Improvements in Apparatus for Grinding or Pulverizing Ores and other Substances.
Year: 1897

page_text: Date of Application, 18th May, 1897--Accepted, 3rd July, 1897
COMPLETE SPECIFICATION.
Improvements in Apparatus for Grinding or Pulverizing Ores and
other Substances.
I, JOSEPH KITHCART CLARK, of Butte City, in the County of Silver Bow and
State of Montana, United States of America, Mining Engineer, do hereby declare
the nature of this invention and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:-
This invention relates to new and useful improvements in apparatus for grinding
or pulverizing ores and other substances.
Heretofore many attempts have been made to produce a pulverizing machine
capable especially of use in grinding ores, which would work rapidly and economi-
cally, which would finely pulverize the ore and which would also deliver the
product at a uniform degree of fineness; but so far as I am aware, while many
pulverizing machines have been invented, none of them have been capable of
doing sufficiently rapid and fine work to make their use economically successful,
especially for working the poorer grades of ores.
To produce a machine which will deliver a much greater product with a given
horse power, than prior machines, and which will also be capable of delivering an
exceedingly fine and uniform product, is the object of my invention, and this
object I accomplish by providing a grinding or pulverizing machine of the ball
and drum type, having axial inlet and outlet openings, with a positive feed for the
material to be reduced, the usual air-blast being discarded; the arrangement being
such that when the material in the drum reaches a certain level further feeding
of the material will cause the overflow, from the other end of the receptacle, of the
material reduced, the discharge of the finished material being thus effected by
displacement instead of by an air-blast, as in prior constructions.
In the accompanying drawing forming a part of this specification, a vertical
longitudinal sectional view of my improved apparatus is shown,
A drum A, preferably made of sheet metal, is provided with lining A' of porcelain
or other suitable material, and contains a greater or less number of porcelain
balls B or flint pebbles, or similar grinding devices.
The drum is provided on one head with the inlet neck C and on the other head
with the outlet neck D), which necks are mounted to turn on suitable bearings E
of any approved constructions, and which bearings are fastened on the supports E¹,
which form the supports for the rotating drum.
As shown in the drawing, the inlet and outlet openings are arranged opposite
each other in the heads of the drum, and the outlet opening is unobstructed by a
sieve or other straining device, so that the pulverized material has a free and
uninterrupted passage from the drum, and can therefore flow therefrom in a
regular stream.
As shown, a cog wheel F is fixed on the outlet neck D, outside of the bearing E,
and said cog wheel is engaged with a driving pinion G, fixed on the same shaft G₁
with the belt pulley H; this arrangement may, however, be varied if desired.
An inclined chute K i arranged below the outer end of the tube J, as shown,
the upper end of said chute being directly below the tube .J.

page_text: In the construction shown in the drawing, L indicates a fixed piece which is
located adjacent to the outer end of the inlet neck C, which neck has an annular
tongue a at its end which is adapted to fit into an annular groove in the said
fixed piece L. The fixed piece L has an L-shaped neck M, the bottoni of which
leads to the bottom part of the inlet neck, and the upwardly projecting part of
which neck is connected with the supply pipe N, for the ore to be ground.
conveyor screw 0, which in the construction illustrated is in the bottom horizontal
part of the neck M, serves to convey the material to be ground into the drum, and
said screw is rotated at the required speed by means of a pulley P' and belt Q,
independent of the means for rotating the drum.
The operation is as follows:
A
The drum, being supplied with a suitable quantity of balls or pebbles, is caused
to rotate, and the ore or other material to be treated is fed into it through the
inlet opening. As the ore is fed into the drum the material in the drum gradually
rises until it reaches the level of the discharge opening, the ore being meanwhne
finely ground by the action of the balls or pebbles in the drum. As the material
is fed into the drum, the larger and heavier particles gravitate to the bottom of
the cylinder, the finely ground material, which is often an impalpable powder, on
account of its lightness rising to the top, and consequently when the material in
the drum rises to the level of the outlet, the lighter material, being displaced by
the heavier incoming material, is slowly crowded through the outlet and is
discharged from the machine, falling (in the construction illustrated) upon the
chute K.
•
}
The delivery of the pulverized product from my improved machine is thus
effected. not by the use of a blast or by suction, as have heretofore been common
practices in machines of this description, but merely by gravitation and displace-
iment under the influence of the positive feed. In this respect my machine
constitutes radical departure from prior constructions, the result being that
whereas in prior machines employing a blast or exhaust for delivering the product,
only from two to four tons per day of product ground to 125 mesh could be
produced, with my machine, in which the discharge of the finished product is
effected by displacement under the influence of the positive feed and without the
use of a blast or exhaust, but causing the discharge by the action of the feed alone,
I am able to and do produce from twenty-four tons of dry product to thirty-five
tons of wet product per day, having a fineness of 125 mesh. A further advantage
of my improved machine is that the fineness of the product may be accurately and
quickly regulated by regulating the feed, as, the degree of fineness being controlled
by the time to which the material is subjected to the action of the pebbles, by
increasing the feed and consequently permitting the material to remain in the
drum a shorter time, the finished product will be of coarser mesh, whereas by
reducing the feed and permitting the material to be subjected to the action of the
pebbles a greater time it may be reduced to a much finer condition.
Instead of a chute, any other suitable device may be used for carrying off the
ground product. When a chute is used, the top thereof should be directly below
the end of the chute J, so that when the machine is operating on dry material the
powder will not drop any appreciable distance upon the chute, as otherwise a draft
might carry away a great part of the same.
Only the finest particles of ore pass out of the drum, as, for the reasons already
stated, they alone rise to the surface and are discharged through the outlet
opening. The apparatus requires practically no attention, as all that is necessary
is to regulate the feed so that the discharged material will have the requisite
fineness.
Although my improved apparatus is intended primarily for the treatment of
ores, it may also be used for pulverizing other minerals and similar substances.
I wish expressly to disclaim any form of pulverizing apparatus of the ball and
drum type which uses a blast to effect the delivery of the pulverized materials;
my invention, as stated, consisting in substituting for the blast a positive feed for
..

page_text: the material to be reduced, and effecting the discharge by displacement under the
action of the feed.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. In a pulverizing apparatus of the class described; the combination with a
rotary receptacle, of grinding balls or pebbles arranged in a mass therein, inlet and
outlet openings in said receptacle, means for gradually feeding the product to be
pulverized into said receptacle through said inlet opening, the apparatus as a whole
being constructed to preserve the contained mineral from the influence of a blast
or current of air, whereby the pulverized product will be discharged through said
outlet opening in a flowing stream substantially under the action of the feed alone,
substantially as described.
2. In a pulverizing apparatus of the class described, the combination with a
rotary cylinder having axial inlet and outlet passages opposite each other, and
grinding balls or pebbles arranged in a mass in said cylinder, of forced feeding
mechanism in said inlet passage, said outlet passage being unobstructed and being
of a diameter considerably less than that of the cylinder, the apparatus as a whole
being constructed to preserve the contained mineral from the influence of a blast
or urrent of air, whereby the pulverized mineral will be caused to rise by
gravitation to the surface of the materials in the cylinder and will be discharged
through said outlet passage in a flowing stream, substantially under the action of
the forced feed alone, substantially as described.
11 1011.
1907
HASELTINE, LAKE & CO.,
45 Southampton Buildings, W.C., Agents for the Applicant.