AN IMPROVED METHOD OF SEPARATING OR SORTING ORES, MINERALS, AND OTHER SIMILAR BODIES
Year: 1881

page_text: LETTERS PATENT to Friedrich Carl Glaser, of Berlin, in the Kingdom of
Prussia and Empire of Germany, Engineer and Patent Solicitor, for an
Invention of "AN IMPROVED METHOD OF SEPARATING OR SORTING ORES,
MINERALS, AND OTHER SIMILAR BODIES." A communication by Franz
Büttgenbach, of Lintorf, Dusseldorf, Germany.
PROVISIONAL SPECIFICATION left by the said Friedrich Carl Glaser at
the Office of the Commissioners of Patents on the 30th November 1881.
FRIEDRICH CARL GLASER, of Berlin, in the Kingdom of Prussia and Empire of
Germany, Engineer and Patent Solicitor. "AN IMPROVED METHOD OF SEPARATING
OR SORTING ORES, MINERALS, AND OTHER SIMILAR BODIES." [A communication
by Franz Büttgenbach, of Lintorf, Dusseldorf, Germany.]
The separation of minerals and ores has up to the present time been effected
either by the aid of their specific gravity, or by their more or less foliated or
granular structure, or by the influence of magnetism after roasting or calcining.
The present Invention relates to the separation of these substances by the aid of
the different degrees of hardness thereof.
If two bodies of different degrees of hardness or of cohesion are thrown against a
hard surface, either the whole will be broken up by the force of impact, if the
velocity be sufficiently great, or at a less speed only the softer or less cohesive
bodies will become disintegrated. If now the velocity be so determined when
acting on a mixture of different bodies that only one of the said bodies is subject
to complete disintegration, then by afterwards separating the product by sifting
according to different degrees of fineness, although an absolute sorting of the
different substances will not be effected, yet a sufficiently effectual result for
practical application will be obtained.
The apparatus employed for this purpose can be of various construction, and
known apparatus may be applied, but a suitable arrangement to be employed is as
follows:-
=
In a raised position is placed a centrifugal machine of any suitable known con-
struction, into the top of which the mixed substances to be sorted are introduced.

page_text: The centrifugal machine is by preference constructed with several stages, one above
the other, so that as the material passes down from top to bottom of the machine it
is repeatedly thrown against the walls of the machine. Arrived at the lower end.
the material is made to pass into a screening drum having screening surfaces of
different degreos of fineness, such that the meshes or perforations increase in size
towards the outer end. The first compartments will consequently deliver the
disintegrated material in an almost pure condition, while the residuum from the
last compartment can be subjected to a further sorting operation.
Experiments have shewn that the most successful result is obtained if all parts
of the mixture are as nearly as possible of uniform size. The speed of the centri-
fugal machine should of course be regulated according not only to the nature of the
material to be acted upon, but also to the size of the particles thereof; thus for
particles of, say, one half inch in size, a much less speed would be required than
for particles of a quarter of an inch, and particles one eighth of an inch in size
would require a still greater speed. It is therefore of importance that all particles
should be as nearly as possible of a uniforın size, but even when this cannot always
be obtained the described construction of the centrifugal machine with different
stages will afford very perfect results.
The above described process can be carried out either in the wet or the dry way.
Experiments have shown however that the admission of a water jet into the
machine, or a water spray playing, over the screening drum, is very advantageous.
When operating with dry materials the practically perfect dryness of those must
be insured, as if they are merely moist, say, to the extent of 4 per cent. of water,
the meshes of tlie drum casily become clogged, and the action of the centrifugal
machine will also be interfered with. If even only a small water supply is available
the process should be worked wet, as clogging and dust are thereby prevented, and
the end product obtained will be purer.
No definite rule can be given as to the speed to be employed, as in order to
determine this not only the size of the particles to be operated upon, but their
structural nature, the regularity of the feed, as also the size and arrangement of the
centrifugal machine, and the size of the teeth or projections which may be applied
to the walls thereof, would have to be taken into account; but the best speed for
any particular description of material will be readily ascertained by a fow
experiments.
The above described process is applicable for all mixtures of substances in which
the difference of cohesion of the component bodies is an appreciable one, and in
which the several bodies are not so intimately united as, to require them to be
reduced to powder to effect their separation.
The centrifugal machine may, as before stated, be of any suitable known con-
struction, with the condition however that its structure should not be such as to
effect the smashing or grinding of the material.
Lastly, it is to be observed that the above described process is much less expensive
than any of the separating or sorting processes now employed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Friedrich Carl Glaser in the Great Scal Patent Office on the
27th May 1882.
FRIEDRICH CARL GLASER, of Berlin, in the Kingdom of Prussia and Empire of
Germany, Engineer and Patent Solicitor. "AN IMPROVED METHOD OF SEPARATING
OR SORTING ORES, MINERALS, AND OTHER SIMILAR BODIES." A communication
by Franz Büttgenbach, of Lintorf, Düsseldorf, Germany.
The separation of minerals and ores has up to the present time been effected
either by the aid of their specific gravity, or by their more or less foliated or
granular structure, or by the influence of magnetism after roasting or calcining.
The present Invention relates to the separation of these substances by the aid of
the different degrees of hardness thereof.
If two bodies of different degrees of hardness or of cohesion are thrown against
a hard surface, either the whole will be broken up by the force of impact, if the
velocity be sufficiently great, or at a less speed only the softer or less cohesive
bodies will become disintegrated: If now the velocity be so determined when
acting on a mixture of different bodies that only one of the said bodies is subject
to complete disintegration, then by afterwards separating the product by sifting
according to different degrees of fineness, although an absolute sorting of the
different substances will not be effected, yet a sufficiently effectual rosult for
practical application will be obtained.
•
The apparatus employed for this purpose can be of various construction, and
known apparatus may be applied, but a suitable arrangement to be employed is as
follows:-
In a raised position is placed a centrifugal machine of any suitable known
construction, into the top of which the mixed substances to be sorted are
introduced. The centrifugal machine is by preference constructed with several
stages one above the other, so that as the material passes down from top to bottom
of the machine it is repentedly thrown against the walls of the machine. Arrived
at the lower end the material is made to pass into a screening drum having
screening surfaces of different degrees of fineness, such that the meshes or perfora-
tions increase in size towards the outer end. The first compartments will
consequently deliver the disintegrated material in an almost pure condition, while
the residuum from the last compartment can be subjected to a further sorting
operation.
Experiments have shewn that the most successful result is obtained if all parts
of the mixture are as nearly as possible of uniform size. The speed of the
centrifugal machine should of course be regulated according not only to the nature
of the material to be acted upon but also to the size of the particles thereof, thus
for particles of, say, one half inch in size, a much less speed would be required than
for particles of a quarter of an inch, and particles one eighth of an inch in size
would require n still greater speed. It is therefore of importance that all particles
should be as nearly as possible of a uniform size, but even when this cannot always
be obtained, the described construction of centrifugal machine with different stages
will afford very perfect results.
The above described process can be carried out either in the wet or the dry
way. Experiments have shown however that the admission of a water jet into
the machine, or a water spray playing over the screening drum is very advan-
tageous. When operating with dry materials the practically perfect dryness of
these must be insured, as if they are merely moist, say to the extent of 4 per cent.

page_text: of water, the meshes of the drum easily become clogged, and the action of the
centrifugal machine will also be interfered with. If even only a small water
supply is available the process should be worked wet, as clogging and dust are
thereby prevented, and the end product obtained will be purer.
No definite rulo can be given as to the speed to be employed, as in order to
determine this not only the size of the particles to be operated upon, but their
structural nature, the regularity of the feed, as also the size and arrangement of
the centrifugal machine, and the size of the teeth or projections which may be
applied to the walls thereof, would have to be taken into account. But the best
speed for any particular description of material will be readily ascertained by a few
experiments.
The above described process is applicable for all mixtures of substances in which
the difference of cohesion of the component bodies is an appreciable one, and in
which the several bodies are not so intimately united as to require them to be
reduced to powder to effect their separation.
The centrifugal machine may, as before stated, be of any suitable known
construction, with the condition however that its structure should not be such as
to effect the smashing or grinding of the material.
Lastly, it is to be observed that the above described process is much loss
expensive than any of the separating or sorting processes now emploved.:
Figs. 1, 2, and 3 of the accompanying Drawing shew respectively a vertical
section, a sectional plan, and an enlarged detail of a suitable apparatus for carrying
out the above described process.
A cylinder of about 900 millimetres height and 1100 millimetres inner diameter
is provided internally with three removable rings of chilled cast iron, constructed
in separate segments and arranged at different heights. These segments are
toothed, as shewn at Fig. 3. A vertical axis & passing centrally through the
cylinder runs in bearings at b and c, and receives rotary motion from a pulley c'.
On the axis are fixed three horizontal discs, on the outer part of which are fixed
radial ribs as shewn. Rapid rotary motion being imparted to the axis and its
discs, and the material to be acted upon being introduced through the hopper at a,
so as to fall on to the upper disc near its centre, the particles will be thrown by
the centrifugal force against the chilled iron rings, and will fall upon the conical
shoots e, e, which direct them towards the centro of the second disc, the above
operation being repeated twice before the particles finally escape through the
Rhoot f.
It depends upon the speed of the discs and on the hardness or cohesion of the
granular material introduced at a whether this becomes crushed or broken up to
the required extent by the treble centrifugal action to which it is subjected. With
a speed of 800 revolutions per minute iron pyrites in granules of from 20 to
25 will leave the apparatus partly as dust and partly as grains of 1 to 1/
whereas at 400 revolutions they will be but little affected. On the other hand
blend will at 800 revolutions be reduced to impalpable dust, while at from 300 to
400 revolutions it will leave the apparatus partly as dust and partly in grains
of, 1, 2, and 3 m/
If now a mixture of pyrites and blend be introduced and subjected to a speed of
400 revolutions the pyrites will issue almost intact, while the blend will be broken
up, and the two can then be readily separated by screening.
In order to effect the separation in a systematic manner suitable for continuous
practical working, the arrangemont shewn in elevation and plan at Figs. 4 and 5
may be used with advantage. a is the centrifugal crushing apparatus, which is
charged at b, and from which the crushed material passes through the shoot c into
the screening or separating drum d, which has an inclination of 6 in 100 and a

page_text: speed of 92 revolutions per 100 revolutions of the crushing apparatus. This drum
is divided into three compartments; the first has apertures or meshes of one
millimetre, the second of 2, and the third of 3 / The particles remaining
in the drum pass through a second drum, which has two divisions, of which the
first allows particles of 6 / to pass, and the second particles of 8 m/m
Particles over 8 / escape at f. This second drum bas an inclination of
6 in 100, and makes 8 revolutions for every 100 of the crushing machine.
If now a granular mixture of pyrites and blend of a size of 20 mm. be
introduced into the machine at a speed of 300 revolutions, over 80 per cent., of
the blend contained in the mixture will be crushed into different sized granules,
which will be sorted in the three compartments g, g', g. The two first com-
partments will give almost pure blend, the third will still contain pyrites, but
the mixture will have three times the quantity of blend contained in the original
mixture. The compartment e will give pyrites with a few large granules of blend.
In most cases the 3rd division g' will yield a mixture so rich in blend that a second
operation would not be advantageous. The grains of the first division
quantity of about 5 to 10 per cent of the total is separated, can with idvantage
be subjected to a second operation; the second division e' yields almost prře pyrites,
as does also the discharge f.
where a
As herein before stated, the speed should be proportioned to the size of the
granules, and it is therefore of importance that the mixture to be treated should be
sorted as nearly as practicable into particles of uniform sizes. But as this is not
always possible, the arrangement of the screening drums with different divisions
affords means for obtaining an almost perfect result by a second operation. Thus,
for instance, if a mixture of granules of from 8 to 20 / passes through the
machine, most of the blend will pass off sufficiently pure at g, g', but at g³, e and e',
on the other hand, there will be so much blend present as to render a second
operation advantageous. Each of these different sizes will however have to be
treated separately, and the speed be proportioned to the size of grain in order to
obtain a good result.
Having thus described the nature of the snid Invention and in what manner the
same is to be performed, as communicated to me by my correspondent, I claim,-
The method of separating or sorting inixtures of ores, minerals, and other
similar bodies by the aid of their different degrees of hardness or cohesion, such
method consisting in throwing the mixed material with such centrifugal force
against a bard surface as to cause the more friable particles of the mixture to be
broken up while the harder particles are left. intact, the mixture being then
separated into different sizes by screening, substantially as herein describod.
In witness whereof, I, the said Fredrich Carl Glaser, have hereunto set my
hand and seal, this Twenty fourth day of May, in the year of our Lord One
thousand eight hundred and eighty two.
F. C. GLASER. (L.S.)