CA1299777C - Recovery of platinum-group metals and other metal valuables - Google Patents
Recovery of platinum-group metals and other metal valuablesInfo
- Publication number
- CA1299777C CA1299777C CA000540395A CA540395A CA1299777C CA 1299777 C CA1299777 C CA 1299777C CA 000540395 A CA000540395 A CA 000540395A CA 540395 A CA540395 A CA 540395A CA 1299777 C CA1299777 C CA 1299777C
- Authority
- CA
- Canada
- Prior art keywords
- trithiocarbonate
- group
- collector
- froth flotation
- combination
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
ABSTRACT
A froth flotation promotor and/or collector for the recovery of metals from the platinum-group which comprises one or more compounds from the group of compounds including trithiocarbonates or phosphates; alkyl derivatives thereof having 2 to 16 carbon atoms; and the ammonium or alkali me tal salts of any of these compounds. The sodium salt of isopropyl trithiocarbonate was found to be particularly use-ful as promotor and/or collector. A method of utilizing these compounds in a froth flotation process for the recov-ery of platinum-group metals is also disclosed.
A further feature of the invention is a froth flota-tion collector for the recovery of a metal valuable compris-ing a combination of at least two different compounds of which one is a mono alkyl TTC in which the alkyl group can be linear or branched and can have 2 to 16 carbon atoms, and/or the ammonium and/or alkali metal salts of any of these compounds, and the other compound is at least one com-pound of the group of compounds including a TTC; DTC; DTP;
mercaptan (except where the metal valuable is a PGM); the alkyl derivatives of any of these compounds in which the al-kyl group can be linear or branched and can have 2 to 16 carbon atoms; MBT (except where the metal valuable is copper or iron); the ammonium and/or alkali metal salt of any of the aforesaid compounds.
A froth flotation promotor and/or collector for the recovery of metals from the platinum-group which comprises one or more compounds from the group of compounds including trithiocarbonates or phosphates; alkyl derivatives thereof having 2 to 16 carbon atoms; and the ammonium or alkali me tal salts of any of these compounds. The sodium salt of isopropyl trithiocarbonate was found to be particularly use-ful as promotor and/or collector. A method of utilizing these compounds in a froth flotation process for the recov-ery of platinum-group metals is also disclosed.
A further feature of the invention is a froth flota-tion collector for the recovery of a metal valuable compris-ing a combination of at least two different compounds of which one is a mono alkyl TTC in which the alkyl group can be linear or branched and can have 2 to 16 carbon atoms, and/or the ammonium and/or alkali metal salts of any of these compounds, and the other compound is at least one com-pound of the group of compounds including a TTC; DTC; DTP;
mercaptan (except where the metal valuable is a PGM); the alkyl derivatives of any of these compounds in which the al-kyl group can be linear or branched and can have 2 to 16 carbon atoms; MBT (except where the metal valuable is copper or iron); the ammonium and/or alkali metal salt of any of the aforesaid compounds.
Description
lL~9gi~77 RECOVERY OF PLATINUM-GROUP METALS
AND OTHER ~ETAL VALUABLES
This invention relates to the benefication of metal-liferous ores, particular ores containing metals of the plat-inum-group, i.e. platinum, rhodium, palladium, osmium, irid ium and ruthenium. Such ores are, for example, found in the Merensky and other related reefs where the metals occur in either the free or combined form, in copper, nickel, iron and chrome ores, and in minerals such as pentlandite, pyrohtite, chalcopyrite, troilite and chromite.
It is known to employ the soluble salts of mercaptans, dithiocarbonates, and dithiophosphates as promotors and/or collectors in the froth flotation of the aforementioned ores.
It is also known to utilize these substances in combination with one another to improve the recovery of platinum-group metals in such processes.
These known3 so called thio-promotors and/or collec-tors, are characterized by the fact that they contain either one or two sulphur atoms on one of their terminal carbon at-oms.
Applicant has now found other thio-compounds which are even more selective froth flotation promotors and/or collec-tors for the platinum-group metals, individually and/or in groups thereof than what the case is with any of the afore-said known thio-compounds.
According to the invention a froth flotation promotor and/or collector for the recovery of metals from the platinum-group is provided which includes a trithiocarbonate (other than a dialkyl or ethoxy ester derivative thereof) and/or an alkyl derivative thereof having 2 to 16 carbon atoms and/or the ammonium or alkali metal salts of any of these compounds.
Applicant has found these trithiocarbonates or phos-phates, when used as independent promotors and/or collectors in the flotation of the aforementioned ores, to give much bet-ter recovery of the platinum-grouP metals than what is pos~
sible with the known dithiocarbonates~ dithiophosphates, or ~r 7~
mercaptans used either individually or in combination with one another.
Not only is the yield of the platinum-group metals higher and the grade better when using the compounds of the invention, but it is also possible to float lower mass con-centrates while achieving tailings with lower metal concen-trations.
Compounds which the Applicant has found particularly useful in this regard are:
sodium ethyl trithiocarbonate, sodium n-propyl trithiocarbonate, sodium isopropyl trithiocarbonate, sodium n-butyl trithiocarbonate, sodium isobutyl trithiocarbonate, sodium sec-butyl trithiocarbonate~
sodium tert-butyl trithiocarbonate, sodium n-pentyl trithiocarbonate, sodium isopentyl trithiocarbonate, and sodium benzyl trithiocarbonate.
Of these compounds the one which the Applicant found most useful was the sodium salt of isopropyl trithiocarbo~
nate.
Applicant has also found a combination of the compounds of this invention and the mercaptans to give good results as a froth flotation collector and~or promotor in the recovery of metals of the platinum-group.
The invention also includes within its scope a method for the recovery of platinum-group metals by means of a froth flotation process in which one or more of the promotors and/
or collectors of the invention are utilized.
This invention further relates to the recovery of metal valuables, and to substances suitable for use in such recovery.
More particularly this invention relates to the froth flotation of metalliferous ores, such as those containing metals of the platinum-group as well as other sulphide ores, particularly copper bearing sulphide ores.
Ores containing metals of the platinum-group are, for _ 3 _ example, found in Southern Arica in the Merensky and other related reefs, in which the metals occur in either the free or combined form; in copper, nickel, iron, and chrome ores;
and in minerals such as pentlandite, pyrohtite, chalcopyrite, troilite and chromite. The metals of the platinum-yroup, which will in the rest of this specification be referred to as the PGM, include platinum, rhodium, palladium, osmium, iridium and ruthenium.
One copper bearing ore of the aforesaid type is, for example, that found in the Bushveld Igneous Complex at Phala-borwa in the Northern Transvaal in the Republic of South Af-rica. This ore, which will hereafter be referred to as the PMC-ore, usually comprises a mixture of the minerals chalco-pyrite (60%); bornite (28%); cubanite (6~); and valleriite (6%). Such an ore body usually contains between 0.2 and 10.0%
copper, although the lower copper level can in some instances even be less.
It is known to recover metal valuables of the afore-said kinds by means of a froth flotation process, and amongst the froth flotation agents which have been used. In this re-gard, are certain of the so called dithiocarbonates (hereaf-ter referred to as DTC), such as, for example, potassium amyl xanthate (hereafter referred to as PAX); certain of the so called dithiophosphates (hereafter referred to as DTP), such as, for example, di-isobutyl dithiophosphate (hereafter re-ferred to as di-iC4DTP); mercaptobenzothiazole (hereafter re-ferred to as MBT); and certain of the mercaptans.
Applicant itself has also found that certain trithio-carbonates (hereafter referred to as TTC) can be used as froth flotation collectors for metal valuables of the aforesaid kinds.
As a result of the constant depletion of the previously existing very rich ore bodies, the grade of ore which has to be worked gets lower all the time, and there is accordingly a continued search for better collectors. It is an object of this invention to provide such a collector.
Accordin~ to a further feature of the invention a froth 2~ 7~
flotation collector for the recovery of a metal valuable co~n-prises a combination of at least two diEferent compounds of which one is a mono al`kyl TTC in which the alkyl groups can be linear or branched and can have 2 to 16 carbon atoms, andJ
or the ammonium and/or alkali metal salts of any of those com-pounds and the other compound is at least one compound of the group of compounds including a TTC; DTC; DTP; mercaptan (ex-cept where the metal valuable is a PGM); the alkyl derivatives of any of the aforesaid compounds in which the alkyl group can be linear or branched and can have 2 to 16 carbon atoms; MBT
(except where the metal valuable is copper or iron); an am-monium and/or alkali metal salt of any of the aforesaid com-pounds, the compounds of the combination being added to the reaction medium either as a blend or separately.
Applicant has found that when such a combination is em-ployed as a collector in the recovery of metal valuables of the aforesaid kinds, an unexpected synergistic effect results and the overall collecting properties, including the rate of collection, are better than the combined properties of the individual compounds of the combination.
Further according to the invention at least one of the compounds of the combination is iC3TTC (i.e~ isopropyl TTC~.
Further according to one embodiment of the invention a froth flotation collector combination for the recovery of a PGM includes an iC3TTC and iC4TTC; or an iC3TTC and/or iC4TTC
and at least one of the compounds iC4DTP and MBT.
Further according to another embodiment of the inven-tion a froth flotation collector combination for the recovery of copper includes at least two compounds of the group of com-pounds including iC3TTC, nC4TTC, iC4DTP and PAX.
Still further according to this embodiment of the in-vention the collector comprises iC4DTP and at least one of the compounds iC3TTC, nC4TTC and PAX.
Still further according to this embodiment of the in-vention the collector comprises iC4DTP, nC4TTC and PAX, pre-ferably in equimolecular quantities.
The invention also includes within its scope a method ~ ~ 3Z423CA
Eor the recovery oE metAl vAluAbles particularly plat:Lnum, or copper from a copper containLng sulpIlide ore, employing a collec-tor accord:Ing to the invention.
~ OF T~IE DRAWINGS
F:lgure 1 shows PGM recove,ry of the stanclard :Ln iC3TTC a-t 45 g/t.
F:Lgure 2 shows PGM recovery of -the standard in iC3TTC at 30 g/t.
Figure 3 shows PGM recovery of the standard and i.C4TTC at 30 g/t.
Figure 4 shows the regression line for collector A at 45 g/t.
Figure 5 shows ths regression line for collector A at 30 g/-t.
Figure 6 shows the regression line for collec-tor B at 30 g/t.
Figure 7 shows the regression line for collector ~ at 45 g/t.
Figure 8 shows the regression line for collector E at 10 g/t.
Figure 9 shows the regression line for collector E at 20 g/t.
Figure 10 shows the regression line for collector E at 30 g/t.
Figure 11 shows the regression line for collector E a-t 40 g/t.
Figure 12 shows the regression line for collector E at 45 g/t.
Figure 13 shows the time-recovery data for copper USillg iC3TTC.
Figure 14 shows -the time-recovery data for Gangue for iC3TTC.
Figure 15 shows the time-recovery data for copper using iC4DTP.
Figure 16 shows the time-recovery data for Gangue using iC4DTP.
Figure 17 shows the -time-recovery data for copper using nC4TTC.
Figure 18 shows the time-recovery data for Gangue using nC4TTC.
Figure 19 shows the time-recovery data for copper using PAX.
Figure 20 shows the time-recovery data for Gangue using PAX.
Figure 21 shows the time-recovery data for copper using iC3TTC ancl iC4DTP.
Figure 22 shows the time-recovery data for Gangue using :LC3TTC and iC4DTP.
Figure 23 shows -the time-recovery data for copper using iC3TTC and PAX.
Figure 24 shows the time-recovery data for Gangue using iC3TTC and P~X .
Figure 25 shows the time-recovery data for copper using :LC3TTC and nC4TTC.
Figure 26 shows -the time-recovery data for Gangue USiDg iC3TTC and nC4TTC.
Figure 27 shows the time-recovery data for copper using nC4TTC and iC4DTP.
~' .
~9~ 32423CA
Figllre 28 shows -the -time-recovery data for Gangue uæing nC4TTC
and iC4DTP.
Figure 29 shows the time-recovery data for Ganglle l1s~ng nC4'r'rC nn(l P~X .
Figure 30 shows the time-recovery data Eor copper usLng nC4TTC ancl P~X .
Figure 31 shows the time-recovery da-ta for copper using iC3TTC and iC4DTP and PAX.
Figure 32 shows -the time-recovery data for Gangue using iC3'rTC and iC4DTP and PAX.
Figure 33 shows the time-recovery da-ta for copper using iC3TTC and nC4TTC and PAX.
Figure 34 shows the -time-recovery data for Gangue using iC3TTC and nC4TTC and PAX.
Figure 35 shows the time-recovery data for copper using iC3TTC and nC4TTC and iC4DTP.
Figure 36 shows the time-recovery data for Gangue using iC3TTC and nC4TTC and iC4DTP.
Figure 37 shows the time-recovery data for copper using nC4TTC and iC4DTP and PAX.
Figure 38 shows -the time-recovery da-ta for Gangue using nC4TTC ancl iC4DTP and PAX.
Figure 39 shows the comparison of time-recovery data for iC3TTC and nC4TTC.
Figure 40 shows the comparison of time-recovery data for iC3TTC and iC4DTP.
Figure 41 shows the comparison of time-recovery data for iC3TTC and PAX.
Figure 42 shows the comparison of time-recovery da-ta for nC4TTC and iC4DTP.
Figure 43 shows the comparison of time-recovery data for nC4TTC and PAX.
Figure 44 shows the comparison of time-recovery dnta for iC3TTC and nC4TTC and iC4DTP.
Figure 45 shows the comparison of time-recovery da-ta for iC3TTC and PAX and iC4DTP.
Figure 46 shows -the comparison of time-recoVery data for nC4TTC and iC4DTP and PAX.
~2~9~7 Figure 47 shows the comparison of -time-recovery dat~ for iC3TTC and nC4TTC and P~X.
Figure 48 shows the R and K value for compos:lt:Lons ranging frt)m tO0% iG4TTC and 0% lC4DTP to 100% lC4DTP and 0% lC4TTC.
The inventlon will now be described further by way of the following non-limitillg examples:
EX~MPLE 1 In a typical laboratory scale froth flotation process 1640 grams of Merensky Reef ore were mllled at a mlll feed speclflc gravlty of 2.0 for 34 mlnu-tes to obtain a milled feed -to flotation containing 55% minus 200 mesh.
The milled ore was added to a 4.5 lltre batch flotatlon cell and adjus-ted to a pump speclflc gravlty of 1.25. The rotor speed of the flotation machlne was adjusted to 1800 r.p.m. and 5 ml of a copper sulphate solution (100 g/t) and 10 ml of dextrin (starch) solutlon (80 g/t) were added and condltloned wlth the pulp for one minute.
In the reference float 5 ml of sodium lsobutyl xanthate solution (40-50 g/t~ and 5 ml of aeropromotor 3477 solutlon (80-100 g/t) were used as the collector standard.
25 Grams per ton solid feed Dowfroth 200 were added and the pulp condl-tioned for half a minute. The alr to the flotation machlne was then turned on as follows:
Concentrate l: for three minutes after the froth bed developed;
Concentrate 2: for nine minu-tes.
The above procedure was repeated replaclng the sodlum lsobutyl xanthate and fleropromotor 3477 (di-isobutyl dithiophosphate) collector sys-tem with different types of trlthlocarbonates according to the lnventlon at different dosages. The results are reflected in Table I on page 8.
~2~
H ~ O O ~ ~-1 O r~
~ o c~) ~ ~t c~l n ~
~ ~ O r~ ~ O ~ ~ ~
r~ O ~1 C`~ C`~ C~ C~i ~
Z C~ o cr~ u~ C~l ~ O u~ O
0~ O ~ ~ ~0 ~ ~ ~
h ~ ~ O ~ 00 ~ ~ ~ ~ P~
p:; ~ o ~1 co ul ~ o ~ R
:~ ~ C~ ,~ ~ ~ ~ ~) ~i ~Y) O
~! z; o ~) ~1 C~ J~ o u~ ~ ~O ~ L~ c~ R
¢ ¢ ~ CO CO ~o oo ~ ~
IY ~ o ~Q oo U~ ~_1`J ~ O
~ Z O r-l ~ ~ C~l tO ~
~: 1_1 ~ O ,_1 r~ C~ C~l~1 r~
E~ r~ o oo ~1 C~l ~ o c~ r~
~ ~ ~i ~ c~ ~ c~c~l ~ g k~ P~ * ii' OCl~ ~ u~ r~ ?
O O O r~ O ~ O h ~1~ O Pl~
¢ U~ O O O O O O ~
o r~ ~-1 u~ ~ u~~ u~ W
a~ c~ ,~ ~ ~ a) R O R o R O R ~1 ,R ~ ~~ R ~ u w ::1 .q ::) .CI ~~ ~ e ~ ~ ,q ~ ~ h o O h O ~ O 1~1 0 Il) O h O C) O h O h O
rn ~ ~ ~ rn J rn ~ rn ern ~ U~ eu~ ~ rn ~ *
:3.2~77~7 32423CA
From Table I it wlll be noted -that by employLng the compouncls according to the inven-tion, both the yield, grade, nnd tailings grade of the Pt-metal recovery improved compared to those obta:Lrled wLth the stflndard .
In a typical pilot plant scale Ero-th fLo-tation process, 4 kilograms of Nerensky Reef ore wi-tb the desired particle size dis-tribu-tion were pulped in an eight liter D12 Denver flotation machine at 1500 r.p.m. and at na-tural pH. Copper sulphate was added at 100 g/t and the system allowed to condition for five minutes. Thereafter a collector according to the invention was added in the form oE a one percent solution and dextrin. A -talc depressant was added a-t 80 g/t and a further five minutes were allowed for conditioning. The frother, a cresylic acid, was added one minute before aeration. Aera-tion at a rate of 1.5 cell volumes per minute was initiated and the first concentrate was continuously collected during ths first four-and-a-half minutes.
Thereafter two further concentrates were collected, respectively for five-and-a-half minutes, and ten minutes. The floats were done in triplicate and the platinum-group metals (PGM) were analy~ed for in the concentrates tails and feed of the flotation cell. Copper and nickel analyses served as controls for the PGM's analyses.
A con-trol set of experiments was also carried out using a standard collector suit which consisted of Aero 3477 promotor and sodium isopropyl xan-thate (hereafter SiPX).
In the first of our experiments the standard collector suit used contained Aero 3477 promotor and SiPX in a ratio of 70 to 30 percent, which is the optimum ratio, at a combined dosage of 140 g/-t.
The resul-ts of this experiment are reflected in Figure 1 of the drawings attached here-to by the line labeled "standard". ~ second set of experiments were performed identlcally to the first set, except that the collector in this instance was sodium isopropyl tri-thiocarbonate at a dosage of ~5 g/t. From -the results, which are reflec-ted in the aforesaid Figure 1 by the line labeled "TTC", it w:Lll be noted that an improvement in the order of a-t least two percent in the recovery of PGM's was obtaLned.
32423C~
In a third set of identical experiments a pur:Lf:Led vers:Lon o:E
sodium isopropyl tri-thiocarbona-te was substltutecl for the standard Acro 3477/SiPX combinatlon at A dosage of 30 g/t. T~e result~: are :refLected in Figure 2 of the draw:Lngs attached hereto. Again fl s:Lgniflcant :Lmprovemen-t in the order of at least two percent l:n the recovery of PGM's was reallzed. It was also found ln thls and i.n the prcvious instance that the grade of the concentratcs fllso :Lmproved, partly at least because less talc was recovered.
In a fourth set of ideDtical exper:iments, -the collector utllized comprised sodium isobu-tyl trlthiocarbonate at a dosage of 30 g/t and the results obtained are reflected in Figure 3 of the drawings a-ttached hereto.
The results of further identical experiments which were carried out w;.th the aforesaid collectors at different concentrations (and/or p~lrities) and with other collectors falling within the scope of the invention, are reflec-ted in Figures 4 to 12 of the drawings a-ttached hereto. In these figures the three legends used for the collectors denote the following:
A = sodium isopropyl trithiocarbonate, B = sodium ben~yl trithiocarbonate, and E = sodium n-butyl trithiocarbonate.
Applicant has also found that, apart from the sodium salts, the potassium and ammonium salts of the aforesaid compounds also give good results as promotors and/or collectors, Eor the pla-tinum-group metals.
It ~li].l be appreciated that there are many variations i.n detail possible with promotors and/or collectors according -to the invention and their use in -the recovery of PGM which do not fall outside the scope of the appended claims.
Recovery of a PGM
Approximately 1.5 kg of Merensky Reef ore were milled at a mill feed specific gravity of 2.0 for thir-ty-four minu-tes to obtain a milled feed to flotation containing 55% minus 200 mesh.
32423C~
11 æ;~
The mi]led ora WflS added to a 4.5 li.tre batch Elotat:Lon c~ll and adjusted to a pump specific gravity oE 1.25. The rotor speecl of the flotation machine was adJusted to 1800 r.p.m. and 5 ml of a copper sulphate solution (100 g/t) and 10 ml of dextr:Ln (starch) solut:Lon (80 g/-t) were added and cond:Ltloned wl-th -the pu1p for one mi.nllte.
In the reference floa-t 5 ml of sodium isobutyl xanthate solution (40 g/t) and 6 ml of sodium dithiophosphate solu-tion (30 g/t) were used as the collector s-tandard.
25 Grams per -ton solid feed Dowfroth 200 were added and the pulp conditioned for thirty minutes. The air to the ilotation machine was then turned on as follows:
Concentrate 1: for three minutes after the froth bed developed;
Concentrate 2: for nine minutes.
The above procedure was repeated replacing the aforesaid standard collector system with differen-t TTC collector combinations according to -the invention at different dosages. The results are reflected in Table II on page 12.
~,~
~29~1~7 OC'l ~ ~1 ~D O ~`1 Z O~C) I~ C`l ~ 00 ~
C~ r~ r; r~i C~i ~ r1 ~1 H
X ~ o ~ `D O U~ I~ I~
~ ~ O ~ ~ I~ ~ O~ `D
E-l r1r; r~ O O O O
i--~
C`~ C~l C`l ~ ~ ~ ~ ~ ~ ~ C`l C`l C~ ~ o~
E~ O
~ ~:4 ~1 d ~ P~ ~4 K ~ o o 3 ~ 1:~1 C~ ~ ~ .,U ~ ~ C~L~ C~
~ ~q O E~ E~ E~ ~ ~ E~ ~ O ~1 ~ O ~ O
;~ ~1 ~ ~ ~ ~ ~) O Pl h C.) O rl C~ 1 ~ ' rl ~ ~rl ~rl rl ~rl e ~,1 e ~e E3 ~ ~1 e ~
e e 6 6 e e e e e e e 6 6 6 e 6 e ,,q.,P ,,~ ~ ~ ,,~ ,,~ ,,~
~o ~o ~o ~o ~o ~o ~o ~o ~o ~ ~o ~o ~o ~o ~o ~o ~o u~u~ ~ u~cacn u~u~ u~ c~ ~
r ~ ~ ~ U~
~29~7~7 32423CA
In Table II the dosages referred to flre calculatsd on the bas:is of the solicl and/or 100% active ingred:Lent whlle, ~or reasons of confidentiality~ the PGM values are sxprsssed relfltive to the results obtained with the aforesaid standard.
From Table II lt wlll be clear that due to a very sign:lticnnt amount oE synergism betwoen the constituents of the various mixtures dsscribed above, -the collec-tor combinations according to the invention have much better flota-tion propsr-ties in respect of -the recovery oE PGM
than any of the hitherto known collectors.
Recoverv of copper The following thirteen collectors or collec-tor combinations were in turn used to recover copper from a PMC-ore:
1. iC3TTC, 2. Na diiso-CI,DTP, 3. nC4TTC, 4. PAX, 5. iC3TTC -~ Na diiso-C4DTP, 6. iC3TTC -~ PAX, 7. iC3TTC -~ nC4TTC, 8. nC4TTC + Na diiso-DTP, 9. nC4TTC + PAX, 10. iC3TTC + Na diiso-DTP + PAX, 11. iC 3 TTC + nCI,TTC + PAX, 12. iC3TTC + nC4TTC + Na diiso-DTP, 13. nC4TTC + Na diiso-DTP + PA~.
The PMC-ore was ground -to an average size of 40 - 75 microns.
1 Kg of ths ore was weighed into a flotation cell, and the cell filled with water to a predetermined level. While -the pulp was being agitated, the collector or collector-mixture was added and a five minute conditioning -time allowed. The amount oE collector used, was 125 ~mole per kilogram of ore. In -the case of collector-mixtures, 1:1 or 1:1:1 molar ratio of the 125 ~mol/kg dosags was admlnistered. These molar ratios were determined taking the molecular weight and the activity of the specific collector in-to account.
;
77~
~ fter :Eour m:Lnutes of -the mentioned condit:Lorl:Lng t:Lme, 25 ~:l oE the frother was added. ~fter ftve mlnutes o:E cond:Ltion:Lng time, the flir supply to the flotation cell was openecl, care belng take:n to keep the fluid level constAn-t. Thi.s was necessary because the vollJme of the whole fluid sys-tem (pulp ~ froth) decraases as concentrates are being co:llected. Concentra-tes were collec-ted a-t the following cumulative time intervflls: 1~ 2, 4, 6 and 9 minutes.
The concentrates and the tailings -that werc left in -the oatch flota-tion cell were filtered with the aid of Buchner funnels. The filter-cakes were the:n dried in an oven, the weight of each filter-cake measured, and the copper contents of each sample determined.
The results of the aforesaid thirteen experimen-ts were used to de-termine the R and K values of the so called Klimpel model which can mathematically be expressed as r = R r 1 - - (1 - exp (Kt)) L Kt where K = the first order rate constant of the to-tal mass (valua le +
gangue) collected;
R = the ultimate equilibrium recovery after a long -time of flotation;
r = the accumulative recovery at time t.
In a modified model, K was taken as the average slope of the release curve over the first half a minute of the flotation, and R as the value of r after thirty minutes of flotation.
The modified results of -the aforesald thirteen experiments insofar as the copper values in the concen-trate and gangue respectively are concerned, are reflected in the graphs constituting Figures 13 to 38 attached hereto.
The graphs constituting Figures 3~ to 47 at-tached hereto clearly illus-trate the synergistic effect obtained with various combinations of collectors according to the invention when employed in the recovery of copper.
Further combinations of collectors according -to the in-ven-tion which were also investigated under the same conditions as above in the recovery of copper, and which all gave good results, were:
AND OTHER ~ETAL VALUABLES
This invention relates to the benefication of metal-liferous ores, particular ores containing metals of the plat-inum-group, i.e. platinum, rhodium, palladium, osmium, irid ium and ruthenium. Such ores are, for example, found in the Merensky and other related reefs where the metals occur in either the free or combined form, in copper, nickel, iron and chrome ores, and in minerals such as pentlandite, pyrohtite, chalcopyrite, troilite and chromite.
It is known to employ the soluble salts of mercaptans, dithiocarbonates, and dithiophosphates as promotors and/or collectors in the froth flotation of the aforementioned ores.
It is also known to utilize these substances in combination with one another to improve the recovery of platinum-group metals in such processes.
These known3 so called thio-promotors and/or collec-tors, are characterized by the fact that they contain either one or two sulphur atoms on one of their terminal carbon at-oms.
Applicant has now found other thio-compounds which are even more selective froth flotation promotors and/or collec-tors for the platinum-group metals, individually and/or in groups thereof than what the case is with any of the afore-said known thio-compounds.
According to the invention a froth flotation promotor and/or collector for the recovery of metals from the platinum-group is provided which includes a trithiocarbonate (other than a dialkyl or ethoxy ester derivative thereof) and/or an alkyl derivative thereof having 2 to 16 carbon atoms and/or the ammonium or alkali metal salts of any of these compounds.
Applicant has found these trithiocarbonates or phos-phates, when used as independent promotors and/or collectors in the flotation of the aforementioned ores, to give much bet-ter recovery of the platinum-grouP metals than what is pos~
sible with the known dithiocarbonates~ dithiophosphates, or ~r 7~
mercaptans used either individually or in combination with one another.
Not only is the yield of the platinum-group metals higher and the grade better when using the compounds of the invention, but it is also possible to float lower mass con-centrates while achieving tailings with lower metal concen-trations.
Compounds which the Applicant has found particularly useful in this regard are:
sodium ethyl trithiocarbonate, sodium n-propyl trithiocarbonate, sodium isopropyl trithiocarbonate, sodium n-butyl trithiocarbonate, sodium isobutyl trithiocarbonate, sodium sec-butyl trithiocarbonate~
sodium tert-butyl trithiocarbonate, sodium n-pentyl trithiocarbonate, sodium isopentyl trithiocarbonate, and sodium benzyl trithiocarbonate.
Of these compounds the one which the Applicant found most useful was the sodium salt of isopropyl trithiocarbo~
nate.
Applicant has also found a combination of the compounds of this invention and the mercaptans to give good results as a froth flotation collector and~or promotor in the recovery of metals of the platinum-group.
The invention also includes within its scope a method for the recovery of platinum-group metals by means of a froth flotation process in which one or more of the promotors and/
or collectors of the invention are utilized.
This invention further relates to the recovery of metal valuables, and to substances suitable for use in such recovery.
More particularly this invention relates to the froth flotation of metalliferous ores, such as those containing metals of the platinum-group as well as other sulphide ores, particularly copper bearing sulphide ores.
Ores containing metals of the platinum-group are, for _ 3 _ example, found in Southern Arica in the Merensky and other related reefs, in which the metals occur in either the free or combined form; in copper, nickel, iron, and chrome ores;
and in minerals such as pentlandite, pyrohtite, chalcopyrite, troilite and chromite. The metals of the platinum-yroup, which will in the rest of this specification be referred to as the PGM, include platinum, rhodium, palladium, osmium, iridium and ruthenium.
One copper bearing ore of the aforesaid type is, for example, that found in the Bushveld Igneous Complex at Phala-borwa in the Northern Transvaal in the Republic of South Af-rica. This ore, which will hereafter be referred to as the PMC-ore, usually comprises a mixture of the minerals chalco-pyrite (60%); bornite (28%); cubanite (6~); and valleriite (6%). Such an ore body usually contains between 0.2 and 10.0%
copper, although the lower copper level can in some instances even be less.
It is known to recover metal valuables of the afore-said kinds by means of a froth flotation process, and amongst the froth flotation agents which have been used. In this re-gard, are certain of the so called dithiocarbonates (hereaf-ter referred to as DTC), such as, for example, potassium amyl xanthate (hereafter referred to as PAX); certain of the so called dithiophosphates (hereafter referred to as DTP), such as, for example, di-isobutyl dithiophosphate (hereafter re-ferred to as di-iC4DTP); mercaptobenzothiazole (hereafter re-ferred to as MBT); and certain of the mercaptans.
Applicant itself has also found that certain trithio-carbonates (hereafter referred to as TTC) can be used as froth flotation collectors for metal valuables of the aforesaid kinds.
As a result of the constant depletion of the previously existing very rich ore bodies, the grade of ore which has to be worked gets lower all the time, and there is accordingly a continued search for better collectors. It is an object of this invention to provide such a collector.
Accordin~ to a further feature of the invention a froth 2~ 7~
flotation collector for the recovery of a metal valuable co~n-prises a combination of at least two diEferent compounds of which one is a mono al`kyl TTC in which the alkyl groups can be linear or branched and can have 2 to 16 carbon atoms, andJ
or the ammonium and/or alkali metal salts of any of those com-pounds and the other compound is at least one compound of the group of compounds including a TTC; DTC; DTP; mercaptan (ex-cept where the metal valuable is a PGM); the alkyl derivatives of any of the aforesaid compounds in which the alkyl group can be linear or branched and can have 2 to 16 carbon atoms; MBT
(except where the metal valuable is copper or iron); an am-monium and/or alkali metal salt of any of the aforesaid com-pounds, the compounds of the combination being added to the reaction medium either as a blend or separately.
Applicant has found that when such a combination is em-ployed as a collector in the recovery of metal valuables of the aforesaid kinds, an unexpected synergistic effect results and the overall collecting properties, including the rate of collection, are better than the combined properties of the individual compounds of the combination.
Further according to the invention at least one of the compounds of the combination is iC3TTC (i.e~ isopropyl TTC~.
Further according to one embodiment of the invention a froth flotation collector combination for the recovery of a PGM includes an iC3TTC and iC4TTC; or an iC3TTC and/or iC4TTC
and at least one of the compounds iC4DTP and MBT.
Further according to another embodiment of the inven-tion a froth flotation collector combination for the recovery of copper includes at least two compounds of the group of com-pounds including iC3TTC, nC4TTC, iC4DTP and PAX.
Still further according to this embodiment of the in-vention the collector comprises iC4DTP and at least one of the compounds iC3TTC, nC4TTC and PAX.
Still further according to this embodiment of the in-vention the collector comprises iC4DTP, nC4TTC and PAX, pre-ferably in equimolecular quantities.
The invention also includes within its scope a method ~ ~ 3Z423CA
Eor the recovery oE metAl vAluAbles particularly plat:Lnum, or copper from a copper containLng sulpIlide ore, employing a collec-tor accord:Ing to the invention.
~ OF T~IE DRAWINGS
F:lgure 1 shows PGM recove,ry of the stanclard :Ln iC3TTC a-t 45 g/t.
F:Lgure 2 shows PGM recovery of -the standard in iC3TTC at 30 g/t.
Figure 3 shows PGM recovery of the standard and i.C4TTC at 30 g/t.
Figure 4 shows the regression line for collector A at 45 g/t.
Figure 5 shows ths regression line for collector A at 30 g/-t.
Figure 6 shows the regression line for collec-tor B at 30 g/t.
Figure 7 shows the regression line for collector ~ at 45 g/t.
Figure 8 shows the regression line for collector E at 10 g/t.
Figure 9 shows the regression line for collector E at 20 g/t.
Figure 10 shows the regression line for collector E at 30 g/t.
Figure 11 shows the regression line for collector E a-t 40 g/t.
Figure 12 shows the regression line for collector E at 45 g/t.
Figure 13 shows the time-recovery data for copper USillg iC3TTC.
Figure 14 shows -the time-recovery data for Gangue for iC3TTC.
Figure 15 shows the time-recovery data for copper using iC4DTP.
Figure 16 shows the time-recovery data for Gangue using iC4DTP.
Figure 17 shows the -time-recovery data for copper using nC4TTC.
Figure 18 shows the time-recovery data for Gangue using nC4TTC.
Figure 19 shows the time-recovery data for copper using PAX.
Figure 20 shows the time-recovery data for Gangue using PAX.
Figure 21 shows the time-recovery data for copper using iC3TTC ancl iC4DTP.
Figure 22 shows the time-recovery data for Gangue using :LC3TTC and iC4DTP.
Figure 23 shows -the time-recovery data for copper using iC3TTC and PAX.
Figure 24 shows the time-recovery data for Gangue using iC3TTC and P~X .
Figure 25 shows the time-recovery data for copper using :LC3TTC and nC4TTC.
Figure 26 shows -the time-recovery data for Gangue USiDg iC3TTC and nC4TTC.
Figure 27 shows the time-recovery data for copper using nC4TTC and iC4DTP.
~' .
~9~ 32423CA
Figllre 28 shows -the -time-recovery data for Gangue uæing nC4TTC
and iC4DTP.
Figure 29 shows the time-recovery data for Ganglle l1s~ng nC4'r'rC nn(l P~X .
Figure 30 shows the time-recovery data Eor copper usLng nC4TTC ancl P~X .
Figure 31 shows the time-recovery da-ta for copper using iC3TTC and iC4DTP and PAX.
Figure 32 shows -the time-recovery data for Gangue using iC3'rTC and iC4DTP and PAX.
Figure 33 shows the time-recovery da-ta for copper using iC3TTC and nC4TTC and PAX.
Figure 34 shows the -time-recovery data for Gangue using iC3TTC and nC4TTC and PAX.
Figure 35 shows the time-recovery data for copper using iC3TTC and nC4TTC and iC4DTP.
Figure 36 shows the time-recovery data for Gangue using iC3TTC and nC4TTC and iC4DTP.
Figure 37 shows the time-recovery data for copper using nC4TTC and iC4DTP and PAX.
Figure 38 shows -the time-recovery da-ta for Gangue using nC4TTC ancl iC4DTP and PAX.
Figure 39 shows the comparison of time-recovery data for iC3TTC and nC4TTC.
Figure 40 shows the comparison of time-recovery data for iC3TTC and iC4DTP.
Figure 41 shows the comparison of time-recovery data for iC3TTC and PAX.
Figure 42 shows the comparison of time-recovery da-ta for nC4TTC and iC4DTP.
Figure 43 shows the comparison of time-recovery data for nC4TTC and PAX.
Figure 44 shows the comparison of time-recovery dnta for iC3TTC and nC4TTC and iC4DTP.
Figure 45 shows the comparison of time-recovery da-ta for iC3TTC and PAX and iC4DTP.
Figure 46 shows -the comparison of time-recoVery data for nC4TTC and iC4DTP and PAX.
~2~9~7 Figure 47 shows the comparison of -time-recovery dat~ for iC3TTC and nC4TTC and P~X.
Figure 48 shows the R and K value for compos:lt:Lons ranging frt)m tO0% iG4TTC and 0% lC4DTP to 100% lC4DTP and 0% lC4TTC.
The inventlon will now be described further by way of the following non-limitillg examples:
EX~MPLE 1 In a typical laboratory scale froth flotation process 1640 grams of Merensky Reef ore were mllled at a mlll feed speclflc gravlty of 2.0 for 34 mlnu-tes to obtain a milled feed -to flotation containing 55% minus 200 mesh.
The milled ore was added to a 4.5 lltre batch flotatlon cell and adjus-ted to a pump speclflc gravlty of 1.25. The rotor speed of the flotation machlne was adjusted to 1800 r.p.m. and 5 ml of a copper sulphate solution (100 g/t) and 10 ml of dextrin (starch) solutlon (80 g/t) were added and condltloned wlth the pulp for one minute.
In the reference float 5 ml of sodium lsobutyl xanthate solution (40-50 g/t~ and 5 ml of aeropromotor 3477 solutlon (80-100 g/t) were used as the collector standard.
25 Grams per ton solid feed Dowfroth 200 were added and the pulp condl-tioned for half a minute. The alr to the flotation machlne was then turned on as follows:
Concentrate l: for three minutes after the froth bed developed;
Concentrate 2: for nine minu-tes.
The above procedure was repeated replaclng the sodlum lsobutyl xanthate and fleropromotor 3477 (di-isobutyl dithiophosphate) collector sys-tem with different types of trlthlocarbonates according to the lnventlon at different dosages. The results are reflected in Table I on page 8.
~2~
H ~ O O ~ ~-1 O r~
~ o c~) ~ ~t c~l n ~
~ ~ O r~ ~ O ~ ~ ~
r~ O ~1 C`~ C`~ C~ C~i ~
Z C~ o cr~ u~ C~l ~ O u~ O
0~ O ~ ~ ~0 ~ ~ ~
h ~ ~ O ~ 00 ~ ~ ~ ~ P~
p:; ~ o ~1 co ul ~ o ~ R
:~ ~ C~ ,~ ~ ~ ~ ~) ~i ~Y) O
~! z; o ~) ~1 C~ J~ o u~ ~ ~O ~ L~ c~ R
¢ ¢ ~ CO CO ~o oo ~ ~
IY ~ o ~Q oo U~ ~_1`J ~ O
~ Z O r-l ~ ~ C~l tO ~
~: 1_1 ~ O ,_1 r~ C~ C~l~1 r~
E~ r~ o oo ~1 C~l ~ o c~ r~
~ ~ ~i ~ c~ ~ c~c~l ~ g k~ P~ * ii' OCl~ ~ u~ r~ ?
O O O r~ O ~ O h ~1~ O Pl~
¢ U~ O O O O O O ~
o r~ ~-1 u~ ~ u~~ u~ W
a~ c~ ,~ ~ ~ a) R O R o R O R ~1 ,R ~ ~~ R ~ u w ::1 .q ::) .CI ~~ ~ e ~ ~ ,q ~ ~ h o O h O ~ O 1~1 0 Il) O h O C) O h O h O
rn ~ ~ ~ rn J rn ~ rn ern ~ U~ eu~ ~ rn ~ *
:3.2~77~7 32423CA
From Table I it wlll be noted -that by employLng the compouncls according to the inven-tion, both the yield, grade, nnd tailings grade of the Pt-metal recovery improved compared to those obta:Lrled wLth the stflndard .
In a typical pilot plant scale Ero-th fLo-tation process, 4 kilograms of Nerensky Reef ore wi-tb the desired particle size dis-tribu-tion were pulped in an eight liter D12 Denver flotation machine at 1500 r.p.m. and at na-tural pH. Copper sulphate was added at 100 g/t and the system allowed to condition for five minutes. Thereafter a collector according to the invention was added in the form oE a one percent solution and dextrin. A -talc depressant was added a-t 80 g/t and a further five minutes were allowed for conditioning. The frother, a cresylic acid, was added one minute before aeration. Aera-tion at a rate of 1.5 cell volumes per minute was initiated and the first concentrate was continuously collected during ths first four-and-a-half minutes.
Thereafter two further concentrates were collected, respectively for five-and-a-half minutes, and ten minutes. The floats were done in triplicate and the platinum-group metals (PGM) were analy~ed for in the concentrates tails and feed of the flotation cell. Copper and nickel analyses served as controls for the PGM's analyses.
A con-trol set of experiments was also carried out using a standard collector suit which consisted of Aero 3477 promotor and sodium isopropyl xan-thate (hereafter SiPX).
In the first of our experiments the standard collector suit used contained Aero 3477 promotor and SiPX in a ratio of 70 to 30 percent, which is the optimum ratio, at a combined dosage of 140 g/-t.
The resul-ts of this experiment are reflected in Figure 1 of the drawings attached here-to by the line labeled "standard". ~ second set of experiments were performed identlcally to the first set, except that the collector in this instance was sodium isopropyl tri-thiocarbonate at a dosage of ~5 g/t. From -the results, which are reflec-ted in the aforesaid Figure 1 by the line labeled "TTC", it w:Lll be noted that an improvement in the order of a-t least two percent in the recovery of PGM's was obtaLned.
32423C~
In a third set of identical experiments a pur:Lf:Led vers:Lon o:E
sodium isopropyl tri-thiocarbona-te was substltutecl for the standard Acro 3477/SiPX combinatlon at A dosage of 30 g/t. T~e result~: are :refLected in Figure 2 of the draw:Lngs attached hereto. Again fl s:Lgniflcant :Lmprovemen-t in the order of at least two percent l:n the recovery of PGM's was reallzed. It was also found ln thls and i.n the prcvious instance that the grade of the concentratcs fllso :Lmproved, partly at least because less talc was recovered.
In a fourth set of ideDtical exper:iments, -the collector utllized comprised sodium isobu-tyl trlthiocarbonate at a dosage of 30 g/t and the results obtained are reflected in Figure 3 of the drawings a-ttached hereto.
The results of further identical experiments which were carried out w;.th the aforesaid collectors at different concentrations (and/or p~lrities) and with other collectors falling within the scope of the invention, are reflec-ted in Figures 4 to 12 of the drawings a-ttached hereto. In these figures the three legends used for the collectors denote the following:
A = sodium isopropyl trithiocarbonate, B = sodium ben~yl trithiocarbonate, and E = sodium n-butyl trithiocarbonate.
Applicant has also found that, apart from the sodium salts, the potassium and ammonium salts of the aforesaid compounds also give good results as promotors and/or collectors, Eor the pla-tinum-group metals.
It ~li].l be appreciated that there are many variations i.n detail possible with promotors and/or collectors according -to the invention and their use in -the recovery of PGM which do not fall outside the scope of the appended claims.
Recovery of a PGM
Approximately 1.5 kg of Merensky Reef ore were milled at a mill feed specific gravity of 2.0 for thir-ty-four minu-tes to obtain a milled feed to flotation containing 55% minus 200 mesh.
32423C~
11 æ;~
The mi]led ora WflS added to a 4.5 li.tre batch Elotat:Lon c~ll and adjusted to a pump specific gravity oE 1.25. The rotor speecl of the flotation machine was adJusted to 1800 r.p.m. and 5 ml of a copper sulphate solution (100 g/t) and 10 ml of dextr:Ln (starch) solut:Lon (80 g/-t) were added and cond:Ltloned wl-th -the pu1p for one mi.nllte.
In the reference floa-t 5 ml of sodium isobutyl xanthate solution (40 g/t) and 6 ml of sodium dithiophosphate solu-tion (30 g/t) were used as the collector s-tandard.
25 Grams per -ton solid feed Dowfroth 200 were added and the pulp conditioned for thirty minutes. The air to the ilotation machine was then turned on as follows:
Concentrate 1: for three minutes after the froth bed developed;
Concentrate 2: for nine minutes.
The above procedure was repeated replacing the aforesaid standard collector system with differen-t TTC collector combinations according to -the invention at different dosages. The results are reflected in Table II on page 12.
~,~
~29~1~7 OC'l ~ ~1 ~D O ~`1 Z O~C) I~ C`l ~ 00 ~
C~ r~ r; r~i C~i ~ r1 ~1 H
X ~ o ~ `D O U~ I~ I~
~ ~ O ~ ~ I~ ~ O~ `D
E-l r1r; r~ O O O O
i--~
C`~ C~l C`l ~ ~ ~ ~ ~ ~ ~ C`l C`l C~ ~ o~
E~ O
~ ~:4 ~1 d ~ P~ ~4 K ~ o o 3 ~ 1:~1 C~ ~ ~ .,U ~ ~ C~L~ C~
~ ~q O E~ E~ E~ ~ ~ E~ ~ O ~1 ~ O ~ O
;~ ~1 ~ ~ ~ ~ ~) O Pl h C.) O rl C~ 1 ~ ' rl ~ ~rl ~rl rl ~rl e ~,1 e ~e E3 ~ ~1 e ~
e e 6 6 e e e e e e e 6 6 6 e 6 e ,,q.,P ,,~ ~ ~ ,,~ ,,~ ,,~
~o ~o ~o ~o ~o ~o ~o ~o ~o ~ ~o ~o ~o ~o ~o ~o ~o u~u~ ~ u~cacn u~u~ u~ c~ ~
r ~ ~ ~ U~
~29~7~7 32423CA
In Table II the dosages referred to flre calculatsd on the bas:is of the solicl and/or 100% active ingred:Lent whlle, ~or reasons of confidentiality~ the PGM values are sxprsssed relfltive to the results obtained with the aforesaid standard.
From Table II lt wlll be clear that due to a very sign:lticnnt amount oE synergism betwoen the constituents of the various mixtures dsscribed above, -the collec-tor combinations according to the invention have much better flota-tion propsr-ties in respect of -the recovery oE PGM
than any of the hitherto known collectors.
Recoverv of copper The following thirteen collectors or collec-tor combinations were in turn used to recover copper from a PMC-ore:
1. iC3TTC, 2. Na diiso-CI,DTP, 3. nC4TTC, 4. PAX, 5. iC3TTC -~ Na diiso-C4DTP, 6. iC3TTC -~ PAX, 7. iC3TTC -~ nC4TTC, 8. nC4TTC + Na diiso-DTP, 9. nC4TTC + PAX, 10. iC3TTC + Na diiso-DTP + PAX, 11. iC 3 TTC + nCI,TTC + PAX, 12. iC3TTC + nC4TTC + Na diiso-DTP, 13. nC4TTC + Na diiso-DTP + PA~.
The PMC-ore was ground -to an average size of 40 - 75 microns.
1 Kg of ths ore was weighed into a flotation cell, and the cell filled with water to a predetermined level. While -the pulp was being agitated, the collector or collector-mixture was added and a five minute conditioning -time allowed. The amount oE collector used, was 125 ~mole per kilogram of ore. In -the case of collector-mixtures, 1:1 or 1:1:1 molar ratio of the 125 ~mol/kg dosags was admlnistered. These molar ratios were determined taking the molecular weight and the activity of the specific collector in-to account.
;
77~
~ fter :Eour m:Lnutes of -the mentioned condit:Lorl:Lng t:Lme, 25 ~:l oE the frother was added. ~fter ftve mlnutes o:E cond:Ltion:Lng time, the flir supply to the flotation cell was openecl, care belng take:n to keep the fluid level constAn-t. Thi.s was necessary because the vollJme of the whole fluid sys-tem (pulp ~ froth) decraases as concentrates are being co:llected. Concentra-tes were collec-ted a-t the following cumulative time intervflls: 1~ 2, 4, 6 and 9 minutes.
The concentrates and the tailings -that werc left in -the oatch flota-tion cell were filtered with the aid of Buchner funnels. The filter-cakes were the:n dried in an oven, the weight of each filter-cake measured, and the copper contents of each sample determined.
The results of the aforesaid thirteen experimen-ts were used to de-termine the R and K values of the so called Klimpel model which can mathematically be expressed as r = R r 1 - - (1 - exp (Kt)) L Kt where K = the first order rate constant of the to-tal mass (valua le +
gangue) collected;
R = the ultimate equilibrium recovery after a long -time of flotation;
r = the accumulative recovery at time t.
In a modified model, K was taken as the average slope of the release curve over the first half a minute of the flotation, and R as the value of r after thirty minutes of flotation.
The modified results of -the aforesald thirteen experiments insofar as the copper values in the concen-trate and gangue respectively are concerned, are reflected in the graphs constituting Figures 13 to 38 attached hereto.
The graphs constituting Figures 3~ to 47 at-tached hereto clearly illus-trate the synergistic effect obtained with various combinations of collectors according to the invention when employed in the recovery of copper.
Further combinations of collectors according -to the in-ven-tion which were also investigated under the same conditions as above in the recovery of copper, and which all gave good results, were:
14. nC4TTC + iC4DTP + iC4TTC, ..
~i~
~i~
15. iC4TTC + iC4DTP, 16. iC4TTC ~ nC4TTC + iC3TTC ~ MBT, 17. iC3TTC ~ nC4TTC + M~T, 18. iC3TTC ~ iC4TTC + nC4TTC.
The conclusion whlch Applicant has reached from the results from the aforesaid eighteen experiments is that, except for the comb:ination iC4DTP ~ iC3TTC, iC4DTP, and iC4TTC or nC4TTC, are always present in the combinations having the best collectlng properties. A
further conclusion is that a combination of the various TTC's on their own gives poor results.
Applicant has furthermore found that through an appropria-te selection of the concentration of the individual components of a particular mixture of collectors according to the invention, the rate of collection and amount of valuables recovered may be predetermined.
This phenomenum is illustrated in the graph of Figure 48 attached hereto in which the results obtained with a collector-mixture comprising iC4TTC and iC4DTP in the recovery of copper are reflected.
It will be appreciated that because of the unexpected synergism shown by the collector combinations according to the invention, a collector for the recovery of a metal valuable, particularly PGN and/or copper from a copper sulphide ore, is provided which gives better results insofar as its collecting properties and rate of collection are concerned than any of the hitherto known collectors.
It will be appreciated further that there are no doubt many variations in detail possible with a collector combination according to the invention, and to a froth flotation process involving such a combination, without departing from the scope of the appended claims.
The conclusion whlch Applicant has reached from the results from the aforesaid eighteen experiments is that, except for the comb:ination iC4DTP ~ iC3TTC, iC4DTP, and iC4TTC or nC4TTC, are always present in the combinations having the best collectlng properties. A
further conclusion is that a combination of the various TTC's on their own gives poor results.
Applicant has furthermore found that through an appropria-te selection of the concentration of the individual components of a particular mixture of collectors according to the invention, the rate of collection and amount of valuables recovered may be predetermined.
This phenomenum is illustrated in the graph of Figure 48 attached hereto in which the results obtained with a collector-mixture comprising iC4TTC and iC4DTP in the recovery of copper are reflected.
It will be appreciated that because of the unexpected synergism shown by the collector combinations according to the invention, a collector for the recovery of a metal valuable, particularly PGN and/or copper from a copper sulphide ore, is provided which gives better results insofar as its collecting properties and rate of collection are concerned than any of the hitherto known collectors.
It will be appreciated further that there are no doubt many variations in detail possible with a collector combination according to the invention, and to a froth flotation process involving such a combination, without departing from the scope of the appended claims.
Claims (21)
1. A froth flotation promoter and/or collector for the recovery of metal valuables comprising in combination:
a) at least one mono alkyl trithiocarbonate selected from the group consisting of ethyl trithiocarbonate, n-propyl trithiocarbonate, iso-propyl trithiocarbonate, n-butyl trithiocarbonate, iso-butyl trithiocarbonate, sec-butyl trithiocarbonate, tert-butyl trithiocarbonate, n-pentyl trithiocarbonate, iso-pentyl trithiocarbonate, benzyl trithiocarbonate, the ammonium or alkali metal salt of any of these compounds, and any combination of two or more thereof; and b) at least one froth flotation substance selected from the group consisting of mercaptobenzothiozole, the ammonium or alkali metal salt thereof, and any combination of two or more thereof.
a) at least one mono alkyl trithiocarbonate selected from the group consisting of ethyl trithiocarbonate, n-propyl trithiocarbonate, iso-propyl trithiocarbonate, n-butyl trithiocarbonate, iso-butyl trithiocarbonate, sec-butyl trithiocarbonate, tert-butyl trithiocarbonate, n-pentyl trithiocarbonate, iso-pentyl trithiocarbonate, benzyl trithiocarbonate, the ammonium or alkali metal salt of any of these compounds, and any combination of two or more thereof; and b) at least one froth flotation substance selected from the group consisting of mercaptobenzothiozole, the ammonium or alkali metal salt thereof, and any combination of two or more thereof.
2. The froth flotation promoter and/or collector of claim 1 wherein the mono alkyl trithiocarbonate and the froth flotation sub-stance are present in preferably equimolar amounts.
3. The froth flotation promoter and/or collector of claim 1 wherein at least one mono alkyl trithiocarbonate is selected from the group consisting of iso-propyl trithiocarbonate, n-butyl trithiocarbonate, iso-butyl trithiocarbonate, the ammonium or alkali metal salt of any of these compounds, and any combination of two or more thereof.
4. The froth flotation promoter and/or collector of claim 1 wherein at least one mono alkyl trithiocarbonate is selected from the group consisting of iso-propyl trithiocarbonate, the ammonium or alkali metal salt thereof, and any combination of two or more thereof.
5. The froth flotation promoter and/or collector of claim 1 further comprising at least one froth flotation substance selected from the group consisting of alkyl mercaptan, dithiocarbonate, dithiophosphate, the ammonium or alkali metal salt of any of these compounds, and any combination of two or more thereof.
6. The froth flotation promoter and/or collector of claim 5 wherein at least one alkyl mercaptan is selected from the group consis-ting of n-butyl mercaptan, the ammonium or alkali metal salt thereof, and any combination of two or more thereof.
7. The froth flotation promoter and/or collector of claim 5 wherein at least one dithiocarbonate is an alkyl derivative of dithio-carbonate in which the alkyl group can be linear or branched and can have 2 to 16 carbon atoms.
8. The froth flotation promoter and/or collector of claim 5 wherein at least one dithiocarbonate is selected from the group con-sisting of sodium isopropyl. xanthate, potassium amy1 xanthate, and any combination thereof.
9. The froth flotation promoter and/or collector of claim 5 wherein at least one dithiophosphate is an alkyl derivative of dithio-phosphate in which the alkyl. group can be linear or branched and can have 2 to 16 carbon atoms.
10. The froth flotation promoter and/or collector of claim 5 wherein the dithiophosphate is selected from the group consisting of di-isobutyl dithiophosphate, the ammonium or alkali metal salt thereof, and any combination thereof.
11. A method for the recovery of a platinum-group metal by means of a froth flotation process comprising the following steps:
a) milling ores containing at least one platinum-group metal selected from the group consisting of platinum, rhodium, palladium, osmium, iridium, and ruthenium;
b) mixing the milled ore with water and a froth flotation promoter and/or collector to produce a pulp wherein the froth flotation promoter and/or collector for the recov-ery of platinum-group metals comprises in combination:
(i) at least one mono alkyl. trithiocarbonate selected from the group consisting of ethyl. trithiocarbonate, n-propyl. trithiocarbonate, iso-propyl trithiocarbonate, n-butyl trithiocarbonate, iso-butyl trithiocarbonate, sec-butyl trithiocarbonate, tert-butyl trithiocarbonate, n-pentyl trithiocarbonate, iso-pentyl trithiocarbonate, benzyl trithiocarbonate, the ammonium or alkali metal salt of any of these compounds, and any combination of two or more thereof, and (ii) at least one. froth flotation substance. selected from the group consisting of mercaptobenzothiozole, the ammonium or alkali metal salt thereof, and any combination of two or more thereof;
c) aerating the pulp to produce a froth and tail product;
d) separating the froth and tail product from the pulp;
e) recovering the platinum-group metal from the froth and tail product.
a) milling ores containing at least one platinum-group metal selected from the group consisting of platinum, rhodium, palladium, osmium, iridium, and ruthenium;
b) mixing the milled ore with water and a froth flotation promoter and/or collector to produce a pulp wherein the froth flotation promoter and/or collector for the recov-ery of platinum-group metals comprises in combination:
(i) at least one mono alkyl. trithiocarbonate selected from the group consisting of ethyl. trithiocarbonate, n-propyl. trithiocarbonate, iso-propyl trithiocarbonate, n-butyl trithiocarbonate, iso-butyl trithiocarbonate, sec-butyl trithiocarbonate, tert-butyl trithiocarbonate, n-pentyl trithiocarbonate, iso-pentyl trithiocarbonate, benzyl trithiocarbonate, the ammonium or alkali metal salt of any of these compounds, and any combination of two or more thereof, and (ii) at least one. froth flotation substance. selected from the group consisting of mercaptobenzothiozole, the ammonium or alkali metal salt thereof, and any combination of two or more thereof;
c) aerating the pulp to produce a froth and tail product;
d) separating the froth and tail product from the pulp;
e) recovering the platinum-group metal from the froth and tail product.
12. The method of claim 11 wherein the froth flotation promoter and/or collector comprises the mono alkyl trithiocarbonate and the froth flotation substance in preferably equimolar quantities.
13. The method of claim 11 wherein the froth flotation promoter and/or collector is employed in a quantity in the range from about 30 grams per ton of mineral material to about 150 grams per ton of mineral material.
14. The method of claim 11 wherein at least one mono alkyl trithiocarbonate of the froth flotation promoter and/or collector is selected from the group consisting of iso-propyl trithiocarbonate, n-butyl trithiocarbonate, iso-butyl trithiocarbonate, the ammonium or alkali metal salt of any of these compounds, and any combination of two or more thereof.
15. The method of claim 11 wherein at least one mono alkyl trithiocarbonate of the froth flotation promoter and/or collector is selected from the group consisting of iso-propyl trithiocarbonate, the ammonium or alkali metal salt thereof, and any combination of two or more thereof.
16. The method of claim 11 wherein the froth flotation promoter and/or collector further comprises at least one froth flota-tion substance selected from the group consisting of alkyl mercaptan, dithiocarbonate, dithiophosphate, the ammonium or alkali metal salt of any of these compounds, and any combination of two or more thereof.
17. The method of claim 16 wherein at least one alkyl mercaptan of the froth flotation promoter and/or collector is selected from the group consisting of n-butyl mercaptan, the ammonium or alkali metal salt thereof, and any combination of two or more thereof.
18. The method of claim 16 wherein at least one dithiocar-bonate of the froth flotation promoter and/or collector is an alkyl derivative of dithiocarbonate in which the alkyl group can be linear or branched and can have 2 to 16 carbon atoms.
19. The method of claim 16 wherein at least one dithiocar-bonate of the froth flotation promoter and/or collector is selected from the group consisting of sodium isopropyl xanthate, potassium amyl xanthate, and any combination thereof.
20. The method of claim 16 wherein at least one dithiophos-phate of the froth flotation promoter and/or collector is an alkyl derivative of dithiophosphate in which the alkyl group can be linear or branched and can have 2 to 16 carbon atoms.
21. The method of claim 16 wherein at least one dithiophos-phate of the froth flotation promoter and/or collector is selected from the group consisting of di-isobutyl dithiophosphate, the ammonium or alkali metal salt thereof, and any combination of two or more thereof.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA868826A ZA868826B (en) | 1985-09-06 | 1986-11-21 | Recovery of metal valuables |
| ZA86/8826 | 1986-11-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1299777C true CA1299777C (en) | 1992-04-28 |
Family
ID=25578642
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000540395A Expired - Lifetime CA1299777C (en) | 1986-11-21 | 1987-06-23 | Recovery of platinum-group metals and other metal valuables |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1299777C (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9302273B2 (en) | 2011-10-18 | 2016-04-05 | Cytec Technology Corp. | Froth flotation processes |
| US9302272B2 (en) | 2011-10-18 | 2016-04-05 | Cytec Technology Corp. | Froth flotation processes |
| US9302274B2 (en) | 2011-10-18 | 2016-04-05 | Cytec Technology Corp. | Collector compositions and methods of using the same |
| CN114932010A (en) * | 2022-05-30 | 2022-08-23 | 矿冶科技集团有限公司 | Beneficiation treatment method for platinum-palladium ore containing easy-floating magnesium-rich silicate mineral |
-
1987
- 1987-06-23 CA CA000540395A patent/CA1299777C/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9302273B2 (en) | 2011-10-18 | 2016-04-05 | Cytec Technology Corp. | Froth flotation processes |
| US9302272B2 (en) | 2011-10-18 | 2016-04-05 | Cytec Technology Corp. | Froth flotation processes |
| US9302274B2 (en) | 2011-10-18 | 2016-04-05 | Cytec Technology Corp. | Collector compositions and methods of using the same |
| CN114932010A (en) * | 2022-05-30 | 2022-08-23 | 矿冶科技集团有限公司 | Beneficiation treatment method for platinum-palladium ore containing easy-floating magnesium-rich silicate mineral |
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| MKLA | Lapsed | ||
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