Thanks Ian. That's an important point and certainly worth inclusion.
Phil
-----Original Message-----
From: mining-history [mailto:[log in to unmask]] On Behalf Of Ian
Spensley
Sent: 05 July 2011 08:41
To: [log in to unmask]
Subject: Re: Lead/Zinc dressing
Dear Phill
I can't add anything to froth floatation which is too late for my area and
the deposits too small to be worth building a plant.
The one thing worth mentioning is that the calamine was calcined before it
was sent to Sheffield. This is still evident in the Archaeological record
as Calamine House and a large mound of coal ash along with a small amount
of
ore. I suppose that this may be peculiar to Cobscar Mine where it is
likely to have only economical because of its position on the edge of
Preston
Moor Colliery, enabling the calamine to be reduced in volume/weight for
transport to Sheffield, (which must have been expensive).
The first documentation is from 1779 to 1807, Sheffield Brass. The Keld
Heads Mining Co worked it again c.1845.
Apedale Mining Co, worked zinc blende in 1882/3 at Apedale Mine
(Wensleydale). They had a circular buddle for dressing slimes, but the
blende may
have been mainly sorted.
Regards
Ian
In a message dated 04/07/2011 22:10:12 GMT Daylight Time, [log in to unmask]
writes:
Dear Peter,
Zinc did not feature much at Greenside since there was little to none
there
in the first place. Likewise Weadale proper, though from Cowshill to the
top of Killhope it came to be more prevalent until reaching the Nenthead
Mines and westward where it was a significant mineral/metal.
The matter of 'manipulating existing gravity separation methods of ore
preparation', produced problems due - in the early days to SG - so mainly
hand
sorting was resorted to (this will obviously leave little evidence on the
ground). The proof in the Frongoch pudding, is in as much that it was not
until the 1920's (Nancarrow), that zinc could be treated from the
dumps...
indeed, as a specific target (the latter's Plant and aerial ropeway over
to
the Ystwyth Valley (Electrolytic Zinc. Co. etc., etc.) - footings of
plant
extant... but Kitto kept the mine working for many years stripping the
stopes of zinc that the Taylors' had left... but such well handled,
enabled a
clean product - and a touch surprisingly left the dumps alone to wait for
Nancarrow. The 1870's indeed saw a decreasing lead commodity value, and
it was
'handy', to say the least, to some mines, to take on an mineral that
otherwise had previously been treated as a nuisance. As to extant Plants;
well
of course they are not there now, but a little imagination/research into
what plants were elsewhere, and how the matter was handled in other
areas,
will demonstrate eventually what went on in any 'zinc area' of any note
anyway.
A slight problem though, England only is sought - Wales is another matter
and quite a bit of tech. data. is available (1908 onwards - flotation)...
one can only assume that same was duplicated elsewhere. Mind you, there
is
much available on the Nenthead Plant and of course Forcecrag - one
musn't
forget the North Wales Orefield (I enclude the LLanrwst Area), since zinc
featured quite a bit there. 1913 is a completely irrelevant date: zinc was
an
important product twenty years before, and indeed a bit before that, so,
with not a great deal of evidence other than Govt. statistics (&
Taylor's,
Kitto's and Nancarrow's mentioning of handling), one can only resort to
documentary and Stats. evidence really... interpretation must be left to
educated assessment with what is at and in hand.
Enough rambling.
Regards, Bernard
In a message dated 04/07/2011 20:41:24 GMT Daylight Time,
[log in to unmask] writes:
At 19:38 04/07/2011, Bernard Moore wrote:
>Dear Phil,
>Not quite. May I refer you to the Mins.Stats. (Burt. et al), since zinc
>production - & it's increase (pertinent to a gradualy increasing
importance
>and value as a commodity), is clearly evident via this source of info..
Yes - but can that be determined from the archaeological record? What
you have cited is the documentary record which Phil is aware of - as
he stated -
>But there would be no way of knowing
>(other than documentary record or sampling of dressing waste) if it
was
>collected as paying ore or discarded. Archaeological evidence for
specific
>zinc recovery might therefore be difficult to distinguish from that of a
>mine dealing only with lead.
We know that many lead mines shifted to zinc to maintain production
but that was achieved by manipulating the existing gravity separation
methods of ore preparation. How would that be identified in the
physical evidence surviving on the dressing floors? Even the froth
flotation process, when introduced, cannot be said to be a
symptomatic of a shift to zinc production. It was capable of treating
ores from polymetallic deposits and its introduction to what had
previously been primarily a lead producer might imply that zinc ores
were being separate out from lead but that was not always the case.
Greenside, in what is now Cumbria, introduced froth flotation in the
1930s but zinc is not listed as a product - just lead. See Murphy,
Black Gold, (Moiety 1996).
The documentary evidence provides a clearer picture of production but
unfortunately the collated statistics you cite (Burt et al.) end in
1913 - too early to pick up on the changes which might have been
brought about by the introduction of froth flotation.
Peter
Dr Peter Claughton,
Blaenpant Morfil, nr. Rosebush, Clynderwen, Pembrokeshire, Wales SA66
7RE.
Tel. +44 (0)1437 532578; Fax. +44 (0)1437 532921; Mobile +44 (0)7831
427599
Hon. University Fellow - College of Humanities, University of Exeter
http://people.exeter.ac.uk/pfclaugh/about.htm
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