Elmore bulletin. [volume] (Rocky Bar, Idaho) 1889-1906, 1893-10-07
THE IMPROVED CYANIDE PRO.
CESS.

The MacArthur.Forrest (cyanide)
process Of ore reduction has undergone
some improvement in the past Is
months. As it is now used on the
Transvaal gold fields. it il thus de-
scribed:
This process is chemical and may be considered the
oniy one on the TransvaAl fields from which eOmmer
ciai result. have far been obtained. Cyanide OF
potassium which Is the active principle ~ the process
known 10 H. capable o. holding gold ~ solution,
and was actually used for that purpose In the arts
long before the Macarthur Forrest process was heard
Of but it, application 10 extracting gold from ore,
and subsequently, precpitating Il cheapy Is ungues
nonAbly discovery u some Importance, the validity
u the patent o which some have doubted, but which
has been successfully maintained in the supreme
Federal Court u America The process itself IL suit
eiently simple solution OF cyanide ~ potassium Is
run into a vat containing the ore aud II allowed 80
hours b. percolate through the mass into rough
alter below, whence i is run through the boxes,
which loi With zinc shavipgs, cat ~ TO pre-
sent the maximum amount OF surface. Entering al
the bottom u the boxes the solution Is forrhed up
through the slarlnRs, ard enters at the bottom IT
the next box, through the whole series Of which II
passes Tie gold, which, after y leaves the vat y in
the form Of cyanide, u precipatcd on the zinc.
which u gradually replaces and then Is easily re.
coVorbe by fusion In The form Of fine metallic gold
The solution is available inr further use By slight
addition 81 cyanogen. By allowing the 10 re
main In the solution for 80 hours It is claimed that
~ per OF the assay value il recoverable; and that
Is increasing the lime and Rgitating the ore, any
thing between o. and 10 per cent can he eNtntted.
Obviously Whistler the former the latter method
Is the more advisable depends wholly the vAine Of
the tsngs or concentrates. IN the case OF aI-ox.
coneentrate- the ounces which by the longer treat.
nlent would be recovered worth the extra eNpen,
diture Of time, while II is equally Gear that In the
case Of i0-dNt or I24iwt stun, such course would
not be warranted
Coming 10 the important question 81 expense, II Is
claimed that the wole cost Is less than that involved
in the preliminary operation II roasting In any Of the
ehlornation processes No accurate calculation has
been published, but IL stated at the meeting oi
the parent syndicate at Glasgow, sometime last year
that ~ y per ton Of tnngs might be regarded As
fair estimate and II is probable that that figure would
not be exceeded III johannesburg. This, however,
only applies 10 low grade tAngs the cost being reg
ulAi.d by the amount Of cyanide used, which again Is
pToportloned 10 the value ~ the Ct now being
shown that the capacity NJ cyanide for holding gold
IN solution IL strictly mitel that In the OF
rich concentrates the expense may be Increased al
most Indefinitely The process Is AZ work In New
Zealand where the results have been favorable, and
IL " stated that il j. TIN only treatment to which the
tailing- from one mine On the Thames gold-iclds
have been found 70 yield 80 far, however, the South
African patents, which owned by the African
Gold Recovery Company, have proved by far the
most valuable Of any Al the Robinson mine. sork
has been going since the beginning Of the
year, and Ia the FIRST I've months ., zJo
returned.