"Twelve incidents occurred between 1950 and 1955 in which such a spark was the source of an ignition of methane. Of these 6 occurred in the UK, 4 in Germany and 2 in Japan."QRC Conf PaperThe Ignition Hazard from Sparks from Cast Alloys of Magnesium and Alumininm. H Titman. Frictional Sparking of Aluminium, JC Bailey, Transaction of Institution of Mining Engineers 1959 Rob
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Post by John on Jul 15, 2015 11:29:57 GMT -5
Bad idea J, aluminium alloys on rusty steel objects cause an incendive spark ACARP Al & Rusty Steel"Twelve incidents occurred between 1950 and 1955 in which such a spark was the source of an ignition of methane. Of these 6 occurred in the UK, 4 in Germany and 2 in Japan."QRC Conf PaperThe Ignition Hazard from Sparks from Cast Alloys of Magnesium and Alumininm. H Titman. Frictional Sparking of Aluminium, JC Bailey, Transaction of Institution of Mining Engineers 1959 Rob But why were we still allowed the aluminium cased rams heads Rob??? We had new high frequency cast iron rams heads at British Gypsum, but they were smaller than the NCB 50 cycle rams heads.
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Post by quimbyj1745 on Jul 15, 2015 13:41:39 GMT -5
Went on a trip from Stoke mining dept to the safety in mines research establishment in Derbyshire. We watched the explosion of methane in one tunnel followed by a further explosion of a methane + coal dust in second tunnel. A film then showed the second explosion with dust barriers in place to restrict the force of the explosion, all very dramatic. At the discussion after, the person in charge told us that Farnborough research establishment,( busy investigating why the De Havilland comets were falling out of the sky)had phoned the safety in mines people to ask if the mining industry had ever done any research about the possibility of aluminium and steel mix causing ignition. Of course the mining industry had known for years, in fact if you read the inspectors report into the explosion at Cortonwood Colliery that occurred pre 1920 the inspector did raise the possibility of a spark caused by hard rock striking a rusty bar that traces of aluminium in the rust. The men were robbing pillars left by pillar and stall workings and were drawing supports as they retreated.
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Post by andyexplorer on Aug 4, 2015 16:34:33 GMT -5
A thermite reaction of aluminium foil on steel rails was one possibility considered by H S Stephenson HM inspector of mines after the Hapton valley COLLIERY explosion in 1962 which claimed 19 lives
Quimby mentioned a film where there was an controlled explosion, then the same amount of explosives with added coal dust, there is this small American example from pathe news , but unfortunately no sound I was wondering if this was it ?
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