Hi Larry.
I mailed you a week or two back to say I have a detailed plan of an Edwards
plant and would you like a copy????
Take Care.
Roger Baden Bradford,Of Elizabeth, South Australia.
-----Original Message-----
From: Larry Southwick <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Saturday, May 12, 2001 10:58 PM
Subject: Edwards gold process
>Back in April, 2000, a search was being made for a description of the
>Edwards Pyrite & Ore Reduction Co. process as used in Western Australia. I
>only just now came across the search in reading through the various
postings.
>By now the search may have been completed, but following is some useful
>information from an old reference that may be hard to find.
> The book is entitled Gold Mining and Milling in Western Australia, by
>A.G. Charleton, published by Spon in London in 1903. The book is full of
>descriptions and flow sheets. In the section on the Great Boulder Sulfide
>Works (page 332 ff) a photo appears of a series of Edwards roasting
furnaces
>under construction. I've seen these described elsewhere (Eissler,
Metallurgy
>of Gold, 5th edition, 1900, page 306 ff for example has several drawings).
>It also seems to me the Jackling furnaces used at Mercur in Utah in the
>1890's were an adaptation of this design. Such mechanical roasters are
>summarized in Liddell, Handbook of Non-Ferrous Metallurgy, 1st. edition
>(1926), page 310 and 315. James does not have much.
> In any case, the book in hand is a pretty good source. The description
>and photos were taken from the Colonial Mining News of May 1, 1902, as well
>as the July, August and September 1902 Reports of the Chamber of Mines of
>Western Australia. The process is applied to sulfide ores, wherein the
gold
>is refractory until the sulfides have been roasted.
> Basically they are long rectangular box girder furnaces. The ore was
>moved and stirred by rotating rabbles, located along the length and the
whole
>assemble could be tilted about a central pivot point using screw jacks at
the
>discharge end. The rabbles rotated alternatively in opposite directions,
>there being say 15 in a furnace 64 feet long by 6ft 6in wide. Capacity was
>12 tons/day fired with wood, or 15-17 tpd fired with gas. At Great
Boulder,
>after roasting, the ore was treated by pan amalgamation and then the
cyanide
>process.
> Three other plants are described, one at the Kalgurli Sulphide Works
(p.
>354), one at the Golden Horseshoe Smelting Works (p. 403), the last at the
>Tasmania Gold Mining Co. in Beaconsfield, Tasmania (p. 419). An article
can
>also be found in the July 21, 1900 issue of the Engineering & Mining
Journal.
> All of these relate to the Edwards furnace, not a process as such.
>Digging in the sources for the above references may be beneficial if more
is
>needed. Charleton has description of many plants, so if the name of the
>particular plant of interest is known, it might still be a good source.
> Does anyone know if the gentleman doing the search, Graeme Cartledge,
was
>putting together an article or paper on all this? His email address as it
>appeared on th eoriginal posting and as it still appears in the "list of
>mining historians" is no longer valid. Nor could I find him in the list
for
>Australian mining history.
>
>Larry M. Southwick (Cincinnati, Ohio)
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