U.S. patent application number 14/287645 was filed with the patent office on 2014-09-18 for phenoxypyrazole composition and process for the solvent extraction of metals.
This patent application is currently assigned to Cytec Technology Corp.. The applicant listed for this patent is Cytec Technology Corp.. Invention is credited to John Campbell, Lucy Emeleus, Susan Owens, Ronald Matthys Swart.
Application Number | 20140264166 14/287645 |
Document ID | / |
Family ID | 37685758 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140264166 |
Kind Code |
A1 |
Campbell; John ; et
al. |
September 18, 2014 |
PHENOXYPYRAZOLE COMPOSITION AND PROCESS FOR THE SOLVENT EXTRACTION
OF METALS
Abstract
Metal extractants of 2-hydroxyphenyldiazole compounds according
to Formula (2): ##STR00001## and tautomers and salts thereof, are
disclosed, wherein substituents R.sup.5, R.sup.7, R.sup.9, and
R.sup.10 are as defined herein.
Inventors: |
Campbell; John; (Lancaster,
GB) ; Swart; Ronald Matthys; (Tervuren, BE) ;
Emeleus; Lucy; (Hertfordshire, GB) ; Owens;
Susan; (Manchester, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cytec Technology Corp. |
Wilmington |
DE |
US |
|
|
Assignee: |
Cytec Technology Corp.
Wilmington
DE
|
Family ID: |
37685758 |
Appl. No.: |
14/287645 |
Filed: |
May 27, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13904089 |
May 29, 2013 |
|
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14287645 |
|
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|
13333117 |
Dec 21, 2011 |
8470052 |
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13904089 |
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12067719 |
Jun 21, 2008 |
8088810 |
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PCT/US2006/030891 |
Aug 7, 2006 |
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13333117 |
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60717042 |
Sep 14, 2005 |
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Current U.S.
Class: |
252/193 ;
548/374.1; 548/377.1 |
Current CPC
Class: |
C22B 3/0036 20130101;
C22B 3/1666 20130101; Y02P 10/20 20151101; C07D 231/12 20130101;
Y02P 10/234 20151101; C22B 15/0089 20130101; C22B 15/0063 20130101;
Y02P 10/236 20151101; C22B 3/0035 20130101; C07D 231/14
20130101 |
Class at
Publication: |
252/193 ;
548/377.1; 548/374.1 |
International
Class: |
C22B 3/16 20060101
C22B003/16 |
Claims
1. A metal extractant comprising a 2-hydroxyphenyldiazole compound
according to Formula (2) ##STR00012## wherein R.sup.5 is selected
from the group consisting of hydrogen, an optionally substituted
C.sub.1-C.sub.36 hydrocarbyl group, halogen, and nitro; R.sup.7 is
chosen from hydrogen or an optionally substituted C.sub.1-C.sub.36
hydrocarbyl group; each of R.sup.9 and R.sup.10 is independently
selected from the group consisting of hydrogen, an optionally
substituted C.sub.1-C.sub.36 hydrocarbyl group, an optionally
substituted C.sub.1-C.sub.36 hydrocarbyloxy group, an optionally
substituted C.sub.1-C.sub.36 hydrocarbyloxycarbonyl group, an
optionally substituted C.sub.1-C.sub.36 hydrocarbylcarbonyloxy
group, and an optionally substituted C.sub.1-C.sub.36 mono- or
dihydrocarbylaminocarbonyl group; and tautomers or salts thereof,
with the proviso that: when R.sup.7 is H or C.sub.1-C.sub.5, then
at least one of R.sup.9 or R.sup.10 is selected from the group
consisting of an optionally substituted C.sub.9-C.sub.36
hydrocarbyl, C.sub.1-C.sub.36 alkoxy, C.sub.1-C.sub.36
hydrocarbyloxycarbonyl, C.sub.1-C.sub.36 hydrocarbylcarbonyloxy,
and C.sub.1-C.sub.36 mono- or dihydrocarbylaminocarbonyl.
2. The metal extractant compound of claim 1, wherein each
optionally substituted hydrocarbyl group is independently selected
from the group consisting of alkyl, alkenyl, aryl, alkaryl and
aralkyl group.
3. The metal extractant compound of claim 2, wherein each
optionally substituted hydrocarbyl group is independently chosen
from a branched or linear alkyl group.
4. The metal extractant compound of claim 3, wherein the alkyl
group includes up to 23 carbon atoms.
5. The metal extractant compound of claim 4, wherein the alkyl
group includes up to 12 carbon atoms.
6. The metal extractant compound of claim 3, wherein at least one
of R.sup.5, R.sup.7, R.sup.9, and R.sup.10 is chosen from a
branched alkyl group having from 1 to 5 branches in the carbon
chain.
7. The metal extractant compound of claim 2, wherein the alkyl
group is selected from the group consisting of methyl, ethyl,
propyl, butyl, nonyl, hexylnonyl, butylnonyl, dodecyl, pentadecyl,
heptadecyl, and cyclohexyl.
8. The metal extractant compound according to claim 1, wherein
R.sup.7 is H, and at least one of R.sup.9 or R.sup.10 is a
C.sub.9-C.sub.36 hydrocarbyl.
9. The metal extractant compound according to claim 8, wherein at
least one of R.sup.9 or R.sup.10 is a C.sub.9-C.sub.17 alkyl.
10. The metal extractant compound according to claim 1, wherein
each of R.sup.5, R.sup.7, and R.sup.9 is H; and R.sup.10 is an
optionally substituted C.sub.9-C.sub.36 hydrocarbyl.
11. The metal extractant compound according to claim 10, wherein
R.sup.10 is an optionally substituted C.sub.9-C.sub.17
hydrocarbyl.
12. The metal extractant compound according to claim 11, wherein
R.sup.10 is chosen from a member selected from the group consisting
of hexylnonyl, pentadecyl, and heptadecyl.
13. The metal extractant compound according to claim 1, wherein the
metal extractant compound is selected from the group consisting of
4-nonyl-2-(5-nonyl-1H-pyrazol-3-yl)-phenol;
2-{5-[4,6,6-trimethyl-1-(1,3,3-trimethylbutyl)heptyl]pyrazol-3-yl}phenol;
2-(5-nonyl-1H-pyrazol-3-yl)-phenol; and
2-(5-(1-hexylnonyl)-1H-pyrazol-3-yl)-phenol.
14. A solvent extraction composition comprising a water-immiscible
organic solvent; and a metal extractant compound as defined by
claim 1.
15. A solvent extraction composition according to claim 14, wherein
the metal extractant compound is present in an amount of from 1% to
60%, from 5% to 40%, or from 7.5% to 20% by weight of the total
composition.
16. A solvent extraction composition according to claim 15, wherein
the metal extractant compound is present at 10% by weight of the
total composition.
17. A solvent extraction composition according to claim 14, wherein
at least one of R.sup.9 or R.sup.10 of the metal extractant
compound is a C.sub.9-C.sub.36 hydrocarbyl.
18. A solvent extraction composition according to claim 17, wherein
at least one of R.sup.9 or R.sup.10 is a C.sub.9-C.sub.17
alkyl.
19. A solvent extraction composition according to claim 14, wherein
the metal extractant compound is selected from the group consisting
of 4-nonyl-2-(5-nonyl-1H-pyrazol-3-yl)-phenol;
2-{5-[4,6,6-trimethyl-1-(1,3,3-trimethylbutyl)heptyl]pyrazol-3-yl}phenol;
2-(5-nonyl-1H-pyrazol-3-yl)-phenol; and
2-(5-(1-hexylnonyl)-1H-pyrazol-3-yl)-phenol.
20. A solvent extraction composition according to claim 19, wherein
the metal extractant compound is
2-{5-[4,6,6-trimethyl-1-(1,3,3-trimethylbutyl)heptyl]pyrazol-3-yl}phenol.
Description
[0001] This application is a divisional of U.S. Application No.
13,904,089, filed May 29, 2013 (pending), which is a divisional of
U.S. application Ser. No. 13/333,117, filed Dec. 21, 2011 (now U.S.
Pat. No. 8,470,052), which is a divisional of U.S. application Ser.
No. 12/067,719, filed Jun. 21, 2008 (now U.S. Pat. No. 8,088,810),
which is the U.S. National Phase application of International
Application No. PCT/US2006/030891, filed Aug. 7, 2006 (expired),
which claims benefit of priority from U.S. Provisional Patent
Application No. 60/717,042 (expired), filed Sep. 14, 2005, each of
which is incorporated by reference herein in its entirety.
[0002] The present invention concerns solvent extractants, solvent
extraction compositions, a solvent extraction process and
especially a process for the extraction of metals, particularly
copper and nickel, from aqueous solutions, especially solutions
obtained by leaching ores.
[0003] It is known to extract metals, especially copper and nickel,
from aqueous solutions containing the metal in the form of, for
example, a salt, by contacting the aqueous solution with a solution
of a solvent extractant in a water immiscible organic solvent and
then separating the solvent phase loaded with metal, i.e.
containing at least a part of the metal in the form of a complex.
The metal can then be recovered by stripping with a solution of
lower pH followed for example, by electrowinning. Most commonly,
the aqueous metal-containing solutions for extraction are the
result of the acid leaching of ores. However it is known that some
metals, especially copper and nickel, can be leached from certain
ores with ammoniacal solutions. This has the advantage that
solutions containing especially high concentrations of copper and
nickel are derived and that there is little contamination of the
solution with iron.
[0004] Several types of organic solvent extractants have been
proposed for use in the recovery of metals from aqueous solutions.
Whilst many of the proposed reagents have been found to work well
under laboratory conditions and demonstrate affinity for the
recovery of copper and nickel or other metals from solutions, there
are often problems encountered with the application of such
reagents in commercial systems. One concern is the ability of the
reagent to withstand high acidic or basic conditions. There is
therefore a need for reagents, which can resist degradation under
these conditions, and which show enhanced metallurgical
properties.
[0005] Accordingly, there is provided a solvent extractant
comprising one or more optionally substituted
2-hydroxyphenyldiazoles or optionally substituted
2-hydroxyphenyltriazoles.
[0006] Preferred are 2-hydroxyphenyldiazoles or
2-hydroxyphenyltriazoles of Formula (1)
##STR00002##
wherein [0007] R.sup.5, R.sup.6, R.sup.7 and R.sup.8 each
independently are hydrogen, an optionally substituted hydrocarbyl
group, an electron withdrawing group, an electron donating group,
or one or more of R.sup.5&R.sup.6, R.sup.6&R.sup.7,
R.sup.7&R.sup.8 are linked in such way as to form an optionally
substituted ring; [0008] Y is N or CR.sup.9 wherein R.sup.9 is
hydrogen, an optionally substituted hydrocarbyl, optionally
substituted hydrocarbyloxy, optionally substituted
hydrocarbyloxycarbonyl, optionally substituted
hydrocarbylcarbonyloxy group, optionally substituted mono or
dihydrocarbylaminocarbonyl group; [0009] Z is N or CR.sup.19
wherein R.sup.19 is hydrogen, an optionally substituted
hydrocarbyl, optionally substituted hydrocarbyloxy, optionally
substituted hydrocarbyloxycarbonyl, optionally substituted
hydrocarbylcarbonyloxy group, optionally substituted mono or
dihydrocarbylaminocarbonyl group; and tautomers or salts thereof,
with the provision that both Y and Z could be N provided that no
more than one of Y or Z is N.
[0010] Whilst the invention is described herein with reference to a
compound of Formula (1), it is understood that the invention
relates to Formula (1) in any possible tautomeric forms, and also
the complexes formed between compounds of Formula (1) and metals,
particularly copper and nickel.
[0011] Preferred hydrocarbyl groups represented by R.sup.5-10
independently include alkyl, alkenyl and aryl groups, and any
combination thereof, such as aralkyl and alkaryl, for example
benzyl groups.
[0012] Preferred alkyl groups represented by R.sup.5-10 include
linear and branched alkyl groups comprising up to 36 carbon atoms,
particularly from 1 to 22 carbon atoms and preferably from 1 to 12
carbon atoms. When the alkyl groups are branched, the groups
preferably comprise up to 5 branches in the carbon chain, and more
preferably at least 1 branch in the carbon chain. In certain
embodiments, the alkyl group is cyclic, preferably comprising from
3 to 10 carbon atoms in the largest ring and optionally featuring
one or more bridging rings. Examples of alkyl groups represented by
R.sup.5-10 include methyl, ethyl, propyl, butyl, nonyl, hexylnonyl,
butylnonyl, dodecyl and cyclohexyl groups and isomers thereof.
[0013] Preferred alkenyl groups represented by R.sup.5-10 include
C.sub.2-20, and preferably C.sub.2-6 alkenyl groups. One or more
carbon-carbon double bonds may be present. The alkenyl group
optionally carries one or more substituents, particularly phenyl
substituents. Examples of most preferred alkenyl groups include
vinyl, styryl and indenyl groups.
[0014] Preferred aryl groups represented by R.sup.5-10 contain 1
ring or 2 or more fused rings. Preferably the aryl groups include
aromatic and heteroaromatic groups. When the aryl group comprises
fused rings, the fused rings preferably include cycloalkyl, aryl or
heterocyclic rings. Examples of aryl groups include optionally
substituted phenyl, naphthyl, thienyl and pyridyl groups.
[0015] Electron withdrawing groups represented by R.sup.5-10
include halogen or nitro or optionally substituted
hydrocarbyloxycarbonyl, optionally substituted hydrocarbylcarbonyl
group, optionally substituted mono or dihydrocarbylaminocarbonyl
group, including substitution by halogen, nitro SOR, SO.sub.2R,
groups.
[0016] Electron donating groups which may be represented by
R.sup.5-10 include hydrocarbyl, hydrocarbyloxy, optionally
substituted hydrocarbylcarbonyloxy groups. When any of R.sup.5-10
is a substituted hydrocarbyl or heterocyclic group, the
substituent(s) should be such so as not to adversely interfere with
the ability of the extractant to coordinate to metals. Optional
substituents include, but are not limited to halogen, cyano, nitro,
hydroxy, amino, thiol, acyl, hydrocarbyl, perhalogenated
hydrocarbyl, heterocyclyl, hydrocarbyloxy, mono or
di-hydrocarbylamino, hydrocarbylthio, esters, carbonates, amides,
sulphonyl and sulphonamido groups wherein the hydrocarbyl groups
are as defined for R.sup.5 above. One or more substituents may be
present.
[0017] When any of R.sup.5 & R.sup.6, R.sup.6 & R.sup.7,
R.sup.7 & R.sup.8, R.sup.8&R.sup.9 and R.sup.9 &
R.sup.10 are linked in such a way that when taken together with
either the carbon atom and/or atom X of the compound of formula (1)
that a ring is formed, preferably the ring be 5, 6 or 7
membered.
[0018] When any of R.sup.5-10 is an aryl group, the aryl group is
preferably a phenyl optionally substituted with one or more groups
selected from C.sub.1-12 alkyl or halo.
[0019] Phenyl groups optionally substituted with one or more groups
selected from C.sub.1-12 alkyl or halo represented by any of
R.sup.5-10 include those of formula:
##STR00003##
wherein R.sup.11 to R.sup.15 each independently represent H, halo,
or a C.sub.1-12 alkyl group.
[0020] When any of R.sup.11 to R.sup.15 are halo, preferably the
halo is Cl or F.
[0021] When any of R.sup.11 to R.sup.15 are a C.sub.1-12 alkyl
group, the C.sub.1-12 alkyl group can be linear or branched, and
preferably is methyl, ethyl or isopropyl.
[0022] Preferably only R.sup.13 represents a halo group or a
C.sub.1-12 alkyl group, with R.sup.11, R.sup.12.sub.5 R.sup.14 and
R.sup.15 representing H.
[0023] When any of R.sup.5-10 is an optionally substituted phenyl
group, it is most preferred that R.sup.11 to R.sup.15 are all
hydrogen.
[0024] Highly preferred extractant compositions of the present
invention include 2-hydroxyphenyldiazoles of Formula (2)
##STR00004##
wherein [0025] R.sup.5 is hydrogen, an optionally substituted
hydrocarbyl group or an electron withdrawing group; [0026] R.sup.7
is hydrogen, or an optionally substituted hydrocarbyl group; [0027]
R.sup.9 is hydrogen, an optionally substituted hydrocarbyl,
optionally substituted hydrocarbyloxy, optionally substituted
hydrocarbyloxycarbonyl, optionally substituted
hydrocarbylcarbonyloxy group, optionally substituted mono or
dihydrocarbylaminocarbonyl group; [0028] R.sup.10 is hydrogen, an
optionally substituted hydrocarbyl, optionally substituted
hydrocarbyloxy, optionally substituted hydrocarbyloxycarbonyl,
optionally substituted hydrocarbylcarbonyloxy group, optionally
substituted mono or dihydrocarbylaminocarbonyl group; and tautomers
or salts thereof.
[0029] According to a further aspect of the present invention there
is provided a solvent extractant composition comprising a water
immiscible organic solvent, preferably with a low aromatic
hydrocarbon content, and one or more solvent extractants of formula
(1):
##STR00005##
as described above and tautomers or salts thereof.
[0030] Preferences for the solvent extractant of formula (1) are
described as herein before in connection with the first aspect the
present invention.
[0031] The composition may comprise one or more different
optionally substituted 2-hydroxyphenyldiazoles or optionally
substituted 2-hydroxyphenyltriazoles, especially where the
component optionally substituted 2-hydroxyphenyldiazoles or
optionally substituted 2-hydroxyphenyltriazoles are isomeric. Such
isomeric mixtures may have better solubility in organic solvents
than a single optionally substituted 2-hydroxyphenyldiazole or
optionally substituted 2-hydroxyphenyltriazole or and are
preferred.
[0032] The optionally substituted 2-hydroxyphenyldiazoles or
optionally substituted 2-hydroxyphenyltriazoles are often present
in an amount of up to 60% by weight of the composition, commonly no
more than 50%, and usually no more than 40% w/w. Often, the
optionally substituted 2-hydroxyphenyldiazoles or optionally
substituted 2-hydroxyphenyltriazoles comprises at least 1% by
weight, commonly at least 2.5% by weight and usually at least 5% by
weight of composition, and preferably comprises from 7.5 to 20%,
such as about 10%, by weight of the composition.
[0033] Organic solvents which may be present in the composition
include any mobile organic solvent, or mixture of solvents, which
is immiscible with water and is inert under the extraction
conditions to the other materials present. Preferably the organic
solvent has a low aromatic hydrocarbon content.
[0034] Preferred organic solvents are hydrocarbon solvents which
include aliphatic, alicyclic and aromatic hydrocarbons and mixtures
thereof as well as chlorinated hydrocarbons such as
trichloroethylene, perchloroethylene, trichloroethane and
chloroform.
[0035] Highly preferred organic solvents having a low aromatics
content include solvents and solvent mixtures where the amount of
aromatic hydrocarbons present in the organic solvent is less than
30%, usually around 23% or less, often less than 5%, and frequently
less than 1%.
[0036] Examples of suitable hydrocarbon solvents include
ESCAID.RTM. 110, ESCAID.RTM. 115, ESCAID.RTM. 120, ESCAID.RTM. 200,
and ESCAID.RTM. 300 (hydrocarbon drilling fluids commercially
available from Exxon), SHELLSOL.RTM. D70 (petroleum
naphtha-C.sub.11+paraffins and naphthenics) and D80 (low viscosity,
colorless solvent with low aromatics content and mild odor)
(commercially available from Shell), and CONOSOL.RTM. C-170
(synthetic isoalkane solvent commercially available from Conoco).
Suitable solvents are hydrocarbon solvents include high flash point
solvents and solvents with a high aromatic content such as
SOLVESSO.RTM. 150 (an aromatic solvent naphtha commercially
available from Exxon).
[0037] More preferred are solvents with a low aromatic content.
Certain suitable solvents with a low aromatic content, have
aromatic contents of <1% w/w, for example, hydrocarbon solvents
such as ESCAID.RTM. 110 (commercially available from Exxon), and
ORFOM.RTM. SX-10 and ORFOM.RTM. SX-11 (each a low aromatic content
solvent extraction diluent commercially available from Phillips
Petroleum). Especially preferred, however on grounds of low
toxicity and wide availability, are hydrocarbon solvents of
relatively low aromatic content such as kerosene, for example
ESCAID.RTM. 100 which is a petroleum distillate with a total
aromatic content of 23%, or ORFOM.RTM. SX-7, (light petroleum
hydrotreated commercially available from Phillips Petroleum.
[0038] In many embodiments, the composition comprises at least 30%,
often at least 45% by weight, preferably from 50 to 95% w/w of
water-immiscible hydrocarbon solvent.
[0039] Advantageously, it may be preferred to make and supply the
composition in the form of a concentrate. The concentrate may then
be diluted by the addition of organic solvents as described herein
above to produce compositions in the ranges as described herein
above. Where the concentrate contains a solvent, it is preferred
that the same solvent is used to dilute the concentrate to the "in
use" concentration range. In many embodiments, the concentrate
composition comprises up to 30%, often up to 20% by weight,
preferably up to 10% w/w of water-immiscible hydrocarbon solvent.
Often the concentrate composition comprises greater than 5% w/w of
water-immiscible hydrocarbon solvent. The viscosity of the "azoles"
of the present invention means that concentrates do not display
appreciably higher viscosity than extractant compositions at "in
use" concentrations. In certain high strength concentrates it may
be necessary to employ a higher than normal aromatic hydrocarbon
content. In such cases where a high aromatic hydrocarbon containing
solvent is used in the concentrate, solvent of very low aromatic
hydrocarbon content may be used to dilute the concentrate to the
"in use" concentration range.
[0040] If desired, compounds or mixtures of compounds selected from
the group consisting of alcohols, esters, ethers, polyethers,
carbonates, ketones, nitriles, amides, carbamates, sulphoxides,
acids of sulphur and phosphorous compounds, for example sulphonic
acids, and salts of amines and quaternary ammonium compounds may
also be employed as additional modifiers or kinetics boosters in
the composition of the invention. Particularly preferred are
mixtures comprising a first compound selected from the group
consisting of alcohols, esters, ethers, polyethers, carbonates,
ketones, nitriles, amides, carbamates, sulphoxides, acids of
sulphur and phosphorous compounds, for example sulphonic acids, and
salts of amines and quaternary ammonium compounds and a second
compound selected from the group consisting of alkanols having from
6 to 18 carbon atoms, an alkyl esters having from 7 to 30 carbon
atoms, and tributylphosphate.
[0041] According to a third aspect of the present invention, there
is provided a process for the extraction of a metal from solution
in which an acidic solution containing a dissolved metal is
contacted with a solvent extraction composition comprising a water
immiscible organic solvent and a solvent extractant, whereby at
least a fraction of the metal is extracted into the organic
solution, characterised in that the solvent extraction composition
comprises a water immiscible organic solvent, preferably with a low
aromatic hydrocarbon content, and a solvent extractant of formula
(1):
##STR00006##
as referred to above and tautomers or salts thereof.
[0042] Metals that may be extracted in the process according to the
third aspect of the present invention include copper, cobalt,
nickel, manganese and zinc, most preferably copper.
[0043] The extractant of formula (1) and the water immiscible
organic solvent are as herein described before.
[0044] The aqueous acidic solution from which metals are extracted
by the process of the third aspect of the present invention often
has a pH in the range of from -1 to 7, preferably from 0 to 5, and
most preferably from 0.25 to 3.5. Preferably, when the metal to be
extracted is copper pH values of less than 3 are chosen so that the
copper is extracted essentially free of iron, cobalt or nickel. The
solution can be derived from the leaching of ores or may be
obtained from other sources, for example metal containing waste
streams such as from copper etching baths.
[0045] The concentration of metal, particularly copper, in the
aqueous acidic solution will vary widely depending for example on
the source of the solution. Where the solution is derived from the
leaching of ores, the metal concentration is often up to 75 g/l and
most often from 1 to 40 g/l. Where the solution is a waste stream,
the metal concentrations can vary from 0.5 to 2 g/l for a waste
water stream, to somewhat higher for those from other waste
streams, for example Printed Circuit Board waste streams, and can
be up to 150 g/l, usually from 75 to 130 g/l.
[0046] Preferred solvent extraction compositions are those where
the organic solvent solutions may contain the optionally
substituted 2-hydroxyphenyldiazoles or optionally substituted
2-hydroxyphenyltriazoles in an amount approaching 100% ligand, but
preferably the optionally substituted 2-hydroxyphenyldiazoles or
optionally substituted 2-hydroxyphenyltriazoles are employed at
about 10 to 40% by weight. Highly preferred solvent extraction
compositions are those comprising an organic solvent with a total
aromatic content of around 23% or less and one or more optionally
substituted 2-hydroxyphenyldiazoles or optionally substituted
2-hydroxyphenyltriazoles selected from
4-alkyl-2-(5-alkyl-1H-pyrazol-3-yl)-phenol and
alkyl-3-(2-hydroxyphenyl)-1H-pyrazole-5-carboxylate in a total
amount of between 5 to 40% by weight.
[0047] The process of the third aspect of the present invention can
be carried out by contacting the solvent extractant composition
with the aqueous acidic solution. Ambient or elevated temperatures,
such as up to 75.degree. C. can be employed if desired. Often a
temperature in the range of from 5 to 60.degree. C., and preferably
from 15 to 40.degree. C., is employed. The aqueous solution and the
solvent extractant are usually agitated together to maximise the
interfacial areas between the two solutions. The volume ratio of
solvent extractant to aqueous solution are commonly in the range of
from 20:1 to 1:20, and preferably in the range of from 5:1 to 1:5.
In many embodiments, to reduce plant size and to maximise the use
of solvent extractant, organic to aqueous volume ratios close to
1:1 are maintained by recycle of one of the streams.
[0048] After contact with the aqueous acidic solution, the metal
can be recovered from the solvent extractant by contact with an
aqueous acidic strip solution.
[0049] The aqueous strip solution employed in the process according
to the third aspect of the present invention is usually acidic,
commonly having a pH of 2 or less, and preferably a pH of 1 or
less, for example, a pH in the range of from -1 to 0.5. The strip
solution commonly comprises a mineral acid, particularly sulphuric
acid, nitric acid or hydrochloric acid. In many embodiments, acid
concentrations, particularly for sulphuric acid, in the range of
from 50 to 200 g/l and preferably from 150 to 180 g/l are employed.
When the extracted metal is copper, preferred strip solutions
comprise stripped or spent electrolyte from a copper
electro-winning cell, typically comprising up to 80 g/l copper,
often greater than 20 g/l copper and preferably from 30 to 70 g/l
copper, and up to 220 g/l sulphuric acid, often greater than 120
g/l sulphuric acid, and preferably from 150 to 180 g/1 sulphuric
acid. It has been found that these compounds strip at surprisingly
low acid concentrations. This means that lower concentrations of
strip acid can be used with concomitant savings in costs, or a more
normal concentration of strip acid can be used with significant
improvements in the recovery of copper. The very low residual
copper on the extractant also means that loading in the subsequent
extract cycle is more efficient. These compositions have the
additional benefit of moving acid around the circuit. The volume
ratio of organic solution to aqueous strip solution in the process
of the third aspect of the present invention is commonly selected
to be such so as to achieve transfer, per litre of strip solution,
of up to 100 g/l of metal, especially copper into the strip
solution from the organic solution. In many industrial copper
electrowinning processes transfer is often from 10 g/l to 35 g/l,
and preferably from 15 to 20 g/l of copper per litre of strip
solution is transferred from the organic solution. Volume ratios of
organic solution to aqueous solution of from 1:2 to 15:1 and
preferably from 1:1 to 10:1, especially less than 6:1 are commonly
employed.
[0050] Both the separation and stripping process can be carried out
by a conventional batch extraction technique or column contactors
or by a continuous mixer settler technique. The latter technique is
generally preferred as it recycles the stripped organic phase in a
continuous manner, thus allowing the one volume of organic reagent
to be repeatedly used for metal recovery.
[0051] A preferred embodiment of the third aspect of the present
invention comprises a process for the extraction of a metal from
aqueous acidic solution in which:
[0052] in step 1, the solvent extraction composition comprising an
extractant of formula (1) is first contacted with the aqueous
acidic solution containing metal,
[0053] in step 2, separating the solvent extraction composition
containing metal-solvent extractant complex from the aqueous acidic
solution;
[0054] in step 3, contacting the solvent extraction composition
containing metal-solvent extractant complex with an aqueous acidic
strip solution to effect the stripping of the metal from the water
immiscible phase;
[0055] in step 4, separating the metal-depleted solvent extraction
composition from the loaded aqueous strip solution.
[0056] According to a fourth aspect of the present invention, there
is provided a process for the extraction of a metal from solution
in which an aqueous ammoniacal solution containing a dissolved
metal is contacted with a solvent extraction composition comprising
a water immiscible organic solvent and a solvent extractant,
whereby at least a fraction of the metal is extracted into the
organic solution, characterised in that the solvent extraction
composition comprises a water immiscible organic solvent,
preferably with a low aromatic hydrocarbon content, and a solvent
extractant of formula (1):
##STR00007##
as referred to above. and tautomers or salts thereof.
[0057] Metals that may be extracted in the process according to the
fourth aspect of the present invention include copper, cobalt,
nickel, manganese and zinc, most preferably copper and nickel.
[0058] The extractant of formula (1) and water immiscible organic
solvent are as herein described before.
[0059] The aqueous ammoniacal solution from which metals are
extracted by the process of this aspect of the present invention
often has a pH in the range of from 7 to 12, preferably from 8 to
11, and most preferably from 9 to 10. The solution can be derived
from the leaching of ores, particularly chalcocite ores, or may be
obtained from other sources, for example precipitated metal oxide
mattes or metal containing waste streams such as from copper
etching baths.
[0060] Preferred solvent extraction compositions are those where
the organic solvent solutions may contain the optionally
substituted 2-hydroxyphenyldiazoles or optionally substituted
2-hydroxyphenyltriazoles in an amount approaching 100% ligand, but
typically the optionally substituted 2-hydroxyphenyldiazoles or
optionally substituted 2-hydroxyphenyltriazoles will be employed at
about 10 to 40% by weight. Highly preferred solvent extraction
compositions are those comprising an organic solvent with a total
aromatic content of around 23% or less and one or more optionally
substituted 2-hydroxyphenyldiazoles or optionally substituted
2-hydroxyphenyltriazoles from selected from
4-alkyl-2-(5-alkyl-1H-pyrazol-3-yl)-phenol and
alkyl-3-(2-hydroxyphenyl)-1H-pyrazole-5-carboxylate in a total
amount of between 5 to 40% by weight, in a total amount of between
5 to 40% by weight.
[0061] The concentration of metal, particularly copper or nickel,
in the aqueous ammoniacal solution will vary widely depending for
example on the source of the solution. Where the solution is
derived from the leaching of ores, the metal concentration is often
up to 75 g/l and most often from 1 to 40 g/l. Where the solution is
a waste stream, the metal concentrations can vary from 0.5 to 2 g/l
for a waste water stream, to somewhat higher for those from other
waste streams, for example Printed Circuit Board waste streams, and
can be up to 150 g/l, usually from 75 to 130 g/l. Where the
solution is an ammoniacal nickel stream, the metal concentration is
most often 1-20 g/1.
[0062] The process of the fourth aspect of the present invention
can be carried out by contacting the solvent extractant composition
with the metal containing aqueous ammoniacal solution. Ambient or
elevated temperatures can be employed, often a temperature in the
range of from 15 to 60.degree. C., and preferably from 30 to
50.degree. C., is employed. The aqueous solution and the solvent
extractant are usually agitated together to maximise the
interfacial areas between the two solutions. The volume ratio of
solvent extractant to aqueous solution are commonly in the range of
from 20:1 to 1:20, and preferably in the range of from 5:1 to 1:5.
In many embodiments, to reduce plant size and to maximise the use
of solvent extractant, organic to aqueous volume ratios close to
1:1 are maintained by recycle of one of the streams.
[0063] After contact with the aqueous ammoniacal solution, the
metal can be recovered from the solvent extractant by contact with
an aqueous strip solution having a pH lower than that from which
the metal is extracted.
[0064] Alternatively, after contact with the aqueous ammoniacal
solution, the metal can be recovered from the solvent extractant by
contact with aqueous ammoniacal strip solution, particularly
aqueous ammoniacal ammonium carbonate solution. The use of aqueous
ammoniacal ammonium carbonate solution as a stripping solution is
particularly suited to the recovery of metals in the form of metal
carbonates, for example Nickel.
[0065] When an aqueous strip solution having a pH lower than that
from which the metal is extracted is employed as a strip solution
in the process according to the fourth aspect of the present
invention, the aqueous strip solution is usually acidic and is as
described for the strip solution in the process of the third aspect
of the present invention. When the extracted metal is copper,
preferred strip solutions comprise stripped or spent electrolyte
from a copper electro-winning cell, typically comprising up to 80
g/l, often greater than 40 g/l copper and preferably from 50 to 70
g/l copper, and up to 220 g/l sulphuric acid, often greater than
120 g/l sulphuric acid, and preferably from 150 to 180 g/l
sulphuric acid.
[0066] The volume ratio of organic solution to aqueous strip
solution in the process of the fourth aspect of the present
invention is commonly selected to be such so as to achieve
transfer, per litre of strip solution, of up to 100 g/l of metal,
especially of copper or nickel into the strip solution from the
organic solution. In many industrial copper electrowinning
processes transfer is often from 10 g/l to 35 g/l, and preferably
from 15 to 20 g/l of copper per litre of strip solution is
transferred from the organic solution. Volume ratios of organic
solution to aqueous solution of from 1:2 to 15:1 and preferably
from 1:1 to 10:1, especially less than 6:1 are commonly
employed.
[0067] When ammoniacal ammonium carbonate solution is employed as a
strip solution in the process of the fourth aspect of the present
invention, the ammoniacal ammonium carbonate solution may contain
excess ammonia and is preferably stronger than the ammoniacal
ammonium carbonate solution used to leach the ore. The
concentration of the solution used to recover the metal from the
loaded organic phase is preferably in the ranges of NH.sub.3: 210
to 300 gl.sup.-1, CO.sub.2: 150 to 250 gl.sup.-1. Preferably, the
solution strength is close to NH.sub.3: 270 gl.sup.-1, CO.sub.2:
230 gl.sup.-1.
[0068] The contact between the loaded organic phase and the
ammoniacal ammonium carbonate solution may be carried out at any
appropriate temperature and pressure. Preferably this step is
conducted at atmospheric pressure and at a temperature in the range
of 20.degree. C. to 50.degree. C.
[0069] It is preferred that the metal loaded organic phase is
contacted with the ammoniacal ammonium carbonate solution for a
period of between 30 seconds to 60 minutes. Most preferably the
content time is for a period of about 3 minutes.
[0070] Both the separation and stripping process can be carried out
by a conventional batch extraction technique or column contactors
or by a continuous mixer settler technique. The latter technique is
generally preferred as it recycles the stripped organic phase in a
continuous manner, thus allowing the one volume of organic reagent
to be repeatedly used for metal recovery.
[0071] When the process of the invention is applied to the
operation of a continuous counter current mixer-settler apparatus,
the organic/aqueous ratio in the stripping cells is preferably in
the range of 6:1 to 10:1. This contrasts with the preferred
organic/aqueous range in the extraction cells (where comparable
organic agents may be used) of 1:1 to 1.2:1.
[0072] When the metal to be recovered is Nickel, it is preferred
that the nickel loaded organic phase is stripped in a stripping
cell at a temperature of about 40.degree. C. An advantage of
compounds of the present invention is that they are more stable
under these conditions than commercial oxime extractants. The metal
that separates into the aqueous phase can be recovered as a metal
carbonate by any conventional manner. For example, basic nickel
carbonate can readily be recovered by distillation. Nickel can also
be recovered effectively from aqueous ammonium carbonate solution
by hydrogen reduction under pressure. The recovery technique
preferably allows for the NH.sub.3 and CO.sub.2 components of the
strip liquor to be recycled to the metal loaded organic stripping
stage.
[0073] A further advantage of the compounds of the present
invention is the reduced transfer of ammonia across a circuit of
solutions of the compounds of the present invention in diluent
compared to solutions of the current oxime extractants.
[0074] A preferred embodiment of this aspect of the present
invention comprises a process for the extraction of a metal from
aqueous ammoniacal solution in which:
[0075] in step 1, the solvent extraction composition comprising an
extractant of formula (3) is first contacted with the aqueous
ammoniacal solution containing metal,
[0076] in step 2, separating the solvent extraction composition
containing metal-solvent extractant complex from the aqueous
ammoniacal solution;
[0077] in step 3, contacting the solvent extraction composition
containing metal-solvent extractant complex with an aqueous strip
solution of lower pH than the ammoniacal solution to effect the
stripping of the metal from the water immiscible phase;
[0078] in step 4, separating the metal-depleted solvent extraction
composition from the loaded lower pH aqueous solution.
[0079] The metal can be recovered from the aqueous strip solution
by conventional methods, for example by electrowinning
[0080] A further preferred embodiment of this aspect of the present
invention comprises a process for the extraction of a metal from
aqueous ammoniacal solution in which:
[0081] in step 1, the solvent extraction composition comprising an
extractant of formula (3) is first contacted with the aqueous
ammoniacal solution containing metal,
[0082] in step 2, separating the solvent extraction composition
containing metal-solvent extractant complex from the aqueous
ammoniacal solution;
[0083] in step 3, contacting the solvent extraction composition
containing metal-solvent extractant complex with an aqueous
ammoniacal strip solution, particularly aqueous an ammoniacal
ammonium carbonate solution, to effect the stripping of the metal
from the water immiscible phase;
[0084] in step 4, separating the metal-depleted solvent extraction
composition from the loaded aqueous ammoniacal solution.
[0085] The invention is further illustrated, but not limited, by
the following examples.
EXAMPLES
Example 1
Preparation of 1-(2-hydroxy-5-nonyl-phenyl)dodecane-1,3-dione
##STR00008##
[0087] A solution of 2-Hydroxy-5-nonylacetophenone (0.3M) in
toluene (50 ml) is added drop wise to a stirred slurry of sodium
hydride (0.3M) in toluene (150 ml) at 30.degree. C. over 30
minutes. Reaction mixture is stirred at 30.degree. C. for 1 hour
before versatic acid chloride (0.3M) is added drop wise over 1
hour. After the acid chloride addition is complete the reaction
mixture is heated to 80.degree. C. and held at this temperature for
1 hour. Cooled to ambient and potassium hydroxide flake (0.6M)
added, heated to 80.degree. C. and held at this temperature for 2
hours. Cooled to ambient and reaction mass neutralised with aqueous
acetic acid solution (25%). Toluene phase is washed with water
(3.times.25 ml) then vacuum evaporated to leave brown oil.
[0088] H.sup.1NMR (CDCl.sub.3, 300 Hz)
[0089] .delta.0.5-1.8 (multiplets, alkyl 38H), .delta.6.4 (singlet,
CH), 66.9 (doublet, aryl H), 67.1 (multiplet, aryl H), 67.5
(multiplet, aryl H), 69.8 & 10.8 (2.times.singlets, phenol OH
& enol OH)
Example 2
Preparation of 4-Nonyl-2-(5-nonyl-1H-pyrazol-3-yl)-phenol
##STR00009##
[0091] 1-(2-hydroxy-5-nonyl-phenyl)dodecane-1,3-dione (0.1M)
dissolved in ethanol (50 ml), hydrazine hydrate (0.105M) added and
the reaction solution heated to reflux. Held at reflux for 2 hours,
cooled to ambient and organic phase washed with water (2.times.25
ml). Toluene removed by vacuum evaporation to produce a brown
oil.
[0092] Mass Spec: Mol wt 412. found 411 (M-H).sup.-, 413
(M-H).sup.+.
[0093] H.sup.1NMR (CDCl.sub.3, 300 Hz)
[0094] .delta.0.5-1.8 (multiplets, alkyl 38H), .delta.6.2 (singlet,
CH), .delta.6.9 (doublet, aryl H), .delta.7.5 (multiplet,
2.times.aryl H), .delta.11.9 & 15.6 (phenol OH & pyrazole
NH)
Example 3
Preparation of n-octyl-4-(2-hydroxyphenyl)-2-4-dioxobutanoate
##STR00010##
[0096] A mixture of 2-hydroxyacetophenone (0.15M) and ethyl
pelargonate (0.45M) is added carefully to a slurry of sodium
hydride (0.45M) in tetrahydrofuran over 90 minutes at 50-60.degree.
C., the mixture is kept under a atmosphere of nitrogen throughout
the reaction.
[0097] After addition complete the reaction mass is stirred for a
further two hours at 50-60.degree. C. Cooled to 25.degree. C. and
drowned into ice/water (600 g) before acidifying with acetic acid.
Product extracted into hexane (200 ml). Hexane and any unreacted
starting ester removed under vacuum to yield a yellow crystalline
solid. Recrystallised from hexane.
[0098] Yield=18.9 g
[0099] Mass Spec: Mol wt 275. found 275 (M-H).sup.-.
[0100] H.sup.1NMR (CDCl.sub.3, 300 Hz)
[0101] .delta.0.9-2.9 (alkyl chain protons, 17H), .delta.6.2
(singlet, CH), .delta.6.9-7.8 (multiplets, aryl 4H), .delta.12.1
& 15.0 (phenol OH & enol OH)
[0102] NMR suggests keto-enol rather than the 1,3 dione.
Example 4
Preparation of
n-octyl-3-(2-hydroxyphenyl)-1H-pyrazole-5-carboxylate
##STR00011##
[0104] n-octyl-4-(2-hydroxyphenyl)-2-4-dioxobutanoate (0.05M)
dissolved in ethanol (50 ml) and sodium acetate (5 g) added.
Hydrazine hydrate (0.08M) added and the reaction solution heated to
reflux. Held at reflux for 1 hours, cooled to AMBIENT and drowned
into water (400 ml). Product extracted into hexane (200 ml) and the
organic phase separated off and washed with water (2.times.50 ml).
The solvent is removed by vacuum evaporation and the product
recrystallised from hexane to yield a crystalline white solid.
[0105] Wt=11.7 g
[0106] Mass Spec: Mol wt 272. found 271 (M-H).sup.-, 273
(M-H).sup.+.
[0107] H.sup.1NMR (CDCl.sub.3, 300 Hz)
[0108] .delta.0.9-2.8 (multiplets, alkyl 17H), .delta.6.45
(singlet, CH), .delta.6.9-7.7 (multiplets, aryl 4H), .delta.10.1
& 11.2 (phenol OH & pyrazole NH)
Copper Extraction (comparison with a commercially available
reagent, 5-nonyl-2 hydroxy-acetophenone-oxime)
From Acidic Copper Sulphate Solutions
Extraction Isotherms at pH 2.0
[0109] An aqueous solution containing a mixture of 3.0 g/l copper
(Cu.sup.2) and 3.0 g/l iron (Fe.sup.3+) sulphates at pH 2.0, is
contacted with a ligand solution (0.2M) in ORFOM.RTM. SX-7 at
varying organic to aqueous ratios. The solutions are stirred for
one hour at 25.degree. C., to ensure equilibrium is reached. The
organic and aqueous layers are separated and the copper content of
each phase measured by atomic adsorption.
TABLE-US-00001 2-hydroxy-5-nonyl- 2-(5-(1-hexylnonyl)-
acetophenone-oxime 1H-pyrazol- (commercial reagent) 3-yl)-phenol
Organic/Aqueous Organic Aqueous Organic Aqueous Ratio (Cu g/l) (Cu
g/l) (Cu g/l) (Cu g/l) 1.5:1.0 2.02 0.24 2.00 0.13 1.0:1.0 2.79
0.37 2.86 0.32 1.0:1.5 3.45 0.83 3.85 0.57 1.0:2.0 4.31 0.97 4.64
0.83 1.0:3.0 4.87 1.69 5.33 1.33 1.0:4.0 5.01 1.99 6.61 1.65
1.0:8.0 5.56 2.25 6.5 2.29
Strip Isotherms
[0110] An aqueous solution containing a typical acidic spent
electrolyte (30 g/l copper (Cu.sup.2+) and 150 g/l sulphuric acid)
is contacted with a ligand solution (0.2M) in ORFOM.RTM. SX-7,
(which has previously been fully loaded with copper), at varying
organic to aqueous ratios. The solutions are stirred for one hour
at 25.degree. C. to ensure equilibrium is reached. The organic and
aqueous phases are separated and the copper content of the organic
phase measured by atomic adsorption.
TABLE-US-00002 2-hydroxy-5-nonyl- 4-Nonyl-2-(5-nonyl-
acetophenone-oxime 1H-pyrazol- (commercial reagent) 3-yl)-phenol
Organic/Aqueous Organic Aqueous Organic Aqueous Ratio (Cu g/l) (Cu
g/l) (Cu g/l) (Cu g/l) 1.00:2.00 0.413 33.04 0.019 33.89 1.33:1.00
0.508 37.49 0.027 39.13 2.50:1.50 0.647 43.52 0.058 46.44
[0111] The results illustrate the improved acid strip achieved with
4-nonyl-2-(5-nonyl-1H-pyrazol-3-yl)-phenol compared to a commercial
reagent 2-hydroxy-5-nonyl-acetophenone-oxime.
From Ammoniacal Copper Chloride Solutions
[0112] Extraction Isotherms from Basic Solution
[0113] A typical Printed Circuit Board aqueous solution containing
ammoniacal copper chloride (113 g/l Cu.sup.2+/90 g/l NH.sub.3) is
contacted with a ligand solution (0.4M) in ORFOM.RTM. SX-7 at
varying organic to aqueous ratios. The solutions are stirred for
one hour at 25.degree. C., to ensure equilibrium is reached. The
organic and aqueous layers are separated and the copper content of
each phase measured by atomic adsorption.
TABLE-US-00003 4-Nonyl-2-(5-nonyl- 1H-pyrazol- 3-yl)-phenol
Organic/Aqueous Organic Aqueous Ratio (Cu g/l) (Cu g/l) 10:1 8.99
24 8:1 9.8 35 4:1 11.14 69 2:1 12.18 90 1.5:1 12.36 95 1:1 12.25
101
Strip Isotherms
[0114] An aqueous solution containing a typical acidic spent
electrolyte (30 g/l copper (Cu.sup.2+) and 150 g/l sulphuric acid)
is contacted with a ligand solution (0.4M) in ORFOM.RTM. SX-7,
(which has previously been fully loaded with copper, 12.48 g/l
Cu.sup.2+), at varying organic to aqueous ratios. The solutions are
stirred for one hour at 25.degree. C. to ensure equilibrium is
reached. The organic and aqueous phases are separated and the
copper content of the organic phase measured by atomic
adsorption.
TABLE-US-00004 4-Nonyl-2-(5-nonyl- 1H-pyrazol- 3-yl)-phenol
Organic/Aqueous Organic Aqueous Ratio (Cu g/l) (Cu g/l) 1.00:2.00
0.03 36.5 1.00:1.00 0.05 47.7 2.00:1.00 0.25 62.6
Nickel Extraction (comparison with a commercially available
reagent, 5-nonyl-2 hydroxy-acetophenone-oxime) Extraction Isotherms
from Ammoniacal Solution
[0115] An aqueous solution containing 10 g/l Ni.sup.2+/40 g/l
NH.sub.3/20 gl CO.sub.2 (prepared by dissolving ammonium carbamate
(35.8 g/l) in an ammonia solution (77 g at 32% w/w) and diluting to
1 litre with water) is contacted with a ligand solution (0.49M) in
ORFOM.RTM. SX-7 at varying organic to aqueous ratios. The solutions
are stirred for one hour at 25.degree. C., to ensure equilibrium is
reached. The organic and aqueous layers are separated and the
nickel content of each phase measured by atomic adsorption.
TABLE-US-00005 2-hydroxy-5-nonyl- 2-(5-nonyl-1H- acetophenone-oxime
pyrazol-3-yl)- (commercial reagent) phenol Organic/Aqueous Organic
Aqueous Organic Aqueous Ratio (Ni g/l) (Ni g/l) (Ni g/l) (Ni g/l)
1.5:1.0 6.85 0.06 7.02 0.18 1.0:1.0 10.35 0.12 9.98 0.53 1.0:1.5
13.53 0.76 12.78 1.94 1.0:4.0 14.99 6.40 14.49 6.52 1.0:8.0 14.35
8.28 14.94 8.22
Strip Isotherms
(A) Ammoniacal Stripping
[0116] An aqueous solution containing 280 g/l NH.sub.3/220 g/l
CO.sub.2 (prepared by dissolving ammonium carbamate (197 g) in an
ammonia solution (172 ml at 32% w/w) and diluting to 500 ml with
water) is contacted with a ligand solution (0.49M in ORFOM.RTM.
SX-7) (which has previously been fully loaded with nickel) at
varying organic to aqueous ratios. The solutions are stirred for
one hour at 25.degree. C. to ensure equilibrium is reached. The
organic and aqueous phases are separated and the nickel content of
the organic phase measured by atomic adsorption.
TABLE-US-00006 2-hydroxy-5-nonyl- 2-(5-nonyl-1H- acetophenone-oxime
pyrazol-3-yl)- (commercial reagent) phenol Organic/Aqueous Organic
Aqueous Organic Aqueous Ratio (Ni g/l) (Ni g/l) (Ni g/l) (Ni g/l)
4:1 5.73 43.30 2.46 58.12 6:1 7.16 54.31 4.93 68.5 10:1 9.51 68.98
8.21 80.73
[0117] The results illustrate the improved ammoniacal strip
achieved with 4-nonyl-2-(5-nonyl-1H-pyrazol-3-yl)-phenol compared
to a commercial reagent 2-hydroxy-5-nonyl-acetophenone-oxime.
(B) Nickel can Also be Recovered Under Acid Stripping
Conditions
[0118] This can be demonstrated by stripping nickel loaded organic
with acidic spent electrolyte at varying organic to aqueous ratios.
After stirring the solutions for one hour at 25.degree. C. to
ensure equilibrium is reached, the organic and aqueous phases are
separated and the nickel content of the organic phase measured by
atomic adsorption.
Ammonia Transfer
[0119] An aqueous solution containing 280 g/l NH.sub.3/220 g/l
CO.sub.2 (prepared by dissolving ammonium carbamate (197 g) in an
ammonia solution (172 ml at 32% w/w) and diluting to 500 ml with
water) is contacted with a ligand solution (0.49M in ORFOM.RTM.
SX-7), (which had previously been fully loaded with nickel) at
varying organic to aqueous ratios. The solutions are stirred for
one hour at 25.degree. C. to ensure equilibrium is reached. The
organic phases are separated and the ammonia content of the organic
phase measured by acid/base titration.
TABLE-US-00007 2-hydroxy-5-nonyl- acetophenone-oxime
2-(5-(1-hexylnonyl)-1H- (commercial reagent) pyrazol-3-yl)-phenol
Organic/Aqueous Organic Phase Organic Phase Ratio (NH.sub.3 ppm)
(NH.sub.3 ppm) 1:1 2033 35 1:4 763 24
[0120] The results illustrate the reduced ammonia transfer into the
organic phase achieved with
4-nonyl-2-(5-nonyl-1H-pyrazol-3-yl)-phenol compared to a commercial
reagent 2-hydroxy-5-nonyl-acetophenone-oxime.
Reagent Stability Tests
[0121] Stability in Contact with a Typical Acidic Spent
Electrolyte
[0122] A solution of each ligand (32 ml at 0.2M) in ORFOM.RTM. SX-7
is stirred at 300 rpm in contact with an aqueous solution (32 ml)
containing copper sulphate (30 g/l Cu.sup.2+) and sulphuric acid
(150 g/l) at 50.degree. C. Samples are taken at various intervals
and the maximum copper loading of each ligand solution is
measured.
TABLE-US-00008 2-hydroxy-5-nonyl- 2-(5-nonyl- acetophenone-oxime
1H-pyrazol-3- Contact Time (commercial reagent) yl)-phenol at
50.degree. C. Maximum Load Maximum Load (hours) (% of start ML) (%
of start ML) 0 100 100 66 93.5 100 162 91.2 100 306 83.4 100
[0123] The results illustrate the significant improvement in the
stability of 4-nonyl-2-(5-nonyl-1H-pyrazol-3-yl)-phenol when
exposed to a typical acidic spent electrolyte compared to a
commercial reagent 2-hydroxy-5-nonyl-acetophenone-oxime.
Stability in Contact with Typical Ammoniacal Strip Solution
[0124] A solution of each ligand (90 ml at 0.49M) in ORFOM.RTM.
SX-7, previously fully loaded with Ni.sup.2+, is stirred at 600 rpm
in contact with an aqueous solution (90 ml) containing 280 g/l
NH.sub.3/220 g/l CO.sub.2 at 40.degree. C. Samples are taken at
various intervals and the maximum nickel loading of each ligand
solution is measured.
TABLE-US-00009 2-hydroxy-5-nonyl- 2-(5-nonyl-1H- acetophenone-oxime
pyrazol-3- Contact Time (commercial reagent) yl)-phenol at
40.degree. C. Maximum Load Maximum Load (hours) (% of start ML) (%
of start ML) 0 100 100 19 99.8 100 67 100 100 140 99.7 100 308 98.9
100 476 95.6 100 692 90.6 100 1004 70.6 100 1822 32.5 100
[0125] The results illustrate the significant improvement in the
stability of 4-nonyl-2-(5-nonyl-1H-pyrazol-3-yl)-phenol exposed to
a typical ammonia/carbonate strip solution when compared to a
commercial reagent 2-hydroxy-5-nonyl-acetophenone-oxime.
* * * * *