Phil,
There was a device called a 'Berdan pan'. This is a rotating circular tub
leaning over at about 10 - 15 degrees in which large steel weights were
dragged (by the rotating motion) around the perimeter (and lowest point) to
fine grind tailings from a standard stamp battery & amalgam plate
arrangement. Probably belt driven from on top through a central axle.
It closely resembles one of those circular cake tins with the 'spine' up the
middle in shape but would be about 1 m high and 1.5 to 2 metres across.
They were in quite widespread use in Australia for fine gold recovery in the
latter part of the 19th Century and pre-cyanidation era. Mainly for fine
grinding of a tail or middling product - which makes a bit of sense in
regard to your query. Perhaps they put mercury in them to amalgamate the
released gold ?
Cheers
Ian Hodkinson
----- Original Message -----
From: "Newman, Phil" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, November 11, 2002 10:29
Subject: Gold from Mundic!
> > At a copper mine in Devon that I'm currently writing up (Druid), there
was
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