Патент USA US2573524

Oct. 30, 1951
w. A. WASLEY ET AL
FLOTATION APPARATUS
Filed Oct. 4, 1947
2,573,520
Patented Oct. 30, 1951
12,513,520
UNITED STATES PATENT OFFICE
2,573,520
FLOTATION APPARATUS
William Arthur Wesley, Cananea, Mexico, and
John Clement Maclntosh, Bisbee, Aria, assign
V ors to The Cananea Consolidated Copper Com
pany, S. A., a Mexican corporation
Application October 4, 1947, Serial No. 778,006 I
2 Claims. (Cl. 209-169)
1
2
This invention relates to ?otation apparatus,
The chamber is divided by a series of transverse
and is particularly concerned with the provision , partitions 5 into a plurality of individual cells
of improvements in ?otation machines having q-‘(only two cells are shown in the drawing, but
chamber
submerged?ir pumps.
The especially
principal machines
feature of
of the -. 6 ‘ordinarily
contain ?vethe
or six
ceus)_ 1 will be long enough to
Fagergren type.
present invention is the provision, in such ap
A feed box 6 is provided at one end of the
The end wall ‘I of the
chamber which separates the feed box 6 from
paratus, of baflies of improved design which are .5, trough'?like chamber I.
arranged so as not to impede, the-?ow of an ore 5‘
pulp through the machine, but which minimize
' the chamber itself is formed with an opening 8
rotary motion of the pulp' induced by the air 10 near its bottom, so that an aqueous ore pulp in
pump. We have found that the provision of such
troduced into the feed box may enter and ?ow
lengthwise throughthe chamber. Openings 9 in
bailles leads to a decided improyement in the
recovery of mineral values in the‘_ ?otation cone
. the transverse partitions 5 enable the ore pulp
centrate produced in Fagergren Itype ?otationlj,‘ 1‘:‘j’to ?ow lengthwise from the feed box serially
machines.
A typical ?otation machine of the type'to
through the several cells to a tailing discharge
box I!) at the opposite, end of the chamber.
which the invention relates comprises a long, ;_
trough-like chamber‘ divided by transverse pare .
titions into a plurality of cells. The partitions
are formed with openings which permit an ore 20
pulp to flow lengthwise from cell to cell through 1
supported on vertical and horizontal frame mem
bers I3 and I4. The impeller shafts are rotated
in their bearings at fairly high speed by a motor
the chamber.
l5 connected by V-belts Hi to pulleys l1 keyed
An impeller mounted on a ver--.
. A vertical impeller shaft H is mounted sub
stantially centrally in each cell, in bearings l2
to the upper ends of the shafts.
An impeller I8 is mounted at the lower end of
is provided in each cell for introducing air into 25 each shaft beneath the normal level of the ore
the pulp. The impeller and shaft are usually en
pulp in the cell. The impeller comprises fan-like
blades l9 set at an angle such as to force air
closed by a housing that extends upwardly from
downwardly into the ore pulp when the impeller
about the impeller to above the zone in which
tical shaft for rotation in a substantially hori
zontal plane beneath the normal level of the pulp, "
the ?otation froth collects. to prevent recircula
shaft is rotated in its normal operating direc
tion of the froth by the impeller.
30 tion (clockwise, as indicated by the arrow, in the ‘
apparatus shown in the drawings). The im
In apparatus of this character, the invention
provides the improvement comprising a pair of
peller also comprises ‘a squirrel cage of vertical
thin vertical bafiies positioned below the normal
bars 20 which rotate with the blades IS. The
impeller and impeller shaft are surrounded by a
pulp level in each cell. The baiiies extend length
wise of the trough chamber, parallel to the line 35 cylindrical housing 2|, the upper portion 22 of ‘
of pulp ?ow therethrough; they are arranged on
which, above the impeller. is of solid wall con
opposite sides of the impeller housing, and ad—
struction, and the lower portion of which, imme
diately about the impeller, comprises a cage of
vantageously are secured thereto. Except for
stationary vertical bars 20'.
’
'
these baiiles, none are provided in apparatus ac
Inside the solid wall upper portion 22 of the
cording to the invention, so that each cell is sub- 40
stantially free of any, obstruction, apart from
‘housing is, a splash cone 23, which terminates in
the impeller housing, to the ?ow of pulp there
a substantially cylindrical lower portion 24 lo
through, but t e baiiles serve to minimize rotary
cated about at the normal pulp level. A series
?ow of the p p caused by rotation of, the im
of vanes 25 on a. collar 26 extend laterally from
peller.
\
A preferred embodiment of the invention is
shown in the single ?gure of the accompanying
drawing, which shows in perspective, parts being
the impeller shaft inside the lower cylindrical
' portion 24 of the splash cone, and also at about
the normal level of the pulp in the cell. These
laterally extending vanes are pitched at an angle
to the vertical, thereby forming an air screw
broken away, a Fagergren type ?otation ma
chine equipped in accordance with the invention. 50 which assists in forcing air downwardly when
The ?otation machine comprises a long trough
. the impeller shaft is rotated in its normal‘ op
like chamber I having a ?at bottom Land side
erating direction. The vanes 26 also prevent any
walls each having a lower portion 3 which slopes
‘accumulation of ore pulp mud in the splash
outwardly and upwardlyfrom the bottom and an
cone. The air screw formed by thesej‘vanes'j‘ is
upper portion 4 which is substantially vertical. 55 not a part of heretofore known Fagergrenitype
2,573,520
while at the same time the depth of the top edge
of the baffles below the normal level of the pulp
is made maximum at all points. In consequence,
the baiiles have a minimum e?ect in preventing
‘ ?otation machines. They form the subject mat
‘ ter claimed-in our copending patent application
‘ Serial No. 778,436, filed October 7, 1947, and are
, more fully described therein.
In the operation of apparatus as thus far de
‘ scribed, an ore pulp to which suitable ?otation
1 reagents have been added is introduced into the
. feed box 8 and ?ows lengthwise through the ‘
chamber I from cell to cell. “The impeller shafts
the froth, as it rises to the surface of the pulp,
from ?owing laterally to the side edges of-the
cell and over?owing into the collecting launders L.
The substantially improved results obtained
with Fagergren type ?otation machines equipped
. are rotated at a fairly high' speed by the motor 10 in accordance with the invention isshown in the
15, so that the impeller blades l9, assisted by the _ following table. One of -?ve rows of Fagergren
type ?otation machines in aconcentrator plant
‘ air screw vanes 25, suck air downwardly about
treating sulphidic copper ore was equipped with
the impeller shaft through the splash cone 23,
baiiles 21 and air screw vanes 25 of’ the character
Q and deliver it radially outwardly through the
3 squirrel cage bars 20 and the housing bars 20’ 15 herein described, while the remaining rows were
carrying the mineral values of the ore with it _
not so equipped. The second column of the table
shows the percentage of copper in the tailings
withdrawn from the machines in rows 1 to 4 (the
1 into the body of the pulp. _ The air bubbles form ‘
. a froth in the pulp which rises to the surface
and over?ows into collecting launders L arranged
rows in which standard Fagergren machines were
I alongside the upper edges of the vertical side
‘ members 4. The gangue component of the ore
not equipped with baii'les or air screws), and the
third column shows the corresponding analysis
does not ?oat, but flows with the main body of
, the pulp to the tailing discharge box It, through
of tailings from row 5 (the row of machines that
were equipped with ba?ies and air screws). The
‘ which it is withdrawn.
data are given for the twenty-two successive days
It is desirable and important that once air has 25 that formed the test period. The difference be
tween the amount of copper present in the tail
been admitted to the pulp, it be agitated as little
ings from machines in rows 1 to 4 and in the
. as possible, for otherwise many of the froth bub
tailings from the machines in row 5 are given in
bles will be broken and the mineral values car
the fourth column of the table.
ried thereby will sink. The lengthwise ?ow of
1 pulp through the apparatus is su?lciently slow '30
Table I
a so as not to produce excessive agitation. The ‘
‘ rapid rotation of the impeller, however, tends to
3°“ 1' 2'
impart a vigorous rotary or swirling motion to
the pulp. To a considerable extent this is over
1 come by the cage bars 20' of the impeller housing, 35
Days
Row #5 ,
Difference,
aégragedni'
Copper
Per Cent
Copper
Per Cent
Copper
1st day ..................... _.
. 123
. 098
. 030
2nd day.3rd day .
. 139
. 117
. 099
.078
. 040
. 039
‘ but it is not by any means entirely overcome
1 thereby. It is, however, very largely overcome
in accordance with the invention by the provision‘
of a pair of substantially vertical thin sheet ‘
j ballles 21. These baffles extend radially out from 40
a in a vertical plane parallel to the ?ow of pulp
1 lengthwise through the apparatus from cell to
cell.
The bottom edges 28 of the ba?les are par
3 allel and spaced quite closely to the ?oor 2 of 45
the ?otation chamber l. The upper edges 29 of
a the baffles slope downwardly from the side 30
adjacent the impeller housing to the side 3|
‘ remote therefrom.
Thus the width
(vertical
height) of the ba?les is greatest near the impeller, 50
1 and progressively less at progressively greater
distances outwardly therefrom. The baiiles are
sti?ened against lateral de?ection by straps 32
3 and 33, or other suitable stiffening element
‘
weldedtothe baf?e sheets.
'
With the ba?les 21 arranged in a vertical plane
and parallel to the line of pulp ?ow through
I each cell, as shown and described, they impose
no appreciable resistance to the ?ow of pulp
5th day-..
6th day."
7th day___
a the impeller housing 2|, on opposite sides thereof,
‘
4th day..
.128
. 091
. 125
. 093
. 032
.......... __ Mill Down
__________ __
.134
. 090
.037
. 044
8th day. .
.117
.080
.037
9th day-10th day-.
.118
. 121
. 090
. 090
. 028
.031
llth day _________________ -.
.142
. 111
. 031
12th day".-13th day... _ _
. 170
.174
. 144
.147
. 026
. 027
14th day.____
.171
. 152
. 019
15th
16th
17th
18th
.
.
.
.
.
.
.
.
. 020
. 023
. 017
. 022
day..-“
day._._.
day“
day
164
176
158
171
144
153
141
149
19th day.
20th day___-.
. 183
.192
. 169
. 182
.014
. 010
21st day _____ __
. 135
.123
. 012
__
. 160
. 148
~ 012
Averages _____________ __
. 148
.122
. 026
22nd day ____ ..
It is evident from the foregoing table that the
invention
enables a substantial improvement to
55
be achieved in the recovery of copper in the con
, centrate, as indicated by the markedly and con
, sistently less amount of copper present in the
tailings from machines equipped in accordance
, through the cell, and they cause no de?ection 60 with the invention, as compared with the tail
in the direction of pulp ?ow lengthwise through
the apparatus which might contribute to breaking
I of the ?otation froth bubbles.
However, they do ,
1 provide substantial resistance to rotary motion
1 of the pulp induced by rotation of the impeller,
‘ thereby minimizing turbulence in the
pulp.
Rotary motion which the impeller tends to induce
in the pulp is greatest near the impeller and ‘
‘ progressively less as the radial distance there
ings from machines not so equipped but operat
ing concurrently as the same ore pulp.
We claim:
1. In ?otation apparatus comprising a long
trough-like chamber divided by transverse parti- .
tions into a plurality of cells, said partitions be
ing formed with openings adjacent the ?oor of
the cells for permitting an ore pulp to ?ow
lengthwise directly from cell to cell through the
Since the bailles are widest near 70 chamber. an impeller of substantial height ro
tating in~each cell for introducing air into the
‘ the impeller and- slope to substantially less width
‘ from increases.
pulp therein, said impellers being located sub
stantially in the horizontal plane‘of the parti
tion openings, and a housing surrounding each
‘ their length in minimizing rotary motion of the
‘ pulp. This uniform baming emciency is achieved 75 impeller, the improvement comprising a pair of
in the radial direction outwards from the impeller
housing, they are uniformly effective throughout
‘
2,573,520
thin vertical ba?les positioned below the normal
pulp level in each cell and substantially in the
horizontal plane of the impeller therein, said
ba?les extending lengthwise of the trough a sub
stantial distance and parallel to the line of pulp
substantially parallel with the floor of the cham
ber and the top edges thereof being sloped down
wardly from the side thereof adjacent the im
?ow therethrough from cell to cell and being ar
near the impeller, and there being substantially
ranged on opposite sides of the impeller housing,
the height of each ba?le at the housing being
equal to the height of the impeller, and pro- ‘
rotary ?ow of the pulp in the cells.
the cells.
peller housing to the side remote from said hous
ing, the height of the ba?les thus being greatest
gressively less at progressively greater distances
outwardly from the impeller, each cell being
substantially equal to the vertical dimension of
the impeller, each cell being substantially free 10 substantially free of any obstruction apart from
the impeller housing to the ?ow of pulp length
of any obstruction apart from the impeller hous
wise therethrough, but said bai’?es serving to sub
ing to the flow of pulp lengthwise therethrough,
stantially preclude rotary ?ow of the pulp in
but said baiiles serving to substantially preclude
_
'
WILLIAM ARTHUR WASLEY.
JOHN CLEMENT MACINTOSH.
2. In ?otation apparatus comprising a long 15
trough-like chamber divided by transverse parti
tions into a plurality of cells, said partitions be
REFERENCES CITED
ing formed with openings adjacent the ?oor of
the, cells , for permitting _-an,;..ore.- pulp to . ?ow- '1
lengthwise directly ' from cell ‘to'cell through the
The following references are ofgrecord
?le of this patent:
chamber, an impeller of substantial height ro
stantially'in the horizontal pla'ne'of the parti- - Q
tion openings, and a housing surrounding each 25
impeller, the improvement comprising a. pairof
thin vertical ba?les mountedv on opposite sides
of each impeller'housing below the normal level
of the pulp and substantially in the horizontal
plane of the impeller,- said bailies also‘being posi 30
tioned in a vertical plane parallel to the line 01
?ow of the pulp from cell to cell and extending
a substantial distance lengthwise of the cell, the
bottom edges of said bames being close to and
’ '
UNITED STATES
tating ineach celliforlintroducing air into the
pulp therein, said impellers being located ‘sub
"
Number
.
Name
>
"
.
~5
2,073,148
1,984,366
Fahrenwald
Gayford _____
___‘___'_"_‘
__
__-Mar.;,9,,1'931
pea-‘i8, 1934 _'
2,304,270
Mead _________ ..~
_ Dec 8,1942 >
OTHER REFERENCES;
Handbook of Mineral Dressing, Tagg'f"
section 12, pages ~66, 67, and 68.‘ v
_ '
“The Laboratory Fagergren Flotation
chine,” American Cyanamid Company,
teller Plaza, New York, N.‘ Y.
'
"
I
e,
,
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