U.S. patent application number 11/658626 was filed with the patent office on 2009-11-05 for method for producing high-purity nickel.
This patent application is currently assigned to JINCHUAN GROUP LTD.. Invention is credited to Wenying Cao, Zhenhua Chen, Yongjun Li, Yongfeng Ma, Shiqing Qi, Jun Wu, Zhongqiang Yan, Wengang Zheng.
Application Number | 20090272651 11/658626 |
Document ID | / |
Family ID | 34604510 |
Filed Date | 2009-11-05 |
United States Patent
Application |
20090272651 |
Kind Code |
A1 |
Li; Yongjun ; et
al. |
November 5, 2009 |
Method for producing high-purity nickel
Abstract
A method for producing high-purity nickel, which involves using
a hydrochloric acid solution system to electro-deposit high-purity
nickel, characterized in that, it includes the following steps
sequentially: 3N-grade-grade electrolytic nickel was used as anode
and the electro-deposition was carried out in a hydrochloric acid
system, the solution obtained from the electro-deposition was
extracted by a three-level countercurrent extraction using anion
extraction solvents, and then back-extracted and degreased. After
that, the solution was passed through the anion exchange resin to
be further purified by ion exchange, and finally put into the
electrolytic cell to deposit nickel. The amount of the solution
that was put into the cell and the amount of the solution that was
drawn out of the cell after the electro-deposition was the same?
After the glow discharge analysis by a mass spectrography, the
high-purity nickel obtained by the method according to the present
invention was the 5N-grade-grade high-purity nickel. The cost was
low and the contamination was prevented.
Inventors: |
Li; Yongjun; (Jinchang,
CN) ; Wu; Jun; (Jinchang, CN) ; Zheng;
Wengang; (Jinchang, CN) ; Chen; Zhenhua;
(Jinchang, CN) ; Yan; Zhongqiang; (Jinchang,
CN) ; Ma; Yongfeng; (Jinchang, CN) ; Qi;
Shiqing; (Jinchang, CN) ; Cao; Wenying;
(Jinchang, CN) |
Correspondence
Address: |
MORRISON & FOERSTER LLP
425 MARKET STREET
SAN FRANCISCO
CA
94105-2482
US
|
Assignee: |
JINCHUAN GROUP LTD.
Gansu
CN
|
Family ID: |
34604510 |
Appl. No.: |
11/658626 |
Filed: |
April 13, 2005 |
PCT Filed: |
April 13, 2005 |
PCT NO: |
PCT/CN05/00488 |
371 Date: |
November 6, 2008 |
Current U.S.
Class: |
205/99 |
Current CPC
Class: |
C22B 23/06 20130101;
Y02P 10/234 20151101; C25C 1/08 20130101; C22B 3/0005 20130101;
Y02P 10/20 20151101; C22B 3/42 20130101 |
Class at
Publication: |
205/99 |
International
Class: |
C25D 21/22 20060101
C25D021/22 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 28, 2004 |
CN |
200410070648.2 |
Claims
1. Method for producing high purity nickel, characterized in that
it involves the sequential steps: a. Employing 3N-grade
electrolytic nickel as anode and corrosion resistant titanium wire
as cathode, electrolyzing in hydrochloric acid system are
electrolyse to prepare NiCl.sub.2 solution at the current density
of about 100 A/m.sup.2 to 200 A/m.sup.2; and at the end of
electrolysis when the concentration of H.sup.+ is about 1 g/l to 2
g/l, electrolyzing at the current density of about 30 A/m.sup.2 to
70 A/m.sup.2 to a pH of the solution of about 1 to 3 b. After
degreasing the back-extracted solution through the activated carbon
column, then purifying the said solution through ion-exchange
column of mixed anion exchange resin of anion exchange resin 331,
717, D301 and D401 at the exchange follow rate equal to or less
than 2 BV/h. Main impurities of the prepared solution can be
follows: Co and Fe less than 0.001 g/l each, and Cu, Pb and Zn less
than 0.0002 g/l each; and c. electro-depositing in solution
purified by ion exchange resin in electrolytic cell at a pH of
about 1 to 3, the current density of about 100 A/m.sup.2 to 200
A/m.sup.2 and a temperature of about 40.degree. to 60.degree.,
drawing out the electro-deposited solution simultaneously to keep a
constant circulating to obtain high purity nickel.
2. The method for producing high purity nickel according to claim
1, characterized in that the said electrolytic solution is
extracted by 3-stage countercurrent extraction at the extractant
phase ratio of 1:2, and back-extract with pure water 10 mins after
achieving extraction equilibrium.
3. The method for producing high purity nickel according to claim 1
or 2, characterized in that anion extractant contains 20 vol. % to
40 vol. % tertiary amine, 20 vol. % to 45 vol. % butylate, and
sulphonated kerosene.
4. The method for producing high purity nickel according to claim
1, characterized in that it is performed before extracting NiCl2
solution that purifying the organic phase of the anion extractant
by washing and sequentially saturating the said organic phase with
4N high purity hydrochloric acid.
5. The method for producing high purity nickel according to claim
1, characterized in that a hollow fiber ball is employed to
degrease the said solution.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method for producing
nickel. More particularly, it relates to a method for producing
high purity nickel that includes employing 3N-grade electrolytic
nickel to electro-deposited in hydrochloric acid solution
system.
BACKGROUND OF THE INVENTION
[0002] Large quantities of special materials are demanded with the
development of high technology. Many types of high purity metal
which have been found are used for Hi-tech strategic goods. The
production, application and characters of the high-purity or super
high-purity metals are novel and growing in modern material science
and engineering field. High-purity (purer than 5N-grade) metals are
used in producing semiconductor and VLSI widely. More than 20 types
of high purity metal such as Ga, In, As, Sb, Cd, Sn, Te, Bi, S, Zn,
Cu, Se, P and their compounds or alloys are used to produce
electronic components and PCB.
[0003] Nickel is generally used in the conventional stainless
steel, alloy and other fields. In recent years, demand of high
purity nickel increased in several special fields. For example, a
superalloy made of high purity nickel sis applied in aeroengines,
protective materials for nuclear reactor, biomaterials and
low-expansion alloys; Consumption of high purity nickel gradually
increases in electronic industry field. For example, a specific
Ni--Fe alloy is applied in lead frame, and a Cu--Ni--Sn alloy is
applied in wire port; It requires very low content of impurities
such as alkali metals, radioelements, transition metals and gases,
when high-purity nickel is applied in LSI and thereof line
material, magnetic membrane, and special packing materials.
[0004] The methods for producing high purity nickel have been
disclosed in few publications and patents. For example,
WO03/014421A1 (title: method for producing high purity nickel, high
purity nickel, spattering target comprising the high purity nickel,
and thin film formed by using said spattering target) discloses a
method for producing high purity nickel by employing soluble nickel
as an anode and bagging the cathode with membrane, removing
impurities through depositing them as hydroxide, preliminary
electrolyzing or displacing them by displacement reaction by adding
nickel foil to the electrolytic solution, purifying electrolytic
solution, then electrolyzing to produce high purity nickel of
5N-grade (99.999%). Main impurities of the produced nickel can be
follows: O less then 30 ppm, C, N, S, P and F less than 10 ppm
each. (the concentrations of other impurities haven't been
disclosed.)
[0005] Moreover, JP P2000-219988A (title: method for producing high
purity nickel and high purity nickel for forming metallization
film) discloses a method for producing high purity nickel by
performing electrolysis with a soluble anode, and the anode and
cathode are partitioned with two-layer membrane, employing anion
exchange resin to eliminate the impurities in electrolytic
solution, lower the concentration of hydrochloric acid in the
electrolytic solution by diffusion dialysis or evaporation drying,
purifying the electrolytic solution and then electrolyzing to
obtain the high purity nickel. The high purity nickel produced by
this method has fewer impurities. Main impurities of the produced
nickel can be follows: alkali metals less than 1 ppm, Fe, Co, Cr
less than 10 ppm each, U and Th less than 1 ppb each, C less than
50 ppm, and O less than 100 ppm.
[0006] To overcome the problem about the high acid of electric
dissolving stock solution. Boiling and adding alkali to reduce the
acid content are broadly applied in the current methods for
producing high purity nickel, but the said methods result in a high
cost and pollution, and the solution may not be completely
purified. High concentration of impurities in high purity nickel is
caused by the mixing of anolyte and catolyte, due to the adoption
of a soluble anode.
SUMMARY OF THE INVENTION
[0007] On a basis of the foresaid existed technological
deficiencies, the object of the present invention is to provide a
method for producing high purity nickel to settle effectively high
concentration of acid in the electric dissolving stock solution cut
down on production cost, dispel pollution, and depurate solution,
and prevent the anolyte and catolyte from mixing each other.
[0008] An object of the present invention is to provide a method
for producing high purity nickel. The said method involves the
following steps:
[0009] a. Employing 3N-grade electrolytic nickel as anode and
corrosion resistant titanium wire as cathode, electrolyzing in
hydrochloric acid system are electrolyse to prepare NiCl.sub.2
solution at the current density of about 100 A/m.sup.2 to 200
A/m.sup.2; and at the end of electrolysis when the concentration of
H.sup.+ is about 1 g/l to 2 g/l, electrolyzing at the current
density of about 30 A/m.sup.2 to 70 A/m.sup.2 to a pH of the
solution of about 1 to 3;
[0010] b. After degreasing the back-extracted solution through the
activated carbon column, then purifying the said solution through
ion-exchange column of mixed anion exchange resin of anion exchange
resin 331, 717, D301 and D401 at the exchange follow rate equal to
or less than 2BV/h. Main impurities of the prepared solution can be
follows: Co and Fe less than 0.001 g/l each, and Cu, Pb and Zn less
than 0.0002 g/l each; and
[0011] c. Electro-depositing in solution purified by ion exchange
resin in electrolytic cell at a pH of about 1 to 3, the current
density of about 100 A/m.sup.2 to 200 A/m.sup.2 and a temperature
of about 40 to 60.degree., drawing out the electro-deposited
solution simultaneously to keep a constant circulating to obtain
high purity nickel.
[0012] A method according to the present invention for producing
high purity nickel characterized in that the said electrolytic
solution is extracted by 3-stage countercurrent extraction at the
extractant phase ratio of 1:2, and back-extract with pure water 10
mins after achieving extraction equilibrium.
[0013] A method for producing high purity nickel according to the
present invention, characterized in that anion extractant contains
20 vol. % to 40 vol. % tertiary amine, 20 vol. % to 45 vol. %
butylate, and sulphonated kerosene.
[0014] A method for producing high purity nickel according to the
present invention, characterized in that it is performed before
extracting NiCl2 solution that purifying the organic phase of the
anion extractant by washing and sequentially saturating the said
organic phase with 4N high purity hydrochloric acid.
[0015] A method for producing high purity nickel according to the
present invention characterized in that a hollow fiber ball is
employed to degrease the said solution.
[0016] A method for producing high purity nickel according to the
present invention which employs combined anion exchange resin to
form a three dimensional structure to further purify the
solution.
[0017] A method according to the present invention electro-deposit
employs high purity solution purified with ion exchange resin to
produce high purity nickel of 5N-grade purity and determined by
glow discharge mass spectrometry (GDMS) 5N-grade. In the procedure,
reducing the content of acid in the solution by electrolyzing at a
low current density at the end of electrolysis procedure, overcome
the high concentration of acid in the electrolytic solution,
removed acid by boil or neutralization, And it cut down the cost
and prevent pollution. It employs high purity hydrochloric acid to
saturate the purified organic phase, and then extract the high
concentration of NiCl.sub.2 solution with the said organic phase to
remove Co in order to purify the solution. It also employs combined
anion exchange resin forming a three dimensional structure to
further purify the solution. It performs the electrolysis,
extraction, ion exchange and electro-deposition continuously to
further purify the electrolytic solution. It employs an insoluble
anode to produce high purity nickel purer than 5N-grade, so only
purified high purity NiCl.sub.2 solution is in the
electro-deposition cell. Compared with employing a soluble anode.
it prevents the anolyte and catolyte from mixing each other, so
that main impurities of the produced high purity nickel can be
follows: alkali metals less than 0.1 ppm, Fe, Co, and Cr less than
1 ppm each, U and Th less than 0.1 ppb each, C less than 60 ppm,
and O less than 100 ppm.
[0018] Detected impurities in the high purity nickel according to
the present invention include 16 impurities as Co, Fe, Cu, Zn, As,
Cd, Sn, Sb, Pb, Bi, Al, Mn, Mg, Si, P, and S. Concentration of each
impurity element is less than 1 ppm and the concentration of the
main element nickel is more than 99.999%. Preparation high purity
NiCl.sub.2 solution is the basement of producing high purity
nickel. Five impracticable elements, Fe, Co, Cu, Pb and Zn, which
have been chosen from 16 impurities, are detected as the main
impurities. According to the result estimates the purity of the
solution. The experiment shows that choosing the typical impurities
as the main objects to remove can improve the determining
efficiency.
BRIEF DESCRIPTION OF THE DRAWING
[0019] FIG. 1 shows the process flow diagram of the method
according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] A method for producing high purity nickel involves the
sequential steps of:
[0021] a. Employing 3N-grade electrolytic nickel as anode and
corrosion resistant titanium wire as cathode, electrolyzing in
hydrochloric acid system to obtain NiCl.sub.2 solution at the
current density of 100-200 A/m.sup.2; and at the end of
electrolysis when the concentration of H.sup.+ is 1-2 g/l
electrolyzing at the current density of 30-70 A/m.sup.2 to a pH of
the solution of about 1 to 3. Electrolyzing at a low current
density at the end of electrolysis procedure, which can lower the
content of acid in the solution, and avoid the high concentration
of acid in the electrolytic solution. Also, it is less cost and
pollution for without removing acid by boil or neutralization. The
contents of impurities element in prepared NiCl.sub.2 solution by
electrolysis are as follows: 0.006 g/l to 0.009 g/l Co, 0.002 g/l
Cu, 0.002 g/l Fe, 0.001 g/l Pb, and 0.002 g/l Zn.
[0022] b. The said electrolytic solution is extracted by 3-stage
countercurrent extraction with anion extractant which contains 20
vol. % to 40 vol. % tertiary amine, 20 vol. % to 45 vol. %
butylate, and sulphonated kerosene, at the extractant phase ratio
of 1:2, back-extracted with pure water 10 minutes after achieving
extraction equilibrium. Since the concentration of Cl.sup.- is
increased, the impurities of Fe, Co, Cu, Pb and Zn form complexes
anion sufficiently. Fewer impurities exist in the solution after
purifying by extracting with anion exctractant, and the main
impurities can be follows: Cu and Zn less than 0.0003 g/l each, and
Co less than 0.001 g/l.
[0023] c. The extracted solution is degreased through the activated
carbon column, and further purified the said solution through anion
exchange resin 331, 717, D301 and D401 mixed ion-exchange resin
sequentially at the exchange follow rate no more than 2 BV/h. The
purified solution contains Co and Fe are both less than 0.001 g/l,
Cu, Pb and Zn are all less than 0.0002 g/. Since the design
principle of ion exchange system is to ensure that no impurities
from the system pollute the solution, the pure materials is used to
make ion exchange column main body as well as system. The
antipollution metering pump is used to transport and control the
follow of ion exchange solution quantitatively, and the specific
anion exchange resin is used to further purify.
[0024] Extracting residue is degreased, adjusted acidity, purified
by ion exchange resin at the flow rate of about 1 BV/h to 2 BV/h.
Impurities could not be removed efficiently at the too fast flow,
and on the contrary, it will deduce the economic efficiency at the
too slow flow. The impurities such as Pb, Zn, Cu, Fe, and Co in the
solution are reduced after ion exchange and the solution contains
0.006 g/l to 0.009 g/l Co, 0.002 g/l Cu, 0.00 g/l Pb, and 0.002 g/l
Zn.
[0025] d. The solution purified by ion exchange resin is
electro-deposited in electrolytic cell at a pH of about 1 to 3, a
current density of about 100 A/m.sup.2 to 200 A/m.sup.2 and a
temperature of 40 to 60.degree., draw out the electro-deposited
solution simultaneously to keep a constant circulating to obtain
high purity nickel, which is analyzed by glow discharge mass
spectrometry (GDMS) to achieves 5N-grade purity high purity
nickel.
[0026] It is required that no pollution from either electrolytic
cell or environment exists during the producing high purity
experiment. Therefore pure materials are used to make the
electrolytic cell. The electrolytic cell is airproofed and has a
dustproof head cover which is connect with the cell with water
seal. Cathode plate and anode plate assembled with conductive rods
are hung on the head cover. Electrode plates and conductive rods
are made of pure anticorrosive material to prevent acid corrosion
and pollution in solution. Circuit junctions are fastened with
screws and high precision silicon rectifier power is employed in
order to keep constant electrobath voltage and current and
eliminate junction resistance.
EXAMPLES
[0027] As hereunder, Examples of the present invention will be
illustrated, but the following disclosure shows preferred examples
of the present invention only and does not limit the scope of the
present invention at all.
Example 1
[0028] 3N-grade electrolytic nickel was electrolyzed in
hydrochloric acid system to prepare NiCl.sub.2 solution at a
current density of 100 A/m.sup.2. When the concentration of H.sup.+
was 1 g/l, the current density was changed to 30 A/m.sup.2 and
electrolyzed till the pH of the solution to 3, wherein the
concentration of Cl.sup.- was 6 mol/L and the impurities were shown
in the table 1.
TABLE-US-00001 TABLE 1 Contents of impurities in original solution
unit: g/l No. Name Co Cu Fe Pb Zn 1 original solution 0.009 0.002
0.002 0.001 0.001
[0029] Anion extractant contained 25 vol. % tertiary amine, 45 vol.
% butylate, and 30 vol. % sulphonated kerosene was washed by high
purity water, saturated with 4 mol/l high purity hydrochloric acid.
The electrolytic solution was extracted by 3-stage countercurrent
extraction at the extractant phase ratio of 1:2, and then
back-extracted with pure water 10 minutes after achieving
extraction equilibrium. The concentration of Co was decreased from
0.009 g/l to 0.001 g/l. The ingredients of extracting residue were
shown in table 2.
TABLE-US-00002 TABLE 2 Contents of impurities in extract residue
unit: g/l No. Item Co Cu Fe Pb Zn 1 Extract 0.001 0.0003 0.001
0.001 0.0003 residue 2
[0030] The back-extracted solution was degreased through activated
carbon column, further purified through ion exchange column mixed
ion exchange resin from anion exchange resin 331, 717, D301 and
D401 at the exchange follow rate of 2 BV/h. Ingredients in solution
further purified by ion change were shown in table 3.
TABLE-US-00003 TABLE 3 Contents of impurities in purified solution
by ion exchange unit: g/l No. Item Co Cu Fe Pb Zn 1 Purified
solution <0.0004 0.0001 <0.0004 <0.0001 0.0001 by ion
change
[0031] Eletrowinning conditions: current density was 100 A/m.sup.2,
pH of NiCl.sub.2 solution was 3, Eletrowinning temperature was
50.degree.. An insoluble anode was employed to electro-deposit the
solution further purified by ion exchange to produce 5N-grade high
purity nickel. Main impurities of the produced high purity nickel
were as follows: alkali metals less than 0.1 ppm, Fe, Co and Cr
less than 1 ppm each, U and Th less than 0.1 ppb each, C less than
60 ppm, and O less than 100 ppm. Contents of some impurities in
high purity nickel were shown in table 4.
TABLE-US-00004 TABLE 4 Impurities in high purity nickel determined
by glow discharge mass spectrometry (GDMS) impurities in No.
Impurities sample 1 (ppm) 1 Cu <0.8 2 Fe 0.38 3 Co <0.04 4 Pb
0.28 5 Zn <0.03 6 Cd <0.01 7 Bi <0.005 8 Sb 0.14 9 Sn
<0.5 10 As <0.8 11 Al 0.02 12 Mg <0.001 13 Mn <0.005 14
Si 0.04 15 P <0.01 16 S 0.1 Total impurities in high purity
nickel <3 Contents of nickel (%) >99.9997%
Example 2
[0032] 3N-grade electrolytic nickel was electrolyzed in
hydrochloric acid system to prepare NiCl.sub.2 solution at a
current density of 150 A/m.sup.2. When the concentration of H.sup.+
was 1.5 g/l, the current density was changed to 50 A/m.sup.2 and
electrolyzed till the pH of the solution to 3, wherein the
concentration of Cl.sup.- was 6 mol/L and the impurities were shown
in the table 5.
TABLE-US-00005 TABLE 5 Contents of impurities in original solution
unit: g/l No. Item Co Cu Fe Pb Zn 1 original solution 0.008 0.003
0.001 0.001 0.001
[0033] Anion extractant contained 40 vol. % tertiary amine, 20 vol.
% butylate, and 40 vol. % sulphonated kerosene was washed by high
purity water, saturated with 4 mol/l high purity hydrochloric acid.
The electrolytic solution was extracted by 3-stage countercurrent
extraction at the extractant phase ratio of 1:2, and then
back-extracted with pure water 10 minutes after achieving
extraction equilibrium. The concentration of Co was decreased from
0.008 g/l to 0.001 g/l. The ingredients of extract residue were
shown in table 6.
TABLE-US-00006 TABLE 6 Contents of impurities in extract residue
unit: g/l No. Item Co Cu Fe Pb Zn 1 Extraction 0.001 0.0002 0.0009
0.001 0.0003 residue 2
[0034] The back-extracted solution was degreased through activated
carbon column, further purified through ion exchange column mixed
ion exchange resin from anion exchange resin 331, 717, D301 and
D401 at the exchange follow rate of 1.5 BV/h. Ingredients in
solution further purified by ion change were shown in table 7.
TABLE-US-00007 TABLE 7 Contents of impurities in solution purified
by ion exchange unit: g/l No. Item Co Cu Fe Pb Zn 1 Solution
purified <0.0004 0.0001 <0.0004 <0.0001 0.0001 by ion
change
[0035] An insoluble anode was employed to electro-deposit
NiCl.sub.2 solution. Eletrowinning conditions were as follows:
current density was 100 A/m.sup.2, pH of NiCl.sub.2 solution was 3,
Eletrowinning temperature was 50.degree.. An insoluble anode was
employed to electro-deposit in the solution further purified by ion
exchange to produce 5N-grade high purity nickel. Main impurities of
the produced high purity nickel were as follows: alkali metals less
than 0.1 ppm, Fe, Co, and Cr less than 1 ppm each, U and Th less
than 0.1 ppb each, C less than 60 ppm, and O less than 100 ppm.
Contents of some impurities in high purity nickel were shown in
table 7.
TABLE-US-00008 TABLE 7 Impurities in high purity nickel determined
by glow discharge mass spectrometry (GDMS) Impurities in No.
Impurities sample 1 (ppm) 1 Cu <0.9 2 Fe 0.35 3 Co <0.05 4 Pb
0.45 5 Zn <0.03 6 Cd <0.02 7 Bi <0.005 8 Sb 0.14 9 Sn
<0.3 10 As <0.8 11 Al 0.02 12 Mg <0.005 13 Mn <0.005 14
Si 0.05 15 P <0.01 16 S 0.15 Total impurities in high purity
nickel <3 Contents of nickel (%) >99.9997%
Example 3
[0036] Employed electrolytic solution such as example 2 and the
anion extractant contained 20 vol. % tertiary amine, 45 vol. %
butylate, and 35 vol. % sulphonated kerosene, Ingredients in
solution further purified by ion change were shown in table 8.
TABLE-US-00009 TABLE 8 Contents of impurities in solution purified
by ion exchange unit: g/l No. Item Co Cu Fe Pb Zn 1 Solution
purified <0.0004 0.0001 <0.0004 <0.0001 0.0001 by ion
change
[0037] An insoluble anode was employed to electro-deposit in
NiCI.sub.2 solution. Electro-deposition conditions were as follows:
current density was 200 Am.sup.2, pH of NiCl.sub.2solution was 2.
Electro-deposition temperature was 60.degree.. An insoluble anode
was employed to electro-deposit the solution further purified by
ion exchange to produce 5N-grade high purity nickel. Main
impurities of the produced high purity nickel were as follows:
alkali metals less than 0.1 ppm, Fe, Co and Cr less than 1 ppm
each, U and Th less than 0.1 ppb each, C less than 60 ppm, and O
less than 100 ppm. Contents of main impurities in high purity
nickel were shown in table 9.
TABLE-US-00010 TABLE 9 Impurities in high purity nickel determined
by glow discharge mass spectrometry (GDMS) Impurities in No.
Impurities sample 2 (ppm) 1 Cu <0.4 2 Fe 0.11 3 Co 0.58 4 Pb
0.28 5 Zn <0.02 6 Cd <0.07 7 Bi <0.005 8 Sb <0.04 9 Sn
<1.1 10 As <0.15 11 Al 0.004 12 Mg <0.005 13 Mn <0.005
14 Si <0.005 15 P 0.02 16 S 0.08 Total impurities in high purity
nickel <3 Contents of nickel (%) >99.9997%
Example 4
[0038] 3N-grade electrolytic nickel was electrolyzed in
hydrochloric acid system to prepare NiCl.sub.2 solution at a
current density of 200 A/m.sup.2. When the concentration of H.sup.+
was 2 g/l, the current density was changed to 70 A/m.sup.2 and
electrolyzed till the pH of the solution to 1, wherein the
concentration of Cl.sup.- was 6 mol/L and the impurities were shown
in the table 10.
TABLE-US-00011 TABLE 10 Contents of impurities in original solution
unit: g/l No. Item Co Cu Fe Pb Zn 1 original solution 0.006 0.002
0.002 0.001 0.001
[0039] Then the solution was purified by ion exchange resin at the
follow rate of 1 BV/h. Ingredients in solution further was purified
by ion change were shown in table 11.
TABLE-US-00012 TABLE 11 contents of impurities in solution after
ion exchange unit: g/l No. Item Co Cu Fe Pb Zn 1 Solution purified
<0.001 0.0002 <0.001 <0.0002 0.0001 by ion change
[0040] An insoluble anode was employed to electro-deposit in the
high purity NiCl.sub.2 solution. Electro-deposition conditions were
as follows: current density was 160 A/m.sup.2, pH of NiCl.sub.2
solution was 1, Electro-deposition temperature was 50.degree.. An
insoluble anode was employed to electro-deposit in the solution and
further was purified by ion exchange to produce 5N-grade high
purity nickel. Main impurities of the produced high purity nickel
were as follows: alkali metals less than 0.1 ppm, Fe, Co and Cr
less than 1 ppm each, U and Th less than 0.1 ppb each, C less than
60 ppm, and O less than 100 ppm. Contents of main impurities in
high purity nickel were shown in table 12.
TABLE-US-00013 TABLE 12 Impurities in high purity nickel determined
by glow discharge mass spectrometry (GDMS) Impurities in No.
Impurities sample 2 (ppm) 1 Cu 0.38 2 Fe 0.11 3 Co 0.6 4 Pb 0.3 5
Zn <0.02 6 Cd <0.07 7 Bi <0.005 8 Sb <0.04 9 Sn <1.2
10 As 0.13 11 Al 0.004 12 Mg <0.005 13 Mn <0.005 14 Si
<0.005 15 P 0.02 16 S 0.08 Total impurities in high purity
nickel <3 Contents of nickel (%) >99.9997%
* * * * *