CA1267979A - Collector composition for froth flotation - Google Patents

Abstract

ABSTRACT

This invention concerns a novel composition which is useful as a collector for the recovery of nonferrous metal-containing sulfide minerals and sul-fidized metal-containing oxide minerals from ores in a froth flotation process. The novel composition com-prises (a) a hydrocarbon containing one or more mono-sulfide units, wherein the carbon atoms to which the sulfur atom(s) are bound are aliphatic or cycloali-phatic carbon atoms, and the total carbon content of the hydrocarbon portion is such that the hydrocarbon has sufficient hydrophobic character to cause the metal-containing sulfide mineral or sulfidized metal--containing oxide mineral particles to be driven to an air/bubble interface; and (b) an alkyl thiocarbonate, a thionocarbamate, a thiophosphate, or mixtures thereof.

34,276-F

Description

~Z6~79~

NOVEL COLLECTOR CC)M POS I T I ON
FOR FROTH FLOTATION
:`
This invention concerns a novel collector composition useful for the recovery of metal-containing sulfide minerals and sulfidized metal-containing oxide ' minerals from ores by froth flotation.

Flotation is a process of treating a mixture of finely di~ided minexal solids, e.g., a pulverulent ~ ore, suspended in a liquid whereby a portion of such ; solids is separated from other finely divided solids, e.g., clays and other like materials present in the ore, by in-troducing a gas ~or providing a gas ln situ) in the liguid to produce a frothy mass containing certain of the solids on the top of the liquid, and leaving suspended (unfrothed) other so~id components of the ore. Flotation is based on the principle that introducing a gas into a liquid containing solid par-ticles of different materials suspended therein causes adherence of some gas to certain suspended solids and not to others and makes the particles having the gas thus a &ered thereto lighter than the liquid. Accord-ingly, these particles rise to the top of the li~uidto form a froth.

34, 276-F -1-.
, ~ -2-~6797~1 Various flotation agents have been admixed with the suspension to improve the frothing process.
Such added agents are classed according to the function to be performed: collectors, for sulfide minerals including xanthates, thionocarbamates and the like;
; frothers which impart the property of forming a stable froth, e.g., natural oils such as pine oil and euca-lyptus oil; modifiers such as activators to induce flotation in the presence of a collector, e.g., copper sulfate; depressants, e.g., sodium cyanide, which tend to prevent a collector from functioning as such on a mineral which it is desired to retain in th~ liquid, and thereby discourage a substance from being carried up and forming a part of the froth; pH regulators to produce optimum metallurgical results, e.g., lime, soda ash and the like.

It is of importance to bear in mind that additives of the hereinbefore described types are selected for use according to the nature of the ore, ~; 20 the mineral(s) sought to be recovered, and the other additaments which are to be used in combination there-with.

An understanding of the phenomena which makes flotation a particularly valuable industrial operation is not essential to the practice of the present inven-tion. The phenomena appear, however, to be largely associated with selective affinity of the surface of particulated solids, suspended in a liquid containing entrapped gas, for the li~uid on the one hand, the gas on the other.

, :

34,276~F -2 . .

~ -3-~26~97!~

The flotation principle is applied in a number of mineral separation processes among which is the selective separation of such metal sulfide minerals as those containing copper, zinc, lead, nickel, molyb-denum, and other metals from iron-containing sulfide minerals such as pyrite and pyrrhotite.

Among collectors commonly used for the recov-ery of metal-containing sulfide minerals or sulfidized ; metal-containing oxide minerals are xanthates, dithio-phosphates, and thionocarbamates. These volatile sulfur compounds are often released to the atmosphere through smokestacks, or are removed from such smoke-stacks by expensive and elaborate scrubbing eguipment.
Many nonferrous metal-containing sulide minerals or metal-containig oxide minerals are found naturally in ores which also consist of iron-containing sulfide minerals. When the iron-containing sulfide minerals are recovered in flotation processes along with the nonferrous metal~containing sulfide minerals and sul-fidized metal-containing oxide minerals, there is excess sulfur present which is released in the smelting processes resulting in an undesirably high amount of sulfur present during the smelting operations. What is needed is a collector composition useful for selectively recovering the nonferrous metal-containing sulfide minerals and sulfidized metal-containing oxide minerals, without recovering the iron-containing sulfide minerals.
::
Of the commercial collectors, the xanthates, thionocarbamates, and dithiophosphates do not selec-tively recover nonferro~s metal-containing sulide minerals in the presence of iron-containing sulfide minerals. On the contrary, such collectors collect and recover all metal-containing sulfide minerals.

34,276-F -3-~2~7979 What is needed is a flotation collector composition which will selectively recover the non-ferrous metal-containing sulfide minerals or sulfidized metal-containing oxide minerals in the presence of ~ 5 ferrous sulides.

This invention concerns a novel composition which is useful as a collector for the recovery of nonferrous metal-containig sulfide minerals and sulfid-ized metal-containing oxide minerals from ores in a froth flotation process. The novel composition com-prises:
(a) a hydrocarbon con-taining one or more monosulfide units, wherein the carbon atoms to which the sulfur atom(s) are bound are aliphatic or cycloali-phatic carbon atoms, and the total carbon content ofthe hydrocarbon portion is such that the hydrocarbon has sufficient hydrophobic character to cause the metal-containing sulfide mineral or sulfidized metal--containing oxide mineral particles to be driven to an air/bubble interface; and (b) an alkyl thiocarbonate, a thionocarba-mate, a thiophosphate, or mixtures thereof.
`:
The novel collectors of this invention result in surprisingly high recovery of nonferrous metal-con-taining sulfide minerals or sulfidized metal-containing oxide minerals and good selectivity toward such non-ferrous metal-containing sulfide minerals and sulfi-; dized metal-containing oxide minerals when such metal-;~ containing sulfide minerals or sulfidized metal-con-taining oxide minerals are found in the presence of ~- iron-containing sulfide minerals. These collectors demonstrate good recovery and good kinetics.

34,276-F -4-lZ~;797~

One component of the novel collector compo-sition of this invention is a hydrocarbon which con-tains one or more monosulfide units wherein the sulfur atoms of the sulfide units are bound to non-aromatic carbon atoms, i.e., aliphatic or cycloaliphatic carbon atoms. Monosulfide unit refers herein to a unit wherein a sulfur atom is bound to two carbon ato~s of a hydro-carbon moiety only. Such hydrocarbon compounds con-taining one or more monosulfide units, as used herein, include such compounds which are substituted with hydroxy, cyano, halo, ether, hydrocarbyloxy and hydro~
carbyl thioether moieties. Non-aromatic carbon atom refers herein to a carbon atom which is not part of an aromatic ring.

Preferred hydrocarbons containing monosulfide units include those corresponding to the formula ; Rl_s-R~ I
wherein R1 and R2 are independently a hydrocarbyl radical or a hydrocarbyl radical substituted with one or more hydroxy, cyano, halo, ether, hydro-carbyloxy or hydrocarbyl thioether moieties;

wherein R1 and R2 may combine to form a heterocyclic ring structure with S; with the proviso that S is bound to an aliphatic or cycloaliphatic carbon atom; with the further proviso that the total carbon content of the hydrocarbon sulfide be such that it has sufficient .
34,276-F -5-~ -6-~67~79 hydrophobic character to cause the metal~containing sulfide mineral or sulfidized metal-containing oxide mineral particles to be driven to an air/bubble inter-face.

Preferably, Rl and R2 are independently an aliphatic, cycloaliphatic or aralkyl moiety, unsubsti-tuted or substituted with one or more hydroxy, cyano, halo, oR3, or SR3 moieties, wherein R3 is a hydrocarbyl radical, wherein R1 and R2 may combine to form a hetero-cyclic ring with S. Rl and R2 are more preferably an aliphatic or cycloaliphatic moiety, unsubstituted or substituted with one or more hydroxy, cyano, halo, OR , or SR3 moieties; wherein Rl and R2 may combine to form a heterocyclic ring with S. In a more preferred embodi-ment, R1 and R2 do not combine to form a heterocyclicring with sulfur and Rl and R2 are alkyl, alkenyl, alkynyl, cycloalkyl or cycloakenyl, unsubstituted or substituted with one or more hydroxy, halo, cyano, oR3 SR3 moieties, wherein R3 is aliphatic or cycloaliphatic.
In a most preferred embodiment, Rl is methyl or ethyl.
R is a C6_11 alkyl or alkenyl group. In the most preferred embodiment, R and R are not the same hydro-carbon moiety, that is, the monosulfide is as~mmetrical.
R3 is preferably aliphatic or cycloaliphatic. R3 is more preferably alkyl, alkenyl, cycloalkyl or cyclo ,~ alkenyl.

` The total carbon content of the hydrocarbon portio~ of the hydrocarbon monosulfide must be such that the hydrocarbon sulfide has sufficient hydrophobic character to cause the metal-containing sulfide mineral or sulfidized metal-containing oxide mineral particles to be driven to the air/bubble interface. Preferably, 34,276-F -6-lZ167~379 the total carbon content of the hydrocarbon monosulfide is such that the minimum carbon number is 4, more preferably 6, and most preferably 8. The maximum carbon content is preferably 20, more preferably 16, and most preferably 12.
Examples of cyclic compounds which are hydrocarbon sulfides of this invention include the following structures.

(R )2~~C~(R )2 and R S

Ia Ib wherein R is independently hydrogen, aryl, alkaryl, aralkyl, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, hydroxy, cyano, halo, OR , SR , wherein the aryl, alkaryl, aralkyl, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl may optionally be substituted with a hydroxy, cyano, halo, oR3 or SR3 moiety, and :~ the like; and R is a straight- or branched-alkylene, -alkenylene, or -alkynylene, unsubstituted or substituted with a ~ydroxy, cyano, halo, OR or SR moiety.
In another preferred embodiment of this invention, the hydrocarbon sulfides useful in this invention correspond to the formula 20(R )3_nC(H)n-s-c(H)n~R )3-n Ic or R )2-C - CH2 Id S
wherein R is defined as above;
: R is independently hydrocarbyl, or hydrocarbyl substi*uted with a hydroxy, cyano, halo, ~ . h ~Z67~7~
ether, hydrocarbyloxy or hydrocarbyl thioe-ther moiety; wherein two R6 moieties may combine to form a cyclic ring or heterocycl.ic ring with the sulfur atom;
n is an integer of 0, 1, 2 or 3; with the proviso that the total carbon content of the hydrocaxbon portion of the collector is such that the collector has sufficient hydrophobic character to cause the metal-containing sulfide mineral or sulfidized metal-containing oxide mineral par-ticles to be driven to the air/bubble interface.

Preferably, R6 is aliphatic, cycloaliphatic, aryl, alkaryl or aralkyl, unsubstituted or substituted with a cyano, hydroxy, halo, oR3 or SR3 moiety, wherein R3 is as hereinbefore defined. More preferahly, R6 is an aliphatic or cycloaliphatic moiety, unsubstituted or substituted with a hydroxy, cyano, aliphatic ether, cycloaliphatic ether, aliphàtic thioether or cycloali-phatic thioether moiety. Even more preferably, R6 is ~- 20 an alkyl, alkenyl, cycloalkyl or cycloalkenyl moiety Most preferably, one -C(H)n(R6)3 n is a methyl or ethyl moiety, and the other is a C6 11 alkyl or alkenyl moiety. Preferably, n is 1, 2 or 3, and more prefer-ably 2 or 3.

Examples of hydrocarbon sulfides within the scope of this invention include methylbutyl sulfide, methylpentyl sulfide, me-thylhexyl sulfide, methylheptyl sulfide, methyloctyl sulfide, methylnonyl sulfide, methyldecyl sulfide, methylundecyl sulfide, methyl-dodecyl sulfide, methylcyclopentyl sulfide, me-thyl-cyclohexyl sulfide, methylcycloheptyl sulfide, methyl-cyclooctyl sulfide, ethylbutyl sulfide, ethylpentyl 34,~76-F -8-1~6~7~7g sulfide, ethylhexyl sul~ide, ethylheptyl sulfide, ethyloctyl sulfide, ethylnonyl sulfide, ethyldecyl sulfide, ethylundecyl sulfide, ethyldodecyl sulfide, ethylcyclopentyl sulfide, ethylcyclohexyl sulfide, ethylcycloheptyl sulfide, ethylcyclooctyl sulfide, propylbutyl sulfide, propylpentyl sulfide, propylhexyl sulfide, propylheptyl sulfide, propyloctyl sulfide, propylnonyl sulfide, propyldecyl sulfide, propylundecyl sulfide, propyldodecyl sulfide, propylcyclopentyl sulfide, propylcyclohexyl sulfide, propylcycloheptyl sulfide, propylcyclooctyl sulfide, dibutyl sulfide, butylpentyl sulfide, butylhexyl sulfide, butylheptyl sulfide, butyloctyl sulfide, butylnonyl sulfide, butyl-decyl sulfide, butylundecyl sulfide, butyldodecyl sulfide, butylcyclopentyl sulfide, butylcyclohexyl sulfide, butylcycloheptyl sulfide, butylcyclooctyl sulfide, dipentyl sulfide, pentylhexyl sulfide, pentyl-heptyl sulfide, pentyloctyl sulfide, pentylnonyl sul-fide, pentyldecyl sulfide, pentylundecyl sulfide, pentyldodecyl suLfide, pentylcyclopentyl sulfide, : pentylcyclohexyl sulfide, pentylcycloheptyl sulfide, pentylcyclooctyl sulfide, dihexyl sulfide, hexylheptyl sulfide, he~yloctyl sulfide, hexylnonyl sulfide, hexyl-decyl sulfide, hexylundecyl sulfide, hexyldodecyl sulfide, hexylcyclopentyl sulfide, hexylcyclohexyl ; sulfide, hexylcycloheptyl sulfide, hexylcyclooctyl sulfide, diheptyl sulfide, heptyloctyl sulfide, , heptylnonyl sulfide, heptyldecyl sulfide, heptylundecyl sulfide, heptyldodecyl sulfide, heptylcyclopentyl sulfide, heptylcyclohexyl sulfide, heptylcycloheptyl sulfide, heptylcyclooctyl sulfide, dioctyl sulfide, octylnonyl sulfide, octyldecyl sulfide, octylundecyl 34,276-F -9-` --10--31;Z67~

sulfide, octyldodecyl sulfide, octylcyclopentyl sul-fide, octylcyclohexyl sulfide, octylcycloheptyl sul-fide, octylcyclooctyl sulfide, octylcyclodecyl sulfide, dinonyl sulfide, nonyldecyl sulfide, nonylundecyl sulfide, nonyldodecyl sulfide, nonylcyclopentyl 5ul-fide, nonylcyclohexyl sulfide, nonylcycloheptyl sul-fide, nonylcyclooctyl sulfide, didecyl sulfide, decyl-undecyl sulfide, decyldodecyl sulfide, decylcyclopentyl sulfide, decylcyclohexyl sulfide, decylcycloheptyl sulfide, and decylcyclooctyl sulfide. More preferred sulfides include methylhexyl sulfide, methylheptyl sulfide, methyloctyl sulfide, methylnonyl sulfide, methyldecyl sulfide, ethylhexyl sulfide, ethylheptyl sulfide, ethyloctyl sulfide, ethylnonyl sulfide, ethyl-decyl sulfide, dibutyl sulfide, dipentyl sulfide,dihexyl sulfide, diheptyl sulide, and dioctyl sulfide.

The second component of the novel collector composition of thi~ invention is an alkyl thiocarbon-ate, a thionocarbamate, a thiophosphate, or mixtures thereof. Alkyl thiocarbonates refer herein to those compounds which contain a thiocarbonate moiety and at least one alkyl moiety wherein the alkyl moiety has sufficient hydrophobic character 50 as to cause a metal-containing sulfide mineral or sulfidized metal-containing oxide mineral particles associated therewithto be driven to an air/bubble interface. Preferred alkyl thiocarbonates correspond to the formula ' X

R7-X-C-S-M+ II

34,276-F -lO-~LZ~7~7~ -wherein R7 is a C1 20 alkyl group;
X is independently in each occurrence S or O;
M is an alkali metal cation.

Preferred alkyl thiocarbonates include alkyl monothiocarbonates, alkyl dithiocarbonates, or alkyl trithiocarbonates.

Preferred alkyl monothiocarbonates cor-respond to the formula o R7-o-C-S M IIa wherein R7 and M are as defined hereinbefore.

Examples of preferred alkyl monothio~
carbonates include sodium ethyl monothiocarbonate, sodium isopropyl monothiocarbonate, sodium iso-butyl monothiocarbonate, ~odium amyl monothiocar-bonate, potassium ethyl monothiocarbonate, potas-sium isopropyl monothiocarbonate, potassium iso-butyl monothiocarbonate, and potassium amyl mono-thiocarbonate.

Alkyl dithiocarbonates are commonly referred -to as xanthates. Preferred alkyl di-thiocarbonates correspond to the formula .
,::
, ~

: :~
34,276-F -11-12679~9 R7-o-c-S M Ila wherein R7 and M are as hereinbefore defined.

Preferr~d alkyl dithiocarbonates include potassium ethyl dithiocarbonate, sodium ethyl dithiocarbonate, potassium amyl dithiocar-bonate, sodium amyl dithiocarbonate, potassium isopropyl dithiocarbonate, sodium isopropyl di-thiocarbonate, sodium sec-butyl dithiocarbonate, potassium sec-butyl dithiocarbonate, sodium iso-butyl dithiocarbona-te, potassi~n isobutyl dithio-carbonate, and the like.

Preferred alkyl trithiocarbonates cor-respond to the formula ~ ~ S
R7-S-C-S M IIc .~
wherein R7 and M are as hereinbefore defined.

Examples of alkyl trithiocarbonates include sodium isobutyl trithiocarbonate and potassium isobutyl trithiocarbonate.

Preferred thionocarbamates correspond to the formula :

34,276-F -12-~ -13-~Z~7~

~R )a-N-C-Y III
(H)b wherein R8 is independently in each occurrence a Cl 10 alkyl group; 9 Y is -S M or -OR9, wherein R is a :~ 10C1_10 alk~l group;
a is the integer 1 or 2; and b is the integer 0 or 1, wherein a+b must equal 2.

Preferred thionocarbamates include dialkyl dithiocarbamates and alkyl thionocarba-mates. Preferred dialkyl dithiocarbamates cor-respond to the formula ., R S
~-C-S M+ IIIa wherein M is as hereinbe~ore defined; and R8 is independently a C1 10 alkyl group.

Examples of preferred dialkyl dithio-carbamates include methyl butyl dithiocarbamate, methyl isobutyl dithiocarbamate, methyl sec-butyl dithiocarbamate, methyl propyl dithiocarbamate, methyl isopropyl dithiocarbamate, ethyl butyl 34,276-F ~13-,~., , i7979 dithiocarbamate, ethyl isobutyl dithiocarbamate, ethyl sec~butyl dlthiocarbamate, ethyl propyl dithiocarbamate, and ethyl isopropyl dithiocar-bamate.

Preferred alkyl thionocarbamates cor-respond to the formula R8-NH-C-OR9 IIIb wherein R8 is as hereinbefore defined and R9 is a C1 10 alkyl group.

E~amples of preferred alkyl thionocar-bamates include N-methyl butyl thionocarbamate, N-methyl isobutyl thionocarbamate, N-methyl sec--butyl thionocarbamate, N-methyl propyl thiono-` carbamate, N-methyl isopropyl thionocarbamate, ,~ ~ N-ethyl butyl thionocarbamate, N-ethyl isobutyl thionocarbamate, N-ethyl sec-butyl thionocarba-mate, N-ethyl propyl thionocarbamate, and N-ethyl isopropyl thionocarbamate. More preferred thiono-carbamates include N-ethyl isopropyl thionocarba-mate and N-ethyl isobutyl thionocarbamate.
.

; Preferred thiophosphates generally cor-respond to the formula RlOO S
\ + IV
,~ x-rq Rl O o~

34,276-F -14-. -15-~67~7~
wherein R10 is independently hydrogen, a Cl_10 alkyl group or an aryl group;
: X is oxygen or sulfur; and M is an alkali metal cation.

Preferred thiophosphates include monoalkyl dithiophosphate, dialkyl dithiophosphate, diaryl dithio-phosphate, and dialkyl monothiophosphate. Preferred monoalkyl dithiophosphates corresponcl to the formula P-S M+ IVa HO~

wherein R10 and M are as hereinbefore defined.

Examples of preferred monoalkyl dithio-~ phosphates include ethyl dithiophosphate, propyl ;~ ~ dithiophosphate, isopropyl dithiophosphate, butyl ` dithiophosphate, sec-butyl dithiophosphate, and isobutyl dithiophosphate.

Preferred dialkyl and diaryl dithiophos-phates correspond to the formula S M+ IVb ~:: :

34, 2i6 F -15-~ iL267979 wherein R10 and M are as hereinbefore defined.

Examples of dialkyl and dlaryl dithiophos-phates include sodium die-thyl dithiophosphate, sodium di-sec-butyl dithiophosphate, sodium diisobutyl dithio-phosphate, sodium diisoamyl dithiophosphate, and sodiumdicresyl dithiophosphate.
Preferred dialkyl monothiophosphates cor-respond to the formula \P-O M IVc RlOo/

wherein R10 and M are as hereinbefore defined.

Preferred monothiophosphates include sodium diethyl monothiophosphate, sodium di-sec-butyl mono-thiophosphate, sodium diisobutyl monothiophosphate, and sodium diisoamyl monothiophosphate.

R is8preferably C2_16 alkyl, more preferably C3 12 alkyl. R is preferably Cl 4 alkyl and most preferably Cl 3 alkyl. R9 is preferably C2 10 alkyl, more preferably C2 6 alkyl and most preferably C3 4 alkyl. R is preferably C2 8 alkyl or cresyl.

Preferably, the composition of this invention comprises: (a) the hydrocarbon sulfide of formula I to (b) the alkyl thiocarbonate of formula II, thionocar-bamate of formula III, thiophosphate of formula IV, or mixture thereof, in a ratio such that the composition , 34,276-F -16-~ -17-~;26~79 is an effective collector for metal-containing sulfide minerals and sulfidized metal-containing oxide minerals in a froth flotation process.

- The composition of this invention preferably comprises: (a) between a~out 10 and about 90 percent by weight of hydrocarbon sulfide of formula I; and (b) between about lO and about 90 percent by weight of an alkyl thiocarbonate of formula II, thionocarbamate of formula IIIj thiophosphate of formula IV, or mixtures thereof.

The composition of this invention more pre-ferably comprises: (a) between about 20 and about 80 percent by weight of a hydrocarbon sulfide of formula I; and (b) between about 20 and about 80 percent by weight of an alkyl thiocarbonate of formula II, thio-nocarbamate of formula III, thiophosphate of formula IV
or mixtures thereof.

The composition of this invention even more preferably comprises: (a) between about 30 and 70 percent by weight of a hydrocarbon sulfide of formula I; and (b) between about 30 and 7Q percent by weight of an alkyl thiocarbonate of formula II, thionocarbamate of formula III, thiophosphate of formula IV or mixtures thereof. In its most preferred embodiment, the ratio of hydrocarbon sulfide of formula I to alkyl thiocar-bonate of formula II, thionocarbamate of formula III, thiophosphate of formula IV or mixtures thereof is such that the recovery of metal~containing sulfide minerals or sulfidized metal-containing oxide minerals in a froth flotation process is higher than either component alone could recover at the same weight dosage. More preferably, 34,276-F -17-~2~;~9 ~

the dosage at which ~he collector is used, is that dosage at which the component (b) of formula II, III, or IV of the composition when used alone gives a higher recovery than the hydrocarbon sulfide of formula I
gives at such level.

The novel collector composition of this invention gives higher recoveries, often with better metal grade(s), than can be achieved with the use of either collector component alone. Grade is defined as the fractional amount of a desired metal contained in the materil collected in the froth.

` Hydrocarbon means herein an organic compound containing carbon and hydrogen atoms. The term hydrocarbon includes the following organic com-pounds: alkanes, alkenes, alkynes, cycloalkanes,cycloalkenes, cycloalkynes, aromatics, aliphatic and cycloaliphatic aralkanes and alkyl-substituted aromatics.

Aliphatic refers herein to s-traight-and branched-chain, and saturated and unsaturated, hydrocarbon compounds, that is, alkanes, alkenes or alkynes. Cycloaliphatic reers herein to satu-rated and unsaturated cyclic hydrocarbons, that is, cycloalkenes and cycloalkanes.

Cycloalkane refers to an alkane contain-ing one, two, three or more cyclic rings. Cycloal-kene refers to mono-, di- and polycyclic groups containing one or more double bonds.

34,276-F -18-, ~ --19--~7~
~ ydrocarbyl means herein an organic radical containing carbon and hydrogen atoms. The term hydro-carbyl includes the following organic radicals: alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aliphatic and cycloaliphatic aralkyl and alkaryl. The term aryl refers herein to biaryl, biphenylyl, phenyl, naphthyl, phenanthrenyl, anthracenyl and two aryl groups bridged by an alkylene group. Alkaryl refers herein to an alkyl-, alkenyl- or alkynyl substituted aryl substituent, wherein aryl is as deflned hereinbe-fore. Aralkyl means herein an alkyl group, wherein aryl is as defined hereinbefore.

Cl 20 alkyl includes straight- and branched-~chain methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, hep-tadecyl, octadecyl, nonadecyl and eicosyl groups.

Halo means herein a chloro, bromo or iodo group.

The novel collector compositions of this ; invention are useful for the recovery by froth flota-tion o~ metal-containing sulfide minerals and sulfi-dized metal-containing oxide minerals from ores. An ore refers herein to material as it is taken out of the ground and includes the desired metal-containing minerals in admixture with the gangue. Gangue refers herein to that portion of the material which is of no value and needs to be separated from the desired metal--containing minerals.

34,276-F -19-~L26797~
In a preferred embodiment, metal-containing sulfide minerals are recovexed. In a more preferred embodiment of this invention sulfide minerals contain-ing copper, nickel, lead, zinc or molybdenum are recov-ered. In an even more preferred embodiment, sulfideminerals containing copper a.re recovered. Also pre-ferred metal sulfide-containing minerals are those which have high natural hydrophobicity in the unoxi-dized state. The term "hydrophobicity in the unoxi-dized state" applies to a freshly ground mineral ora mineral having a fresh surface which demonstrates a tendency to float without collector addition.

Ores for which these compositions are useful include sulfide mineral ores containing copper, zinc, molybde~um, cobalt, nickel, lead, arsenic, silver, chromium, gold, platinum, uranium, and mixtures thereof.
Examples o metal-containing sulfide minerals which may be concentra-ted by froth 10tation using the pro-cess of this invention include copper-bearing minerals such as, for example, covellite (CuS), chalcocite (Cu2S), chalcopyrite (CuFeS2), valleriite (Cu2Fe4S7 or Cu3Fe4S7), tetrahedrite (Cu3SbS2), bornite (Cu5FeS4), ,! cubanite (Cu2SFe4S5), enargite [Cu3(As1Sb)S4], ten-nantite (Cu12As4S13), brochantite [Cu4(OH)6S04], ant-lerite [Cu3S04(0H~4], famatinite ~Cu3(SbAs)S4~, and bournonite (PbCUSbS3); lead-bearing minerals such as, for example, galena (PbS); antimony-bearing minerals such as, for example, stibnite ~Sb2S3); zinc-bearing minerals such as, for example, sphalerite (ZnS);
silver-bearing minerals such as, for example, steph-anite (Ag5SbS4), and argentite (Ag2S); chromium-bearing minerals such as, for example, daubreelite (FeSCrS3);

34,276-F -20-~2~7g7~

nickel-bearing minerals such as, for example, pent-landite [(FeNi)gS8]; molybdenum-bearing minerals such as, for example, moly~denite (MoS2); and platinum- and palladium beariny minerals such as, for example, cooper-ite [Pt(AsS)2]. Preferred metal-containing sulfide minerals include molybdenite (MoS2), chalopyrite (CuFeS2), galena (Pbs), sphalerite (ZnS), bornite (Cu5FeS4~ and pentlandite [(FeNi)gS8].

Sulfidized metal-containing oxide minerals are minerals which are treated with a sulfidization chemical, so as to give such minerals sulfide mineral characteristics, so the minerals can be recovered in froth flotation using collectors which recover sulfide minerals. Sulfidization results in oxide minerals having sulfide characteristics. Oxide minerals are sulfidized by contact with compounds which react with the minerals to form a sulfur bond or affinity. Such methods are well-known in the art. Such compounds include sodium hydrosulfide, sulfuric acid and related sulfur containing salts such as sodium sulfide.

Sulfidized oxide minerals for which this process is useful include oxide minerals containing copper, aluminum, iron, titanium, tungsten, molybdenum, magnesium, chromium, nickel, manganese, tin, uranium, and mixtures thereof. Examples of metal-containing ; oxide minerals which may be concentrated by froth flotation using the process of this invention include copper-bearing minerals, such as cuprite (Cu2O~, tenor-ike (CuO), malachite [(Cu2OH)2CO3], azurite ~Cu3(OH)2-30 (CO3)2], atacamite [Cu2Cl(OH)3], chrysocolla ~cusio3);
aluminum-bearing minerals, such as corundum; zinc-con-taining minerals, such as zincite (ZnO), and smithsoni-te 34,276-F -21-~Z~7979 (ZnC03); tungsten-bearing minerals such as, for example, wolframite [~Fe,Mn)W04]; nickel-bearing minerals such as, for example, bunsenite (NiQ); molybdenum-bearing minerals such as, for example, wulfenite (PbMoO4) and powellite (CaMoO4); iron-containing minerals, such as hematite and magnetite; chromium~containing minerals, such as chromite (FeOCr203); iron- and titanium-con-taining minerals, such as ilmenite; magnesium- and aluminum-containing minerals, such as spinel; iron-chromium-containing minerals, such as chromite; tita-nium-containing minerals, such as rutile; manganese-containing minerals, such as pyrolusite; tin-containing minerals, such as cassiterite; and uranium-containing minerals, such as uraninite; and uranium-bearing miner-als such as, or example, pitchblende [U205(U308)~ and gummite (U03nH20)-The collectors of this invention can be used in any concentration which gives the desired recovery of the desired minerals. In particular, the concen-tration used is dependent upon the particular mineralsto be recovered, the grade of the ore to be subjected to the froth flotation process, the desired quality of the mineral to be recovered, and the particular mineral which is being recovered. Preferably, the collectors of this invention are used in concentrations of 0.001 ; to 1.0 kg per metric ton of ore, more preferably between 0.010 and 0.2 kg of collector per metric ton of ore to be subjected to froth flotation.

Frothers are preferably used in the froth flotation process of this invention. Any frother well-known in the art, wh.ich results in the recovery of the desired mineral is suitable.

34,276-F -22-`` -23-~Z6~9~9 Frothers useful in this invention include any frothers known in the art which give the recovery of the desired mineral. Examples of such frothers include C5 8 alcohols, pine oils, cresols, C1 4 alkyl ethers of polypropylene glycols, dihydroxylates of pol~propylene glycols, glycols, fatty acids, soaps, alkylaryl sulfo-nates, and the like. Furthermore, blends of such frothers may also be used. All frothers which are suitable for beneficiation of ores by froth flotation can be used in this invention.

Further, in the process of this invention it is contemplated that collectors of this invention can be used in mixtures with other collectors well-known in the art. Collectors, known in the art, which may be used in admixture with the collectors of this invention are those which will give the desired recovery of the desired mineral. Examples of collectors useful in this invention include dialkyl thioureas, dialkyl and diaryl thiophosphonyl chlorides, dialkyl and diaryl dithio-phosphonates, alkyl mercaptans, xanthogen formates,xanthate esters, mercapto benzothiazoles, fatty acids and salts of fatty acids, alkyl sulfuric acids and salts thereof, alkyl and alkaryl sulfonic acids and salts thereof, alkyl phosphoric acids and salts thereof, alkyl and aryl phosphoric acids and salts thereof, sulfosuccinates, sulfosuccinamates, primary amines, secondary amines, tertiary amines, quaternary ammonium salts, alkyl pyridinium salts, guanidine, and alkyl propylene diamines.

` 30 Specific Embodiments The following examples are included for illustration and are not intended to limit the scope of , 34,276-F -23-~Z~75~79 the invention. Unless otherwise indicated, all parts and fractions are by weight. Synergism is defined herein as when the measured result of a blend o~ two or more components exceeds the weighted average results of each component when used alone.
This term also implies that the results are compared under the condition that the total weight of the collector used is -the same for each ex~eriment.
i Example 1 - Froth Flotation of a CopperjMolybdenum Ore from Western Canada Bags of homogeneous ore containing chal-copyrite and molybdenite minerals were prepared with each bag containing 1200 g. The rougher flotation procedure was to grind a 1200 g charge with 800 ml of tap water for 14 minutes in a ball mill having a mixed ball charge (to produce approximately a 13 percent plus 100 mesh grind). This pulp was transferred to an Agitair 1500 ml flotation cell ou*fitted with an auto-mated paddle removal system. The slurry pH was adjusted to 10.2 using lime. No further pH adjustments were made during the test. The standard frother was methyl isobutyl carbinol (MIBC). A four-stage rougher flo-tation scheme was then followed.

STAGE 1: Collector - 0.0042 kg/metric ton MIBC - 0.015 kg/metric ton - condition - 1 minute - float - collect concentrate for 1 minute STAGE 2: Collector - 0.0021 kg/metric ton MIBC - 0.005 kg/metric ton - condition - 0.5 minute - float - collect concentrate for 1.5 minutes 34,276-F -24-~LZ~7~3~9 STAGE 3: Collector - 0.0016 kg/metric ton MIBC - 0.005 kg/metric ton = condition - 0.5 minute - float - collect concentrate for 2.0 minutes STAGE 4: Collector - 0.0033 kg/metric ton MIBC - 0.005 kgJmetric ton - condition - 0.5 ~inute - float - collect concentrate for 2.5 minutes :

The results are compiled in Table I.

TABLE I
~r Cu Moly Cu Mo Collector R_72 R~72 Grade3 Grade3 potassium amyl 0.776 0.725 0.056 0.00181 xanthate1 1,2-epithiooctane1 0.710 0.691 0.093 0.00325 50/50 blend of potas- 0.794 0.766 0.054 0.00177 : sium amyl xanthate :~ 20 and 1,2-epithiooctane methyl hexyl sulfide1 0.699 0.697 0.107 0.00386 50/50 blend of potas- 0.790 0.793 0.056 0.00169 sium amyl xanthate and methyl hexyl sulfide ~,~
1Not an example of the invention 2R-7 is the experimental fractional recovery after 7 minutes 3Grade is the fractional content of specific metal contained in total weight collected in the froth The 95 percent confidence region of statistical error associated with the Cu R-7 experimental values in Table I is ~ 0.010. Thus the statistical range of R-7 value for Cu in Table I associated with potassium amyl ;`'' .
: .
:
34,276-F -25-~26~979 xantha-te is O . 776 ~ O . 010 or O . 766 to O . 786 . The statistical error associated with the Mo R-7 experi-mental values in Table I is ~ 0.015. Applying these limits clearly indicates the recoveries of Cu and Mo at 7 minutes with the collector blends of this invention exceed the 7-minute recoveries that would be expected from a weighted average effect of the individual compo-nent used alone; synergism has occurred.

Example 2 - Froth Flotation of a Copper/Nickel Ore from Eastern Canada A copperjnickel ore containing chalcopyrite, pentlandite, and pyrrhotite minerals was floated using 0.0028 kg/metric ton of DOWFROTH~ 1263 frother and a collector dosage of 0.28 kg/metric ton. A series of samples were drawn from the eeders to plant rougher bank and placed in buckets to give approximately 1200 g of solid. The contents of each bucket were then used to perform a time-recovery profile on a Denver cell using an automated paddle and constant pulp level device with individual concentrates selected at 1.0, 3.0, 6.0 and 12.0 minutes. The chemicals were added with a condition time of one minute before froth removal was started. There was no stage addition of ;~ reagents. Individual concentrates were dried, weighed, ; 25 ground and statistically representative samples pre-; pared for assay. The results are compiled in Table II.

34,276-F -26-~ -27-iZ67~7~

TABLE II

Pyrrho-Cu Ni tite Collector R-122 R-122 R-122 sodium amyl xantha-tel O.930 0.839 0.358 1,2-epithiooctane1 0.927 0.751 0.247 dibutyl sulfide1 0.928 0.630 0.190 50/50 blend of 1,2-epi- 0.927 0.844 0.344 thiooctane and sodium amyl xanthate 50/50 blend of dibutyl 0.931 0.824 0.245 sulfide and sodium amyl xanthate 1Not an example of the invention 15 2R-12 is the experimental fractional recovery after 12 minutes .
The recoveries of Cu at 12 minutes are all so high in Table II (approaching the theoretical limit of 1.0) that the use of statistical confidencQ limits does not apply. The 95 percent confidence level of the R-12 values for Ni in Table II is ~ 0.012. It is clear that the collector blends of this invention give Ni recoveries that significantly exceed those recoveries that would be expected from a weighted average of each component used alone; synergism has occurred.
:' ~ .
Example 3 - Froth Flotation of a complex Pb/Zn/Cu/Ag Ore from Central Canada Uniform 1000 g samples of ore, containing galena, sphalerite, chalcopyrite, and argentite, are prepared. For each flotation run, a sample was added to a rod mill along with 500 ml of tap water and 7.5 ml 34,276-F -27--~ -28 1~6797~
f S2 solution. Six and one-half mlnutes of mill time were used to prepare a feed of gO percent less than 200 mesh (75 microns). After grinding, contents were transferred to a cell fitted with an automated paddle for froth removal, and the cell attached to a standard Denver flotation mechanism.

A two-stage flotation was then performed. In Stage I a copper/lead/silver rougher was used, and in Stage II a zinc rougher was used. To start the Stage I
flotation, 1.5 g/kg Na2CO3 was added (pH of 9 to 9.5), followed by the addition of collector(s). The pulp was then conditioned for 5 minutes with air and agitation.
This was followed by a 2 minute condition period w:ith agitation only. MIBC frother was then added (standard dose of 0.015 ml/kg). Concentrate was collected for 5 minutes of flotation and labeled as copper/lead rougher concentrate.

The Stage II flotation consisted of adding 0.5 kg/metric ton of CUSO4 to the cell remains of Stage I. The pH was than adjusted to 10.5 with lime addition.
This was followed by a condition period of 5 minutes with agitation only. pH was then rechecked and adjusted back to 10.5 with lime. At this point, the collector(s) were added, followed by a 5-minute condition period with agitation only. MIBC frother was then added (standard dose of 0.020 ml/kg). Concentrate was col-lected for 5 minutes and labeled as zinc rougher con-centrate.

Concentrate samples were dried, weighed, and appropriate samples prepared for assay using X-ray 34,276-F -28-~;797~

techniques. Using the assay data, fractional recover-ies and grades were calculated using standard mass balance formulae. The results are compiled in Table llI.

;
.

.

34,276-F -29-, . .. ...
::

~7979 , o , o , o o C`l ~, ~ oo o ~,- ,`
o o o o o o ~ o ,~ ~ .
~ . . o ~ o , o N ~

~' OOOOOO

~1 ~ ~ , o) o C
O
~ C~
_1 C~ C:~ I O I O

~ O O O O O O ~ i Cr~ OC~ O 3~ O O

,,"C~io ~ ~ ,~ Ln C C

O ~

¢ ~ ~ q ~ ~ E ~ E E ~, D 1~ E a~

~ ~ ~ o ~ ~ U
:~ -1 ~ ~ I I I I 0 C

34, 276-F -30-~ -31-7g7~
In Table III, then are two -test conditions which logically allow comparision of the recoveries associated with the collector blends of this invention to those recoveries achievable with a component col-lector used alone.

Comparing the Cu/Pb flotation (Stage I) Run 2 with collector D used alone verses the Cu/Pb flotation (Stage I) of Run 3 using the collector blend D + B, the results illustrate the greater Ag, Cu, Pb recoveries achieved with the collector blends of this invention. The 95 percent confidence level of statistical error is for Ag, i 0.01, for Cu, i 0.01, and for Pb t 0.02.

The Zn flotation (Stage II) of Run 3 compared to the Zn flotation (Stage II) of Run 2 also illustrates the obvious increase in the Zn recovery associated with the blend versus that of the component used alone. The 95 percent confidence level of statistical error for Zn is i 0.01.

Other runs using single components in various stages are not repor-ted in Table III as many of the single components when used alone simply do not perform adquately enough to collect m~ningful data for comparison. For example, collector B used alone in Stage I for Cu and Pb gives less than 0.500 recovery.

Example 4- Froth Flotation of a Complex Cu/Mo Ore from South America 34,276-F -31-~ -32 ~Z6'79~

A 500 g quantity of a Cu/Mo ore, containing several copper containing sulfide minerals and moly-bdenite, was placed in a rod mill having one-inch ~2.5 cm) rods along with 257 g of deionized water and a quantity of lime. Then the mixture was ground for 360 revolutions at a speed of 60 rpm to produce a size di~tribution of suitable fineness. The ground slurry was transferred to a Agitar 1500 ml flotation cell outfit-ted with an automated paddle removal system. The slurry was agitated at 1150 rpm and the pH adjusted to the appropriate value ~shown in Table IV) with either more lime or hydrochloric acid At this point, the collector(s) were added to the float cell (45 g/metric ton), followed by a condi-tioning time of one minute, a-t which time the frother, DOWFROTH~ 250 was added (34.4 g/metric ton). After an additional conditioning time of one minute, the air to the float cell was turned on at a rate of 4.5 liters/-minute and the automatic froth removal paddle was started. Samples of the froth were collected at 0.5, 1.5, 3.0, 5.0, and 8.0 minutes.

The samples were dried overnight in an oven along with the flotation tailings. The dried samples were weighed, pulverized to a suitable degree of fineness for dissolution, and dissolved in acid for analysis on a DC Plasma Spectrograph. The results are compiled in Table IV.

34,276-F -32-~i79~7~

o ~ ~
o ~ ~ oo `: I ~ ~ o o o a~l o I~ ,_1 ,, ~ ~ , oo o ~ ~ . ~ ~ o ~ o C~o o o U~ U~ ~ o o o o o o oo oo oo .
~_ h C 3~
J-H ~1~ /~ ~ ';t~ 1--- 1~ 1` ~ ~ ~ 1_ ~~ U ~ P

a o .C `
~: d~3~ v P~ p~ J ~ ~
h ~:: ~q ~ 6 h U~ ~ E ~ ~ 6 s~ ~ v O ~ O ~ ~ O ~ 3 0 P~ ,~ O p~
, v ~ ~ ~,1 u ~ ~ ~1 V p~ ~a rl V ~ ~3 ~rl V O ~U
~1 ~ O~ ~J O ~1~ U O ,Q~ ~ O D~
i O 0 6 o o 6 O S,l ~ 3.--1 1.1 1;~ ~ ~ h ~ l h d ~ l H C) C~ 0~ r~ 04~ ~ o~"~ 0~-,~ 6P' ~a ~ o ~~ o ~ ~ 1 0 J~ ~ 0 ~) ~ S

., N

34, 276-F -33-~267~7~

The recoveries of Cu at 8 minutes are all so high in Table IV (approaching) the theoretical limit of 1.0) that the use of statistical confidence limits does not apply.

5THe 95 percent condifience level of statistical error or Mo recovery at 8 minutes is 0.012. Clearly, the collector blends of this invention provide Mo recoveries that significantly exceed those recoveries that would be expected from the individual components used alone. For example, the Mo recovery of Run 3 clearly exceeds that expected from the weighted average of Runs 1 and 2. Synergism has occurred.

: ' 34,276-F ~34~

Claims (20)

The embodiments of the invention for which an exclusive property or privilege is claimed are defined as follows:

1. A novel composition which comprises:

(a) a hydrocarbon containing one or more monosulfide units, wherein the carbon atoms to which the sulfur atom(s) are bound are aliphatic or cycloaliphatic carbon atoms and the total carbon content of the hydrocarbon portion is such that the hydrocarbon has sufficient hydrophobic character to cause the metal-containing sulfide mineral or sulfidized metal-containing oxide mineral particles to be driven to an air/bubble interface; and (b) an alkyl thiocarbonate, a thionocar-bamate, a thiophosphate, or mixtures thereof.

2. The composition of Claim 1 wherein the ratio of (a) hydrocarbon sulfide to (b) the alkyl thio-carbonate, thionocarbamate, thiophosphate, or mixtures thereof, is such that the composition is an effective collector for metal-containing sulfide minerals and sulfidized metal-containing oxide minerals in a froth flotation process.

34,276-F -35-

3. The composition of Claim 1 wherein the hydrocarbon sulfide corresponds to the formula R1-S-R2 ;

I
the thiocarbonates correspond to the formula II
the thionocarbamates correspond to the formula III
and the thiophosphates correspond to the formula , IV
wherein R and R2 are independently a hydrocarbyl radical or hydrocarbyl radical substituted with one or more hydroxy, cyano, halo, ether, hydro-carbyloxy or hydrocarbyl thioether moieties;
wherein R1 and R2 may combine to form a hetero-cyclic ring structure with S;

34,276-F -36-with the proviso that S is bound to an aliphatic or cycloaliphatic carbon atom; with the further proviso that the total carbon content of the hydrocarbon sulfide be such that it has sufficient hydrophobic character to cause the metal-containing sulfide mineral or sulfidized metal-containing oxide mineral particles to be driven to an air/bubble interface;
R7 is a C1-20 alkyl group;
R8 is independently a C1-10 alkyl group;
R9 is a C1-10 alkyl group;
R10 is independently hydrogen, a C1-10 alkyl group or an aryl group;
M is an alkali metal cation;
X is independently in each occurrence S or O;
Y is -S-M+ or OR9;
a is the integer 1 or 2; and b is the integer 0 or 1, wherein a+b=2.

4. The composition of Claim 3 which com-prises:

(a) between about 10 and about 90 percent by weight of hydrocarbon sulfide; and (b) between about 10 and about 90 per-cent by weight of an alkyl thiocarbonate, thionocarbamate, thiophosphate, or mixtures thereof.

5. The composition of Claim 4 which comprises:

34,276-F -37-(a) between about 20 and about 80 per cent by weight of a hydrocarbon sulfide; and (b) between about 20 and about 80 per-cent by weight of an alkyl thiocarbonate, thionocarbamate, thiophosphate, or mixtures thereof.

6. The composition of Claim 3 wherein R1 and R2 are independently an aliphatic, cyclo-aliphatic or aralkyl moiety, unsubstituted or substituted with one or more hydroxy, cyano, halo, OR3 or SR3 moieties;
R3 is a hydrocarbyl radical;

wherein R1 and R2 may combine to form a heterocyclic ring with S;
R7 is C2-16 alkyl;
R8 is C1-4 alkyl;
R9 is C2-10 alkyl;
R10 is C2-8 alkyl or cresyl; and M is a sodium or potassium cation.

7. The composition of Claim 6 wherein the total carbon content of the hydrocarbon sulfide is from 4 to 20 carbon atoms.

8. The composition of Claim 7 wherein R1 and R2 are a cycloaliphatic or aliphatic moiety, unsubstituted or substituted with one or more hydroxy, cyano, halo, OR3 or SR3 moieties; wherein and R2 may combine to form a heterocyclic ring 34,276-F -38-with S; R7 is C3-12 alkyl; R8 is C1-3 alkyl; R9 is C2-6 alkyl;
and R10 is C2-8 alkyl or cresyl.

9. The composition of Claim 8 wherein the hydrocarbon sulfide has a total carbon content of from 6 to 16 carbon atoms.

10. The composition of Claim 9 wherein R1 and R2 are independently alkyl or alkenyl.

11. The composition of Claim 10 wherein R1 is methyl or ethyl, and R2 is C6-11 alkyl or C6-11 alkenyl group.

12. The composition of Claim 3 wherein the hydrogen sulfide corresponds to the formula (R6)3-nC(H)n-S-C(H)n(R6)3-n or Ic Id wherein R4 is independently hydrogen, aryl, alkaryl, aralkyl, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, hydroxy, cyano, halo, OR3, SR3, wherein the aryl, alkaryl, aralkyl, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl may optionally be substituted with a hydroxy, cyano, halo, OR3 or SR3 moiety wherein R3 is hydrocarbyl radical;
R6 is independently hydrocarbyl, or hydrocarbyl substituted with a hydroxy, cyano, halo, ether, hydrocarbyloxy or hydrocarbyl thioether moiety; wherein two R6 moieties may combine to form a cyclic ring or heterocyclic ring with the sulfur atom;

n is an integer of 0, 1, 2 or 3; with the proviso that the total carbon content of the hydrocarbon portion of the collector is such that the collector has sufficient hydrophobic character to cause the metal-containing sulfide mineral or sulfidized metal-containing oxide mineral par-ticles to be driven to the air/bubble interface.

13. The composition of Claim 12 which com-prises:

(a) a hydrocarbon sulfide; and (b) an alkyl thiocarbonate which comprises an alkyl monothiocarbonate, alkyl dithiocarbonate or alkyl trithiocarbonate.

14. The composition of Claim 3 wherein R1 and R2 are not the same hydrocarbon moiety.

15. The composition of Claim 1 wherein the metal-containing sulfide minerals are those which have a high natural hydrophobicity in the unoxidized state.

16. A process for recovering metal-con-taining sulfide minerals or sulfidized metal-containing oxide minerals from an ore which comprises subjecting the ore, in the form of an aqueous pulp, to a froth flotation process in the presence of a flotating amount of a flotation collector wherein the collector com-prises a composition of Claim 1.

17. The process of Claim 16 wherein a metal--containing sulfide mineral is recovered in the froth.

18. The process of Claim 17 wherein the metal-containing sulfide mineral recovered in the froth contains copper, zinc, molybdenum, cobalt, nickel, lead, arsenic, silver, chromium, gold, platinum, uranium, or mixtures thereof.

34,276-F

19. The process of Claim 18 wherein the metal-containing sulfide mineral recovered in the froth is molybdenite, chalcopyrite, galena, sphalerite, bornite, or pentlandite.

20. The process of Claim 19 wherein the sulfide collector is present in a concentration of from 0.001 to 1.0 kg of collector/metric ton of ore to be sugjected to froth flotation.

34,276-F -42-