Idaho semi-weekly world. [volume] (Idaho City, Idaho Territory) 1875-1908, 1892-05-03
n.eARrHUR.roRREsr PROCESS

AocA I'm Y .rVRW G0A EDVN1DS
what Il IL, and How II 10 Applied
A Revelation In Ore Reduetion-
The Experlnents in Callfornla.
Mining and Scientific Press.
1t being generally known that the
Calumet company was the frat to in.
troduce the Macarthur process into
Ca'ifornia on any practical working
scale, my time has been considerably
taxed in answering letters from very
many mining men, not only in Cali
fornia, but lsewhere, al inquiring Is
TO the practicability Of the process,
etc, etc. Seeing so many are inter-
ested, have concluded to write .
description OF it, giving data 90 many
desire, and let you publish it:
To preface, the process was first
promoted by the Cassel Gold. Extract.
ing company, Of Glasgow, Scotland
from there II was introduced into
Australia, South Africa, Now Tea
land, and tho United States. The
patents for this country are held BY
the Gold and Silver Extracting, Min.
ing and Milling company, Of Denver,
Colorado, OF which ex-senator Tabor
is president, and Col. T. L. Wiswall
secretary. This company was formed
some two years ago, but little pro.
gross was made, however, until within
the past year, aud since the Denver
company completed their fifteen.
ton mill and commenced working
ores, which gave such unexpected
and satisfactory returns, in the way
OF high per cent, that every invssti-
gator was filled with wonder, and saw
the revolution likely to follow.
On my attention being called to it,
nov one year ago, l at once started
for Denver, and was allowed oil the
desired privileges for close investl-
CATION. The more investigated the
more merit the process presented,
and soon became convinced that it
was worthy Of more than passing
consideration; in fact, in my own
mind, concluded to "sail in and
and find out all about it, on practical
working Of our own ores. Returning
to California, ! commenced series
OF experiments, agreeable to instruc-
lions received in Denver from their
leading chemist, and soon made bet
ter results on our ore than made in
Denver. 1t now took no time to de-
eide as to the propriety Of introducing
the process on large scale in the
Calumet mill, under my management,
and whore it is now doing satisfaoto-
~ work and being extended, and
will be up to 100 tons day.
It may be information to many ia
state that in South Africa thirteen
mills arc now operating the process
with great success, and that mills are
already in operation in Colorado
Utah, Montana, Dakota and Califor.
MIA At the Needles, in San Bernar.
dino county, Cal, 100 ton mill IL in
course Of erection. Being among the
first in this country to accept its mer.
its, I fancy, by this time, ] know
something about it, and hence pre-.
sumo to speak.
The Macarthur Forrest process il
the use OF weak solution of cyanide
OF potassium. The strength Of Cyan
ide should be, as testing your ore will
show, the proper per cent. for extract.
ing highest per cent. of the preciou,
metals, say from one-half Of one pei
cent. to II, then treating your ore fol-
a given length of time with this solu'
ton; time for treatment is according
to the character of your ore and met
ais, how much base and what kind
To get at this correctly, few test,
are necessary; but it is easily worked
out. And here it is proper to state
that time is more the factor of pei
cent. than a high per cent. of cyan
ide. We have made many tests or
this point, and all clearly establish
this fact. have failed in per cent
Of extraction on some ore, and then
by few experiments, gained high
per cents. from same. 1t is process
of study, but once you get time and
per cent. determined, then there is nc
failure in your extraction from that
especial ore, no matter to what ex,
tent you may 20. So true has thi'
been with our working, on small and
Il L