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

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