Process for eluting indium from a chelate resin containing adsorbed indium

A process for eluting indium from a chelate resin having a phosphorus atom-containing, chelate-forming group which contains adsorbed indium, which comprises contacting said resin firstly with a primary eluent containing an acid containing no halogen atom in the molecule at a concentration of 0.1N or higher and then with an eluent for indium which is selected from the group consisting of (1) a solution of an acid containing a halogen atom in the molecule, (2) a mixed solution of (a) a metal halide, an ammonium halide or a mixture thereof and (b) an acid and (3) a mixed solution of a sulfide and a base compound.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a process for eluting indium from a chelate resin 
adsorbing indium. More particularly, the invention relates to a process 
for selective elution of indium which comprises firstly eluting cationic 
metals other than indium preferentially from a chelate resin having a 
phosphorus atom-containing, chelate-forming group which contains said 
metals including indium adsorbed and then eluting indium. 
2. Description of the Prior Art 
As a process for recovering indium from an indium-containing solution 
obtained by subjecting a sludge as a by-product in refining of zinc, lead 
or the like to a treatment such as leaching by sulfuric acid, there has 
hitherto been known a process for recovering indium by allowing a chelate 
resin having a functional group of iminodiacetic acid type to adsorb the 
indium in the solution [Anal. Chem. Acta., 40 (1968) 479-485]. However, 
because such a chelate resin has low adsorptivity for indium, the recovery 
amount of indium per unit amount of chelate resin used is low. For 
improvement of this problem, the present inventors had previously proposed 
a process for recovering indium by the use of a chelate resin having a 
phosphorus atom-containing, chelate-forming group [Japanese Patent 
Application Kokai (Laid-open) No. 172256/1983]. This chelate resin has 
much higher adsorptivity for indium. However, the resin, similarly to 
other known chelate resins, simultaneously adsorbs other metals such as, 
for example, iron, zinc, nickel, cobalt, copper and the like together with 
indium; accordingly, when an indium-containing solution wherein these 
other metals are also present is subjected to adsorption by the resin, the 
other metals are also adsorbed; and, in elution of indium from the resin 
by the use of an eluent, the other metals are eluted together with indium. 
Because of the above problem, in recovery of indium from an 
indium-containing eluate obtained as above, a very complicated refining 
process has been required such as (1) a process wherein said eluate is 
neutralized to precipitate indium and other metal ions in the form of 
hydroxide and the hydroxides are dissolved in an acid or an alkali and 
this step is repeated to gradually increase the concentration of indium 
and (2) a process wherein said eluate is subjected to extraction by an 
indium-extracting agent and then the resulting extract is subjected to 
back extraction by a back extracting agent. 
In view of the above situation, the present inventors have made extensive 
study on a process for selectively eluting and separating indium from a 
chelate resin containing adsorbed indium which is obtained by contacting 
an indium-containing solution with a particular chelate resin having a 
phosphorus atom-containing, chelate-forming group, of high adsorptivity 
for indium. As a result, it has been found that indium can easily be 
isolated from said chelate resin containing adsorbed indium by a two step 
treatment which comprises firstly contacting the chelate resin with a 
particular primary eluent capable of preferentially eluting metals other 
than indium and then contacting the resulting resin with an eluent for 
indium capable of eluting indium. Based on this finding, the present 
invention has been completed. 
SUMMARY OF THE INVENTION 
The object of the present invention is to provide a process for eluting 
indium from a chelate resin having a phosphorus atom-containing, 
chelate-forming group which adsorbed indium, which comprises contacting 
said resin firstly with a primary eluent containing an acid containing no 
halogen atom in the molecule at concentration of 0.1N or higher and then 
with an eluent for indium which is selected form the group consisting of 
(1) a solution of an acid containing a halogen atom in the molecule, (2) a 
mixed solution of (a) a metal halide, an ammonium halide or a mixture 
thereof and (b) an acid and (3) a mixed solution of a sulfide and a base 
compound. 
DETAILED DESCRIPTION OF THE INVENTION 
The chelate resin having a phosphorus atom-containing, chelate-forming 
group used in the present invention has no particular limitation as long 
as the resin has a phosphorus atom-containing, chelate-forming group. As 
the chelate-forming group, there can be mentioned, for example, a 
phosphine group, a phosphonium base, a phosphonic acid ester group, a 
phosphonic acid group, a phosphinic acid ester group, a phosphinic acid 
group, an aminoalkylenephosphonic acid ester group, an 
aminoalkylenephosphonic acid group and the metal salts of these 
chelate-forming groups. A chelate resin wherein one of these 
chelate-forming groups is combined with the main body of the resin via an 
aminoalkylene group is particularly preferable in the present invention 
because such a resin has high adsorptivity for indium and is excellent in 
selective elution of indium. 
The above mentioned metal salts of phosphorus atom-containing, 
chelate-forming groups are metal salts formed by chelate or complex 
bonding between a phosphorus atom-containing, chelate-forming group and a 
metal. This metal has no particular restriction as long as it has a weaker 
bond with the chelate-forming group than indium has. As the metal, there 
can ordinarily be used alkali metals and alkaline earth metals such as 
sodium, potassium, calcium, magnesium and the like. 
As the chelate resin having a phosphorus atom-containing, chelate-forming 
group, there can be mentioned, for example, chelate resins containing a 
phosphine group or a phosphomnium base which are obtained by reacting a 
polymer such as a styrene-divinylbenzene copolymer, a phenol resin, a 
polyethylene, a polypropylene or the like containing a halogenated alkyl 
group (a chloromethyl group, a bromomethyl group or the like) or an 
halogen atom (bromine, iodine or the like) with a phosphide compound or a 
phosphine compound such as lithium diphenylphosphide, sodium 
diphenylphosphide, lithium phenylphosphide, tricresylphosphine or the like 
or with a mixture of these compounds; chelate resins containing a 
phosphonic acid ester group obtained by reacting a styrene-divinylbenzene 
copolymer, a phenol resin, an aniline resin or a m-phenylene polymer 
(hereunder these are referred to as a resin containing a halogenated alkyl 
group) with a phosphorous acid derivative such as triethyl phosphite, 
triphenyl phosphite, trimethyl phosphite or the like or with a mixture of 
these phosphites (hereunder these phosphites and their mixtures are 
referred to as a phosphorous acid derivative); chelate resins containing a 
phosphonic acid group obtained by hydrolyzing said chelate resin 
containing a phosphonic acid ester group or by reacting a polymer such as 
a polystyrene, a phenol resin, a polyethylene, a polypropylene or the like 
with phosphorus trichloride and further with chlorine or oxygen and then 
hydrolyzing the reaction product; chelate resins containing a phosphonic 
acid ester group obtained by reacting said resin containing a halogenated 
alkyl group with a hypophosphorous acid derivative such as diethyl 
hypophosphite, diphenyl hypophosphite or the like or with a mixture of 
these hypophosphites (hereunder these hypophosphites and their mixtures 
are referred to as a hypophosphorous acid derivative); chelate resins 
containing a phosphinic acid group obtained by hydrolyzing said chelate 
resin containing a phosphinic acid ester group or by reacting a polymer 
such as a polystyrene, a phenol resin, a polyethylene, a polypropylene or 
the like with phosphorus trichloride and then hydrolyzing the reaction 
product; chelate resins containing an aminoalkylenephosphonic acid ester 
group or an aminoalkylenephosphinic acid ester group obtained by (1) 
contacting a polymer such as a styrene-divinylbenzene copolymer, a phenol 
resin, a polyethylene, a polypropylene, a polyvinyl chloride, a 
polyacralonitrile, a polyvinylidene cyanide, a polymethacrylonitrile, a 
poly-.alpha.-chloroacrylonitrile or the like containing a "reactive to 
amine" group such as a halogenated alkyl group, a sulfonyl chloride group, 
a carbonyl chloride group, an isocyanate group, a nitrile group, a 
chlorine atom, a bromine atom, an iodine atom, an epoxy group, an aldehyde 
group, a ketone group or the like (hereunder, these polymers are referred 
to as a resin containing a "reactive to amine" group) with an amine 
compound such as ammonia, ethylenediamine, diethylenetriamine, 
triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 
hexamethylenediamine, guanidine, hydrazine or the like, reacting the 
resulting aminated resin with an aldehyde (e.g. acetaldehyde, formaldehyde 
or the like), a ketone (e.g. acetone, acetylacetone or the like) or a 
mixture thereof to obtain a resin containing a Schiff base and then 
reacting the resin with said phosphorous acid derivative, or by (2) 
reacting said aminated resin with an methylating agent (e.g. formalin, 
formaldehyde, paraformaldehyde, trioxane or the like) and said phosphorous 
acid derivative, or by (3) reacting said aminated resin with an 
halogenated alkylphosphonic acid ester (e.g. diethyl 
chloromethylphosphonate, ethyl chloromethylphosphonate, diethyl 
chloromethylphosphonate, dicresyl chloromethylphosphonate or the like), a 
halogenated alkylphosphinic acid ester (e.g. ethyl chloromethylphosphinate 
or the like) or their mixture; chelate resins containing an 
aminoalkylenephosphonic acid group or an aminoalkylenephosphinic acid 
group obtained by hydrolyzing said chelate resin containing an 
aminoalkylenephosphonic acid ester group or an aminoalkylenephosphinic 
acid ester group or by using phosphorous acid in place of a phosphorous 
acid derivative in the production of said chelate resin containing an 
aminoalkylenephosphonic acid ester or an aminoalkylenephosphinic acid 
ester group; and so forth. 
The chelate resin containing adsorbed indium used in the present invention 
is a chelate resin containing indium and other metals adsorbed which is 
obtained by subjecting an indium solution containing indium and other 
metals (e.g. a solution obtained by subjecting a sludge as a by-product of 
metal refining to leaching by sulfuric acid or the like) to adsorption 
treatment by the use of the previously mentioned chelate resin having a 
phosphorus atom-containing, chelate-forming group. In some cases, the 
chelate resin containing adsorbed indium is washed as necessary, prior to 
the practice of the present invention process. 
In the present invention, such a chelate resin containing adsorbed indium 
is contacted firstly with a primary eluent to preferentially elute metals 
other than indium without substantially eluting indium and then with an 
eluent for indium to elute indium. 
As the primary eluent, there are used aqueous solutions containing an acid 
containing no halogen atom in the molecule such as an inorganic acid (e.g. 
sulfuric acid, nitric acid, phosphoric acid, boric acid or the like), an 
organic acid (e.g. acetic acid, formic acid, oxalic acid, lactic acid or 
the like) or a mixture of these acids. Particularly preferable aqueous 
solutions are those containing sulfuric acid, phosphoric acid, nitric 
acid, acetic acid or a mixture thereof. 
The acid concentration in the primary eluent has no particular restriction 
as long as it is at or higher than a minimum concentration at which metals 
other than indium are preferentially eluted. Ordinarily, it is 0.1N or 
higher, preferably 0.3 to 5N. 
The primary eluent is used, as a rule, in the form of an aqueous solution 
of the above mentioned acid. It may contain an organic solvent capable of 
dissolving the acid. 
The amount of the primary eluent used is not particularly restricted and 
can vary depending upon the type and concentration of the acid in the 
primary eluent, the type of chelate resin, the type and amount of other 
metals than indium adsorbed by the chelate resin, etc. The amount of the 
primary eluent used can be determined by conducting a preliminary test as 
necessary. 
The contact temperature between the chelate resin containing adsorbed 
metals and the primary eluent is not particulary restricted; however, the 
temperature is usually 0.degree. to 100.degree. C. The contact time 
between them is not particularly restricted, either. 
The chelate resin from which metals other than indium have preferentially 
been eluted and removed by the primary eluent is contacted with an eluent 
for indium as it is or after water washing as necessary, whereby indium is 
eluted. 
As the eluent for indium, there are used (1) a solution of an acid 
containing a halogen atom in the molecule, (2) a mixed solution of (a) a 
metal halide, an ammonium halide or their mixture and (b) an acid and (3) 
a mixed solution of a sulfide and a base compound. 
As the acid containing a halogen atom in the molecule, there can be 
mentioned inorganic acids containing a halogen atom in the molecule, such 
as hydrochloric acid, hydrobromic acid, hydorfluoric acid, hydroiodic acid 
and their mixtures. These acids are ordinarily used in the form of an 
aqueous solution containing one of the acids or in the form of an mixed 
aqueous solution containing one of these acids and one of the previously 
mentioned acids containing no halogen atom in the molecule. 
As the metal halide, there are preferably used halides of alkali metals and 
alkaline earth metals, such as sodium chloride, sodium bromide, sodium 
fluoride, potassium chloride, potassium bromide, potassium fluoride, 
magnesium chloride, magnesium bromide, calcium chloride, calcium bromide 
and the like. 
As the ammonium halide, there are mentioned, for example, ammonium 
chloride, ammonium bromide and the like. Ammonium chloride is particularly 
preferable. 
The metal halide, the ammonium halide or their mixture is mixed with an 
acid and the resulting mixture is used as an aqueous solution. 
The acid used above may or may not contain a halogen atom in the molecule 
and may be a mixture. Various acids such as mentioned above can be used. 
As the sulfide, there can be mentioned water-soluble inorganic sulfides 
such as sodium sulfide, sodium hydrosulfide, ammonium sulfide, hydrogen 
sulfide, potassium sulfide, ammonium hydrogensulfide, sodium 
hydrogensulfide, lithium sulfide, barium sulfide, magnesium sulfide and 
the like. As the base compound, there can be mentioned inorganic alkali 
compounds such as sodium hydroxide, potassium hydroxide, calcium 
hydroxide, magnesium hydroxide, ammonia and the like as well as 
water-soluble organic amines such as ethylenediamine, diethylenetriamine, 
diethylamine, triethylamine and the like. The sulfide and the base 
compound are mixed and the resulting mixture is used as an aqueous 
solution. 
These eluents for indium are, as previously described, used in the form of 
aqueous solution. They may also contain an organic solvent unless the 
solvent badly affect the elution treatment. 
Of the above mentioned eluents for indium, in the present invention, there 
are particularly preferred an aqueous solution of hydrochloric acid, an 
aqueous solution of a mixture between (a) sulfuric acid, nitric acid or 
acetic acid and (b) sodium chloride, ammonium chloride, calcium chloride 
or magnesium chloride and an aqueous solution of a mixture between (a) 
sodium sulfide, sodium hydrosulfide, ammonium sulfide or hydrogen sulfide 
and (b) sodium hydroxide, potassium hydroxide, calcium hydroxide or 
ammonia. 
In the present invention, there is used an eluent for indium selected from 
three kinds of the eluents (1), (2) and (3) mentioned above. The 
concentration of the active component in the eluent for indium is not 
particularly restricted as long as the concentration is at a minimum level 
at which indium can be eluted. In general, it is preferable that the 
concentration of the active component in the eluent for indium be 0.3N or 
higher. 
The amount of the eluent for indium used has no particular restriction. It 
can vary depending upon the type and concentration of the active component 
in eluent, the type of the chelate resin, the amount of indium adsorbed by 
the resin, etc. and can be determined by conducting a preliminary test as 
necessary. 
The temperature of the contact between the chelate resin containing 
adsorbed indium and the eluent for indium is not particularly restricted. 
It is however, usually 0.degree. to 100.degree. C. 
The time of the contact between them is not particularly restricted, 
either. 
As mentioned above, in the present invention, the chelate resin containing 
adsorbed indium is contacted firstly with the primary eluent and then with 
the eluent for indium. Contact methods used in these contacts are not 
particularly restricted. As the contact methods, there are used ordinary 
contact methods such as, for example, (1) a method wherein an eluent is 
passed through a column packed with a chelate resin containing adsorbed 
indium, (2) a method wherein a chelate resin containing adsorbed indium is 
immersed in an eluent and (3) a method which is a combination of (1) and 
(2). The method (1), namely, a packed column method is preferable in view 
of treatment procedure, efficiency, etc. 
Thus according to the present invention, indium of a high purity can be 
eluted by the eluent effectively by a simple procedure. 
The eluate obtained is subjected to recovery of metallic indium by a method 
such as electrolysis, as it is, or after it has been contacted once more 
with a chelate resin having a phosphorus atom-containing, chelate-forming 
group for refining such as adsorption, elution and the like, or after it 
has been neutralized to obtain sponge indium and then the sponge indium 
has been dissolved in sulfuric acid. 
Hereunder, the present invention will be explained in more detail by way of 
Examples; however, the invention is in no way restricted to these Examples 
.

EXAMPLE 1 
A solution obtained by subjecting a pig iron dust to leaching by sulfuric 
acid was contacted with a chelate resin having an aminomethylenephosphonic 
acid group (DUOLITE ES-467, manufactured by Diamond Shamrock Corp.) 
(hereunder this resin is referred to as chelate resin A) to obtain a 
chelate resin containing 2.2 g of indium, 1,494 g of zinc, 43 g of iron 
and 105 g of cadmium adsorbed per 1 kg of the resin. The resin was packed 
in a column. At the top of the column, a 2N aqueous sulfuric acid solution 
as a primary eluent was charged into the column at room temperature at a 
space velocity of 2 hr.sup.-1 in a total volume of 20 times the volume of 
the resin, whereby 0.01 g indium, 1,494 g of zinc, 43 g of iron and 105 g 
of cadmium were eluted. Subsequently, a 4N aqueous hydrochloric acid 
solution as an eluent for indium was charged at room temperature at a 
space velocity of 1 hr.sup.-1 in a total volume of 5 times the volume of 
the resin, whereby 2.1 g of indium could be eluted by the hydrochloric 
acid solution. 
EXAMPLES 2 TO 11 
Elution was conducted in the same manner as in Example 1 except that the 
types and concentrations of the primary eluent and the eluent for indium 
each used in Example 1 were changed. The results obtained are shown in 
Table 1. 
TABLE 1 
__________________________________________________________________________ 
Primary elution Elution of indium 
Type and 
Amount of metal Amount of metal 
Exam- 
concentration 
eluted (g) Type and concentration 
eluted (g) 
ple of eluent 
In 
Fe Zn Cd of eluent In 
Fe 
Zn 
Cd 
__________________________________________________________________________ 
2 4 N Aqueous 
0.0 
43.0 
1492 
105 
Aqueous solution containing 
2.0 
0.0 
0.3 
0.0 
phosphoric acid 2 N sulfuric acid and 
solution 1 mole/l of sodium chloride 
3 1 N Aqueous 
0.1 
42.7 
1493 
104 
Aqueous solution containing 
2.1 
0.3 
0.2 
0.1 
nitric acid 1 N hydrochloric acid and 
solution 1 mole/l of ammonium 
chloride 
4 2 N Aqueous 
0.0 
43.0 
1492 
104 
Aqueous solution containing 
1.9 
0.0 
0.3 
0.2 
acetic acid 0.5 N hydrofluoric acid and 
solution 2 N potassium fluoride 
5 3 N Aqueous 
0.0 
43.0 
1494 
105 
Aqueous solution containing 
2.0 
0.0 
0.0 
0.0 
sulfuric acid 2 N nitric acid and 
solution 2 moles/l of calcium 
chloride 
6 2 N Aqueous 
0.0 
42.7 
1494 
105 
Aqueous solution containing 
2.1 
0.3 
0.0 
0.0 
sulfuric acid 2 N phosphoric acid and 
solution 2 moles/l of calcium 
chloride 
7 2 N Aqueous 
0.0 
43.0 
1494 
105 
Aqueous solution containing 
2.2 
0.0 
0.0 
0.0 
sulfuric acid 1 N hydrogen bromide and 
solution 1 N magnesium chloride 
8 2 N Aqueous 
0.0 
43.0 
1494 
104 
Aqueous solution containing 
2.0 
0.0 
0.0 
0.1 
sulfuric acid 1 N hydrogen iodide and 
solution 2 N sodium fluoride 
9 2 N Aqueous 
0.0 
42.2 
1493 
103 
Aqueous solution containing 
2.2 
0.7 
0.2 
0.3 
oxalic acid 2 N hydrochloric acid and 
solution 2 moles/l of sodium chloride 
10 2 N Aqueous 
0.0 
42.3 
1492 
103 
Aqueous solution containing 
1.9 
0.6 
0.3 
0.2 
boric acid 2 N sodium hydroxide and 
solution 2 moles/l of sodium sulfide 
11 2 N Aqueous 
0.0 
42.1 
1492 
103 
Aqueous solution containing 
1.8 
0.7 
0.3 
0.3 
formic acid 2 N potassium hydroxide and 
solution 2 moles/l of sodium 
hydrosulfide 
__________________________________________________________________________ 
EXAMPLES 12 TO 19 AND COMATIVE EXAMPLE 1 
A solution containing indium and other metals which had been obtained by 
subjecting a lead slag as a by-product of cadmium refining to leaching by 
sulfuric acid was contacted with the following chelate resins B to J and a 
chelate resin having an iminodiacetic acid group (DUOLITE ES-466, 
manufactured by Diamond Shamrock Corp.). The respective resins adsorbed 
metals as shown in Table 2. 
These resins containing adsorbed metals were then subjected to two stage 
elution by the use of a primary eluent and an eluent for indium as shown 
in Table 2, in the same manner as in Example 1. The results obtained are 
shown in Table 2. 
Chelate resin B: A commercially available resin having a phosphonic acid 
group (DUOLITE ES-63, manufactured by Diamond Shamrock Corp.). 
Chelate resin C: A resin having an aminoalkylenephosphonic acid ester group 
which was obtained by reacting 60 parts by weight of a polyacrylonitrile 
with 103 parts by weight of diethylenetriamine in a water medium to obtain 
an aminated polyacrylonitrile and then reacting the aminated 
polyacrylonitrile with 281 parts by weight of an aqueous formalin solution 
and 498 parts by weight of triethyl phosphite in the presence of 36% 
hydrochloric acid. 
Chelate resin D: A resin having a quaternary phosphonium base which was 
obtained by reacting 200 parts by weight of a chloromethylated polystyrene 
with 200 parts by weight of tributylphosphine in dimethylformamide. 
Chelate resin E: A resin having a phosphine group which was obtained by 
reacting 150 parts by weight of a brominated polystyrene with 64 parts by 
weight of a hexane solution containing 1.6 mol % of n-butyllithium in 
tetrahydrofuran as a solvent to obtain a lithium polystyrene, reacting the 
lithium polystyrene with 300 parts by weight of chlorodiphenylphosphine in 
tetrahydrofuran and oxidizing the reaction product with 371 parts by 
weight of 40% peracetic acid in methylene chloride as a solvent. 
Chelate resin F: A resin having a sodium phosphonate group which was 
obtained by hydrolyzing the chelate resin D with a 20% aqueous sodium 
hydroxide solution. 
Chelate resin G: A resin having a phosphinic acid group which was obtained 
by reacting 100 parts by weight of a polystyrene with 150 parts by weight 
of phosphorus trichloride in chloroform as a solvent and then hydrolyzing 
the reaction product. 
Chelate resin H: A resin having a phosphinic acid ester group which was 
obtained by reacting 100 parts by weight of an aminated polystyrene with 
120 parts by weight of cresyl chloromethylphosphinate in 
1,2-dichloroethane as a solvent. 
Chelate resin I: A resin having a diethylenetriaminomethylenephosphonic 
acid group which was obtained by hydrolyzing the chelate resin C with a 
20% aqueous sodium hydroxide solution. 
Chelate resin J: A resin having an aminoalkylenephosphonic acid group which 
was obtained by using the same procedure as in production of the chelate 
resin C except that 498 parts by weight of triethyl phosphite used in 
production of the chelate resin C was replaced by 246 parts by weight of 
phosphorous acid. 
TABLE 2 
__________________________________________________________________________ 
Amount of metal 
Primary elution 
adsorbed Type and con- 
Amount of metal 
Type of 
(g/kg resin) 
centration of 
eluted (g) 
resin In 
Cd Zn Pb eluent In 
Cd Zn Pb 
__________________________________________________________________________ 
Example 12 
Chelate 
1.8 
413 
875 
0.8 
1 N Aqueous sulfuric 
0.2 
413 
875 
0.8 
resin B acid solution 
Example 13 
Chelate 
3.7 
542 
1391 
1.1 
1 N Aqueous sulfuric 
0.0 
542 
1390 
1.1 
resin C acid solution 
Example 14 
Chelate 
2.4 
403 
1206 
0.9 
1 N Aqueous sulfuric 
0.3 
403 
1205 
0.9 
resin E acid solution 
Example 15 
Chelate 
1.9 
392 
1103 
0.7 
1 N Aqueous sulfuric 
0.2 
392 
1101 
0.7 
resin F acid solution 
Example 16 
Chelate 
1.8 
371 
985 
0.9 
0.5 N Aqueous sulfu- 
0.3 
370 
984 
0.9 
resin G ric acid solution 
Example 17 
Chelate 
4.1 
592 
1447 
1.1 
2 N Aqueous sulfuric 
0.0 
592 
1445 
1.1 
resin H acid solution 
Example 18 
Chelate 
4.7 
692 
1531 
1.3 
2 N Aqueous sulfuric 
0.0 
692 
1530 
1.3 
resin I acid solution 
Example 19 
Chelate 
5.2 
703 
1471 
1.2 
50% Aqueous sul- 
0.0 
703 
1470 
1.2 
resin J furic acid solution 
Comparative 
DUOLITE 
0.4 
453 
1430 
1.9 
1 N Aqueous sul- 
0.4 
453 
1430 
1.9 
Example 1 
ES-466 furic acid solution 
__________________________________________________________________________ 
Elution of indium 
Amount of metal 
Type and concentration 
eluted (g) 
of eluent In 
Cd 
Zn 
Pb 
__________________________________________________________________________ 
Example 12 
2 N Aqueous hydrochloric acid 
1.6 
0.0 
0.0 
0.0 
solution 
Example 13 
3 N Aqueous hydrochloric acid 
3.7 
0.0 
0.3 
0.0 
solution 
Example 14 
2 N Aqueous hydrochloric acid 
2.1 
0.0 
0.2 
0.0 
solution 
Example 15 
Aqueous solution containing 
1.7 
0.0 
0.4 
0.0 
0.5 N hydrochloric acid and 
0.2 N hydrogen fluoride 
Example 16 
1 N Aqueous hydrochloric 
1.5 
0.4 
0.3 
0.0 
acid solution 
Example 17 
2 N Aqueous hydrochloric 
4.1 
0.0 
0.2 
0.0 
acid solution 
Example 18 
Aqueous solution containing 
4.7 
0.0 
0.1 
0.0 
2 N hydrochloric acid and 
2 moles/l sodium fluoride 
Example 19 
Aqueous solution containing 
5.2 
0.0 
0.1 
0.0 
1 N sulfuric acid and 
2 moles/l of ammonium chloride 
Comparative 
2 N Aqueous hydrochloric acid 
0.0 
0.0 
0.0 
0.0 
Example 1 
solution 
__________________________________________________________________________