DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.1327#0164
THE CRYSTAL PALACE AND ITS CONTENTS;
MINING AND METALLURGY.
EXTKACTIOS AND PREPARATION OF MINERAL ORES.
THE ores which exist in minimi veins are, to a certain extent, obtained
-dm
gtho cutting of the longitudinal galleries described in our last
article on this subject; but as those nro situated at considerable distances
from each other, the ores thus raised form but a very inconsiderable portion
of the contents of the entire lode. To extract, therefore, the wholo of the
metals continued in the vein, the mineral ore is worked out between the
different levels, and the space thus loft unoccupied is filled up with unpro-
ductive fragments of rock, arising from the other operations of the mine.
On reaching the surface tho ores are broken by means of largo hammers,
and divided into classes, according to their relative richness in metal, whilst
tho stony and valueless portions are picked out and thrown away. Few
ores contain so large an amount of metal as to render their concentration
by mechanical menus unnecessary, and various contrivances are conse-
quently employed for the removal of theso earthy impurities, before
subjecting them to motalhirgic treatment.
In order to reduce the fragments of mineral ores, and particularly those
of copper, to a proper and uniform sizo for tho subsequent mechanical
concentration, large cylinders of cast iron, moved in contrary directions,
either by water or steam power, arc frequently employed. These rollers
are SO arranged as to admit of being either advanced closer together or
separated at a greater distance, according to tho nature of the ores to be
crushed; and in order to prevent accident from the passage of large pieces
of stone too hard to be broken, a certain elasticity is given to the apparatus
by causing the cylinder to bo constantly forced together by a long lever
acting on the bearings in which they work. The other extremity of this
lever is loaded with a heavy weight, by which, when a largo fragment passes
through, the arrangement is slightly lifted, and the apparatus itself pro-
tected from rupture. On passing through the rollers tho crashed ore falls
into the higher extremity of an inclined cylinder of coarse wire gauz
this, being sot in motion by tho same powor as tho rollers thcmselv
divides the mineral into two distinct classes; the one passing through tho
meshes of the trellis, and falling on the floor— whilst the other, which
too large to pass through tho apertures of the sieve, is carried out at the
lower end of the hollow cylinder, where it falls into the buckets of an
endless chain, by which it is again brought to the level of the mill, where it
is recrashed.
Many minerals, and especially the ores of tin, instead of being pas;
between rollers, as above described, are pounded into small fragments by
largo pestles, moved either by water or steam power. The machine by
which this is effected is called a stamping mill, and the pestles or lifters by
which the ova is crushed are set in motion by an axle, with cams spirally
arranged around it, so that each lifter may give three blows during one
revolution of the axle. The lower part of this machine, where the iron
heads of the pestles come in contact with tho mineral to bo broken, is
inclosed in a large wooden trough,-in which are several openings fitted
lings through which the pounded ore is washed by
h is constantly passing through the gratings; and
i in this way carried off into large pits, where it
a finely-divided sand.
ntration of ore; depends in principle on tho circum-
vcry different snecific gravities, and of nearly the
same dimensions, are fhv-t agitated together in water, and then allowed to
subside, they will be found to have arranged themselves at the bottom of
nail metallic
a current of water, ■
ilie powdered nunc:
subsides in the forn
The mechanical e,
stance that, it'bodio
the \
there
which is thus made to pass through the meshes of the sieves produces on
tho mineral which they contain the same effect as if the sieves wore ll-e"'
selves moved in the water; and therefore, after repoaicdly removingj("'
lighter particles which constantly accumulate on the surface, the ore v:h';2
remains at the bottom of tho sieves is sufficiently pure to be ready r,',',.
immediate meiallurgic treatment. Of the portions which are scraped r,p
the sieves, the lightest, which, contains little or no metallic ore, is tlivov-'i
away, as being entirely useless; but the second-—which consists of a mixture
of gauguo and metalliferous subs unices, together with the fine dust wlndi
passes through the holes of the sieves—is sent to the stamping mil!:;, v.-l„n,.
it. is reduced to the state of a very fine powder, by which means grout-.'
facilities are afforded for its separation from the earthy matters with' whit]-
it is assoeiatod.
Tho water and fmo sand escaping through tho gratings of this machine
arc now conducted into a kind of reservoir, -whore the heavier partie;,--..
are iirst deposited, whilst the poorer and consequently lighter parts a
removed to a greater distance. By this treatment a c '
of tho stamped ore is e flee ted, as those portions which have been e
by the force of the water beyond a given point arc collected in a separate
pit from those which have not arrived so for from the stamping "mills:
The method of washing and preparing these sand.-, lor subsequent metal-
lurgical treatment differs according to the nature of the ores which tlmv
contain, and it is also moro or less regulated by the state of division in
which they occur. In all cases, however, these operations are dependent
on precisely the same physical principles; and the prepared ores, when in
a fini.-died state, should lie so far freed from earthy impurities as to admit
of being advantageously fused in properly constructed furnaces, for the
Inch they contain.
■ relating to this subject exhibited was a
jigging-maehine, ami a huddle for washing gold ores, by Mr. J. Hunt, Tho
jiggiiig-machine consists of a set of sieves, to which a rapid up-and-:1cm:
motion is given by a earned wheel acting on the ends of levers, to which
they are suspended ; and it differ,- only from that in general use, inasmuch
as the sieves arc in most instances moved by either a crank or exocmne,
which, although subject to very much less wear and tear than the cab)
motion, docs not give such decided or rapid movement to the particles of
ore resting on the meshes.
The buddle, or washing-box, for gold ores, differs from that in common
use, in having moveable buttons mi the bead-board, by which an even
thickness of water may be directed over its whole surface. This, in many
Operations, is of much importance, and in such eases the apparatus will bo
found advantageous.
The different processes by which the concentration of the metallic ores
may be effected, were best, exhibited in a model of the Tywarnhailc dressm«
floors, which included seme of the latest and must important improvements
which havc-beeu introduced into this branch of bid
There was also a case in this department, contain
obtained by Mr. Longmaid, in the purifieoti ■■:, 8
process, of the various metallic ores of which su
ingredient. This process consists ill calcining, in a
tity of common salt, by which means, sulphates of
other salifiable bases present, 'are produced ; and those minerals, such as
the oxide of tin. which d.^ not afford a strong base, are subsequently obtained
as a residue of lixiviation.
The less arsenic contained in the ore the better it will be for this puiViose,
although, its presence is not an insurmountable objection, especially if
associated with a small per-centage of copper. A charge is by this method
drawn, about, every twe::cv-lbur hours from the front bed, and each of tnc
three remaining ekng--s will then be moved forward to the next lower bed,
and a fresh charge put into the upper one—each of the charges being
kept regularly raked in its turn. A brisk fee is to bo kept up in the
furnace 'during the whole time, and a damner is amdied to the chimney to
obtain regulation. -Is the dermis'. s:r >:i U';h- s.,'l: and .-re proceeds, tho
s of products
;o his patent
a proper
scl yei
jro the heavit
the lighter e
iated.
.■thy impu
One of the most pimple methods of effecting this object is by the use of
me hand-sieve, which is made of a sheet of perforated copper fixed in a
;lccp wooden hoop. To use tins it is lir.st partial I v Idled with the crushed
ore, and then held by the workman in a lajgo tub fllled with water, where
he gives to it a sort of undulating motion, which causes the richer and
heavier portions to accumulate on tho bottom, and tho earthy grains to
rise on the surface. After a short time he withdraws tho sieve from the
water, and whilst it, \* ivs-tii,- on tho edge of the tub. ho scrapes off. by
means ..f a piece of thin iron, tho particles thrown oil the surface This is
■oil"-" ■ i ' y a ■ ■■■ . 1 washing mid scraping, and when the whole of the
;■.'"'■■'■■' '- ■■■" )' • r,move,l, that which remains at the bottom of the sieve
is snilic-.L-utly pure to l»>_:it mice subjected to metidlurgic treatment.
Instead of u-'i:e hand-sieves, machines are now generally employed for
this purpose. Qn the comment the ieve. instoad of being moved directly
i Jong balanced lover; and iii this
hnosfc superseded by the jig);ing-
eopper sieves fixod in the lid of a
■natcly raised and low
agglomerate, and seems to be
emnerature to which it is here
a that it is eveutuallv drawn
exposed, tl
;;e :',eiao. ' El &*
i? charge soon iieg!"'
lar condition. Tho
:;dt-cako. chloride el
do of tin (if :>")' m.
iron uvrites: and it
country the use of the hand-sieve
machine, winch consists of a number
large cistern, In which tho level of the
by a piston, set in motion by machinery. The water
contained in i
matters by wo
iug the scpara
from the refined liquor, is well washed,
separation of sulphate of soda, and cli
obtained being employed in the hslviatiou
MINING AND METALLURGY.
EXTKACTIOS AND PREPARATION OF MINERAL ORES.
THE ores which exist in minimi veins are, to a certain extent, obtained
-dm
gtho cutting of the longitudinal galleries described in our last
article on this subject; but as those nro situated at considerable distances
from each other, the ores thus raised form but a very inconsiderable portion
of the contents of the entire lode. To extract, therefore, the wholo of the
metals continued in the vein, the mineral ore is worked out between the
different levels, and the space thus loft unoccupied is filled up with unpro-
ductive fragments of rock, arising from the other operations of the mine.
On reaching the surface tho ores are broken by means of largo hammers,
and divided into classes, according to their relative richness in metal, whilst
tho stony and valueless portions are picked out and thrown away. Few
ores contain so large an amount of metal as to render their concentration
by mechanical menus unnecessary, and various contrivances are conse-
quently employed for the removal of theso earthy impurities, before
subjecting them to motalhirgic treatment.
In order to reduce the fragments of mineral ores, and particularly those
of copper, to a proper and uniform sizo for tho subsequent mechanical
concentration, large cylinders of cast iron, moved in contrary directions,
either by water or steam power, arc frequently employed. These rollers
are SO arranged as to admit of being either advanced closer together or
separated at a greater distance, according to tho nature of the ores to be
crushed; and in order to prevent accident from the passage of large pieces
of stone too hard to be broken, a certain elasticity is given to the apparatus
by causing the cylinder to bo constantly forced together by a long lever
acting on the bearings in which they work. The other extremity of this
lever is loaded with a heavy weight, by which, when a largo fragment passes
through, the arrangement is slightly lifted, and the apparatus itself pro-
tected from rupture. On passing through the rollers tho crashed ore falls
into the higher extremity of an inclined cylinder of coarse wire gauz
this, being sot in motion by tho same powor as tho rollers thcmselv
divides the mineral into two distinct classes; the one passing through tho
meshes of the trellis, and falling on the floor— whilst the other, which
too large to pass through tho apertures of the sieve, is carried out at the
lower end of the hollow cylinder, where it falls into the buckets of an
endless chain, by which it is again brought to the level of the mill, where it
is recrashed.
Many minerals, and especially the ores of tin, instead of being pas;
between rollers, as above described, are pounded into small fragments by
largo pestles, moved either by water or steam power. The machine by
which this is effected is called a stamping mill, and the pestles or lifters by
which the ova is crushed are set in motion by an axle, with cams spirally
arranged around it, so that each lifter may give three blows during one
revolution of the axle. The lower part of this machine, where the iron
heads of the pestles come in contact with tho mineral to bo broken, is
inclosed in a large wooden trough,-in which are several openings fitted
lings through which the pounded ore is washed by
h is constantly passing through the gratings; and
i in this way carried off into large pits, where it
a finely-divided sand.
ntration of ore; depends in principle on tho circum-
vcry different snecific gravities, and of nearly the
same dimensions, are fhv-t agitated together in water, and then allowed to
subside, they will be found to have arranged themselves at the bottom of
nail metallic
a current of water, ■
ilie powdered nunc:
subsides in the forn
The mechanical e,
stance that, it'bodio
the \
there
which is thus made to pass through the meshes of the sieves produces on
tho mineral which they contain the same effect as if the sieves wore ll-e"'
selves moved in the water; and therefore, after repoaicdly removingj("'
lighter particles which constantly accumulate on the surface, the ore v:h';2
remains at the bottom of tho sieves is sufficiently pure to be ready r,',',.
immediate meiallurgic treatment. Of the portions which are scraped r,p
the sieves, the lightest, which, contains little or no metallic ore, is tlivov-'i
away, as being entirely useless; but the second-—which consists of a mixture
of gauguo and metalliferous subs unices, together with the fine dust wlndi
passes through the holes of the sieves—is sent to the stamping mil!:;, v.-l„n,.
it. is reduced to the state of a very fine powder, by which means grout-.'
facilities are afforded for its separation from the earthy matters with' whit]-
it is assoeiatod.
Tho water and fmo sand escaping through tho gratings of this machine
arc now conducted into a kind of reservoir, -whore the heavier partie;,--..
are iirst deposited, whilst the poorer and consequently lighter parts a
removed to a greater distance. By this treatment a c '
of tho stamped ore is e flee ted, as those portions which have been e
by the force of the water beyond a given point arc collected in a separate
pit from those which have not arrived so for from the stamping "mills:
The method of washing and preparing these sand.-, lor subsequent metal-
lurgical treatment differs according to the nature of the ores which tlmv
contain, and it is also moro or less regulated by the state of division in
which they occur. In all cases, however, these operations are dependent
on precisely the same physical principles; and the prepared ores, when in
a fini.-died state, should lie so far freed from earthy impurities as to admit
of being advantageously fused in properly constructed furnaces, for the
Inch they contain.
■ relating to this subject exhibited was a
jigging-maehine, ami a huddle for washing gold ores, by Mr. J. Hunt, Tho
jiggiiig-machine consists of a set of sieves, to which a rapid up-and-:1cm:
motion is given by a earned wheel acting on the ends of levers, to which
they are suspended ; and it differ,- only from that in general use, inasmuch
as the sieves arc in most instances moved by either a crank or exocmne,
which, although subject to very much less wear and tear than the cab)
motion, docs not give such decided or rapid movement to the particles of
ore resting on the meshes.
The buddle, or washing-box, for gold ores, differs from that in common
use, in having moveable buttons mi the bead-board, by which an even
thickness of water may be directed over its whole surface. This, in many
Operations, is of much importance, and in such eases the apparatus will bo
found advantageous.
The different processes by which the concentration of the metallic ores
may be effected, were best, exhibited in a model of the Tywarnhailc dressm«
floors, which included seme of the latest and must important improvements
which havc-beeu introduced into this branch of bid
There was also a case in this department, contain
obtained by Mr. Longmaid, in the purifieoti ■■:, 8
process, of the various metallic ores of which su
ingredient. This process consists ill calcining, in a
tity of common salt, by which means, sulphates of
other salifiable bases present, 'are produced ; and those minerals, such as
the oxide of tin. which d.^ not afford a strong base, are subsequently obtained
as a residue of lixiviation.
The less arsenic contained in the ore the better it will be for this puiViose,
although, its presence is not an insurmountable objection, especially if
associated with a small per-centage of copper. A charge is by this method
drawn, about, every twe::cv-lbur hours from the front bed, and each of tnc
three remaining ekng--s will then be moved forward to the next lower bed,
and a fresh charge put into the upper one—each of the charges being
kept regularly raked in its turn. A brisk fee is to bo kept up in the
furnace 'during the whole time, and a damner is amdied to the chimney to
obtain regulation. -Is the dermis'. s:r >:i U';h- s.,'l: and .-re proceeds, tho
s of products
;o his patent
a proper
scl yei
jro the heavit
the lighter e
iated.
.■thy impu
One of the most pimple methods of effecting this object is by the use of
me hand-sieve, which is made of a sheet of perforated copper fixed in a
;lccp wooden hoop. To use tins it is lir.st partial I v Idled with the crushed
ore, and then held by the workman in a lajgo tub fllled with water, where
he gives to it a sort of undulating motion, which causes the richer and
heavier portions to accumulate on tho bottom, and tho earthy grains to
rise on the surface. After a short time he withdraws tho sieve from the
water, and whilst it, \* ivs-tii,- on tho edge of the tub. ho scrapes off. by
means ..f a piece of thin iron, tho particles thrown oil the surface This is
■oil"-" ■ i ' y a ■ ■■■ . 1 washing mid scraping, and when the whole of the
;■.'"'■■'■■' '- ■■■" )' • r,move,l, that which remains at the bottom of the sieve
is snilic-.L-utly pure to l»>_:it mice subjected to metidlurgic treatment.
Instead of u-'i:e hand-sieves, machines are now generally employed for
this purpose. Qn the comment the ieve. instoad of being moved directly
i Jong balanced lover; and iii this
hnosfc superseded by the jig);ing-
eopper sieves fixod in the lid of a
■natcly raised and low
agglomerate, and seems to be
emnerature to which it is here
a that it is eveutuallv drawn
exposed, tl
;;e :',eiao. ' El &*
i? charge soon iieg!"'
lar condition. Tho
:;dt-cako. chloride el
do of tin (if :>")' m.
iron uvrites: and it
country the use of the hand-sieve
machine, winch consists of a number
large cistern, In which tho level of the
by a piston, set in motion by machinery. The water
contained in i
matters by wo
iug the scpara
from the refined liquor, is well washed,
separation of sulphate of soda, and cli
obtained being employed in the hslviatiou