The Black Hills union. [volume] (Rapid City, Pennington County, Dakota [S.D.]) 1889-1904, 1895-09-06
NEW REDUCTION PLANT.

>
Roasting and Teaching PROCESS for Low
Grade Ores VIII soon be Tested
a. Wilkes Montana.
Within two miles Of Wilkes, Montana,
there is now in process of construction
a plant designed for the reduction OF
ores. which when completed will be u
Of the largest enterprises in the state
and which, if it proves a success. will
reyolutionize the reduction of low grade
refractory gold and silver ores.
The plant is at the Minah mine,
owned by the Minah Consolidated com
pany of London. which has leased to
parties in Minnesota. The plant will
cost $4,000 and will be ready to begin
operations in a few days.
Work on this plant has been carried
@ n very quietly and until recently very
little was known concerning it. except
by people in that immediate vicinity.
The plant will consist Of q main build
ing JJx150 feet. four stories high, be-
sides boiler and engine house. 4OXS0
feet, together with several other build
iDgs connected with the main building.
The plant is to be equipped throughout
with the latest improved machinery for
the reduction of ore. Power will be fur
nished by a 1OO-horse power engine.
which will also operate an electric plant
designed to furnish light for both the
mill and the mine.
The new chemical process employed
in the roasting and teaching Of ores has
never yet been tested in this country,
though it has been in successful opera
ton for ON time throughout both Eng
land and Germany.
The ore is conveyed by tram cars di-
rcctly from the sorting-room at the mine
into the fourth story Of the mill, where
it is crushed to a moderate degree Of
%finencss. and then descends to the third
floor. where it is crushed still finer by
means Of Cornish rollers, and returned
to the fourth floor. Here it is passed
through screens for separating the
waste matter from the ore. 1t is then
ready for the roasters. Two Breckner
roasters, of a capacity of seven tons
each twenty-four hours are already in
position at the plant, and preparations
are made for others, which will be put
in Immediately as soon as it is demon
strated that the process is a success in
this country. Connected with the roast
crs are portable furnaces.
In the first story Of the roasting
plant are two Krom rolls OF a capacity
Of fifty tons a day; through these the
ore is passed, after which it is conduct
ed to the teaching plant, which is di-
rectly below the roasting works. The
teaching department is fitted with ma
chinery for applying the chemical pro-
cess through which the ore passes at
ter leaving the ~roasters, and for pre-
cipitating the precious metals.
The gases generated by the roasting
ores are carried off by an immense cov
cred fume, leading from the works to
q large smokestack above. Here the
gases pass through a process which con-
verts them into sulphuric acid in the
smokestack. The arsenic which es-
capes through the 1ume is also caught
and removed. It is estimated that by
the new process rs per cent. of the
value of the ore will be saved at the
start and that before the expiration Of
three months % per cent will be saved.
This is a great consideration, as by the
majority of the processes now in use so
large a percentage of the precious metal
escapes and is lost that it is not profit
able to work any but the tolerably high
grade ores, while if a more economical
process a be perfected in this country
many low grade mines, now lying idle,
can then be worked to advantage.
This group of mines owned by the Mi
nah company is situated near the cele-
brated group and consists Of seven
claims. The mine is in fine shape for
producing ore, as a large amount Of de
yelopment work has been done on the
properties, and there is a large qua
hty of ore on the dump and also in
the slopes, awaiting the starting up of
the new reduction works.
Ihe ore streak averages one foot in
width and carries one-half ounce of
gold and twenty-five ounces of silver.
-Four tunnels have been run in on the
ore vein, three Of which are nearly 2,OOO
feet In length, while the fourth tunnel.
which Is TOO feet below the surface, has