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

after trying percolating gave it the
preference, and are now pushing for
enlarged capacity on this plan. This
mode Of working is being generally
adopted in South Africa, presumably
| by Mr.. MacArthur's instructions.
From my South African oorrespon-
dent l learn they are now construct
ing all mills for this way of operating
the process. The new mill of the
Shasta company is also changing to
the percolatinG plan. The Mercer
mill OF Utah was the first, in this
country, to start on the percolating
plan, on q scale of thirty tons per day.
All peroolated solution, whether from
agitators or tanks, contains cyanide,
gold and silver in solution; conse-
quently, ell vessels receiving the same
should be perfectly tight, as you pre-
sumedly are handling valuable liquid.
This percolated solution is now trans
ferred to the prccipitating box, Of
size according to value of ore and
quantity to be treated. The box
used At Calumet is IA feet long, with
IA apartments. These boxes have
wire screens on the bottom, and are
filed with zinc shavings four inches
deep. The boxes are so constructed
that the solution is made to pass
through the body Of shavings, which
preclpitates the gold and silver in a
dark blacklist powder. BY this part
OF the process given part of the zinc
10 destroyed; but this il of no partic-
ular moment, as the loss is but trifing
in dollars and cents.
Tho process is very simple and
easily worked, when you have your
plant right, and start right on the
per cont Of cyanide and time for
your especial ore. As to reducing
ore, It is ~ yet an unsettled question
whether i il best to crush wet or dry,
oil points being considered. The
majority Of the mills are crushing
their ore dry. The Calumet Co. has
started out on = new lay, which I
think will be the winning ono; to-
wit, crushing by stamps, and running
the cyanide solution through the bat
terry instead Of water. In other words,
crush your quartz in the solution;
thus you combine agitation, percola.
ton and expedition.
This, though now deal, suits us,
and thus far no disadvantages present
themselves, that override the advan-
tages gained. OF course you have to
keep pumping your solution back,
and running round. For dry reduc-
ton, the Shasta Co.'s mill uses pull
vsrizing barrels. The advantage
gained by the use of barrels is, all
the orc is of equal grain, and, as
you do not require fine crushing for
this process, by uniform grain of ore
you do faster percolating. Time,
however, is the essence of per cent
more than fine crushing. As to cost
of working the process, there is a
good deal to know before this ques-
ton can be correctly answered; to
give some idea, will say from 81 to
Is per ton. You can extract the gold
and high per cent. of silver from
any ore. The question is as to time,
and at what per cent of cyanide.
| As to silver extraction, at first l
paid no attention to il, but have found
the process very efficient, except re-
curing more time than gold; yet sill
yer is in so many combinations that
testing should be the only guide for
any especial ore. 1t will work readi-
ly all ores worked by pan amalgama-
ton. Taking California ores, from
some it will often extract more silver
than the total cost of milling. AS to
cost Of plant, for gold it is very much
cheaper than the ordinary first class
mill; for silver, the expense will not
DO half the cost OF the pan mills.
To express myself as to the process
will be to declare it one of the won
ders OF the times. am aware that
it has not the friendship OF some men
of science who talk wisely on what
they don't know. To me all opposi-
ton is as puff of wind in the face OF
every day demonstrated facts as l
handle the process. have been
cursed too often by disappointments
in yields, by our old systems, to not
appreciate the fact of always being
sure of high per cent of the value