Weekly Arizona journal-miner. [volume] (Prescott, Ariz.) 1903-1908, 1904-06-15
.SAMPLING OF
CUSTOM ORES
Explanation of How the
Work is Done.
S. E, BrethertOn, a Yavapai County
Shelter Man, the Inventor of
An Ore Sampler.


the we'll known smelter man, who has
charge of the Bradshaw Mountain
Copper Mining and Smelling Com
pany's smelter at Val Verde, and
appeared in the Mining and Scientific
| Press in November, 1903.
In many custom samplers, whether
independent or in connection with a
smelter, it is best to have every dpart-
ment simple and with as little mys-
terry as possible so that the shipper
will have his ore in plain sight all
through-from the time it is weighed
until he receives portion of the pulp
sealed with the samnling works seal.
| have heard of cases where shippers
also put their seal on the umpire
sample before it is set aside. In this
way he can make perfect check on
the asasys of the purchaser and, if
he is not satisfied with the methods of
sampllng, make his complaint before
the sample is completed.
Methods of hand ssmpling usually
adopted by the smelters in Colorado
are as follows:
First, crush the ore to reduce the
Jumps all below a certain size; then
take out every third, fifth or tenth
shovelful for a sample as the ore is
wheeled away to the storage bins. The
proportion taken for sample depends
either upon the size of the lot to be
sampled or the richness of the ore.
! II fact, the entire bulk of small lots
of rich ore is often treated as sam
pie. Every third shovelful of this
sample is then taken and passed
through a set of rolls; the rolls are
then set up much closer and half of
\ the simplicity taking out every al
terGate shovelful passes through
the rolls again. This reduced sample
is now taken to the sample room.
This sample room is enclosed with
windows for light, and enables the
shipper to watch the work. The floor
where the sampling is done is covered
with steel plates. The sample as
brought from the rolls is deposited
IN two piles, then coned into one cone
and carefully flattened ont and cut
into four quarters, two quarters being
taken for sample and two quarters
being rejected-care being taken to
"alternate;" that is, if the first two
quarters taken up in the wheelbarrow
are rejected and the remaining two
quarters are reconed for sample, the
next time the sample is coned and
quartered the reverse is done by re-
coming the first two quarters lifted
and rejecting the remaining two
quarters on the plate. This is done
in order to avoid any chance to favor
either the shipper or purchaser. (See
Prof. Arthur Lakes sketches Chimes
and Minerals" December, 1903.
After the sample is reduced in
weight to about fifteen or twenty
pounds, it is put through an ordin-
airy sample grinder, which reduces it
to fine powder. From the grinder it
is taken in covered buckets to the
assay Office where the assistant assayer
thoroughly mixes it by continuing the
operation of coming and quartering
until sample is reduced in quantity
to about forty ounces. This forty
ounces is then passed through a 100
or 40 mesh sieve by grinding the pulp
which is too coarse on a smooth, cast
iron bucking board with a heavy
muller. Should any scales of native
gold or silver be caught in the sieve
it is cupelled with a little lead,
weighed, the pulp from which it was
sieved also weighed, the percentage
value calculated, and added to the
assay After the pulp is all through
the sieve it is again thoroughly mixed
and put iuto three different sample
sacks one to be assayed at the works;
one to be sealed and set aside for UNI
pire, in case an umpire should be
called for; and one to be sealed and
handed to the shipper, if present, or
if not, the sample is mailed to him.
Settlements are made as soon as the
assays are compared between the ship
per and smelter, or else the settle
meuts are forwarded on the smelter's |
assays and corrections made afterward !
if the shipper finds any material
difference between his assays on the
shelters pulp and the assays of the
smelter. Should the assays not agree |
a reassay is called for by both parties.
If these repeated assays do not salts |
factorily agree. then an umpire is call
ed into requisition and sent to some |
reputable assayer mutually agreed |
upon between the shipper and pur-
chaser, whose results are to be final.
The same methods as above de-
scribed are followed in the sampling
of concentrates, excepting that no
crushing or rolling are necessary.
In some sampling works and some
smelters samples are first taken out
by hand shoveling, then rolled and
completed with automatic samplers.
If the ore is very rich and spotted,
such as the ores of Cripple Greek,
Colorado, it is all rolled and the en-
tire sampling done automatically.
To the owners of mills where they
mill none but their own ore and
in general, the import
ance of expensive hand sampling for
accuracy does not appeal; but to the
who is not only often in
terested and has to account to the
stockholders for the difference be-
tween metals purchased and sold it
does, especially when running a Gus
tom plant; and while considerable
saving can be made by the usual
methods Of automatic sampling, much
more may be lost by sailing the sam
pies OF large lots with dust from
giving satisfaction to the shipper of |
either the low or high grade ores,
IN account of the ore being at times
ost to his view-the idea being enter {
aimed by them generally that the dust
n the machinery will depreciate the
-alue of their ore, when a very little :
would prove how unTeas- q
Unable their fears are. If 29I. ounces {