CA1265877A - Collectors for the froth flotation of mineral values - Google Patents

Abstract

ABSTRACT
The invention is a collector and process for recovering metal values from a metal ore by subjecting the metal ore, in the form of an aqueous pulp, to a froth flotation process in the presence of a collector wherein the collector comprises a compound corresponding to the formula where R is -CH2- , , -?-, or mixtures thereof, where R can occur in a random sequence; and n is an integer from 1 to 6 or ?R?n is ?CH2?mC? where m is an integer from 0 to 6; R1 and each R2 are independently C1-22 hydrocarbyl or a C1-22 hydro-carbyl substituted with one or more hydroxy, amino, phosphonyl, alkoxy, imino, carbamyl, carbonyl, thiocarbonyl, cyano, halo, ether, carboxyl, hydrocarbylimino groups, with the proviso that R2 can be a divalent radical with both valencies bonded directly to the N atom X is -S- , -O-, -?-R3 , -?-S- , , or -?O-R3 is H, a C1-22 hydrocarbyl or a substituted C1-22 hydrocarbyl radical; a is an integer of 0, 1 or 2; b is an integer of 0, 1 or 2; with the proviso that the sum of a and b equals 2 except when R2 is a divalent radical with both valencies bonded directly to the N atom, in which case, a=1 and b=0 or when ?R?n is ?CH2?mC ? in which case, a+b=0, and with the further proviso that when X is -?-S- ,

Description

NOVEL COLLECTORS FOR
THE FROTH FLOTATION OF
MINERAL VALUES

This-invention relates to novel collectors for the recovery of mineral values rom mineral ores by froth flotation.

Flotation is a process of treating a mixture of finely divided mineral solids, e.g., a pulverulent ore, suspended in a liquid whereby a portion of such solids is separated from other finely divided mineral solids, e.g., clays and other like materials present in the ore, by introducing a gas (or providing a gas in situ~ in the liquid to produce a frothy mass containing certain of the solids on the top of the liquid, and leaving suspended (unfrothed) other solid components of the ore. Flotation is based on the principle that introducing a gas into a liquid containing solid particles of different materials suspended therein causes the selective adherence of some gas to certain suspended solids and not to others and makes the particles having the gas thus adhered thereto lighter than the liquid. Accordingly, these particles rise to the top of the liquid to form a froth.

32,768-F -1-Various agents have been admixed with the suspension to improve the frothing and collection process.
S~lch added agents are classed according to the function to be performed and include, for example; collectors, for sulfide min~rals includiny xanthates, thionocarbam~tes and the like; frothers which impart the property of forn~ing a stable froth, e.g., natural oils such as pine oil and eucalyptus oil, and the like; modifiers such as activators to induce flotation in the presence of a ~0 collector, such as copper sulfate; depressants, such as sodium cyanide, which tend to prevent a collector from functioning as such on a mineral which it is desired to retain in the liquid, and thereby discourage a substance from being carried up and forming a part of the froth; p~
regulators to produce optimum metallurgical results, such as 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, the mineral sought to be recovered, and the other additaments which are to be used in combination therewith.

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

The flotation principle is applied in a number of mineral separation processes among which is the selective separation of such minerals as sulfide copper 32,768-F -2-minerals, sulfide zinc minerals, sulfide molybdenum minerals and others from iron sulfide minerals, e.g., pyrite.

i~mong collectors commonly used for the S recovery of sulfide-containing metal values are xanthates, dithiophosphates, and thicnocarbamates. Collectors for the recovery of sulfide-containing metal values are common and used widely. The difficulty is in the recovery of oxide-containing mineral values, as collectors 1~ suitable for the reco~ery of such mineral values are ~enexally not of a commercially acceptable quality.

What is needed are coll$ctors which are userul for the recovery of a broad range of metal values from metal ores, including the recovery of sulfide-1_ -containing mineral values and oxide-containing mineral values. Furthermore, what is needed are collectors which give high rates of recovery of the mineral values along with good selectivities towards the mineral values over the gangue, that is, the undesired portions of the ~0 mineral ore.

The invention particularly resides in a collector for recovering metal values from a metal ore in which the metal ore, in the form of an aqueous pulp, is subjected to froth flotation, wherein the collector is a compound ~5 corresponding to the formula Rl-X~R~nN~R )a (H)b H O
..
where R is -CH2-, -C- , -C- , or mixtures thereof, OH
where R can occur in a random sequence; and n is an integer from 1 to 6 or ~Rtn is ~CH2tmC-where m is an integer from O to 6; Rl and each R2 are independentlyCl_~2 hydrocarbyl or a Cl 22 hydrocarbyl substitu-ted with one or more hydroxy, amlno, phos~honvl, alkoxy, imino, carbamyl, carbonyl, thiocarbonyl, cyano, ~^t ~er, carboxyl, hydrocarbylthio, hydrocarbyloxy, hydrocarbylamino or hydrocarbylimi.no groups, with the proviso that R2 can be a divalent radical with both valencies bonded directly -to the N atom O O R O
X is -S- , -O- , -N-R3 , -C-S- , -C-N-, or -CO- ;
R is H, a Cl 22 hydrocarbyl, or a substituted Cl 22 ld hydrocarbyl radical;
a is an integer of 0, 1 or 2;
b is an integer of 0, 1 or 2;
~ith the proviso that the sum of a and b equals 2 except when R2 is a divalent radical with both valencies bonded directly to the N atom, in which case, a=l and b=O or when ~Rtn is tCH2tmC- in which case, a+b=O, and with the further proviso that when X is ,. .. . ..
-C-S-, -C-N- , or -CO-the carbonyl moiety is bonded to Rl.
The invention also resides in a method for recovering metal values from a metal ore which comprises subjecting the metal ore, in the form of an aqueous pulp, to a froth flotation process in the presence of a flotation collector under conditions such that the metal values are recovered in the froth, wherein the collector comprises a compound corresponding to the formula Rl-XtR~nNtR )a (H)b ,~ . ~, .

_5_ ~ '7 H O
ereill: R is -CH2-, -C- , -C- , or mixtures thereof, where R
OH
can occur in a random sequence; and n is an integer from 1 to 6 or ~Rtn is tCH2tmC- wherein m is an integer from 0 to 6; Rl and each R are independently C1 22 hydrocarbyl or a Cl_22 hydrocarbyl substituted with one or more hydroxy, amino, phos~honY1 f alkoxy, imino, carbamyl, carbonyl, thiocarbonyl, cyano, ~L~r~ he-E, carboxyl, hydrocarbylthio, hydrocarbyloxy, hydrocarbylamino, or hydrocarbylimino groups; O O ~3 O
' 3 ~ , . "
X is -S- , -o- , -N-R , -C-S- , -C-N- , or -Co- ;
R3 is hydrogen, a C1 22 hydrocarbyl, or a substitued Cl 22 hydrocarbyl radical;
a is an integer of 0, 1 or 2;
b is an integer of 0, 1 or 2;
with the proviso that the sum of a and b equals 2except when R2 is a divalent radical with both valencies bonded directly to the N atom, in which case a=l and b=0 or when tRtn is tCH2tmC-- in whic~ case, a+b=0, and with the further proviso that when X is O R3 o ll ll l ll -C-9- , -C-N- , or -CO-the carbonyl group is bonded to Rl.
~ In a preferred embodiment of the invention, the col-lector comprises a compound corresponding to the formula R -XtCH2tnN~R )a (H)b -6~ '7~

wherein:
R is a Cl 22 hydrocarbyl or Cl 22 hyarocarbyl radical substituted with one or more hydroxy, amino, phosphonyl, or alkoxy moieties;
R2 is a Cl 6 alkyl, a Cl ~ alkylcarbonyl, Cl_6 alkyl group substituted with an amino, hydroxy or phosphonyl moie-ty, or a Cl 6 alkylcarbonyl group subs-tituted with an amino, hydroxy or phosphonyl moiety;
and ~, a, b and n are as herein defined~
The collectors of this invention surprisingly float a 1~ ~road rallge o~ metal values including sulfide ores, oxide ores and precious metals. Furthermore, such collec-tors give improved recoveries o~ the mineral values including mineral oxides, mineral sulfides and precious metals. Not only are surprisingly high recoveries achieved, but the selectivity towards the desired mineral values is surprisingly high.
The preferred novel collectors of this invention include omega-(hydrocarbylthio)alkylamines; omega-(hydrocarbylthio) ~lkylamides; S-(omega-aminoalkyl)hydrocarbon thioates; N-(hydro-~arbyl)-alpha-omega-alkanediamines; (omega-aminoalkyl)hydrocarbon ~a amides; omega-(hydrocarbyloxy)-alkylamines; omega-aminoalkyl }lydrocarbonoates; or mixtures thereof. More ~referred collectors include omega-(hydrocarbylthio-)alkylamines; omega-(hydrocarbyl-thio)alkylamides; n-(hydrocarbyl)-alpha,omega-alkanediamines; and omega-(hydrocarbyloxy-)alkylamines; or mixtures thereof. Most preferred collectors include omega-(hydrocarbylthio)alkylamines;
omega-(hydrocarbylthio)alkylamides; N-(hydrocarbyl)-alpha,omega-alkanediamines, or mixtures thereof. The most preferred class of -7~

collectors are -the omega-(hydrocarbylthio)-alkylamines and omega-(hydrocarbylthio)alkylamides.
In the hereinbefore presented formula of the preferred embodiment, Rl is preferably C2 14 hydrocarbyl, and more preferably C~ 11 hydrocarbyl. R2 is preferably Cl 6 alkyl or Cl 6 alkyl-carbonyl, more preferably C1_4 alkyl or C1_4 alkylcarbonyl, a most preferably Cl_2 alkyl or C1_2 alkylcarbonyl. R3 is prefer-abl~y hydrogen or C2_14 hydrocarbyl, more preferably hydrogen or C4 11 hydrocarbyl~ and most preferably hydrogen. Preferably, a 1(~ i3 the integer O or 1. Preferably b is the integer 1 or 2.
Preferably, n is an integer from 1 to 4, and most preferably the integer 2 or 3. X is preferably -S-, -N-R , or -O-. X is more preferably -S- or -N-R . X is most preferably -S-.
Preferred S-(omega-aminoalkyl) hydrocarbon thioates correspond to the formula R1-C-S~CH2tnN~R2)a (H)b t~herein Rl, R2, a, b and n are as hereinbefore defined.
Preferred omega-(hydrocarbylthio)alkylamines or omega-(hydrocarbylthio)alkylamides corresponding to the formula ~a Rl-StCH2tnN~R )a (H)b wherein Rl, R2, a, b and n are as hereinbefore defined. In those embodiments wherein X is -S- or o --C--S--R is preferably C4 10 hydrocarbyl.
Preferred N-(hydrocarbyl)-alpha,omega-alkanediamines oorrespond to the formula R -NtCH2tnNtR )a R3 (H)b wherein Rl, R2, R3, a, b and n are as hereinbefore defined.
Preferred N-(omega-aminoalkyl) hydrocarbon amides correspond to the ~ormula Rl-C-N~CH2tnN~R Jb R3 (H)a ~13 _9_ wherein Rl, R2, R3, a, b and n are as hereinbefore defined. In those e~bodiments wherein X is "
-N- or ~C-N- , the total carbon content of the groups R1 and R3 is preferably from l to 23, more preferably from 2 to 16, l~ and most preferably from 4 to 15.

Preferred omega-(hydrocarbyloxy-)alkylamines correspond to the formula R1-OtCH2tnNtR )a (H)b wherein Rl, R2, a, b and n are as hereinbefore defined.

Preferred omega-aminoalkyl hydrocarbonoates correspond to the formula R ~CotcH2tnN~R )a (H)b wherein R1, R2, a, b and n are as hereinbefore,defined.
In those embodiments wherein X is -co or -o-Rl is most preferably C6 11 hydrocarbyl.

32, 768-F -9-1~ t ~
-- 10 - ~693-3666 Hydrocarbon means herein an organic compound containing carbon and hydrogen atoms. The term hydrocarbon includes -the olLowin~ organic compounds: alkanes, alkenes, alkynes, cycloalkanes, cycloalkenes, cycloalkynes, aromatics, aliphatic and cycloaliphatic aralkanes and alkyl-substituted aromatics.
Aliphatic refers herein to straight- and branched-chain, and saturated and unsaturated, hydrocarbon compounds, that is, alkalles, alkenes or alkynes. Cycloaliphatic refers herein to saturated and unsaturated cyclic hydrocarbons, that is, l(~ cycloalkerles and cycloalkanes. The term aromatic refers herein to biaryl, benzene, naphthene, phenanthracene, anthracene and two aryl groups bridged by an alkylene group.
Cycloalkane refers to an alkane containing one, two, t~ree or more cyclic rings. Cycloalkene refers to mono-, di- and polycyclic groups containin~ one or more double bonds.
Hydrocarbyl means herein an organic radical containing carbon and hydrogen atoms. The term hydrocarbyl includes -the following organic radicals: alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aliphatic and cycloaliphatic aralkyl and ~d alkaryl. Aliphatic refers herein to straight- and branched-, and saturated and unsaturated, hydrocarbon chains, that is, alkyl, alkenyl or alkynyl. Cycloaliphatic refers herein to saturated and unsaturated cyclic ~ydrocarbons, that is, cycloalkenyl and cycloalkyl. 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 ~' '7 ~
- l:L - 6~693-3666 as clefined hereinbefore. Arallcyl means herein an alkyl, alkenyl or alkynyl group substit~ted with an aryl group, whereirl aryl is as defined hereinbefore. Alkenearyl re-fers herein to a radical which contains at least one alkene portion and one aroma-tic portion, and includes those radicals in which ~ore than one alkene radical alternates with more than one aryl radical. C1_20 alkyl includes straight- and branched-chain methyl, ethyl, propyl, l~utyl, ~entyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, ~o~e~yl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, l~ o~t~decyl, nonadecyl and eicosyl groups. Cl_5 al.kyl includes methyl, ethyl, propyl, butyl and pentyl.
Cycloalkyl refers to alkyl groups containing one, two, three or more cyclic rings. Cycloalkenyl re-fers to mono-, di- and polycyclic groups containing one or more double bonds.
Cycloalkenyl also refers to cycloalkenyl groups wherein two or moxe double bonds are present.
The process of -this invention is uselul for the recovery by froth flotation of metal values from metal ores. ~ metal ore xefers herein to the metal as it is taken out of the ground and includes the metal values in admixture with the gangue. &angue re~ers herein to those materials which are of no value and need to b~ separated from the metal values. This process can be used to recover metal oxides, metal sulfides and other metal values.
Sulfide ores for which these compounds are useful include copper sulfide-, æinc sulfide-, molybdenum sulfide-, cobalt sulfide-, nickel sulfide-, lead sulfide-, arsenic sulfide-, silver sulfide-, chromium sulfide-, gold sul~ide-, platinum sulfide- and uranium sulfide-containing ores and lX

- 12 ~ 6~693-3666 mixtures thereof. Examples of sulfide ores from which me~al sulfides may be concentrated by froth flotation using the process o~ this invention include copper-bearing ores such as, for e~ample, covellite (CuS), chalcocite (Cu2S), chalcopyrite ~CuFeS2), valleriite (Cu2Fe4S7 or Cu3Fe~S7), bornite (CusFeS4), cubanite (Cu2SFe4Ss), enargite (Cu2(As1Sb)S~), tetrahedri-te (~u3SbS~), tennantite (Cul2As4S13), bronchantite (Cu4(0H)6S04), alltlerite (Cu3S04(0H)~), famatinite (Cu3(SbAS)S4), and bournonite ~P~Cu~bS3); lead-bearing ores such as, for example, galena (PbS);
~n antimony-bearing ores such as, for example, stibnite (Sb2S3);
~inc-bearing ores such as, for example, sphalerite (ZnS);
silver-bearing ores such as, for example, stephanite (~gsSbS4), an~ argentite (Ag2S) chromium-bearing ores such as, for example, daubreelite (FeSCrS3); and platinum- and palladium-bearing ores sucl~ as, or example, cooperite (Pt(AsS)2).
Oxide ores fox which this process is useful include copper oxide-, aluminum oxide-, iron oxide-, iron titanium oxide-, magnesium aluminum oxide-, iron chromium oxide-, titanium oxide-, manganese oxide-, tin oxide-, and uranium oxide-containing ores.
Examples of oxide ore from which metal oxides may be concentrated by froth flotation using the process o this invention include copper-bearing ores, such as cuprite (Cu20), tenorite (CuO), malac~ite (Cu20H)2C03), azurite (Cu3(0H)2(C03)2), atacamite (Cu2Cl(OH3), chrysocolla (cusio3 ); aluminum-bearing ores, such as corundum zinc-containing ores, such as zincite ( ZnO ), and smithsonite (znc03); iron- containing ores, such as hematite and magnetite; chromium-containing 'X

~is~
-12a-ores, SUC}I as chromi-te (FeOCr2~3~; iron- and titanium-containing ores, such as ilmenite; magnesium- and aluminum-containing ores, such as spinel; iron-chromium-containing ores, such as chromite;
titanium-containing ores, such as rutile; manganese-containing ores, such as pyrolusite; tin-containing ores, such as cassiter-ite; and uranium-containing ores, such as -13~ 5~77 uraninite; and uranium-bearing ores such as, for example, pitchblende (U2o5(U3O8)) and gummite (U03n~I20).

Other metal values for which this process is useful include gold-bearing ores, such as sylvanite (AuAgTe2) and calaverite (AuTe); pla-tinum- and palladium--bearing ores, such as sperrylite (PtAs2); and silver-bearing ores, such as hessite (AgTe2).

In a preferred embodiment of this invention, oxide- or sulfide-containing values are recovered. In a more preferred em~odiment of this invention copper sulfide, n~ickel sulfide, lead sulfide, zinc sulfi~e or molybdenum sulfide values are recovered. In an even more preferred embodiment, copper sulfide values are recovered.

The collectors of this invention can be used in any concentration which gives the desired recovery of the desired metal values. In particular, the concentration used is dependent upon the particular metal value to be recovered, the grade of the ore to be subjected to the froth flotation process, the desired quality of the metal value to be recovered, and the par-ticular mineral value which is being recovered. Preferably, the collectors of this invention are used in concentrations of from 5 g to 250 g per metric ton of ore, more preferably from 10 g to 100 g of collector per metric ton of ore to be subjected to froth flotation.

Froth flotation of this invention usually reguires the use of frothers. Any frother well-known in the art, which results in the recovery of the desired metal value is suitable. Further, in the process of this 30 invention it is contemplated that collectors of this 32,768 F -13-invention can be used in mixtures wi-th other collec-tors well-known in the art.

Collectors, known in the art, which may be used in admi~ture with the collectors of this invention are those which will give the desired recovery of the desired mineral value. Examples of collectors useful in this invention include alkyl monothiocarbonates, alkyl dithio-carbonates, alkyl trithiocarbonates, dialkyl dithio-carbamates, alkyl thionocarbamates, dialkyl thioureas, monoalkyl dithiophosphates, dialkyl and diaryl dithio-phosphates, dialkyl monothiophosphates, thiophosphonyl chlorides, dialkyl and diaryl dithiophosphonates, 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.

Frothers useful in this invention include any frothers known in the art which give the recovery of the desired mineral value. Examples of such frothers include C5 8 alcohols, pine oiIs, cresols, Cl 4 alkyl ethers of polypropylene glycols, dihydroxylates of polypropylene glycols, glycols, fatty acids, soaps, alkylaryl sulfonates, and the like. Furthermore, blends of such frothers may also be used. All frothers which are suitable for benefici-ation of mineral ores by froth flotation can be used inthis invention.

32,768-F -14-The omega-(hydrocarbylthio)alkylamines or omega-(hydrocarbylthio)alkylamides can be prepared by the processes disclosed in serazosky et al., United Sta-tesPa-ten-t4,086,273;
French Patent 1,519,829; or Beilstein, 4, 4 Ed., 4th Supp., 1655 11979). The N-(omega-aminoalkyl) hydrocarbon amides can be prepared by the processes described in Fazio, United States Patent 4,326,067; Acta Polon Pharm, 19, 277 (1962); or Beilstein, 4, ~th Ed., 3rd Supp., 587 (1962). The omega-(hydrocarbyloxy-) al~ylamines can be prepared by the processes described in British 1(~ Patent 869,409; or Hobbs, United States Patent 3,397,238. The ~-(omega-aminoalkyl) hydrocarbon thioates can be prepared by the processes described in Faye et al., United States Patent 3,328,442;
or Be lstein, 4, 4th Ed., 4th Supp., 1657 (1979). The omega-amin~alkyl hydrocarbonoates can be prepared by the process des-cribed in J. Am. Chem. Soc., 83, 4835 (1961); seilstein~ 4, 4th Ed., 4th Supp., 1413 (1979); or Beilstein, 4, 4th Ed., 4th supp., 1735 (1979). The N-(hydrocarbyl)-alpha,omega-alkanediamines can be prepared by the process well-known in the art, one example is the process described in East German Patent 98,510.
~a The following examples are included for illustration and ~re not intended to limit the scope of the invention or claims.
Unless otherwise indicated, all parts and fractions are by weight.
In the following examples, the performance of the froth-ing processes described is shown by giving the rate constant of floatation and the amount of recovery at infinite time. These numbers are calculated by using the formula 1 -Kt r = R [1 - Kt ]

- l6 - 64693-36~6 ~herein: r is the amount of mineral recovered at time t, K is the rate constant for the rate of recovery and R is the calculated amount of the mineral which would be recovered at infinite time.
The amount recovered at various times is de~ermined experimentally and the series of values are substituted into the equa-tion to obtain the R and K values. The above formula is explained in "Selection of Chemical Reagents for Flotation", Chapter 45, pp.
~07-934, Mineral Processing Plant Design, 2nd Ed., 1980, by R.
Klimpel AIME ~Denver).
E~ample 1 - Froth Flotation of Copper Sulfide In this example several of the collectors of -this invention are tested for flotation of copper sulfide values. A
500-g quantity of Chilean copper ore, chalcopyrite copper sulfide ore, previously packaged is placed in a rod mill with 257 g o-f deionized water. The copper ore comprises 80.2 percen-t with a particle side of about 75 micrometers or less. A quantity of lime is also added to the rod mill, based on the desired pH for the subsequent flotation. The rod mill is then rotated at 60 rpm for a total of 360 revolutions. The ground slurry is transferred to a 2n 1500 ml cell of an Agitai ~ Flotation machine. The float cell is agitated at 1150 rpm and the pH is adjusted to 10.5 by the addition of further lime, if necessary.
The collector is added to the -float cell (at a rate of 50 g/metric ton), followed by a conditioning time of one minute, at which time the frother, DOWFROT~ 250 (Trademarlc of The Dow ~X

- 16a - 64693-3666 Chemical Company) is added (at a rate of 40 g/metric ton). After the additional one-minute conditioning time, the air to the float cell is turned on at a ra~e of 4.5 liters per minute and the automatic rroth removal paddle is started. The fro-th samples ~ere _17_ taken off at 0.5, 1.5, 3, 5 and 8 minutes. The froth samples are dried overnight in an oven, alon~ with the flotation tailings. The dried samples are weighed, divided into suitable samples for analysis, pulverized to insure suitable fineness, and dissolved in acid for analysis. The samples are analyzed using a DC Plasma Spectrograph.

The collectors that were tested for flotation o~ copper sulfide values of a Chilean copper ore are compiled in Table I and demonstrate that a wide variety of compounds within the scope of the invention are effective in the recovery of copper sulfide values. A
base case example which employed no collector is included in Table I for comparison. It should be noted that the collectors of the invention in Table I were not selected for optimum performance, but represent arbitrary selection of compounds that show a significant response in the recovery and selectivity of mineral values.

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o --~ E- c `_ Z ' r~

32, 768-F -22-E~ample 2 A Central African copper oxide ore (Cu2o) is subjected to the fro-th flotation process described in Example 1 using 40 grams per metric ton of the frother, DOWFROTH~ 250 (Trademark of The Dow Chemical Company).
The results are compiled in Table II with Collectors A and B being chosen from Table I.

TABLE II

10 Collector ~ pH K R R-8 A 160 5.1 2.480.335 0.308 A 80 9.5 2.550.249 0.234 B 80 9.5 2.910.313 0.289 C 160 5.1 4.080.135 0.130 15 A - C6H13-S~CH2)2 NH2 o B - C7H15C-NHtCH2)2 NH2 C - Sodium isopropyl xanthate, not an embodiment of this invention It is well known in the mining indus-try that existing commercial collectors such as sodium isopropyl xanthate do not float oxide minerals very e~fectively.
It is therefore surprising that Collector A at a concentration of 80 g/ton will increase the recovery of copper values by 84.4 percent as compared to the Standard Collector C which was employed at a concentratlon of 160 g/ton, i.e. twice as much. When the performance of 32,768-F -23-. -24-Collector A, employing 160 g/ton is compared against the Standard C lt can be seen that the recovery of copper values was increased by 148 percent. The fact that the collectors of this invention will float a substantially S greater amount of copper values from copper oxide ore is indicative of the fact that the collectors of the invention are less sensitive to the form of the metal containing mineral, i.e. sulfide or oxide ore as compared to existing collectors.

Example 3 A Central Canadian sulfide ore containing copper sulfide, nickel sulfide, platinum, palladium and gold metal values is subj ected to a series of froth flotations as described in Example 1 using the collectors of this invention and several collectors known in the art. The frother used is DOWFROTH~ 1263 (Trademark of The Dow Chemical Company) at a concentration of 0.00625 lb/-ton (3.12 g/metric ton) The collectors are used at a concentration of 0.0625 lb/ton (31.2 g/metric ton). The 20 froths produced are recovered at 0.5, 1.0, 2.0, 4.0, 7.0, `1.0 and 16.0 minutes. The results are compiled in Table III with collectors chosen from Table I.

32,768-F -24-'7~7 ~:J~ O O O O
O O O O O
U~ 1~ 0 ~ ~9 ~ ~::
~S ~ O
,_1 ~ O
~1 1~Q O O O O
. O ~ ~ ~ ~ rJ
~ ~ O O ~ ~ J~

O
~ ~`3 0 1 O
t`~) ~9 U) O ~ U~ ~ ~ U~
i~ ~Dr~ 9~ r-l CO ~ a) ~1 -1 ~ ~P d' ~1 ~I h ~ 1~
O O O O O
~ If~ 9 ~
~ ~1 ~ o ~ a~
X O O O ~1 O

~ O C` ~) 9~ W
~ 1` ~ O ~ ) O ~0 t-l U~ ~ O U~ ~ o U
1 ~1 u~
co ~ a) ~ I~ td o u~
~ ~ ~ . - ~
~ ~ ,~ ~9 o ~o n r~
O ~ ~ ~9 r~
~9 1` t` (~
~Z; ~ . . . . O ,~:
~') OD ~ ~01:1 C o IIJ C
. . . O
~1 0 ~ ~ ~ rl ~ ~ I
U~ O ~ --o ~ ~ ~ c P;
. ,, . . . ,, ~1 u a N u~ O ~ :~
~D ~ a:) ~ ~ ~ -~1 u~o ~ a~ ~1 r~ ~ ~ S a)~ I ~1 ~ ,s: ~ o h l t5~
P~ . . . . . ~:s C
,~ W ~ o ~ U :~
O ~ 0~ 0~1 El E3 C~ O rl ~C
) ~ o~ ~ a) 9~00 ~ ~ U ,~ h O
d' . 0 d'd' E3 h h ~ ~ C
U-) d1 d' ~ ~ ~ ~JIJ E~ ~ w a) w s:~
o ~4~ o E i O
h O
* E~ O ~ ~ X
h a aJ ~ ~ ~ a) h U2 h O ~ h h ~ t~
u ~ a) o a) ~ O1~ 0 0 U ~1 U U C ~
O Oa~ ~ ~ h 51 h O
O O ~d X I tl~d' O Zi P~ P~ O ~ O
c,) u~ o ~- Z ~ 9 1--~r t~

~5~
Table III illustra-tes the use of two novel compounds of this inven-tion, i.e. OHTEA and NOPA as compared to three optimized industrial collector standards.
The ore was complex containing varlous metal values. The collectors are comparable in performance in the xecovery of copper values. The OHTE~ collector was clearly superior in the recovery of nickel, platinum, palladium and gold.
In the recovery of nickel, the.R-16 value of OHTEA when compared to Z-211~ showed a slight increase but a very surprising and significant decline in the recovery of pyrrhotite, i.e. 15.5 percent. A substan-tial improvement was also realized in the reduction of the tailings for platinum and palladium - the values were about equal for gold.

The collector NOPA showed a good recovery for copper and nickel when compared against the best known collectors employed in the field. It showed a superior performance in the reduction of R-16 pyrrhotite values when compared against the standards. The ratio of nickel recovery to pyrrhotite recovery is clearly superior when compared to known collectors, i.e., a 30 percent increase in the ratio. The selectivity of NOPA is significant if it is desired to lower the demand on smelters since much of the flotation product is undesired sulfur containing ~5 material.

Example 4 - Froth flotation of Copper Sulfide In this example several of the collectors of ~his invention are tested for flotation of copper sulfide values. A 500 gram quantity of Western Canada copper ore, a relatively high grade chalcopyrite copper sulfide ore with little pyrite, is placed in a rod mill having 1 inch rods, with 257 gram of deionized water and ground for 32,768-F -26-- 27 - ~4693-3666 ~20 revolutions at a speed of 60 rpm to produce ~ size ~istribu.ion of 25 percent ]ess than 100 mesh. A quantity of lime is also added to the rod mill, based on the desired pH for the subsequent flotation. The around slurry is transferred to a 1500 ml cell of an Agitair~ Flotation machine. The float cell is agitated at 1150 rpm and the pH is adjusted to 8.5 by the addition of further lime.
T~e collector is added to the float cell at the rate of ~ q/metric ton, followed by a conditioning -time of 1 minute, at which time the frother, DOWFROT~ 250 (Trademark of The Dow Chemical Company) is added at the rate of 18 g/metric ton. After the additional 1 minute conditioning ~ime, -the air to the float cell is turned on at a rate of 4.5 liters per minute and the automatic froth removal paddle is started. The froth samples were t~ken off at 0.5, 1.5, 3, 5 and 8 minutes. The froth samples are ~rie~ overnight in an oven, along with the flotation tailings.
The dried samples are weighed, divided into suitable samples for analysis, pulverized to insure suitable fineness, and dissolved in acid for analysis. The samples are analyzed using a DC Plasma ~n Spe~trograph. The results are compiled in Table IV. The compounds that were used in Examples 1 through 31 in Table IV are separately tabulated herein below:
1*. ~o collector 2. C6H13S~CH2)2NH2 ~1 0 "
3. (t-butyl)S(CH2)2NH2 4. C6H13S~CH2)2N-C-c2H5 H O
ll 5. CloH2ls-(cH2)2N-c-c2H5 6. (c4Hg)2-N-tcH2)2NH2 X

H O O H
7- (t-butyl)s~cH2)2N-c-c2H5 8. CgHlgC~N~CH2)2NH2 H O E[ O
9. C4HgS-(cH2)2N-c C2H5 10~C12H25S-(c~2)2N C C2 5 O H O
ll . C8Hl7S- ( CH2 ) 2 C NH2 12 . ~S ( CH2 ) 2N C CH3 13. C8Hl7S-(cH2)3NH2 14.C6Hl3S(CH2)2NCS

H ~CH3 15 . ~S ( CH2 )2 2 16 . C6H13-~;-S ~ CH2 ~2 ~

H H
17. C8Hl7S(CH2)2, 18. C8H17S(CH2)2,

2 0 ~C ~N~C
N-C-N
ll l ~5 CH3-C~C=C-CH3 H

H H &H3 l9. C8Hl7S(CH2)2, 20.C6H13-C S(CH2)2 \
N- C-N=C CH3 CH3 H O OH
21.C5HllS(cH2)3N C 2 5 22. C8Hl7s-cH2cH2NH2 23 . C8H17S ( CH2 ) 2NH2 24 . C4HgS ( CH2 ) 2NH2 HCl H O O H
25. C8H17-S(CH2)2N CC2H5 26-C4H9C-OC2H~L-N-(CH2)2NE~2 32, 768-F -28-H H S
I l 27- C5HllS(CH2) C, (CH2)NH2 28. C6H13S(cH2)N-P ( c2 5)2 OH
H H
29. C6~13-S(cH2)2N IC P3 2 H

3 2)2N CH2-CH(OH)-C~2-O-CH2-CH(c ~ ) c '~ 31 NH -CH -CH(OH)-CH2-O-C~2-CH(C2H5) 4 9 C~ ~lJ~ - 5 f~c ~
1* - Not an example of the invention.

TABLE IV

Example Copper Gangue copper Gangue Number K R K R R-8 R-s Selectlvlty 1* 2.11 . 306 1. 61 .068.291 . 066 4.4 202 4.19 .629 3.63 .140.606 .136 4.5 3 3.65 .621 4.28 .121.600 .121 5.0

4 3.79 .943 2.95 . 196 .906 . 189 4.8 2.69 .789 2.37 .160.730 .148 4.9 6 2, 04 .382 1.88 .0735 .358 . 0692 5.2 ~S 7 3 86 . 585 3.44 .118 . 562 . 114 4.9 8 2. 36 . 435 2.15 .0858 . 409 . 0815 5.0 9 5.16 . 742 4. 43 . 157 .719 . 153 4. 7 2.38 .499 2.10 .100 .469.0951 4.9 32,768-F -29-- 30 - 6~693-3666 TABL~_IV (Cont.) ~ample Cop~er Gangue Copper Gangue Number K R _K R R-8 R-8 Selectivity_ _ _ _ _ 11 4.53 .869 3.59 .184 .838 .l79 4.7 12 ~.06 .4~8 1.80 .0895 .418 .0840 5.0 13 3.90 .572 3.22 .126 .551 .123 ~.5 14 2.12 .863 1.59 .192 .809 .179 4.5 l~ 3.43 .534 2.gO .108 .513 .106 4.8 lh 2.94 .424 2.45 .0841 .408 .0816 5.0 17 5.00 .641 4~33 .148 .622 .145 4.3 1`3 3.51 .682 3.01 .175 .649 .168 3.9 19 2.68 .451 2.29 .097 .429 .Og~ 4.6 ~0 3.46 .449 2.96 .092 .431 .090 4.8 ~1 4.58 .909 3.44 .187 .878 .181 4.8 22 ~.~2 .540 3.60 .124 .523 .123 4.3 ~3 ~.61 .514 2.96 .111 .493 .107 4.6 24 3.54 .542 3.21 .121 .520 .117 4.4 ~5 3.54 .832 2.73 .162 .802 .156 5.1 ~6 2.14 .367 1.61 .080 .345 .075 4.6 ~7 3.6~ .520 2.98 .119 .501 .116 4.3 2~ 1.97 .848 1.56 .180 .788 .166 4.7 29 2.41 .308 2.11 .0676 .296 .066 4.5 2.35 .340 2.14 .0702 .324 .0676 4.8 31 2.25 .355 2.18 .0737 .338 .0710 ~.8 32 7.17 .7~3 5.32 .156 .707 .155 4.6 l* - Not an example of the invention.

Example 4 is slmilar to Example l except that various different compounds within the scope of the invention were tested on a different copper sulfide ore.
No optimization of the collectors was attempted but all of the compounds were lound to be clearly superior when compared against "no collector" in the recovery of copper values. The collectors of this inven-tion will show superior recovery and selectivity when compared to the standard known collectors and when optimized with regard 1~ to a particular ore under consideration.

Example 5 - Froth Flotation of Copper Sulflde and Molybdenum Sulfide sags of homogeneous ore are prepared with each bag containing 1200 grams. The rougher flotation procedure is to grind a 1200 gram charge with 800 cc of tap water for 14 minutes in a ball mill having a mixed ball charge (to produce appoximately a 13 percent plus lO0 mesh grind).
This pulp is transferred to an Agitair~ 500 flotation cell outfitted with an automated paddle removal system. The slurry pH is adjusted to 10.2 using lime. No further pH
adjustments are made during the test. The standard frother is methyl isobutyl carbinol (MIBC). A four-stage rougher flotation scheme is then followed.

STAGE l: Collector - 0.0042 kg/ton ~5 MIBC - 0.015 kg/ton - condition - l minute float - collect concentrate for l mlnute STAGE 2: Collector - 0.0021 kg/ton MIBC - 0.005 kg/ton - condition - 0.5 minute - float - collect concentrate for l.5 minutes 32,768-F -31-

5~'~7 - 32 - 6~693-3666 5TAGE 3: Collector ~ 0.0016 kg/ton MIBC - 0.005 kg/ton - condition - 0.5 minute - :Eloat - collect concentrate for 2 minutes STAGE ~: Collector - 0.0033 kg/ton ~IBC - 0.005 kg/ton - condition - 0.5 minute - float - collect concentrate for 1~ 2.5 minutes ~ABLE V
Copper/Molybdenum Ore from Western Canada Cu Mo Rec Rec Dosage kg/- R-7 R-7 Cu Mo Fe Collector metric ton min min Grade Grade Grade .
~ 0.0112 0.776 0.725 0.056 0.00181 0.25 B 0.0112 0.688 0.682 0.063 0.00233 0~108 B 0.0067 0.659 0.759 0.099 0.00402 0.137 B 0.01121 0.648 0.747 0.080 0.00314 0.127 A - potassium amyl xanthate tNot an example of the invention) o B - C6Hl3s(cH2)2N-c-c2H5 H
The slurry was not treated with lime and the pH was adjusted to 8.2 - 33 - 64693-36~6 Table V illustrates that a substantially higher grade was achieved for copper and molybdenum as compared to the Standard Collector A. For copper, the minimum increase was over 10 percent and the maximum increase was 77 percent. For molybdenum, the mini~um increase in grade was about 30 percent and the maximum optimized increase was about 122 percent. Such improvements place a substantially smaller load on the smel~er of a mining operation.
The grade for iron with any of the Collectors B of the l~ invention again show a substan-tial reduction of about 50 percent a3 compared to the Standard Collector A, indicating that substantially less of the undesirable pyrite is collected. This surprising selectivity in the collec-tion of metal sulfide values over iron sulfide values is highly advantageous in the downstream operation of a mining operation as it reduces sul-fur emissions.
Example 6 - Froth Flotation of a Nickel/Cobalt Ore from Western Australia A series of 750 gram charges of a nickel/cobalt ore are prepared in slurry form (30 percent solids). The flotation cell a is an Agitai ~ LA-500 outfitted with an automatic peddle for ~roth removal operating at 60 rpm's. A standard run is to first add 0.2 kg/metric ton of CuSO4, condition for 7 minutes, add 0.1 kglton collector, condition for 3 minutes, add 0.14 kg/ton guar ~epressant for talc, and 0.16 kg/metric ton collector, add a frother (e.g., triethoxybutane) to form a reasonable froth bed.
Concentrate collection is initiated for 5 minutes (denoted as rougher concentrate). Then 0.16 kg/metric ton collector plus 0.07 kg/metric ton guar is added to remaining cell contents along with whatever frother is necessary and concentrate collection is initiated for 9 minutes (denoted as middlings) with the remaining cell con-tents denoted as flotation tails.
After this, the rougher concentrate ls transferred to a smaller cell, 0.08 kg/metric ton collector plus 0.14 kg/-metric ton guar is added to the cell with no frother, concentrate collection is initiated for 3 minutes (denoted as cleaner concentrate) with the cell contents denoted as cleaner tails. Samples are filtered, dried, and assayed using X-ray analysis methodology. Recoveries are calculated using standard metallurgical procedures. The results of this test are compiled in Table VI. The compounds that were used for Examples 1 to 5 in Table VI are tabulated hereinbelow:
Collector .
l* - Sodium ethyl xanthate ~0 2 - C6H13S(CH2)2NH2 O
3 - C6H13S(cH2)2N C C2 5 H
4 _ (C4Hg)2-N-(CH2)2 NH2 O H
ll l - C7H15C N-(CH2)2NH2 *Not an example of the invention 32, 768-F -34-CO ~ N

E I ô
~0 t~ ~ ~~ ~ O ~) Ul 11~a) ~,, . . . , ~ ~, V E~
U~ ~ O
O ~
U ~ o ul d~ t~) ~ +~ N~U~
~ o~ ~ ~ 3 U~ ~ C) 3 :4 o C
O a~ O ~N ~) u~ N o ~:
a o ~ v ,~
Ln o ~ ,~

' ~ o C3 ,~ ~ t~~ O ~ ~ N ~) ~_~
X U N~ , X
.,, O .,, Z ,~ U~
r- o ~ a r~
~ ~) a~ o E~ u~
o ~ 4 o s~
a~
a~
~D ~ ~ O ~, ~!;J O N1~ o ~U C~ ~ Lr) X
a O
o I ~ ~ ~) O ~J r~ N t~ ~ Ll O
V r-l ,~

3Z, 768-F

The data in Table VI represents a full scale simulation of a continuous industrial flotation process.
The data in the column entitled ~Flotation Tail" is the most significant data since it shows actual metal loss, i.e. the lower the value in the Flotation Tail column, the lo~er the metal loss. The superiority of the experimental collectors of the invention over ~he industrial standard in this category is apparen-t. At a minimum, the Flotation Tail for nickel recovery showed an 1~ 8 percent drop, at a ~aximum, the flotation tail drop showed a surprising 81 percent drop. For cobalt, similar improvements were realized except for Collector 3.

Example 7 - Froth Flotation of a Complex Pb/Zn/Cu/Ag Ore from Central Canada Uniform 1000 gram samples of ore are prepared.
For each flotation run, a sample is added to a rod mill along with 500 cc of tap water and 7.5 ml of SO2 solution.

6-1/2 minutes of mill time are used to prepare a feed in which 90 percent of the particles have a size of less than 200 mesh (75 microns). After grinding, the con-tents are transferred to a cell fitted with an automated paddle for froth removal. The cell is attached to a standard Denver flotation mechanism.

A two-stage flotation procedure ls then performed.
In Stage I, a copper/lead/silver rougher, and in Stage II, a zinc rougher. To start the Stage I ~lotation, 1.5 g/kg Na2CO3 is added and the pH adjusted to 8.5, followed by the addition of the collector(s). The pulp is then conditioned for 5 minutes with air and agitation.
This is followed by a 2-minute condition period with agitation only. MIBC frother is then added (standard dose 32,768-F ~-36-r7~

of 0.015 ml/kg). Concentrate is collected for 5 minutes of flotation and labeled as copper/lead rougher concentrate.

The Stage II flotation consists of adding 0.3 kg/-metric ton of CUSO4 to the cell remains of Stage I.
The pH is then adjusted to 9.5 with lime addition. This is followed by a condition period of 5 minutes with agitation only. The pH is then rechecked and adjusted back to 9.5 with lime. At this point, the collector(s) is added, followed by a 5-minute condition period with ld agitation only. MIBC frother is -then added ~standard dose o~ 0.020 ml/kg). The concentrate is collected for S minutes and labeled as zinc rougher concentrate.

Concentrate samples are dried, weighed, and appropriate samples prepared for assay using X-ray techniques. Using the assay data, recoveries and grades are calculated using standard mass balance formulae.

32,768-F -37-S~'7>9 a~
I ~ I
I ~ I
I , I
o o N ~ 0 tr Lt) l ~
P~ . .
o o o o ~1 In 'l I o . ~1 . I . I
o o co u~ O d~
u~
~ l ~
0~
o o o o S~
O
I ~
(1~ ~ I ~1 V ~ o I o :>~3 O
LO ~ U~
~1l ~) o ~ O
~ ~1:~ O o o O
o a~ ~ o ~ ' OD I ~ I
h g~ ~ O . O ~
tY~ ~ ~O CO
F: ~11 ~ O ~
N l ) ~1 oo~1 . . . ~1 ~
O o ~ O
1~ ~ rl LO
t~ ~ 1~o u~
~ ~ o o(~ ~1 0 o<\1 :~
IQ l:J O O O O O O O O h o ~ .. .. .. . ~ a) ~1 ~_ O o o o o o O d ~ O
I o ~1 ~
o o ~: m ~ ~ ~ m ~ x ~
o a~ - ~ ~ z ~ o ~1 o ~1) R ,q O ~ ~ V
P~
o U~ V
N ;:1 N
V~ O V V ~rl ~ O ~1 ~
_, O rl ~ ~O U~ rd I ~ n O
Z;
mv~ p;

32, 768-F -38-~tj~i~'7 Table VII illustrates the performance of optimized industrial standard collectors when compared to the collector of the invention in the recovery of metal values. Stage I of t~st 1 employed a combination of standard collectors A and B, while Stage II employed a combination of standard collectors A and C. Stage I of test 2 employed a mixture of a standard collector B and . collector D of the invention in approximate equal amounts.
Stage II of test 2 employed collector D of the lnvention.

The goal in this test was to maintain the recovery level for silver and copper in Stage I and to increase the zinc recovery in Stage II. The results show that collectox D approximately maintained the level of recovery for silver and copper with an accompanying improvement in grade. Most importantly, both the recovery (R-5) and grade of zinc in Stage II of test 2 were increased by 3 percent and 6 percent, respectively, over the standard collectors of test 1.

32,768-F -39-

Claims (13)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A collector for recovering metal values from a metal ore, in the form of an aqueous pulp, is subjected to froth flo-tation, wherein the collector is a compound corresponding to the formula I

(I) where R is -CH2- , , -?- , or mixtures thereof, where R

can occur in a random sequence; and n is an integer from 1 to 6 or ?R?n is ?CH2?mC? where m is an integer from 0 to 6; R1 and each R2 are independently C1-22 hydrocarbyl or a C1-22 hydrocar-byl substituted with one or more hydroxy, amino, phosphonyl, alkoxy, imino, carbamyl, carbonyl, thiocarbonyl, cyano, carboxyl, hydrocarbylthio, hydrocarbyloxy, hydrocarbyl-amino, or hydrocarbylimino groups, with the proviso that R2 can be a divalent radical with both valencies bonded directly to the N atom X is -S-, -O- , -?-R , -?-S , , or -?O-R3 is H, a C1-22 hydrocarbyl, or a substitued C1-22 hydrocarbyl radical;
a is an integer of 0, 1 or 2;
b is an integer of 0, 1 or 2;
with the proviso that the sum of a and b equals 2 except when R2 is a divalent radical with both valencies bonded directly to the N atom, in which case, a=1 and b=0 or when ?R?n is ?CH2?mC? in which case, a+b=0, and with the further proviso that when X is -?-S , , or -?O-the carbonyl moiety is bonded to R1.

2. The collector of Claim 1, wherein said compound corresponds to the formula wherein:
R1 is a C1-22 hydrocarbyl or a C1-22 hydrocarbyl rad-ical substituted with one or more hydroxy, amino, phosphonyl, or alkoxy moieties;
R is a C1-6 alkyl, C1-6 alkylcarbonyl, C1-6 alkyl group substituted with an amino, hydroxy or phosphonyl moiety, or C1-6 alkylcarbonyl group substituted with an amino, hydroxy or phosphonyl moiety;
and X, a, b, and n are as defined in Claim 1.

3. The collector of Claim 2 wherein R1 is C2 14 hydro-carbyl; R2 is C1-6 alkyl or C1-6 alkyl-carbonyl; R3 is hydrogen or C2-14 hydrocarbyl; a is the integer 0 or 1; b is the integer 1 or 2; and n is an integer of from 1 to 4.

4. The collector of Claim 3, wherein R1 is C4-11 hydro-carbyl; R2 is C1-4 alkyl or C1-4 alkyl-carbonyl; R3 is hydrogen or C4-11 hydrocarbyl; n is the integer 2 or 3; and x is -S-, -?-R or -O-.

5. The collector of Claim 4 wherein X is -S- or -?-R3.

6. The collector of Claim 4 wherein X is -S-.

7. The collector of Claim 1 or 2 wherein the compound is selected from omega-(hydrocarbylthio)alkylamines; omega-(hydro-carbylthio)-alkylamides; S-(omega-aminoalkyl) hydrocarbon thioates;
N-(hydrocarbyl)-alpha, omega-alkanediamines; (omega-aminoalkyl) hydrocarbon amides; omega-(hydrocarbyloxy-)-alkylamines; omega-aminoalkyl hydrocarbonoates or mixtures thereof.

8. A process for recovering metal values from a metal ore, comprising the steps of subjecting the metal ore, in the form of an aqueous pulp, to a froth flotation process in the presence of a flotation collector under conditions such that the metal values are recovered in the froth, wherein the collector comprises a compound corresponding to the formula I as defined in Claim 1.

9. The process of Claim 8 wherein said compound corresponds to the formula wherein:

R1 is a C1-22 hydrocarbyl substituted with one or more hydroxy, amino, phosphonyl, or alkoxy moieties;
R2 is a C1-6 alkyl, C1-6 alkylcarbonyl, C1-6 alkyl group substituted with an amino, hydroxy or phosphonyl moiety, or C1-6 alkylcarbonyl group substituted with an amino, hydroxy or phos-phonyl moiety;
and X, a, b and n are as defined in Claim 1.

10. The process of Claim 9 wherein R1 is C2-14 hydrocarbyl, R2 is C1-6 alkyl or C1-6 alkylcarbonyl; R3 is hydrogen or C2-14 hydrocarbyl; a is the integer 0 or 1; b is the integer 1 or 2; and n is an integer of from 1 to 4.

11. The process of Claim 10 wherein R1 is C4-11 hydrocarbyl;
R2 is C1-4 alkyl or C1-4 alkylcarbonyl; R3 is hydrogen or C4-11 hydrocarbyl; n is the integer 2 or 3; and X is -S-, -?-R3 or -O-.

12. The process of Claims 8, 9 or 10 wherein the collector is added in an amount of from between 5 to 250 grams per metric ton.

13. The process of Claim 8 wherein the metal value recovered is a metal sulfide, metal oxide or precious metal.