Western Kansas world. [volume] (WaKeeney, Kan.) 1885-current, 1896-02-01
TESTING THE ORES.
How Samples from the Diggings Are Pre-
pared for the Assay Once.

How Samples from the O1SS1nSS are XIV
pared for the Assay once.
To the uninitiated but observant
stranger who wanders up and down in
| the labyrinth of shafts and tunnels,
diggings and dumps of n genuine min
| ing camp perhaps there is no subject
more full Of interest than the process
by which lump of brown ore, which,
to his inexperienced eye, looks not in
/ the least attractive, is made to yield
| it's share of silver and gold, or the
means and methods by which the min
| ing man at his side so confidently as
sures him that ton of that ore will
go 1888 ounces in silver and $17.55 in
gold. Even the eastern mining expert
or graduate from some mining school
will wonder how, in the log cabin or
pine shanty, destitute of all the elab-
crate paraphernalia TO which he has
been accustomed, these results are SO
readily and accurately obtained.
As a general rule the majority of the
ores, except those containing the pre-
cious metals, for purposes of purchase
and sale are valued according to the
cost of mining and shipping, SO that, ex-
cept for metallurgical purposes, it is uE-
necessary to seek to determine with
much accuracy the contents and value
of such ores. In case of ores rich in
the precious metals, however. it is en-
tirely different, as in their purchase
and sale both parties, the buyer as well
as the seller, want to ascertain ac-
curately and to a certainty the value
of the entire lot The methods by
which this knowledge is obtained are
so simple as to be easily understood
and practiced by many man who does
not know the technical symbols of the
metals he is determining or could not
give a scientific exposition of the proc
ess, but, nevertheless, in his line, he
is an accurate and successful assayer.
When a quantity OF ore is to be sam
pied for assaying it is first broken by
an ordinary rock crusher into pieces
the size of an English walnut, after
which it is shoveled back into the car,
but in such a manner that every fifth
shovelful is thrown aside by itself, the
remaining four-ffths being finally
taken away This fifth portion, known
as the sample is then reduced to q
much greater degree of fineness by
means of Cornish rolls. 1t is then piled
on the floor. in cone flattened out, and
divided into four equal portions, AND
two opposite quarters are then removed.
The remaining quarters Ire again
thoroughly mixed and again piled in
cone, fiattened and quartered; this
operation being epeated until the sam
pie is reduced to 100 pounds. It is then
weighed repeatedly for the purpose Of
determining the amount of moisture
contained in the ore, which in some
ores, especially those of the concen.
trates, is so considerable as to make
very appreciate difference in the
| weight. The moisture is then expelled
and the orc is crushed to such degree
of fineness that it can be passed through
| sieve containing 100 holes to the lineas
inch. The sample is next put up il
| small bottles, which are scaled witt
sealing wax and then stamped for the
purpose of preventing the possibility
of their being opened or tamDered with
without detection.
The above is the process of samplins
used among the mines, and the sam.
pie is now ready to be assayed, but
only d SlIldI1 pOIllOu IL IL w III NC uSCO
for that purpose, and the quantity gen
orally taken is what is known as an
''assay ton," which weighs 90, 166 MILL
grams, or little more than $50 grains
troy weight. This definite amount is
taken, partly as matter of conven-
fence, and also because the assayer
wishes to ascertain, as quickly as posi-
BILE, how many ounces of the precious
metals to the ton are contained in this
ore The method used depends upon
the following principle: The avoirdu-
pois grams ton of 1000 pounds contains
80, 166 ounces troy weight; hence, when
| &c, 166 milligrams of the unassayed ore
are taken, the weight of the resulting
BUTTON of gold or silver in the MILL
grams represents at once, without any
further calculation, the number of troy
ounces of gold or silver in the avoirdu-
pois ton of the ore.
This method was invented in the
Columbia School of Mines in New York
city and is in general use throughout
the world wherever there is assaying to
be done.-Boston Transcript.