Note: Descriptions are shown in the official language in which they were submitted.
-`~ t~ J 11165CA
ORE FLOTATION WITH COMBINED COLLECTORS
The present invention relates generally to mineral recover~ by
; flotation operations. In one aspect the invention relates to a new
composition comprising two flotation ingredients. In another aspect the
invention relates to a new composition comprising three flotation
~5 ingredients. Another aspect of this invention rela-tes to ore flotation
processes, such as, for example, those processes involving the recover~
o-f copper, nickel, molybdenum and iron.
Flotation processes are used for recovering and concentrating
minerals from ores. In froth flotation processes, the ore is crushed and
wet~ground to obtain a pulp. Additives, such as min~ral flotation or
collecting agents, frothers, suppressants, stabilizers, etc., are added
to the pulp to assist the separation of valuable materials from the
undesired minerals or gangue portions of the ore in one or more
subsequent flotation steps. The pulp is then aerated to produce a froth
at the surface. The minerals which adhere to the bubbles or froth are
skimmed or otherwise removed and the mineral-bearing froth is collected
and further processed to recover the desired minerals. Typical mineral
flotation collectors include xanthates, amines, alkyl sulfates, arenes,
sulfonates, dithiocarbamates, dithiophosphates and thiols.
U.S. Patent 2,600,737 describes alkali metal salts of tertiary
alkyl trithiocarbonates and processes for making such salts. This patent
also describes the use of such compounds in ore flotation. Sodium
diethyl dithiophosphate has also been described in other references as a
collector in the separation of ~inc and copper. The prior art has also
`~J
:a~
described potassium ethyl xanthate and potassium isoamyl xanthate as ore
flotation collectors for copper.
U.S. Patent 4,341,715 discloses the synthesis of S-allyl-S'-
n-butyl trithiocarbonate, and further discloses the use of such compound
as a mineral sulfide collector in ore flotation. This patent does not
mention the ~Ise of such compound with other collectors in an ore
flotation process.
U.S. Patent 4,316,797 discloses the use of trith-iocarbona-tes,
such as, for example, allyl butyl tri~hiocarbonate, which are blended on
a 1:1 weight ratio with S02 extract oil to produce a product wh:ich is
useful as a mineral sulfide collector. This patent does not mention the
employment of such a product blend with other collectors in an ore
flotation process.
While the art of ore flotat~ion has reached a significant degree
lS of sophistication, it is a continuing goal in the ore recovery industry
to increase the productivity of ore flotation processes and, above all,
to provide specific processes which are selective to one ore or to one
metal over other ores or other metals, respectively, which are present in
the materials being treated in such processes.
It is thus one object of this invention to provide a new
composition which is useful in ore flotation.
Another object of this invention is to provide an ore flotation
process.
A further object of this invention is to provide an improved
flotation process using new compositions to improve the recovery of
copper and nickel.
A still further object of this invention is to provide a
flotation process employing new compositions to improve the recovery of
copper and iron.
These and other objects, advantages, details, features and
embodiments of this invention will become apparent to those skilled in
the art from the following detailed description of the invention and the
appended claims.
In accordance with this invention it has been found that the
recovery of copper, nickel and iron is synergistically improved when
5 ' d 5:01 9;: /ZO/bCi ~ c :I Sd1111 Hd 1~0,~1
. B ~ 31165CA
S~all~ n-butyl trlthioca~bonate ~nd n-dodecyl ~ercapt~n a~e used
together in ~ ~lotation proees~.
~ urth~r in accordanc~ with ~his invention i~ has been
di~covered that the re~oYery o~ copper, nickel ~nd iron is
sy~ergistic~lly improved when S-allyl-S'-n-hutyl trithioc~rbonate and a
composition comprislng n-dodecy:L mercaptan a~d pol~propylene glycol) are
used in combination a~ ~ flot~tio~l ~gent.
Thus, in aceordance with a firs~ embodiment of ~his invelltion,
novel ore f~otation oompo~iti4n~. are provided. '~hese novel ore ~lotation
composition~ include a mixture o~ sub~an~ial quantities o~ allyl n-butyl
trithiocarbonate ~nd n-dodecyl m~rcaptan and a mixture containing
su~stantial quantities of allrl n-4utyl trithiocarbonate t n~dodecyl
~crcaptan and poly(propylen~ glycol).
The ~ 1 n-butyl trithiocarbonate fo~ ~se in the presen~
invention is herein alternatively desi~nated ~211~ ~'-n-butyl
trithlocarbonate and is further ch~racteriæed by the following
str~ctural formula
C,3H~-S~C-S-~-C4H~ .
The two synergi~tlc~lly combined components o~ t~e two novel
ore ~lot~tion compositions o~ the present in~ention ~re pref~bl~
pre~ellt in the composition in wei~ht ratios in the ran~e of from ~bont
~0:7~ ~o abollt 70:30, ~nd more preferabl~ in the range from abo~t ~5:5S
t~ about 55:45~ Most prefer~bly~ the t~o ~ne~istically a~ting
~omponents of the ~lot~tion aBent~ o~ ~he pre~ent invention ar~ present
in ~oughly ~h~ ~ame qu~ntity by weight.
In ~he inventive ore flotation compositio~ comprisin~ ~ blend
of n-dodecy~ mercapt~n and po].~propylene gl~col), it is presentl~
preEcrred that these compounds ~ire respec~ively present in the bl~nd in a
welg~l~ ratio generally in the ranse fro~ ~bout 6;1 to ahout 3:1l and i~
is pre~ently preferred that the weight ratio of thi~ blend o~ n-dodecyl
m~captan a~d poly(prop~lene glycol) i9 roughly about 4;1.
~ t is al~o presently preferred that the polytpr~p~lene ~lycol)
~ployed in the inventive bleAd ~ a disp~rsant have a molecular weight
generally in the range Erom a'bout 400 to a'bout 900, with a molecu:Lar
weight of about 450 being presently preferred.
The production of the unsymmetr:ical S~ally'l-S'-n-butyl
trithiocarbonate is described in detail in 'U.S. Patent 4,3~1,715.
In accordance with another embodiment of this invention a
f~otation process is provided. This flotation process involves the steps
of mixing mineral materials, water and either of the inventive
compositions described above to establish a pulp. Th:is step is followed
by aerating the thus esta'blished pulp to produce a froth and a tail
product, separating the froth and -the tail product and recovering mineral
values from the froth. Mineral values can also be recovered from the
-tail product.
The process steps described above axe conventional except for
the use of the composition in accordance with the present inven-tion as a
collector as described. Although the allyl n-butyl trithiocarbonate,
n-dodecyl mercaptan or the blend of n-dodecy] mercap-tan and
poly(propylene glycol) described above can be added separa-tely during the
froth flotation operation, it is preferred that the composition
comprising allyl n-butyl trithiocarbonate and n-dodecyl mercaptan and the
composition comprising allyl n-'butyl trithiocarbonate and the blend of
n~dodecyl mercaptan and poly(propylene glycol) be premixed, blended or
otherwise combined be:Eore using either of these novel compositions in an
ore flota-tion process. ~lile any amount of inventive collector blend can
be employed in an ore flotation process which will achieve the desired
2S results, such collec-tor blend is generally employed in the range from
about 0.001 to about 1.0 lb/ton of ore, and is more preferably employed
in -the range from about 0.01 to about 0.1 lb/ton of ore.
It is generally believed that the inventive compositions
disclosed herein are useful for separating any valuable metal from its
corresponding gangue material. It is also understood that the inventive
compositions may separate a mixture of metals that are contained in a
particular mining deposit or ore, such mixture being further separated by
subsequent froth flotations or any other conventional separa-ting methods.
The inventive compositions herein disclosed are particularl~ useful for
separating copper, nickel, iron and molybdenum minerals from the total
ore. Such molybdenum bearing ore~ include, but are not limited to such
materials as
Molybdenum-Bearing ores:
Molybdenite MoS2
Wulfenite PbMoO4
Powellite Ca~Mo,W)O4
Ferrimolybdite 2 3 12 2
Other metal bearing ores within the scope of this invention
are, for example, but not limited to, such materials as
Copper-bearin~ ores:
Covallite CuS
Chalcocite Cu2S
Chalcopyrite CuFeS2
Bornite Cu5FeS4
Cubanite Cu2SFe4S5
Valerite Cu2Fe4S7 or Cu3Fe4S7
Enargite Cu3(As~sb)s4
Tetrahedrite Cu3SbS2
Tennani-te Cul2As4Sl3
Cuprite Cu2O
Tenorite CuO
Malachite Cu2~OH)2CO3
Azurite Cu3~OH)2CO3
Anklerite 3SO~OH)4
Brochankite Cu4~OH)6SO4
Atacamite Cu2Cl(OH)3
Chrysocolla CuSiO8
Famatinite Cu3~sb~As)s4
Bournonite PbCuSbS3
Lead-Bearing ore:
Galena PbS
An-timony-Bearing ore:
Stibnite Sb2S3
Zinc-Bearing ores:
Sphalerite ZnS
Zincite ~nO
Smithsonite ZnC03
Silver-Bearing ores:
Argentite Ag2S
Stephanite Ag5SbS4
Hessite AgTe2
Chromium-Bearing ores:
Daubreelite FeSCrS3
Chromite FeO Cr2O3
Gold-Bearing ores:
Sylvanite AuAgTe2
Calaverite AuTe
Platinu,n-Bearing ores:
Cooperite Pt(AsS32
Sperrylite PtAs2
Uranium-Bearing ores:
Pitchblende U205(U3O8)
Gummite UO nH O
The presently preferred ores in connec~ion with which the
process of this inven~ion is applied are molybdenum, copper and lron ores
~5 or minerals.
Any Eroth flotation apparatus can be used in this invelition.
The most commonly used commercial Elotation machilles are the Agitar (a
trademark oE Galigher Co~), Denver Sub-A (a -trademark of Denver Equipment
Co.~, and the Fagergren (a trademark of Western ~achinery Co.). Smaller
30 laboratory scale apparatus such as the Hallimond cell can also be used.
The instant invention was demonstrated in tests conducted a-t
ambient room temperature to about 37C (100F) and atmospheric pressure.
However, a~y temperature or pressure generally employed by those skilled
in the art is within the scope of this invention.
2h~
The following examples serve to illustrate -this invention
without undue limitation of the scope thereof.
EXAMPLE I
This example describes a typical procedure used herein to
evaluate ore flotation agents. The example is a control illustrating the
efficiency of one of the ingredients in the 2-ingredient blend of the
instant invention to act as a copper and nickel collector. In Run 1, 750
grams of a copper/nickel-bearing ore along with 1125 milliliters of water
was added to a ball mill and was ground for about 16 minutes and 48
seconds to produce a slurry or pulp. The slurry was transferred to a 2.5
Liter Denver D-12 (a trademar~ of Denver Equipment Co.) flotation cell
along with enough water to fill the cell to 1 inch from the lip (about
35% aq~eous solids). Also added to the cell while stirring the contents
at about 1000 rpm was a frother, pine oil (0.1 lb/ton of ore~, and a
collector, S-allyl-S'-bu-tyl trithiocarbonate (0.1 lb~ton of ore), and the
resulting slurry was conditioned in the cell for 3 minutes, aerated and
floated for 5 minutes. The float concentrate in the resnlting froth and
the resulting tails were filtered, dried and analyzed. The procedure was
repeated for Run 2. The results listed in Table I show the average
weight percentages recovery of Cu and Ni were 73.35/O and 21.48%,
respectively.
TABLE ~
Effect of S-Allyl-S'-Butyl Trithiocarbonate(a)
as a Cu-Ni Collec _ r ___
(750 grams ore)
Tails, ~rams _ Concentrate, grams__
m Total Total % Recovery
No~ Wt Cu Ni Wt Cu Ni Cu Ni
l 7~92~92 6.61 40.03 5.80 1.2~ 66.51 15.80
3n 2 ~8~41~56 4.~0 51.30 6.31 1.64 80.18 27.15
Average = 73.35 21.48
~a)n I l~/toll oE ore
EXA~IPLE II
This example is a contr~l illustrating the effectiveness of the
other ingredient in the 2-ingredient blend of the instant invention to
act alone as a copper and nickel collector. The procedure described in
~f~
Example I was repeated except ~he collector used was a blend of 80 wt.%
n-c~odecyl mercaptan plus 20 wt.% poly(propylene glycol) dispersan~
(mol.wt. 450), the collector being used at O.l lb/~on of ore. The
results listed in Table II show an increase in the average weight
5 percentages of Cu and Ni recovery (79.37% and 4l.79% respectively)
compared to the average weight percentages of Cu and Ni recovery obtained
in Example I.
TABLE II
Effect of Dodecyl Mercaptan-Poly(Propylene Glycol) Mixture( )
as a Cu-Ni Collector_
Tails, grams _ Concen-~rate, grams
Run Total Total % Recovery
No. Wt Cu Ni Wt Cu Ni Cu Ni
3 67~1.4 2.35 Ç.00 70.78 7.363.68 75.80 38.02
4 676.1 1.58 4.59 72.54 7.6g3.84 82.94 45.55
Average = 79.37 ~1.79
0.1 lb/ton oE ore
EXA~PLE III
This example illustrates the effec-tiveness of a presently
preferred embodiment of the invention as a copper and nickel collector
when each of the collec-tors used separately in Examples I and II are
pre-mixed (blended) and used together. The procedure described in
Example I was a8ain repeated except the collec-tor was a l:l wt. ratio
blend of S-allyl-S'-butyl trithiocarbonate and the mixture 80 wt.%
n-dodecyl mercaptan-20 wt.% poly(propylene glycol) (mol.wt. 450), the
collector being used at O.l lb/ton of ore. The results listed in Table
III show an increase in bo-th Cu and Ni recoveries compared to previous
recoveries when each collector in the blend was used separately.
TABLE III
Effect of a 1:1 Weight Ratio Blend of S-Allyl-S'-Butyl
Trithiocarbonate/80 wt.% n-Dodecyl Mercaptan-20 wt.%
Poly(Propylene Glycol) (Mol.wt.450) as a Cu-Ni Collector
Tails, grams Concentrate, ~rams
Run Total Total ~/0 Recovery
No. Wt Cu Ni Wt Cu Ni Cu Ni
~73.4 1.50 4.11 71.25 7.044.13 82.44 50.12
6 ~70.7 1.53 4.~3 71.70 7.673.73 83.37 44.62
Average = 82~91 47.37
0.1 lb/ton of ore
The results disclosed in Examples I, II, III are summarized in
Table IV and indicate a 1:1 weight ratio blend oE two collectors gives a
higher recovery of Cu and Ni compared to when the collectors are used
IS separately.
TABLE IV
Summary of Data
Average w-t.
% Recovery
20 Example Collector 0.1 lb/ton of Ore Cu Ni
Control:
I S-allyl-S'-butyl trithiocarbonate 73.35 21.48
II 80 wt.% dodecyl mercaptan-20 wt.% 79.37 41.79
poly(propylene glycol) (mol.wt. 450)
25 Invention:
III 1:1 wt.ratio of S-allyl-S'-butyl 82.91 47.37
trithiocarbonate and the mixture 80
wt.% dodecyl mercaptan-20 wt.%
poly(propylene gycol) (mol.wt. ~50)
3~ EXAMPLE IV
This example illustrates that the inventive blend disclosed in
E~ample III is a useful collector with other type ores containing other
minerals. The amounts of materials used were different than those
~lescribed in Example I. For example, 2000 grams of a
copper-molybdem ~-iron-bearing ore plus 1000 milliliters of water was
added to a ball mill. Also added was 0.04 lb/ton fuel oil and 0.04
lb~ton of the collector blend of a 1:1 wt.ratio of S-allyl-S'-butyl
trithiocarbonate and the mixture 80 wt.% n dodecyl mercaptan/20 w-t.%
poly(propylene glycol) (mol.wt. 450~. ~he mixture was ground for about
23 minutes 42 seconds and transferred to a 5-liter Denver D-12 flotation
cell. Additional water was added so that -the top surface of the slurry
was within 2 inches from the lip. A frother, methylisobutyl carbinol
(MIBC), 0.04 lb/ton was added, the mixture stirred at 1500 rpm,
conditioned for 3 minutes and floa-ted for 3 minutes. The resul-ting
concentrate and tails were separately filteredg dried and analyzed. The
procedure was repeated 3 times and an average recovery calculated from
these 3 runs (Runs 13, 14 and 15). The process was repeated, at the same
0.04 lb/ton dosage, with two control collectors, namely S-4037 (80%
thionocarbonate/20% dithiophosphate available from American Cyanamid Co.)
(Runs 7, 8 and 9) and S-allyl-S'-butyl trithiocarbonate (Runs 10, 11 and
l2). The results from these flotations are listed in Table V where it
can be seen that the inventive blend collector (Runs 13, 14 and 15) gives
higher average wt.% recoveries of copper and iron than are given by the
control collectors (Runs 7-12). It will also be seen that the inventive
blend collector gives good recovery of molybdenum.
2~
TA~LE V
Comparison of Collec-tors
(2000 gram~ ore)
Concentrate Grams _ Wt.% Recovery
5 Run Total
~o. Collector Wt. Cu Mo Fe Cu Mo Fe
Control:
7 S-4037( ~ 22.93 2.98 .089 2.11 65.5 36.0 2.92
8 25.05 3.13 .093 7.57 65.2 35.1 g.64
9 21.43 3.02 .~99 6.51 ~4.1 38.8 8.37
Average = 64.9 36.6 7.0
(b) 25.81 3.48 .101 7.67 71.9 39.3 9.79
11 24.64 3.47 .10~ 7.37 72.7 41.5 9.42
12 22.82 3.49 .105 6.~ 71.3 41.2 8.71
Average = 72.0 40.7 9.3
Invention:
13 Blend(C) 30.15 3.41 .097 10~1 70.7 37.3 12.5
14 28.80 3.51 .101 8.81 72.8 39.4 11.1
29.81 3.55 .104 g.03 77.6 40.3 11.5
~0 Average = 73.7 39.0 11.7
(a)A blend of 80% of a thionocarbonate and 20% of a dithiophosphate
(b)S-allyl-S'-butyl tri-thiocarbonate
(C)1:1 blend of S-allyl-S'-butyl trithiocarbonate and a mixture of 80
wt.% n-dodecyl mercaptan/20 wt./~ poly(propylene glycol) (mol.wt. 450)
Reasonable variations and modifications which will become
apparent to those skilled in the art can be made in this invention
without departing from -the spirit and scope thereof.
