CA1289509C - Energy-saving type zinc electrolysis method - Google Patents
Energy-saving type zinc electrolysis methodInfo
- Publication number
- CA1289509C CA1289509C CA000478871A CA478871A CA1289509C CA 1289509 C CA1289509 C CA 1289509C CA 000478871 A CA000478871 A CA 000478871A CA 478871 A CA478871 A CA 478871A CA 1289509 C CA1289509 C CA 1289509C
- Authority
- CA
- Canada
- Prior art keywords
- sulfuric acid
- zinc
- sulfur dioxide
- anode
- anolyte
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C1/00—Electrolytic production, recovery or refining of metals by electrolysis of solutions
- C25C1/16—Electrolytic production, recovery or refining of metals by electrolysis of solutions of zinc, cadmium or mercury
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
ABSTRACT
An energy saving type zinc electrolysis process wherein there is a cathodic chamber and an anodic chamber in an electrolyzer and a cathodic chamber solution is prepared by adding a small quantity of iodine ions or iodine to sulfuric acid-zinc solution. An anodic chamber solution is prepared by the addition of sulfur dioxide gas and a small quantity of oxidizing catalyst to sulfuric acid and then both solutions are electrolyzed.
An energy saving type zinc electrolysis process wherein there is a cathodic chamber and an anodic chamber in an electrolyzer and a cathodic chamber solution is prepared by adding a small quantity of iodine ions or iodine to sulfuric acid-zinc solution. An anodic chamber solution is prepared by the addition of sulfur dioxide gas and a small quantity of oxidizing catalyst to sulfuric acid and then both solutions are electrolyzed.
Description
~289S~9 ENER Y-SAVING TypE ZINC _LECTROLYSIS METHOD
Field of Invent_on I'his invent.:i.on relates to the met.hod of zinc electrolysis which saves energy by adding sulfur dioxide and a sma.ll. quantity of iodide ions to the anolyte, that play a catalytic function in the o~idizing reaction of sulfur dioxide at the anode instead of o~ygen evolution reaction t SO
that the electrol~sis ma~ proceed under a lower voltage.
Background o _the~ Inyention There are two kinds ot' known zinc manufacturing methods the dry process and the wet process. Of these, based on the electrolytic collection of sulfllric acid-zinc bath, the wet process is adopted in most countries.
In the known sulfuric acid-zinc bath electrolysis different electrochemical reactions take place at the cathode and anode.
Renction formulAs And electrode potentials at equilibril.lm state are as follows:
Cathode: Zn{ 2 + 2e ) Zn E = -0.76V t1) Anode : 2H20 > o2 + 4H{ + 4e E = 1.23V (2) Accordingly, the cell voltage at eq-lilibrium state is only 0.76 V + 1.23 V = 1.99 V, but the reaction proceeds in fact with 3.5 V at the current density of 5n mA/cm2 due to o~gen over-voltage.
`;~'`3 1;~89S09 While the theoretical energy consumption is 1,630 kwh/t at the equilibrium cell voltage of 1.99 V, it is 2,870 kwh/t at the actual voltage of 3.5 V. When the loss due to electric current efficiency, the loss resulting from the conversion of alternating current to direct current and the loss due to conductor resistance between the rectifier and electrolyzer are put together, the energy of approximately 3,500 kwh is required per metric ton of zinc electrolyzed.
The much higher cell voltage required as compared with the theoretical value, if attributable to the remarkably high anodic reaction over-voltage of 0.84 V, where as the cathodic reaction over-voltage is 0.06 V and almost negligible.
Thus, the greatest disadvantage of the known zinc electrolysis method lies in the tremendous energy consumption of the anodic reaction. The huge amount of oxygen generated from the anode in the electrolytic production has no particular uses but rather has such side defects as vaporizing the solution and causing the corrosion of electrodes.
Such an anode over-voltage can be decreased using sulfur dioxide which is a known anodic depolarizing medium.
Reference for this may be had to A.J. Appleby and B.J.
Pichon, Electroanalytical Chem., 95, 59 (1979). The oxidizing reaction of sulfur dioxide and the zinc electrolyzing reaction in the acidic solution are as follows:
1289~9 Anode : S02 + 2H20 > HS0~- ~ 3H' + 2e E = 0.12V (3) Cathode: Zn~ 2 + 2e > Zn E = -0.76V (1) Consequently, the zinc elect,rol,vtic voltage in the sulfur dioxide solution is only 0.76 V + 0.12 V = 0.88 V, a decrease of 1.l V from the cell voltage in the conventional sulfuric acid-zinc bath, with no oxygen over-voltage occurring either.
Summary of the Invention This invention relates, instead of' merely oxidizing the sulfur dioxide solution which usually proceed.s very slowly to the method of allowing faster oxidation of sulfur dioxide at a lower electric potential by adding a small quantity of iodide ions ~potassium iodide or iodine) which play a catalytic function in the oxidation of the sulfur dioxide solution.
Brief Descri~tion of the DrawinRs Fig. l~a) is a cross-sectional view of cathode and nnode of an electrolyzer with one separator from among the zinc electrolyzers of this invention.
Fig. l(b) is a cross-sectional view of cathode and anode of an electrolyzer with two diaphragms f'rom among the zinc electrolyzers of this invention.
Fig. 2 is the process flow sheet for zinc electrolysis of this invention.
Detailed DescriPtion of the_Invention In accordance with the invention, solutions are C preferably chosen *~ to be 1.5M su1fllric acid + sulfur .- dio~ide + iodide ions in the anodic chamber and 1.5M sulfuric acid + 0.8M zinc in the cnthodic chamber, while the electrolysis is conducted at 50 mAJcm2 current density by using a porous graphite anode and an aluminum cathode. The electrolytic voltage is about 2.0 V, a voltage drop of 1.5 V
as compared with the field operation voltage of the known method.
When the electrolysis is conducted without the catalyst II-) ~n*~ the anodic solution, the electrolytic voltage is about 2.5 V, a voltage drop of approximately 1.0 V
as compared with the field operation voltage of the known method.
Accordingly, a voltage drop of about 0.5 V can be expected by adding a small quantity of catalyst instead of simply usin~ sulfur dio~ide solution.
The oxidizing reaction of sulfur dioxide in the catalytic solution is attributable to the catalytic reaction in the oxidation of triiodide ions (I3-) and iodine (I2) produced by reaction formulas ~I) nnd (5) at the lower electric potential. (G.S. Calabrese and M.S. Wrighton, J.A.
C.S., 103 121), 6273 (1981)).
1~39S09 3I- > l.~- + 2e E = 0.536 V i4) 2I- -~ I2 + 2e E = 0.621 V (5) SO2 + 2H20 + I3- ~ H2SO~ + 2H' + 3I- (6) S(j2 + 2H20 + L2 - > 1~2SO4 + 2H' + 2I- (7) Preferably condit.ions in the oxidizing reaction of sulfllr dioxide are G.OOlM-O.1~ iodide ion concentration, -0.5M-2. OM sulfuric acid concentration, O.lM-2. OM sulfur dioxide concentration and 20C-40C temperature.
When less expensive iodine per unit weight of iodide ion is used as the catalyst, instead of potassium iodide, the iodine oxidizes sulfur dioxide to be reduced to iodide ions, thus producing the same effect as the method using potassium iodide, with the catalyst cost also decreased.
The cell voltage in this invention is 2.0 V, while t.he energy consumption is 1,640 kwh/t. When the loss due to electric current efficiency, the loss resulting from the conversion of alternating current to direct current and the loss due to conductor resistance between i.ts rectifier and eleet.rol~zer are combined, the energy of about 2,000 kwh is ~0 required per metric ton of zinc electrolyzed.
The present invention requires about 57 percent of the energy consumption required in prior methods which represents a saving in energy of approximatelv 1,500 kwh per metric ton of æinc electrolyzed.
~ 1289509 According to this invention, sulfur dio~ide is o~idized to produce s~llfuric acid in the ~nodic chamber, thus increasin~ the concentration. G~psum is produced bv the reaction of this anodic chamber solution with limestone or slaked lime. The anodic solution, after filtration, can be reused thus not only producing gypsum, but also ensuring a continuous process with no consumption of iodide ions. (M.
, ~ JY~ rk Grayson and D. Eckroth, ~ t-Othmer encyclopedia of chemical technology, ~1,443 (1978)).
H2SO4 + CaC03 or Ca~OH)z--~CaSO~ . 2H20 ~8) Moreover, since sulfur dio~ide in the anodic solution reacts with slaked lime to produce gypsum, the sulfur dio~ide in the produced sulfuric acid poses no problem.
SO2 + Ca(OH)2 - -- ~ CaS03 . 1/2 H20 (9) 2CaS03 . 1/2 H20 + 02 + 3H20-- ~ 2CaSOs . 2H20 (10) The presence of iodide in catholyte for long term electrolysis, which can be accumulated b~ diffusion throu~h separator from the anodic chamber, dose not disturb the cathodic process. but rather it may help to produce a porefree zinc deposition on cathode. This observation was confirmed also several times b~ adding a small quantity of iodide to catholyte.
In this invention, when the current densit~ is raised to 100 mA/cm2 for operation. double the worlcin~ current density of the Icnown method. the volta~e is nt the level of . . ~ .~..~
. ~
2.2 V, whereas when the working current density is raised to 100 mA/cm' in the known sulfuric acid-zinc bath electrolysis process, the voltage not only rises greatly (to 3.8 V) but also Pb-Ag anode dissolves due to the high voltage which causes the electrodeposition of Pb on the cathode, thus adversely affecting the purity of the product. Also as the anodic potential becomes higher, more NnO, electrodeposits on the anode. This lowers the electric conductivity of the anode thereby causing the voltage to rise.
On the other hand, since the anodic over-voltage increase due to an increase in the current density is relatively small and the anodic potential is lower in this invention, the dissolution of graphite anode and the electrodeposition of MnO, do not occur. When the working current density is doubled by this invention, the productivity is doubled, thus the equipment installation and other expenses as compared with the known electrolysis a~e, h~t~
process ~h~reduced to~ e~.
As mentioned above, this invention has the advantage of not only drastically reducing the energy required for zinc electrolysis, but also producing gypsum with sulfuric acid manufactured at the anode and providing double the productivity by doubling the working current density.
Example 1 The electrolysis was conducted for 20 hours at the current densi.ty of 50 mA/cm2 in the electrol~tic bath (a~ of Fig. 1 by fixing the interelectrode distance between the porous ~raphite anode and the aluminum cathode at five centimeters, while maintaining the anolvte at 1.5M sulfuric acid + lM sulfur dioxide + O.OlM potassium iodide and the catholyte at 1.5M sulfuric acid + 0.8M zinc. Here, the anolyte and the catholyte were continuously recycled in order to prevent the lowering of the concentration of sulfur dioxide and zinc, while a battery diaphragm was used for the separator.
- The electric current efficiency of the obtained electrolytic zinc was 89 percent, and the cell voltage in the electrolysis showed 2.0 V.
1289~9 Example 2 The electrolysis was conducted in accordance with the electrolytic conditions and electrolysis method of Example 1, while the anolyte was maintained at 1.5M sulfuric acid + lN sulfur dioxide + O.lM potassium iodide and the catholyte at 1.5M sulfuric acid + 0.8M zinc.
The electric current efficiency of the obtained electrolytic zinc was 89 percent, and the cell voltage in the electrolysis showed 1.9 V.
Exam~L~_~
The electrolysis was conducted in accordance with the electrolytic conditions and electrolysis process of Example 1, while the anolyte used was maintained at 1.5M sulfuric acid + lM sulfur dioxide + O.OlM potassium iodide and the catholyte at 1.5M sulfuric acid + 0.8M zinc + O.OlM
potassium iodide.
The electric current efficiency of obtained electrolytic zinc was 91 percent, and the presence of iodide ions in the catholyt did not disturb cathodic zinc deposition, but helped to form porefree electrolytic zinc.
The cell voltage here also showed 2.0 V.
E~m~le 4 The electrolysis was conducted for 20 hours at the current density of 50 mA/cm' in the electrolytic cell (b) of Fig. 1 by fixing the interelectrode distance between the porous graphite anode and the aluminum cathode at six centimeters, while maintaining the anolyte at 1.5M sulfuric acid + sulfur dioxide + O.OlM potassium iodide.
and the catholyte at 1.5M sulfuric acid + 0.8M zinc.
Here, the anolyte (the anodic chamber solution) and the catholyte (the cathodic chamber solution) were continuouæly recycled in order to prevent the lowering of the concentration of sulfur dioxide and zinc, while a battery diaphragm was used for the separator.
The electric current efficiency of the obtained electrolytic zinc was 90 percent, and the electrolytic voltaqe in the electrolysis showed 2.1 V.
g
Field of Invent_on I'his invent.:i.on relates to the met.hod of zinc electrolysis which saves energy by adding sulfur dioxide and a sma.ll. quantity of iodide ions to the anolyte, that play a catalytic function in the o~idizing reaction of sulfur dioxide at the anode instead of o~ygen evolution reaction t SO
that the electrol~sis ma~ proceed under a lower voltage.
Background o _the~ Inyention There are two kinds ot' known zinc manufacturing methods the dry process and the wet process. Of these, based on the electrolytic collection of sulfllric acid-zinc bath, the wet process is adopted in most countries.
In the known sulfuric acid-zinc bath electrolysis different electrochemical reactions take place at the cathode and anode.
Renction formulAs And electrode potentials at equilibril.lm state are as follows:
Cathode: Zn{ 2 + 2e ) Zn E = -0.76V t1) Anode : 2H20 > o2 + 4H{ + 4e E = 1.23V (2) Accordingly, the cell voltage at eq-lilibrium state is only 0.76 V + 1.23 V = 1.99 V, but the reaction proceeds in fact with 3.5 V at the current density of 5n mA/cm2 due to o~gen over-voltage.
`;~'`3 1;~89S09 While the theoretical energy consumption is 1,630 kwh/t at the equilibrium cell voltage of 1.99 V, it is 2,870 kwh/t at the actual voltage of 3.5 V. When the loss due to electric current efficiency, the loss resulting from the conversion of alternating current to direct current and the loss due to conductor resistance between the rectifier and electrolyzer are put together, the energy of approximately 3,500 kwh is required per metric ton of zinc electrolyzed.
The much higher cell voltage required as compared with the theoretical value, if attributable to the remarkably high anodic reaction over-voltage of 0.84 V, where as the cathodic reaction over-voltage is 0.06 V and almost negligible.
Thus, the greatest disadvantage of the known zinc electrolysis method lies in the tremendous energy consumption of the anodic reaction. The huge amount of oxygen generated from the anode in the electrolytic production has no particular uses but rather has such side defects as vaporizing the solution and causing the corrosion of electrodes.
Such an anode over-voltage can be decreased using sulfur dioxide which is a known anodic depolarizing medium.
Reference for this may be had to A.J. Appleby and B.J.
Pichon, Electroanalytical Chem., 95, 59 (1979). The oxidizing reaction of sulfur dioxide and the zinc electrolyzing reaction in the acidic solution are as follows:
1289~9 Anode : S02 + 2H20 > HS0~- ~ 3H' + 2e E = 0.12V (3) Cathode: Zn~ 2 + 2e > Zn E = -0.76V (1) Consequently, the zinc elect,rol,vtic voltage in the sulfur dioxide solution is only 0.76 V + 0.12 V = 0.88 V, a decrease of 1.l V from the cell voltage in the conventional sulfuric acid-zinc bath, with no oxygen over-voltage occurring either.
Summary of the Invention This invention relates, instead of' merely oxidizing the sulfur dioxide solution which usually proceed.s very slowly to the method of allowing faster oxidation of sulfur dioxide at a lower electric potential by adding a small quantity of iodide ions ~potassium iodide or iodine) which play a catalytic function in the oxidation of the sulfur dioxide solution.
Brief Descri~tion of the DrawinRs Fig. l~a) is a cross-sectional view of cathode and nnode of an electrolyzer with one separator from among the zinc electrolyzers of this invention.
Fig. l(b) is a cross-sectional view of cathode and anode of an electrolyzer with two diaphragms f'rom among the zinc electrolyzers of this invention.
Fig. 2 is the process flow sheet for zinc electrolysis of this invention.
Detailed DescriPtion of the_Invention In accordance with the invention, solutions are C preferably chosen *~ to be 1.5M su1fllric acid + sulfur .- dio~ide + iodide ions in the anodic chamber and 1.5M sulfuric acid + 0.8M zinc in the cnthodic chamber, while the electrolysis is conducted at 50 mAJcm2 current density by using a porous graphite anode and an aluminum cathode. The electrolytic voltage is about 2.0 V, a voltage drop of 1.5 V
as compared with the field operation voltage of the known method.
When the electrolysis is conducted without the catalyst II-) ~n*~ the anodic solution, the electrolytic voltage is about 2.5 V, a voltage drop of approximately 1.0 V
as compared with the field operation voltage of the known method.
Accordingly, a voltage drop of about 0.5 V can be expected by adding a small quantity of catalyst instead of simply usin~ sulfur dio~ide solution.
The oxidizing reaction of sulfur dioxide in the catalytic solution is attributable to the catalytic reaction in the oxidation of triiodide ions (I3-) and iodine (I2) produced by reaction formulas ~I) nnd (5) at the lower electric potential. (G.S. Calabrese and M.S. Wrighton, J.A.
C.S., 103 121), 6273 (1981)).
1~39S09 3I- > l.~- + 2e E = 0.536 V i4) 2I- -~ I2 + 2e E = 0.621 V (5) SO2 + 2H20 + I3- ~ H2SO~ + 2H' + 3I- (6) S(j2 + 2H20 + L2 - > 1~2SO4 + 2H' + 2I- (7) Preferably condit.ions in the oxidizing reaction of sulfllr dioxide are G.OOlM-O.1~ iodide ion concentration, -0.5M-2. OM sulfuric acid concentration, O.lM-2. OM sulfur dioxide concentration and 20C-40C temperature.
When less expensive iodine per unit weight of iodide ion is used as the catalyst, instead of potassium iodide, the iodine oxidizes sulfur dioxide to be reduced to iodide ions, thus producing the same effect as the method using potassium iodide, with the catalyst cost also decreased.
The cell voltage in this invention is 2.0 V, while t.he energy consumption is 1,640 kwh/t. When the loss due to electric current efficiency, the loss resulting from the conversion of alternating current to direct current and the loss due to conductor resistance between i.ts rectifier and eleet.rol~zer are combined, the energy of about 2,000 kwh is ~0 required per metric ton of zinc electrolyzed.
The present invention requires about 57 percent of the energy consumption required in prior methods which represents a saving in energy of approximatelv 1,500 kwh per metric ton of æinc electrolyzed.
~ 1289509 According to this invention, sulfur dio~ide is o~idized to produce s~llfuric acid in the ~nodic chamber, thus increasin~ the concentration. G~psum is produced bv the reaction of this anodic chamber solution with limestone or slaked lime. The anodic solution, after filtration, can be reused thus not only producing gypsum, but also ensuring a continuous process with no consumption of iodide ions. (M.
, ~ JY~ rk Grayson and D. Eckroth, ~ t-Othmer encyclopedia of chemical technology, ~1,443 (1978)).
H2SO4 + CaC03 or Ca~OH)z--~CaSO~ . 2H20 ~8) Moreover, since sulfur dio~ide in the anodic solution reacts with slaked lime to produce gypsum, the sulfur dio~ide in the produced sulfuric acid poses no problem.
SO2 + Ca(OH)2 - -- ~ CaS03 . 1/2 H20 (9) 2CaS03 . 1/2 H20 + 02 + 3H20-- ~ 2CaSOs . 2H20 (10) The presence of iodide in catholyte for long term electrolysis, which can be accumulated b~ diffusion throu~h separator from the anodic chamber, dose not disturb the cathodic process. but rather it may help to produce a porefree zinc deposition on cathode. This observation was confirmed also several times b~ adding a small quantity of iodide to catholyte.
In this invention, when the current densit~ is raised to 100 mA/cm2 for operation. double the worlcin~ current density of the Icnown method. the volta~e is nt the level of . . ~ .~..~
. ~
2.2 V, whereas when the working current density is raised to 100 mA/cm' in the known sulfuric acid-zinc bath electrolysis process, the voltage not only rises greatly (to 3.8 V) but also Pb-Ag anode dissolves due to the high voltage which causes the electrodeposition of Pb on the cathode, thus adversely affecting the purity of the product. Also as the anodic potential becomes higher, more NnO, electrodeposits on the anode. This lowers the electric conductivity of the anode thereby causing the voltage to rise.
On the other hand, since the anodic over-voltage increase due to an increase in the current density is relatively small and the anodic potential is lower in this invention, the dissolution of graphite anode and the electrodeposition of MnO, do not occur. When the working current density is doubled by this invention, the productivity is doubled, thus the equipment installation and other expenses as compared with the known electrolysis a~e, h~t~
process ~h~reduced to~ e~.
As mentioned above, this invention has the advantage of not only drastically reducing the energy required for zinc electrolysis, but also producing gypsum with sulfuric acid manufactured at the anode and providing double the productivity by doubling the working current density.
Example 1 The electrolysis was conducted for 20 hours at the current densi.ty of 50 mA/cm2 in the electrol~tic bath (a~ of Fig. 1 by fixing the interelectrode distance between the porous ~raphite anode and the aluminum cathode at five centimeters, while maintaining the anolvte at 1.5M sulfuric acid + lM sulfur dioxide + O.OlM potassium iodide and the catholyte at 1.5M sulfuric acid + 0.8M zinc. Here, the anolyte and the catholyte were continuously recycled in order to prevent the lowering of the concentration of sulfur dioxide and zinc, while a battery diaphragm was used for the separator.
- The electric current efficiency of the obtained electrolytic zinc was 89 percent, and the cell voltage in the electrolysis showed 2.0 V.
1289~9 Example 2 The electrolysis was conducted in accordance with the electrolytic conditions and electrolysis method of Example 1, while the anolyte was maintained at 1.5M sulfuric acid + lN sulfur dioxide + O.lM potassium iodide and the catholyte at 1.5M sulfuric acid + 0.8M zinc.
The electric current efficiency of the obtained electrolytic zinc was 89 percent, and the cell voltage in the electrolysis showed 1.9 V.
Exam~L~_~
The electrolysis was conducted in accordance with the electrolytic conditions and electrolysis process of Example 1, while the anolyte used was maintained at 1.5M sulfuric acid + lM sulfur dioxide + O.OlM potassium iodide and the catholyte at 1.5M sulfuric acid + 0.8M zinc + O.OlM
potassium iodide.
The electric current efficiency of obtained electrolytic zinc was 91 percent, and the presence of iodide ions in the catholyt did not disturb cathodic zinc deposition, but helped to form porefree electrolytic zinc.
The cell voltage here also showed 2.0 V.
E~m~le 4 The electrolysis was conducted for 20 hours at the current density of 50 mA/cm' in the electrolytic cell (b) of Fig. 1 by fixing the interelectrode distance between the porous graphite anode and the aluminum cathode at six centimeters, while maintaining the anolyte at 1.5M sulfuric acid + sulfur dioxide + O.OlM potassium iodide.
and the catholyte at 1.5M sulfuric acid + 0.8M zinc.
Here, the anolyte (the anodic chamber solution) and the catholyte (the cathodic chamber solution) were continuouæly recycled in order to prevent the lowering of the concentration of sulfur dioxide and zinc, while a battery diaphragm was used for the separator.
The electric current efficiency of the obtained electrolytic zinc was 90 percent, and the electrolytic voltaqe in the electrolysis showed 2.1 V.
g
Claims (6)
1. An electrolysis process for obtaining zinc comprising:
providing a cathodic chamber and an anodic chamber separated by an electrolytic separator in an electrolyzer, preparing an anolyte by adding sulfur dioxide and a small quantity of oxidizing catalyst to sulfuric acid, preparing a catholyte of zinc containing sulfuric acid, and electrolyzing both solutions, said oxidizing catalyst being iodide or iodine which promotes the oxidation of sulfur dioxide at the anode.
providing a cathodic chamber and an anodic chamber separated by an electrolytic separator in an electrolyzer, preparing an anolyte by adding sulfur dioxide and a small quantity of oxidizing catalyst to sulfuric acid, preparing a catholyte of zinc containing sulfuric acid, and electrolyzing both solutions, said oxidizing catalyst being iodide or iodine which promotes the oxidation of sulfur dioxide at the anode.
2. The process of claim 1, further comprising working conditions in the anolyte being 0.01M in iodide ion concentration, 0.5M-2.0M in sulfuric acid concentration, 0.1M-2.0M in sulfur dioxide concentration and 20°C-40°C in temperature.
3. The process of claim 1, including at least one separator to intercept mixing the electrolytes between said chambers.
4. The process of claim 3, wherein said electrolytic separator is a diaphragm or an ion exchange membrane.
5. The process of claim 1, wherein said anodic chamber includes a porous graphite electrode as its anode.
6. The process of claim 1, further comprising producing gypsum by the reaction of sulfuric acid generated in the anodic chamber with limestone or slaked lime and recovering iodide ions of the anolyte for reuse.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019840005302A KR870002075B1 (en) | 1984-08-30 | 1984-08-30 | Zinc electrolysis method of saving energy |
| KR1984-5302 | 1984-08-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1289509C true CA1289509C (en) | 1991-09-24 |
Family
ID=19235244
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000478871A Expired - Fee Related CA1289509C (en) | 1984-08-30 | 1985-04-11 | Energy-saving type zinc electrolysis method |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS6160894A (en) |
| KR (1) | KR870002075B1 (en) |
| AU (1) | AU561640B2 (en) |
| CA (1) | CA1289509C (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0357521A (en) * | 1989-07-24 | 1991-03-12 | Yoshitsuka Seiki:Kk | Linear feeder of press apparatus |
| JPH04238634A (en) * | 1990-12-28 | 1992-08-26 | Kanai Hiroyuki | Positioning and transporting device for wheel disk for automobile |
| KR100397296B1 (en) * | 1998-12-21 | 2004-02-11 | 주식회사 포스코 | Manufacturing method of electro galvanized steel sheet with excellent surface appearance |
| CN104911630A (en) * | 2015-05-11 | 2015-09-16 | 北京工业大学 | Low bath voltage zinc electrolysis method |
-
1984
- 1984-08-30 KR KR1019840005302A patent/KR870002075B1/en not_active IP Right Cessation
- 1984-12-25 JP JP59272153A patent/JPS6160894A/en active Granted
-
1985
- 1985-04-11 CA CA000478871A patent/CA1289509C/en not_active Expired - Fee Related
- 1985-05-10 AU AU42264/85A patent/AU561640B2/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| AU561640B2 (en) | 1987-05-14 |
| AU4226485A (en) | 1986-04-10 |
| KR870002075B1 (en) | 1987-12-03 |
| JPS6256238B2 (en) | 1987-11-25 |
| JPS6160894A (en) | 1986-03-28 |
| KR860001903A (en) | 1986-03-24 |
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