The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1909-06-13
SILVER ORES AND
THEIR CYAN|DATION
University of Utah Graduate by
Wall Fellowship Is Secur-
Ing Results.
COMPLEX WORK is
GONE INTO THOROUGHLY
Researches Mean Great Deal to
the Silver Ore Miner and
Mill Man.

IneodOre 4. holJ. VINO leCcuIiJ eN"h
his degree rs master Of science IN metal
lurgy at tho University Of Utah, has
lust finished his thesis, ''Features IN the
Cyanidation OF Silver Ores Very Ut
tie reliable data has over been pub
lished along this line up to date, but
the rapidly growing Importance OF the
questions relating to the treatment Oh
silver ores by this process makes Mr'
Holt's work most timely and valuable
IT. is an interesting fact that nearly all
of the big steps in the cyanide lndus-
try have been started in Utah. Jhe
first practical gold cyanidatlon plant
ever built was the Golden Gate mil
at Murcur Utah. This plant was INC
pioneer in this line, and SINCE tDat UNI, tiln9
thousands of mills have gone mp AZ
over tho country for the treatment OIL
gold ores aud amalgamatlon ana cohcen'
tration of tailiTgs.
In 1856 Mr. Louis JanDin, IT., OF Tue
Ontario Silver Mining company OF farE
City, did the first experimental Work
which amounted to anything win
view 10 solving the problem oil treat
ment Of silver ores by cyanide methods.
The first strictly silver cyanide plant
was built and operated at Chiorlde
Point, Toole county, Utah, In io9S'
And now another Utah man comes fort9
with the first extensive experimental
work tending TO solve tho pToolcIns
which are puZzlinp modern metalurgists
who arc treating their silver ores by
cyanide methods Mr.. Holt has not yet
completed his work, but will continue
the solution Of tho problems next year.
The work this year has been done under
the Wall Research Fellowship, and as
Mr.. Holt has been selected for tins fcl-
lowship next year he Will have another
entire year to devote TO the work. An
idea Of the amount of work already
done can be obtained in the results of
400 tabulatcd experiments. Mr.. Holt
assistance from DR.. Ii.
II. Bradford, under whose direction the
work was done, and several other mem
bers Of the faculty who assisted hlm IN
special parts of the problem.
In Mr. Holt's experiments the ez-
traction was accomplished in every case
by means of agitation methods, as this
seems to be rapidly replacing the old
methods Of teaching a sand product of
VARYING cOarseness. The agitation was
done in eight ounce bottles, only part.
" filed with solution, placed in suit
able wooden frame that the pulp
L
frame was revolved 10y means of water
motor.
In summing up his work Mr., Holt
says: "The chemistry OF the cyanide
process as applied 10 silver ores is COM
plex and imperfectly understood. Each
silver mineral presents IFS own peculiar
The fundamental laws of
chemistry explain In remarkable way
many of the reactions otherwise obscure.
Results obtained by experimentation on
ores are often misleading, due to their
nature. II is therefore advis-
able TO work on artificial ores of known
composition before MAX
ing generalizations regarding the sew
eral minerals.
'The halogen compounds OF silver
are the most soluble form in which it
occurs, and no oxygen is required for
their solution In potassium cyanide.
Native silver is next in order in solu
biGty, in IN aerated solution, and II
dissolves in accordance with Elsner S
equation.
"Argentite, the silver sulphide, re-
Qures the removal OF the soluble sui
salts are applied for this purpose and
litharge, though less used, presents de-
cided advantages over lead acetate
"Mercury compounds are effective by
virtue OF their ability 10 form insolu.
bic sulphides, and not by their prop
crty TO dissolve the rebellious minerals
Oxygen, or an oxidizer, is essential TO
the continued solution Of the silver sui
phide in cyanide, even in the presence
Of lead salts. The presence Of lead or
mercury compounds decrease the solu.
bility OF the complex antimony and
arsenic silver compounds in n cyanide
Bromo' cyanide is not n solvent for the
silver minerals. In the presence Of free
cyanide it may give beneficial results
by virtue OF Its power as an oxidizer.
"a chloridizing roast is about equally
effective on all silver minerals and sub
sequent treatment by cyanidation will
give equally good results.
1.-THE problem of interfering minerals
is more serious in the cyanidation of
is due TO the stronger solutions used
and to, the great chemical activity of
silver
The thesis includes a complete tabu-
Iatlon of the work done. showing not
only the results obtained by the treat |
ment of different combinatio Of miner
ais and ores, but the effects Of varying
period of agitation, fneness of the
crushed ore. strength Of solution applied
and other variable conditions An in
genlous system of graphical represen-
tatlons by means of curves shows the |
effects Of time and solution strength ou |
the various ores under varying condi. |
lions of treatment.
MI Holt has written n number Of |
articles for some Of the mining journals |
recently. and others will follow giving |
much Of the data which he has oh |
sained