Process for Centrifugally Treating Particles of Metallic or Mineral Bearing Substances of Different Degrees of Specific Gravity.
Year: 1891

page_text: Date of Application, 13th Jan., 1891-Accepted, 7th Mar., 1891
An Improved
COMPLETE SPECIFICATION.
Process for Centrifugally Treating Particles of
Metallic or Mineral Bearing Substances of Different Degrees
of Specific Gravity.
I, ORRIN BURTON PECK, Mining Engineer, of 162, Thirty Fourth Street,
Chicago, in the County of Cook and State of Illinois, United States of America,
do hereby declare the nature of my invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
The object of my invention is the process of treating and separating metallic
or mineral bearing substances of different degrees of specific gravity when in a
fine or powdered condition, by subjecting them to the action of gradually decreasing
centrifugal force in a revoluble vessel, which is rotated at a high degree of speed at
the commencement of the operation, and at a gradually decreasing speed to the end
of the operation, and my improved process consists in the mode of so treating fine
or powdery material and of operating a machine or vessel to accomplish such treat-
ment as hereinafter described and claimed.
In the drawings, Figure 1 represents a side elevation partly in section, of
mechanical means which may be employed in carrying out and applying my new
process or method of treating fine or powdered materials containing particles of
different degrees of specific gravity; Fig. 2 is a vertical section taken on the line 2-2
of Fig..1 looking in the direction of the arrow, and Fig. 3 is a vertical section of
the revoluble vessel in which the material is treated.
I have found in the treatment of fine or powdered substances in an open revoluble
vessel to subject them to the action of centrifugal force that the quantity of the
matter which remains in the revoluble vessel is governed by the rate of speed
at which the vessel is rotated. If the revoluble vessel be rotated at a high rate of
speed, the material treated will be thrown by the action of centrifugal force up
around the sides of the vessel into a position more nearly approaching a vertical
line than when the vessel is run at a reduced speed. The lines shown in Fig. 3
diverging from the top of the vessel to the bottom on one side will serve to illustrate
the position and quantity of material in the revoluble vessel at differont degrees of
speed. I have also learned that the heavier particles are more difficult to discharge
than the lighter ones under the same conditions, requiring a greater centrifugal
force, and hence a higher speed of the vessel. In order, therefore, to avail myself
of the advantages of the facts above explained, I have conceived the idea of
subjecting the matter treated to the action of centrifugal force in a vessel run at a
constantly decreasing rate of speed. In other words, I have conceived the idea of
running the vessel at a high rate of speed when I begin to introduce the matter to
be treated, and to constantly and gradually decrease its speed until the end of the
operation, which will be when the vessel has become sufficiently filled for emptying.
In this way a portion of the matter treated is permitted to gradually and constantly
accumulate on the surface of that already retained in the vessel, thereby gradually
increasing the quantity retained or accumulated as the speed, and consequently the
centrifugal force developed, is diminished. And as the heavier particles are more
easily and readily retained in the vessel than the lighter particles, they constantly
lodge on the surface of the accumulating mass in the vessel, and form by far the
larger portion of the material caught and retained as the speed of the vessel
decreases.
In arranging mechanical means for carrying out or applying my processes, I
mount an open and suitable revoluble vessel A on a rotatable shaft B, arranged and
supported in any proper and suitable bearings, so that it may be rotated, and with

page_text: it rotate the revoluble vessel at a high rate of speed. This shaft may be driven by
a belt C arranged on a pulley D, adapted to be driven by the engine in any con-
venient way. The shaft on which this pulley is mounted, and which I will term a
power shaft, although, as shown in the drawings, it is an extension of the crank
shaft of the engine, is provided with a taper pulley or sheeve E, which of course
rotates with it. A belt e runs over this pulley to another taper pulley F on a shaft
for driving the governor of the engine. The taper pulleys E and F are inclined in
opposite directions. The shaft for driving the governor of the engine is provided
with a pulley G, which connects by the belt g with the governor of the engine, as
shown in Fig. 1. The shaft for carrying the pulley G also carries a pinion wheel H
at its lower end, which engages or meshes with the series of gear wheels shown in
Fig. 2, so that as it rotates the train of gear wheels will also be rotated. Through
means of these gear wheels a threaded rod I is rotated. The arrangement of the
gear wheels is intended to be such that the rod I will rotate at a very slow rate of
speed. A lever J is fulcrumed in any convenient position so as to carry at one end
a belt guide K, and at the other a nut L engaging with the screw threaded rod I.
Of course it will be understood that the belt guide and the nut are connected to the
lever J by a proper link or connection capable of moving them up and down in a
vertical plane, as the ends of the lever are raised or lowered. The belt guide K
engages with the belt e so as to carry it up and down, as it may be moved in one
direction or the other. When it is intended to treat material in the revoluble
vessel, it is started while empty at a high rate of speed through the power of the
engine rotating the pulley D and driving the belt G. The requisite speed of the
revolving vessel can be secured in a very short time, and the material to be treated
in a fine or powdery condition introduced or poured into it, preferably in a small or
appropriate stream, and preferably mixed with water, as shown in Fig. 1. As the
shaft on which the pulley D is mounted is rotated, the taper pulley E will also be
rotated, and also the pulley F through the connection of the belt e. At the com-
mencement of the operation the belt e is at its highest position, or on the smallest
part of the pulley E and the largest part of the pulley F, and with the pulley F the
pulley G, that connects by belting with the governor of the engine, will be rotated
at a low rate of speed, as compared with the speed of rotation of the pulley E and
of the revoluble vessel. As the pulley F and its shaft rotate, however, they will
rotate the threaded rod I through the connection of the gear wheels. This will
gradually cause the nut L to rise, and the belt guide K to descend. As this takes
place the belt E will constantly be moved toward the smaller end of the pulley F.
This will increase the speed of rotation of such pulley, and the pulley connecting
with the governor of the engine. As the speed of the governor is thus increased,
it will gradually shut off or diminish the supply of steam from the engine to the
cylinder, so that the shaft B and the revoluble vessel will rotate at a diminishing
rate of speed. This constant diminishing of the rate of speed of the revoluble
vessel will continue until the end of the operation, which is intended to be timed so
that the vessel will be filled as much as intended with the heavier particles of the
matter treated. This may require an hour, or more or less, according to its size
and the amount of material which it is deemed advisable to retain in the vessel.
But the intention is, that the rotation of the vessel shall commence at a high rate
of speed, and gradually diminish until the operation is completed. The means
described above will effect this end, although it is obvious that other means can be
employed for reducing the speed of the revolving vessel from a high to a diminished
speed of rotation; and I do not therefore desire to confine myself to the specific
means described, nor do I desire in this case to claim the mechanical features shown
and described, as I propose to make them the subject of another application.
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 :-
The process of treating and separating particles of metallic or mineral bearing

page_text: substances of different degrees of specific gravity, which consists in subjecting them
as introduced to the action of centrifugal force in a revoluble vessel rotating at a
high degree of speed at the commencement of the operation and afterwards at a
diminishing speed, substantially as described.
•
Dated this 13th day of January 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.