Waste metal?

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Easylife
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There is a 1 acre horsefield on a hillside with visible rigg and furrow. I previously searched the top and one side of it and mainly found Georgian coins. This time the grass was short on the otherside of the field so I gave that a bit of a go and about halfway down the hillside was a patch of a fair amount of copper alloy melted waste from perhaps metal working? I filed the edge of one piece and it showed brass. There was also what appears to be lead casting waste with a 15mm diameter sprue (bottom right), so perhaps from a large lead item?
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I left the rest of the field for another time as the further down the hill the drier the ground but no doubt there will be some more of the same, though another Georgian coin did show and that was about all. So just what to make of the metal waste? :Thinking:
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figgis
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Could be either waste or there was one helluvva fire. I've also found a fair bit of "casting waste" on one hot spot but later discovered some burned roof tile which raised the question as to what it actually was. Fields used to be burned off but I don't know that the temperatures raised would have been high enough or long enough to have caused it
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Easylife
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figgis wrote: Mon Oct 04, 2021 6:49 pm Fields used to be burned off but I don't know that the temperatures raised would have been high enough or long enough to have caused it.
There is evidence of stubble burning on the neighbouring pasture field above this shown by a thin constant charcoal layer at about 6" deep but not on this one. Google says that brass melts at just over 900c and a good bonfire can reach 1100c, though I would guess that stubble burning would not get quite hot enough? Maybe a bit odd that it hasn't melted into smoother blobs? :Thinking:
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Metalurgy
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I don’t believe stubble burning would ever melt any metals,they just used to go wumpff and burn incredibly quickly but they were an great sight to watch,until they were banned.
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Metalurgy wrote: Mon Oct 04, 2021 8:45 pm I don’t believe stubble burning would ever melt any metals, they just used to go wumpff and burn incredibly quickly but they were an great sight to watch until they were banned.
It would seem so.
"Stubble fires will peak at >250°C and the bed of the fire is >150°C. The duration of exposure is usually short (<5 minutes) but if there are heavy stubbles or windrows the temperatures may persist for longer."
So not really even enough to melt lead which needs just 327°C.
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