The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1923-12-06
Platinum Takers
fcontinued from Page -

lCOnlluuCQ e-oC -
lido as conducted by johnson Bros
is entirely misleading. as they ne
Lot 10 rid their solutions of nitric
Pa and the coloration is produced
~, the liberation of iodine. If the
sootion is not clearly defined, con-
o,+rated sulphuric acid is added,
,.bich nberates an abundance of
iodine which settles to the bottom in
the form of sponge platinum"
Mr. Dozier's establishment was next
,,,sited and his method of platinum
.,alvsis ascertained. Owing to the
rsct that the platinum in the samples
which Mr.. Dozier assays occurs. ac-
cording TO him, as minute particles of
platinum arsenide, sperrylite, it is
imnerative that the ore receive a pre-
uminary roast to drive off the arsenic
and thus prevent the subsequent vola-
tuization of the platinum. The roast
ing is effected by placing the pulp in
short iron nipple capped on each end
and introducing the whole into a wood
FIRE where it is left at red heat for
about twenty minutes. The arsenic
escapes through the pores of the
metal filtered as it were. while the
nlatinum is obedient and stays be-
hind After this operation the residue
is treated with aqua regia and, when
decomposition is complete, is filtered.
The residue is discarded, while
saturated solution of ammonium
chloride is added to the filtrate. Bar
ring faulty technique, it would now
seem quite proper to filter off the
ammonium platinum chloride, but no;
the whole filtrate, with its acid
soluble salts, including soluble silica
ammonium chloride, and what not, Is
evaporated to dryness. The residue
from this operation is scraped into
another nipple, or gun as Mr..
Dozier calls it, and packed down
firmly with liberal amounts of scrap
paper rammed home with an iron bolt
and hammer. The threads on the
nipple are treated with moistened
soapstone and the caps frightened with
a wrench. The gun" goes into the
fire, where it remains at red heat for
about twenty minutes. It is then re-
moved and the contents are dumped !
into a gold pan. Any hard Jumps are
secured and broken up with a whet- |
stone. After panning off the waste
carbon and like matter the residue is
dried and further cleaned by picking |
out the waste with any convenient !
article, such as a pencil or penholder |
The flakes of platinum" and "plati- |
mum sponge" are then weighed and |
reported Mr. Dozier is able to dis !
tinguish between the metals of the |
platinum group and separates them |
into piles with the aforementioned |
pencil Literally, a pencil assay.
The material which Mr.. Dozier OBJ
tains consists of particles of carbon,
which he calls sponge platinum, pieces
of metallic iron, silicon and some
other substances, as well as a metallic /
alloy reduced from the salts present |
by the carbon in the paper in con-
junction with heat and pressure.
Several pieces of this alloy were
tested for platinum, with negative
results. There were indications also
that some carbon was converted into
graphite.
Mr. Dozier's process is evidently
crude attempt to duplicate method
used more than a century ago to con-
vert platinum sponge to metal. The
sponge was obtained by treatment of
crude placer platinum.
Mr. Dozier does not claim to have
had the benefit of a technical training
and. in fact. refers to himself as just
a plain old clodhopper, which latter
statement was allowed to pass I'M
challenged.
We have here three different me-
thods by three different assayers, all
purporting to find platinum where
none is present. This one detects
platinum in a eoIloidal form; a second
takes advantage of the faulty tech
nique of the commercial assayer; a
third heats the pulp to prevent
volatilization of the platinum.
When one considers the hundreds
Of thousands of dollars being thrown
away in useless work when they |
might be diverted to more remunera-
tive channels, this matter of unre-
liable assaying becomes a problem