Note: Descriptions are shown in the official language in which they were submitted.
t`~i
--1 -
FROTHERS USEFUL IN TH:E RECOVERY OF FINE
PARTICLES OF ~ETAL VALUES IN FROTH FLOTATION
The i~vention resides in a frother com-
position and a froth flotation process for the
recovery of mineral values from ore. The process o
this i~vention is not only effective in beneficiating
ores in general but is also effective in the benefi-
ciation of ores having a particle size of 75 micro-
meter6 or le~s. Fine particle size ores are generally
xe~erxed to in khe art as slimes.
The frothe.r composi~ion and pxocess of
the invention are capable of selectively recoverlng
the fine particles o~ mineral ~alues from ores con-
taining me-tallic or non-metallic mineral values
without carrying over undersirable portions of the
ore, i.e. gangue, in the fxoth.
In the recovery of fine mineral values from
ore, about 75 percent of the ore has a particle size
of 75 micrometers or less. Preferably, 80 percent of
~'
33, 232 F
,`i ~
the ore has a particle size of 75 micrometers or less,
and most preferably, 90 percent of the ore comprises
particles having a siæe of 75 micrometers or less.
The ine par~icle size ores useful in this
invention can be prepared by classifying the ore, i.e.
by separating the fine particles rom the medium and
large;par~icles. This can be done by the use of a
sieve of the appropria~e size or the use of a hydro-
cyclone or other metho~s known in the art. Altexna-
tively, the ore can be comminu~ed until the ore com-
prises the desired perce~tage of fine particles. Com-
minution refers to the size reduction of orPs. This
can be achieved by one of several means known in the
ar~, for example, grinding the ore in a rod mill.
Alternatively, flotation can be performed in a two-
-circuit syst~m wherein the large and medium size
mineral value par~icles are recovered in a firs t step
froth flotation process and the tailings which contain
mineral values o a ~ine particle size can then be
recovered by second s~ep froth 10tation process using
the frother composi tion and process o this inv~ntion.
The term "ore" refers herein to the ore as
it is taken out of the ground and includes the mineral
values in admixture with the gangue. Gangue refers
herein to those materials which are of no value and
which need to be separated from ~he mineral values.
The frother composition and process of the invention
can be used to recover metal oxides, metal sulfides
and other metal values.
Froth flotation is a commonly employed process
for concentrating mineral values from ores. In a flo-
tation process, the ore is crushed and wet ground to
33,232-F -2-
-3-
obtain a pulp. A frothing agent, usually employed with
a collecting agent, is added to an aqueous ore pulp to
assist in separating valuable minerals from the unde-
sired or gangue portions of the ore in subse~uent flo-
tation steps. The pulp is then aerated ~o produce afroth a~ the surface thereof and the collector assists
~he frothing agent in separating the mineral
values from the ore by causing ~he mineral values to
adhere to ~he bubbles fonmed during this aeration step.
The adherence of the mineral values is selectively
accomplished so that the portion of the ore not containing
mineral values, i.e. the gangue, does not adhere to the
bubbles. The mineral-bearing froth is collected and
furthex processed to obtain the desired mineral values.
That portion of the ore which is not carried over with
the froth, usually identified as "flotation tailings",
is usually not further processed for extraction of
mineral values therefrom. The frother composition and
process of the invention i5 generally applicable -to
ores containing metallic or non-m~tallic mineral values.
In froth flotation, it is yenerally desir-
able to recover as much of the mineral values as pos-
sible from the ore while efecting the recovery in a
selective manner, that is, without carrying over unde-
sirable portions of the ore, i.e. ~he gangue, in thefroth. While a large numbex of compounds have foam
or froth producing prope~ties, the frothers most widely
used in commercial froth flotation operakions are mono-
hydroxylated compounds such as C5 8 alcohols, pine oils,
cresols and Cl 4 alkyl ethers of polypropylene glycols
as well as dihydroxylates such as polypropylene glycols.
The frothers most widely used in froth flotation opera-
tions are compounds containing a non-polar, water-
33,232-F -3-
g_
-repellent group and a single, polar, wa~er-seeking
group such as hydroxyl (OH). Typical of ~his class
of fxothers are mixed amyl alcohols, methylisobutyl
carbinol, he~yl and heptyl alcohols, cresols, ter-
pineol, and the like. Other efective frothers usedcommercially are the Cl 4 alkyl ethers of polypropylene
glycol, especially the methyl ether and the polypropylene
glycols o~ 1~0-2100 molecular weight and particularly
those in thé 200-500 range. In addition, cer~ain
alkoxyalkanes, e.g., triethoxybutane, are used as fro~hers
in the flotation of certain ore~.
Although mineral value recovery improvements
from a preferred frother in the treatment of an ore can
be as low as only about 1 percent over other frothers,
this small improvement is o great importanc~ ec~nomic~
ally since commercial operations often handle as much
as 50,000 tons o ore daily. With the high throughput
rates noxmally encountered in commercial flotation
pxocesses, relatively small improvements in the rate
of mineral value recovexy result in the recovery of
additional tons of mineral values daily. Obviously
then, any frother which promotes improved minexal
value recovery, even though it is by a small per-
centage, is very desirable and can be highly advan-
tageous in commercial flotation operations.
It is well-known in the practice of froth
flotation, that the recovery o fine (slime) particles of
mineral values with a reasonable selectivity in favor of
the mineral values over the gangue is quite difficult.
Normally the problem is not one of achieving high recovery
of the valuable component i.e. the mineral value, but
rather one of accepting a much lower than desired recovery
33,232-F _~
,~ r ~
J~ J~'~3
-5-
of the mineral values so as to achieve a product of an
acceptable quality or grade (selectivity). In practice,
it is normally found that as the recovery of the fines of
the mineral values increases, the quality of ~he product
~selectivity) dramatically decr ases. Thus, an economic
optimization occurs between increasing the amount of
recovered product versus the drop in product value with
the decreasing product yrade.
Accordingly, the present invention provides
an improved frother co~positio~ and a process for a
substantially higher recovery of fine particles of
mineral values by froth flotation. Frothers of the
invention are capable of the selective recovery of
the ine particles of mineral values, having a par-
ticle ~ize of 75 micrometers or less.
The invention particularly resides in a flo-
tation froth~r composition for recovering mineral
values from an aqueous ore pulp, wherein 75 percent
or more o the raw ore comprises particles of a size
of 75 micrometers or less, said frother comprising
the reaction product of 1) a polyhydroxy alkane having
from l to 20 carbon atoms or a polyhydroxy cycloalkane
having from 3 to 20 carbon atoms and 2) propylene oxide
or a mixture of propylene oxide and ethylene oxide, with
the proviso that at least 50 mole percent of ~he mixture
is propylene oxide, and wherein the reaction product
has a molecular weight of from 150 to 1400.
Another aspect of this invention resides
in a process for recovering mineral values from ore,
wherein 75 percent or more of the ore comprises par-
ticles of a size of 75 micrometers or less, wherein
33,232-F -5-
--6--
the ore, in the form of an aqueous pulp, is subjected
to a flotation process in the presence of a flotation
collector and a flotation frother, charac-terized in
that the frother comprises the reaction product of
1) a polyhydroxy al~ane having from 1 to 20 carbon
atoms or a polyhydroxy cycloalkane having from 3 to
20 carbon atoms and 2) propylene oxide, or a mixture
of propylene oxide and ethylene oxide, with the pro-
viso ~hat at least 50 mole percent of the mixture is
propylene oxide, wherein the reaction product has a
molecular weight of from 150 to 1400.
The frother composition and process of this
invention results in a surprisingly high recovery of
mineral values wi~h a high selectivity toward the mineral
values i~ preference to the gangue. Critical to this
recovery are rothers which are not only useful for
floating mineral values o~ large o~ medi~ size par--
ticles but are also particularly ef~ective in the flo-
tatiun of the ine particle sizes i.e. a particles size
of 7S micrometers or less, resul~ing in an enhanced
selectivity in favor of the fine mineral values over
~he gangue.
In a preferred embodiment, the reaction
product of the invention corresponds to -the formula
R1 R1
R~o tcH-cHo~nH)Tl,
wherein R is a C1_20 alkane or a C3_20 cy
radical; Rl is hydrogen or methyl; m is an integer
of from 3 to 10; and n is a number of from 1 to 8;
33,232-F -6-
--7~
with the proviso that each ether unit can contain
only one methyl group, and with the further proviso
that at least 50 percent of ~he ether units must
have one methyl group.
Any polyhydroxy Cl 20 alkane or polyhydroxy
C3 20 cycloalkane which will react with propylene oxide,
or a mixture of ethylene oxide and propylene oxide, can
be used in this inventio~. Polyhydroxy C3 12 alkanes
polyhydroxy C3_12 cycloalkanes are preferred. Poly-
hydroxy C3 6 alkanes and polyhydroxy C5 ~ cycloalkanes
are more preferred with trihydroxy propa~es being most
preferred.
The polyhydroxy alkanes and polyhydroxy
cycloalkanes useful in thi5 invention include those
which correspond to the formula R~O~)m wherein R and
m a:re as herei~before deined. Desirable polyhydroxy
alka~es inc~ude ~he trihydroxy ethanes, trihydroxy
propanes, trihydroxy butanes, trihydroxy pentanes,
trihydroxy hexanes, trihydroxy heptanes, txihydroxy
octanes, diglyc~rol, sorbitol, pentaerythritol, a
monosaccharide, a disaccharide, sucrose or mixtures
thexeo. More preferred polyhydroxy alkanes include
the trihydroxy propanes, trihydroxy butanes, tri
hydxoxy pentanes, and trihydroxy hexanes. A most
preferred polyhydroxy alkane is trihydxoxy 1,2,3-propane.
Poly refers herein to 3 or more. The alkane polyols
include C~ 20 alkanes containing from 3 to 10 hydroxyl
moieties, inclusive, more preferably from 3 to 8 hydroxyl
moieties, inclusive, even more preferably from 3 to 6
hydroxyls, inclusive, and most preferably 3 hydroxyls.
33,232-F .7_
The polyhydroxy Cl_20 alkanes or polyhydroxy
C3 20 cycloalkanes are reacted with either propylene
oxide ox a mixture of ethylene and propylene oxide wherein
such mixture contains at least 50 mole percent of propylene
S oxide. The alkylene oxides generally correspond to the
formula
; RlC~- CHR
wherein Rl is as hereinhefore defined, wi~h the proviso
that only one Rl can be methyl. Preferably, the polyhy-
droxy Cl_20 alkane or polyhydroxy C3 20 cycloalkane is
reacted with propylene oxide. In the hereinbefore pre-
sen~ed formulas, R is preferably a C3 12 alkane radical
or C3 12 cycloalkane radical, more preferably C3 6
alkane radical or C5 8 cycloalkane radical, and most
preferably a C3 alkane radical. Preerably, m is an
integer of from 3 to 8; more preerably an integer
of from 3 to 6 and most ~referably 3. ~referably,
n is from 1 to 4, and most preferably from 1 to 3.
The frothers of this invention can be pre-
pared by contacting a polyhydroxy C1 20 alkane or
polyhydroxy C3_20 cycloalkane with the appropriate
molar amount of propylene oxide, or a mixture of
ethylene oxide and propylene oxide, in the presence
of an alkali catalyst such as an alkali metal hydroxide,
an amine, or boron trifluoLide. Generally, from 0.5
to 1 percent of the total weight of the reactants
of the catalyst can be used. In general, temperatures
of up to 150C and pres~ures of up to 689 kPa can be
used for the reaction. In the embodiment wherein a
mixture of propylene and ethylene oxi.d~ is used,
33,232-F -8-
- 9 -
-the propylene and ethylene oxide may be added simul
taneously or in a seguential manner.
The polyhydroxy Cl_20 alkane or polyhydroxy
C3 ~0 cycloalkane is reacted with a sufficient amount of
propylene oxide or a mix~ure of e~hylene oxide and pro-
pylene o~ide 50 as to prepare a reaction product of the
desired molecular weight, i~ particular, a molecular
weight of from 150 to 1400, more preerably from 200
to 800, and most preferably from 250 to 500.
Sulfide ores for which the compounds of ~he
invention are useful include copper sulfide-, zinc sulfide-,
molybdenum sulfide-, cobalt sulfide , nickel sulfide-,
lead sulfide-, arsenic sulfide-, silver sulfide-, chromium
sulfide-, gold sulfide-, platinum sulfide- and uranium
sulfide-containing ores. Examples of sulide ores from
which metal sulfides may be concentrated by froth 1O-
tation usin~ the process o this i~ven~ion include
copper-bearing ores such a~, for example, covellite
(CuS~, chalcocite (Cu2S), chalcopyrite (CuFeS2), val-
leriite (Cu2Fe~S7 or C~3Fe4S7), bornite (Cu5FeS4),
cubanite (Cu2SFe~S5), enargite (Cu3(As1Sb)S4), tetra-
3SbS2), ~ermantite (CUl2As,~,sl3), brocharltite
~CU4(0H)6S04), antlexite (Cu3S04(0H)4), famatinite
(CU3(SbAS)S4), and bournonite (PbCUSbS3); lead-bearing
ores such as, for example, galena (PbS); antimony-bearing
ores such as, for example stibnite (Sb2S3); zinc-bearing
ores such as, or example, sphalerite (ZnS); silver-
-bearing ores such as, for example, stephanite (Ag5SbS4),
and argentite (Ag2S); chromium-bearing ores such as,
for example, daubreelite (FeSCrS3); and pla~inum-
and palladium-bearing ores such as, for example,
cooperite (Pt(AsS)2).
33,232-F _g_
d~`~5i
--10--
Oxide ores for which this process is useful
include copper oxide-, aluminum oxide-, iron oxide-, iron
titanium oxide-, magnesium aluminum oxide-, iron chromium
o~ide-, ti-tanium oxide-, manganese o~ide-, tin oxide-,
5 and uranium oxide-containing ores. Examples o oxide
ores from which metal oxides may be concentrated by froth
flotation usin~ the process of this in~ention include
copper-bearing ores r such as cuprite ~Cu20), tenorite
(CuO), malachite ~Cu2(0H)2C03), azurlte ~Cu3(0H)2(C03)2),
~0 atacamite (CU2C1(0~)3), chrysocolla (CuSiO3); aluminum-
bearing ores, such as corundum;- zinc-con~aining ores,
such as zincite (ZnO), and smithsonite ~ZnC03); iron-
containing ores, such as hematite and magnetite; chromium-
containing ores, such as chromite (FeOCr203); iron- and
titanium-containing or~s, such as ilmenite; magnesium-
and aluminum-containing ores, such as spinel; ironchromium-
containing ores, such as chromite; titanium-containing
ores, such as rutile; mangane~e-containing ores, such
as pyrolusite; tin-containing ores, such as cass.i-
~erite; and uranium-containing ores, such as urani~
nite; and uranium-bearing ores such as, or example,
p.itchblende (U205(U308)) and gummite (U03nH20). Other
metal values for which this process is useul include
gold-bearing ores, such as sylvanite (AuAgTe2) and
calaverite (AuTe); platinum- and palladium-bearing
ores, such as sperrylite (PtAs2); and silver-bearing
ores, such as hessite (AgTe2).
.
In a preerred embodiment o,f this invention,
oxide- or sulfide-containing values are recovered. In a
more preferred embodiment of thi~ invention copper sul-
fide, nickel sulfide, lead sulfide, zinc sulfide or
molybdenum sulfide values are recovered. In an even
more preferred embodiment, copper sulfide values
are recovered.
33,232-F -10-
,,~i
~11--
The amount of the frother used or fro~h
flotation depends upon the type, the grade and the
size of the ore particles and the particular frother
used. Generally, that amount which separates the
desired mineral values from the ore is suitable. It
has been discoverPd that less than 0.05 kg/metric
ton can be used. Preferably, an amoun~ of from
0.0025 to 0.0~ kg/metric ton is used. Most pre-
ferably, an amount of from 0.005 to 0.05 kg/metric
ton is used. The fro~h flotation process of this
invention, usually xequires ~he use of collectors.
Any collector well-known in the art, which results
in the recovery of ~he desired mineral value is suit-
able. Further, in the process of this invention it
is contemplated that the frothers of this invention
can be used in mixtures with other frothers known in
the art.
Ex~mples of collectors useful in this inven-
tion include alkyl mono~hiocarbonates, alkyl dithiocar-
bonates, alkyl trithiocarbonates, dialkyl dithiocar-
bamates, alkyl thionocarbamates, dialkyl thioureas,
monoalkyl dithiophosphates, dialkyl and diaryl
dithiophosphates, dialkyl monothiophosphates, thiophos-
phonyl chlorides, dialkyl and diaryl dithiophosphona~es,
al~yl mercaptans, xan~hogen formates, xanthate esters,
mercapto benzothiazoles, fat~y acids and salts of fatty
acids, alkyl sulfuric acids and salts thereof, alkyl and
alkaryl sulfonic acids and salts ~herecf, alkyl phos-
phoric acids and salts thereof, alkyl and aryl phosphoric
acids and salts thereof, sulfosuccinates, sulfosuccina-
mates, primary amines, secondary amines, tertiary amines,
33,232-F -11-
.
r
~12~
quaternary ammonium salts, alkyl pyridinium salts, quani-
dine, and alkyl propylene diamines. Furthermore, blends
of such kno~n collectors can be used in this invention
also.
The frothers described hereinbefore can be
used in admixture with o~her well known frothers.
Example~ of such frothers include C5 8 alcohols, pine
oils, cresols, C1~4 alkyl ethers of pol~propylene glycols,
dihydroxylates of polypropyle~e ylycols, glycols, fatty
acids, soaps, alkylaryl sulfonates, and ~he like.
Furthe.rmore, blends of such frothers may also be used.
~11 frothers which are suitable for beneiciation of
ores by froth flotation can be used in ~his invenkion.
The frothers of this i~vention result in
selectivity improvements o 5 percent or more over
~hose selectivities achieved using e.g. methylisobutyl
carbinol (MI~C) at the same recovery levels, pre-
ferably a 10 percent selectivity increase, and most
preerab1y a 20 percent selectivity inc~ease.
The following examples are included for
illustration and are not intended to limit the scope
o the invention or claims. Unless otherwise indi-
cated, all parts and percentages are by weight.
In the following examples, the performance
of the rother compositions described hereinbefore is
shown by giving the ra~e constant of flo~ation and the
amount of recovery at infi~ite time. These numbers are
calculated by using the ormula
33,232-F -12
: .
D~;D~
--13--
r = R~ [1 Kt ]
wherein: r is the amount of mineral value recovered
at time t; K is the ra~e constant for t~e rate of
recovery, and R~ is ~he c~lculated ~mount of the
mineral value which would be recovered at i~finite
time. The amoun~ recovered at various times is
detenmined experimen~ally and ~he series of values
are substituted into the equatlon to obtain R~ and K.
The above fonmula is explained in "Selection of Chemical
Reagents for Flotation"by R. Klimpel, Chapter 45,
pp. 907-934, Mineral Processing Plan Design, 2nd Ed.,
1980, AIME (Denver).
Example_1
In this example three fro~hers are tested
for 1Otation o copper sulfide values. A 500-g quan-
ti-ty of Pinto Valley copper ore, iOe. chalcopyrite
copper sulfide ore, is plac~d in a rod mill with
2S7 g of deionized water. The copper ore comprises
~0.2 perce.nt with a par~icle si2e of about 75 micro-
meters or less. A ~uantity of lime is also added ~o
e rod mill, based on the desired pH for the subse-
~uent flotation. The rod mill is then rotated at
60 .rpm for a total of 360 revolutions. The ground
slurry is transferred to a 1500 ml cell o an Agitair~
Flotation machine. The float cell is agitated at 1150
rpm and the pH is adjusted to 10.0 by the addition of
fur~her lime, if necessary.
A collector, potassium amyl xanthate, is
added to the float cell (0.035 kg/metric ton), follow~d
33,232-F ~13
,
2~
-14~
by a conditioning time of one minute, at which time the
frother is added (O.036 kg/metxic ~on). After the addi-
tional one minute conditioning time, -the air to the float
cell is turned on at a ra-~e of ~O5 liters per minute and
~he automatic froth removal paddle is started. The roth
samples were taken of at 8 minutes. The fxoth samples
are dried overnight in an oven, along with the flotation
tailin~s. ~he drieA samples are weighed, divided into
suitablé samples for analysis, pulverized to insure suit
able ~ineness, and dissolved in acid for analysis. The
samples are analyzed using a DC Plasma Spectrograph. The
resul~s are compiled in Table I.
33,232-F -14
.~
C`~
CO N U~ ~ ~ N Ll~ N
~ o o a ~D
la ~ ~ r~ N t~
O O O C~ O C~ O O
U~
O O u~ O ~
r-~ O a~ I o
~1 ~1 ~ ~1
~ .,
~ .
U~
~ ~ C~ D O O a~
P a) ~ ~ L
q3 ~ ~1 0 ~ o co a
O O O ~ O O O
O O O O O O O O ~ a
P~ O
P
U tJl
~ . 1~
o o
z a~ co o ~ ~ o
~ ~ ~ ~O ~ ` p P~ O
h l~ . . . . . . . ~ ~ ~1 ~ ~
8 ~, ~ o ~ o ~o
~ a~ u~ ~u
s~ ~ .,,
h 1-~~1 o ~ r` t` t~ 0 rl ~ ~ O O u~
a~ 1 0 1~: ~
P~ P0 aD ~ a) u~ u~
P, O. . . . . . ~ ~ O ~ El ~
c~ au~o o o o o o oo ~ ~ ~ ~ u
~: 1:~ ~ O
.~1 .,1 _I
O N
O O O ~ ~
N N ~l 0 r/ rl X
o o ~1 o o O P~ U
,1: o ~ Ln o
N U ~I ~ 1~ d1 la Ul ~ ~1 ~)
o , ~, , ~, ~, ~+ a~ ~ o
~ ~ ~ ~ ~ O ~ O O U~
~ a ~: a ~
33, 232-F 15-
-16
Table I demonstrates that the frothers of
this inve~tion demonstrate good recovery of the copper
values with high selectivity toward the copper values.
The selectivities of the frothers of this invention are
better than the selectivities of the commerc:ial frothers
tested side by side with them. In fine mineral particle
flota~ion there i5 relatively little valuable metal
recove~y diffexence when employing the different
fxothers. The biggest difference in effectiveness
between frothers is the amount of gangue ~hat is
recovered in the roth (i.e., s~lectivity).
In Table I and the following Table II,
MIBC refer~ to me~hyl isobutyl carbinol. DF-200
refers herein to DOWTROI~X~200 (Trademark of The Dow
Chemical Company) which is a me~hyl ether of propylene
glycol with an average molecular weight of about 200.
DF-250 refers herein to DOWFROT~ 250 (Trademark of
The Dow Chemical Company) which is a methyl ether of
polypropylene glycol with an average molecular weight
of about 250. DF-1012 refer~ to DOWFROTH~ 1012
(Trademark o The Dow Ch~mical Company) which is a
methyl e~her o polypropylene glycol with an average
molecular weight of about 400. Voranol0 2025 refers
herein to the reaction product of glycerol and pro~
pylene oxide with an average molecular weight of 250.
Voranol~ CP 450 refers herein to the reaction product of
glycerol and propylene oxide with an average molecular
weight of 700. Voranol~ 2070 refers herein to the reac-
tion product of glycerol a~d propylene oxide with an
30 average molecular weight of 700. Sorbi~ol~/propylene
oxide adduct refers herein ~o ~he reaction product of
Sorbitol~ and propylene oxide with an average molecular
weight of 762 (or equivalent weigh~ of 127). Sucrose/-
33,232-F -16-
.:
~f~
-17~
propylene oxide adduct refers herein to the reaction
product of sucxose with propylene oxid~ with an average
moleculax weight o.- 984 (or equivalent weight of 123).
An El Tenien~e copper ore, wherein 91.1 per-
cent comprises particle sizes of 75 micrometers or less,
is floated by a fxo~h flo~a~ion machine using the proce-
dure of Example 1. The pH of the aqueous pulp in the
cell is 8.5. The collector is methyl isopropyl ~hiono-
carb~mate (Z-200~, a Trademark of The Dow Chemical Com-
pany) and used in an amount o 0.052 kg/ton. The
frothers are used in concentrations o 0.025 kg/ton.
The results are compiled in Table II.
33,232 F- -17~
--18 ~
O ~0 0 aD c~
n~-~ ~ ~ I~ n ~ d' O
~1 :' N
U
U~
~ o ~ u~ ~n o o
.,.~
O O t~ rl N
U ; ;
U~
~ ~ u~ o ~
o~
; d~
~0 r~ 0 a~
v~ b~ O c~ O ~1 0 0 0 0
t~ o o o o o C~ h
O (~
u
u ~ ~ ~ O~ ~ ~ O O
i~ O h O ~ Il) ~1 N N a~
n ~ P ,~ p P P ~ p
h h ~r1
~ 4l t~
h h ~t OD 1~ i-l u) 00 dt ~ ~ O o
~ ~ ~--1 0 ~ ~ ) ~ O ~: G ~rl
;~ a P a~ 0 ~ a~ ~ ~ ~
c~ U O O O O ~ O O ~ ~ ~ ~ .
~ ~ ~t O
rl r~
o ~
h ~ t ~t
~rl O~rl O ~\
~3~X ~aOe 5~
v~ ~/~, ~ O Q~
o ~ o ~ ~ U V~t O U
e~ O O L~l ~rl O O a~ :1 0 ~
O ~ I I I L! ~t~ U ~t~ ~ + ~1 ~
v~t-t ~t ~t ~ O ~ ~ ¢ O u~ u~ Z
33, 2~2-F -18-
,
-l9~
Table II demonstrates that the use of the
frothers of this invention result in higher recoveries
of copper than the commercial frothers ~hey are com-
pared to. Fur~her, the frothexs of this invention
result in surprisingly better selectivities for the
copper values over the gangue than the commercial
frothers allow.
33,232-F -19
-20-
Example 3
In this example three frothers are tested
for flotation of coper sulfide values. A 500-g
~uantity of copper ore, chalcopyrite copper sul~ide
ore, previously packaged in plaçe in a rod mill
with 257 g of deionized water. A quantity of lime
is also added to the rod mill, based on the desired
pH for ~h~ subsequen~ flotation. The rod mill is
then rotated at 60 rpm for a total of 360 revolutions
to produce a feed in which 50.1 percent of the particles
have a size less than 75 micrometers. The ground
slurry i~ transferred to a 1500 ml cell of an Agi-tair
Flotation machine. The float cell is agitated at 1150
rpm and the pH is adjusted to the desired pH (10.0)
by the addition of urther lime, if necessary.
The collecto~, potassium amyl xanthate, is
add~d to the float cell (0.004 kg/metric ton),
followed by a conditioning time o one minute, at which
tim~ the frothe~ is added (0.058 kg/metric ton).
After an additional one minute conditioning time,
the air to the 1Oat cell is turned on at a rate of
4.5 liters per minute and the automatic froth
removal paddle is started. Froth was taken for 8.0
minutes. The froth samples are dried overnight
in an oven, along with the flotation tailings.
The dried samples are weighed, divided into
suitable samplesOfor analysis, pulverized to
insure suitable fineness, and dissolved in
acid for analysis. The samples are analyzed
using a DC Plasma Spectrograph. The weights of
recovered froth and tailings samples and the
analyses are used in a computer program to calculate
metal and ganguge recovery, and the R and K parameters.
The results are compiled in Table III.
33,232-F ~20-
21
~ I ~
.~ ~ I
Ei ~ D
¦N
~ o ~ d' r~ a
lo
~ o~
~ r~l ~ d~ N r
~ E I o o o o o
E ~ ~ O ~ O
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33,232-F ~21
-22-
Table III demonstrates that the use of CP-450
frothers o~ this invention resulted in a substantially
higher recovery of copper particles having a size of
less than ~bout 200 microns. The recovery of gangue
in the coarse particle size of greater than 200 microns
as well a~ in the xecovery of gangue in the fine
particle size below ~00 microns was substantially
less. Ac~ordingly, ~he selectivity recovered for both
coarse and fine particles was substantially greater.
The percentage selectivi~y for fine particles is
improved by at least 19 percent.
33,232~F -22
