Scrap Metal Fire

[SillyOldDufferModerator @sillyoldduffer]

[SillyOldDufferModerator @sillyoldduffer]

Local news reporting 20,000 tons of scrap metal on fire in Avonmouth and they're having trouble putting it out!

BBC Pictures here.

Cause unknown, so we can have fun guessing what's on fire, and what ignited it.

My suggestion: magnesium swarf, plenty of air in the heap, and it got hot enough to ignite Aluminium and maybe steel… Maybe lightning started it?

I've read Magnesium is the most machinable of all metals. Shame it ignites at 473℃ and explodes when you try put the fire out with water!

Dave

[OldironParticipant @oldiron]

Just saw this online. My first thoughts were that oil & aluminium most likely scenario. Going to be difficult to put out. Could burn for a long time.

regards

[old martParticipant @oldmart]

It's a mystery to me exactly what is burning. If oil was a component, I would expect the smoke to be black. If there was a lot of plastic in the pile, the smoke would be black also. Magnesium does emit white smoke, but the quantities of it relative to the more common metals is small and those piles of metal would have been separated magnetically before piling up prior to being loaded into ships. Putting water on burning magnesium is not the correct way to control it, but fire services will have extremely limited options with such a large fire.

[Tim Rowe 1Participant @timrowe1]

Looks to me like an exothermic reaction has started. There is a lot of oxygen tied up in rusty iron or steel. Introduce a reactive metal such as aluminium which could still be stuck to ferrous material even after magnetic separation and you have a process akin to Thermite.
Get the steel hot enough and even that will "burn" as can easily be seen in oxy-gas cutting processes.

Tim R

[old martParticipant @oldmart]

You may well have the answer there, Tim, iron rust and aluminium are a bad mix, that is why aluminium is banned from coal mines.

[JAParticipant @ja]

I think there was a scrap metal fire a few years ago in Swindon that burnt for weeks. Burning mixed metals must be very difficult to deal with. Water on most burning metals does not help.

I guess they will try to move as much metal as possible and just let the rest burn. The M4 & 5 are not too busy at this time of year.

JA

Other metals have thermite reactions such as aluminium and copper (oxide).

Edited By JA on 05/10/2020 15:51:10

[pgk pgkParticipant @pgkpgk17461]

no-one mentioned titanium yet..local aerospace and RR??
But my vote still goes to ally and rust

pgk

[JAParticipant @ja]

Unlikely to be titanium since any such scrap was kept separate and returned directly to the refiners (where I worked, any way). I only managed to get hold of titanium once, little piece of sheet 1" x 2".

The fire is at the Sims Metal Management depot. According to their web site they are a long established international company dealing in general waste metal, both ferrous and non-ferrous. Their head offices are in Australia. Not a fly by night outfit.

JA

Comment deleted.

Edited By JA on 05/10/2020 16:54:30

Edited By JA on 05/10/2020 16:55:02

[Howard LewisParticipant @howardlewis46836]

You may have trouble setting a steel RSJ non fire, but steel swarf will burn well, small local mass with plenty of room for oxygen! Probably with some oil mas well!

Add some magnesium or Aluminium to the mix and off we go!

Should be interesting to know What burned, How much, For How long, and how it started

Howard

[Michael GilliganParticipant @michaelgilligan61133]

Interesting … Sims also had a serious fire in Redditch on 09-January : **LINK**

30 firefighters battle Redditch industrial estate blaze through the night

… I wonder what charges there might have been to recycling protocols

MichaelG.

.

Edit : https://wasteadvantagemag.com/scrap-metal-fires-mitigating-risk/

Edited By Michael Gilligan on 05/10/2020 17:51:39

[Mark RandParticipant @markrand96270]

I guess at the end of it, they can just ship the remains to Port Talbot to be turned back into steel.

[SteviegtrParticipant @steviegtr]

I hope it is not Titanium, i have just bought some for making rings.

Steve.

[HopperParticipant @hopper]

When you look at the pictures of the fire, the mountain of scrap metal is like most these days: consists mostly of domestic appliances and car bodies and parts, all of which are painted and have various bits of plastic attached and in the case of fridges, may still contain some oil in the compressor. Paint burns quite well, as does plastic of course.

In this post-industrial era the chances of the pile containing burnable amounts of swarf, magnesium or even RSJs etc are slim.

 

Edited By Hopper on 06/10/2020 02:27:07

[ChrisHParticipant @chrish]

Steel will burn. On some water-tube boilers, if fired and water levels allowed to drop, the tube can ignite and develop what is known as a hydrogen fire. Trying to put that out with water is doomed to failure, as the water turns back into component parts hydrogen and oxygen gases and away it goes. Saw the results of a hydrogen fire on a little water tube boiler on a ship I joined once – not a pretty sight. Boiler had to be replaced, wasn't worth even considering to repair!  More common on dirty superheaters when overheated with a lack of steam flow through them.

Edited By ChrisH on 06/10/2020 09:30:54

Edited By ChrisH on 06/10/2020 10:00:32

[not done it yetParticipant @notdoneityet]

Steel will burn (think cutting steel with oxy-gas) but at a high temperature and with a plentiful supply of oxygen or very large surface area (steel wool). Aluminium will burn – think here of HMS Sheffield in 1982. Some metals will burn just by pouring water over them 🙂 – well not quite but the evolved hydrogen gas will.

[HOWARDTParticipant @howardt]

Why not call in the local airport fire service, they have equipment to extinguish metal fires.

[JAParticipant @ja]

I have just got back from Avonmouth. The fire appears to be out, no smoke.

JA

[BazyleParticipant @bazyle]

Forget the burning steel. As Hopper says it was washing machines and fridges. For years these have not had steel bodies just plasticised wood – very frustrating when you are looking for a nice sheet of steel and the fridges are full of expanded polystyrene. If they have thrown some weight lifting tackle in there is isn't cast iron any more either, just concrete sheethed in plastic.

[old martParticipant @oldmart]

The latest I could find out is that the number of fire crews is being reduced, they have won the battle, good work.

[ChrisBParticipant @chrisb35596]

Those mentioning titanium, I have yet to see a titanium metal fire after 20 years working with it. I find the probability of a scrap yard fire involving the said metal next to impossible.

[old martParticipant @oldmart]

The apprentices at work were given the task of removing tooling lugs from titanium aircraft parts part way through their milling. They spent the day cutting them off with the toolmakers vertical bandsaw. This saw is kept spotless inside and out by the toolmakers, so when it burst into flames, it had to be the titanium. It was put out using CO2, the same way a magnesium fire would be. That was the only titanium fire I saw in 17 years there, but magnesium was alight every couple of years.

[duncan webster 1Participant @duncanwebster1]

You were lucky to put out magnesium fire with CO2, magnesium swarf will burn underwater and according to **LINK** it will burn in CO2. I think you're supposed to smother it in sand, one of those Halon extinguishers would probably have worked but they are now banned?

[SillyOldDufferModerator @sillyoldduffer]

The chemistry of light metal fires is interesting. Burning in this sense is combining with Oxygen with release of energy.

Carbon and Hydrogen both burn in Oxygen to produce stable compounds: Carbon Dioxide and Dihydrogen Monoxide (Water). These are difficult to split apart, but it can be done; plants convert CO² into Carbon and Oxygen with sunlight and Water is easily broken apart by electrolysis.

Being pre-burnt and cheap as chips makes Carbon Dioxide and Water good for fighting ordinary fires. They deny the fire oxygen and cool the flame. If enough heat is removed the reaction stops.

Metal fires are a different kettle of fish. Metals like Magnesium and Titanium have a stronger affinity for Oxygen than Carbon and Hydrogen. Get Magnesium hot enough and:

4Mg + CO² → 2MgO + C plus heat, and Carbon is also inflammable.

Fortunately it takes a lot of heat to start the reaction, but very difficult to put out once going. Powder and swarf are easier to ignite than solids. This photo was a factory in the US making Titanium golf club handles:

And this one, a recycler. Note the flying white hot debris caused by hosing water on to burning Titanium. It exploded.

Amateurs get caught out because common-sense says a fire extinguisher will put a small fire out, and although it might, the result could be disastrous. Professional firefighters get caught when they don't know burning metal is involved. Out come the hoses and the explosion catches the unlucky and spreads the fire to adjacent properties. The golf club handle fire destroyed 4 adjacent businesses as well…

Dave

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