US3257299A - Composition and method for electrolytic stripping of coatings from metals - Google Patents

Composition and method for electrolytic stripping of coatings from metals Download PDF

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Publication number
US3257299A
US3257299A US140925A US14092561A US3257299A US 3257299 A US3257299 A US 3257299A US 140925 A US140925 A US 140925A US 14092561 A US14092561 A US 14092561A US 3257299 A US3257299 A US 3257299A
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percent
stripping
workpiece
metal
coatings
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Mekjean Matthew
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Occidental Chemical Corp
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Hooker Chemical Corp
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Priority to BE622847D priority Critical patent/BE622847A/xx
Priority to NL124986D priority patent/NL124986C/xx
Priority to NL283267D priority patent/NL283267A/xx
Priority to US140925A priority patent/US3257299A/en
Application filed by Hooker Chemical Corp filed Critical Hooker Chemical Corp
Priority to GB35539/62A priority patent/GB1020592A/en
Priority to FR910444A priority patent/FR1334293A/fr
Priority to DE19621421994 priority patent/DE1421994A1/de
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Publication of US3257299A publication Critical patent/US3257299A/en
Assigned to OCCIDENTAL CHEMICAL CORPORATION reassignment OCCIDENTAL CHEMICAL CORPORATION CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). EFFECTIVE APRIL 1, 1982. Assignors: HOOKER CHEMICALS & PLASTICS CORP.
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F5/00—Electrolytic stripping of metallic layers or coatings
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F1/00—Electrolytic cleaning, degreasing, pickling or descaling

Definitions

  • This system generally comprises a metallic pot containing an electrolyte or molten bath composition. Immersed in this electrolyte, or in contact therewith are anode means and cathode means. The pot may act as the cathode means. The system may also comprise a consumable electrode to be used in the system as the anode or cathod means in lieu of the pot.
  • surface coating any covering on the surface of a basis metal workpiece (of any size or shape), which colors, protects, beautifies, strengthens, increases wear resistance, reduces friction, increases the value and/ or utility of the workpiece.
  • Oxide coatings such as anodizing of aluminum, blueing of steels, etc.
  • the invention is in no way limited to the stripping of copper objects.
  • Salvage of the coating material itself e.g., as in the reclaiming of tin from tin cans, either in the form of tin salts or as metallic tin or reclaiming previous metal coatings from baser metal objects.
  • Salvageof the basis metal as scrap in a rough form of refining. For example: in detinning of tin cans, the stripped steel cans are compacted in bales and returned to the steel mills as scrap; the dissolved tin is also eventually reclaimed as salts (sodium stannate), or is refined to tin itself. For example: in stripping tin, lead, solder, etc., from copper wire and heavy cables, for upgrading the quality of the reclaimed copper. If the size of the operation warrants the economics of the process, the stripped metal may also be recovered as a salt or as the metal.
  • the lead coating removed formed a lead oxide sheath on the workpiece, thereby preventing the required contact of the workpiece surface with the molten bath; also lead oxide was formed in the bath proper, resulting in substantial deactivation of this same bath.
  • an alkali metal hydroxide bath the components of which could not be deactivated by lead or tin, or be slowed down as these metals tend to saturate the melt.
  • the active (reducing) agents were supplied on demand by direct current, which represented an inexhaustible external source of energy.
  • the workpiece is initially made (first step) anodic.
  • an oxide coating is created on the surface of the plated metal.
  • tin metal
  • the next (step 2) is to make the workpiece cathodic by reversing the current.
  • Steps 1 and 2 are repeated as often as required to remove the coating of interest.
  • the novel composition of the bath of this invention comprises an alkali metal hydroxide having added thereto an agent comprising any or all of the following: carbonates, halides, sulfates, phosphates, borates, stannates, zincates, plumbates, silicates, molybdates, fiuosilicates, titanates, zirconates, fluotitanates, fluozirconates, fluoborates, or mixtures thereof.
  • the proportions of these components are at least fifty percent alkali metal hydroxide to one to fifty percent of the above mentioned agents.
  • the preferred embodiment of this composition comprises about eighty to eightyefive percent technical grade NaOH, five percent of Na PO two to five percent Na SnO and ten percent potassium hydroxide.
  • Other more specific baths preferred are:
  • Bath A Percent by weight Sodium hydroxide 82 to 84 Sodium carbonate 0.5 to 1.5 Sodium chloride 0.5 to 1.5 Disodium hydrogen phosphate 5 Potassium chloride
  • Bath B Percent by weight Sodium hydroxide 82 to 84 Sodium carbonate 0.5 to 1.5 Sodium chloride 0.5 to 1.5 Trisodium phosphate 5 Potassium chloride 10
  • Bath C Percent by weight Sodium hydroxide 82 to 84 Sodium carbonate 0.5 to 1.5 Sodium chloride 0.5 to 1.5 Monosodium hydrogen phosphate 5 Potassium hydroxide 10
  • the pot usually acts as anode, but not exclusively. There are occasions when the pot, acting as an electrode, is made either anode or cathode.
  • auxiliary consumable electrodes usually in the form of grids to allow free circulation of electrolyte in the system, and the metallic workpieces act as the opposite electrode, either at any one moment, as cathode or anode means.
  • Standard prior art stripping methods involve aqueous chemical and electrochemical processes.
  • Aqueous chemical acid systems for dissolving these coatings also attack the base metal-metal losses are excessive, process rates of removal are relatively slow, base metal surfaces are etched and pitted, and costs make the process uneconomical.
  • the evolution of hydrogen, acid mists, nitrous oxide, etc. also introduce safety hazards to operating personnel, and such equipment requires extensive and costly ventilation.
  • Oxidizing caustic soda aqueous systems for removal of tin coatings from steel, as in stripping of tin cans, is straightforward and well-known in the art. Complications arise, however, in other systems. In removing tin from copper or copper-base alloys or from steels, or lead coatings from copper-base alloys, or zinc galvanizing from steel or aluminum coatings from steel or from copper base alloys, or of chromium plates from steel or copper-based alloys, or copper plating on steel, or silver plates from copper or copper-base alloys, or any metal plate or coating from any other metal as a base; these all require special stripping techniques, special compositions of matter, and specific processes.
  • electrolytic stripping in which the workpiece is the anode.
  • Electrolytic solutions vary in life and in stripping rate.
  • the basic principle is a form of reverse plating in which the part to be stripped is the anode, losing its plate to the cathode, where it is replated and/ or reclaimed.
  • Most electrolytic stripping electrolytes present problems of stripping rates and voltages at which the basis metal will not dissolve or become pitted.
  • the best of these electrolytes are cyanide solutions because of high electrical efficiency, but they are toxic.
  • each application must be evaluated on its own merits. Specific voltages, current densities, temperatures, solution concentrations, pH, as well as a few other minor factors, must be predetermined experimentally. Only the more precious metal can successfully absorb the cost of these processes.
  • FIGURE I is a diagramatic View illustrating the system of this invention.
  • FIGURE 11 is a diagramatic view illustrating an alternate concept of the system of this invention.
  • FIGURE III is the same as FIGURE II wherein the current reversal is illustrated.
  • pot 1 preferably constructed of steel, contains a molten bath composition 2'.
  • the composition comprises an alkali-metal hydroxide having added thereto a non-oxidizing agent selected from the group consisting of carbonates, halides, sulfates, phosphates, borates, 'stannates, zincates, plumbates, silicates, molybdates, fiuosilicates, fiuoborates, or mixtures thereof.
  • the preferred composition of this invention comprises about eighty-five percent NaOI-I, about five percent Na PO and about ten percent KCl. Immersed in said composition is a metal workpiece 3 (or a steel basket containing the pieces to be stripped of metal coat-ing).
  • Workpiece 3 is suspended from a hoist 4, and attached to a suspension means 5.
  • the workpiece 3 is electrically connected to a source of energy by electrical lead 6, hoist 4 and suspension means 5 being electrical conductors.
  • Pot I is likewise connected to a source of electrical energy by an electrical lead 8.
  • the current is then turned on making the pot 1 anodic and workpieces 3 cathodic.
  • the amount of current and" voltage will depend on the bulk of the workpiece. A five pound workpiece usually requires from one hundred to three hundred amperesat about 4.5 volts. The variation in size of the workpiece would accordingly modify the required current. If the workpiece has an unusually heavy coating of metal on the base metal, the current is reversed making the pot anodic and the workpiece cathodic.
  • This reversal of polarity may be repeated as often as desired depending on the thickness of the coated metal.
  • the workiece may, if desired, be allowed to drain for a few seconds, then quenched in steam preferably to rid the workpiece 3 of salt or other contaminants.
  • FIGURES II and III the structure of the system is similar to that of FIGURE I, except that anodes 9 are immersed in the system rather than using metal pot It) as the anode of the system.
  • Workpiece 11 is immersed into molten salt composition 12, as in the systom of FIGURE I.
  • Anodes 9 are as in FIGURE I connected to a source of direct current, workpiece 11. is also connected to a direct source of electrical energy. The electrical current is then turned on causing a stripping effect of the metal coatings on said workpiece 11.
  • the workpieces are made cathodic, while anode means 9 are made anodic.
  • the polarity of these electrodes may be reversed if a heavy coated metal is desired to be removed.
  • FIGURE III illustrates the same embodiment as FIG- URE II wherein the electrodes are reversed, the anode of FIGURE II is now thecathode, and the cathode of FIGURE II is now the anode.
  • the same electrode reversal can be accomplished with the structure of FIG- URE I.
  • Example I -Str1'pping of Lead and Tin Samples of wire for salvage were obtained and the insulation was burned off or otherwise removed. The wire was then chopped into small lengths averaging between two to four inches. These chopped short pieces were deposited into a steel basket; a source of direct current was connected to this basket. The basket was then immersed into a steel pot containing a molten eightyfive percent NaOH, five percent Na PO and ten percent KCl composition, maintained at about nine hundred degrees Fahrenheit. The pot was initially made anodic and the basket made cathodic; the current was then reversed, making the basket anodic and the pot cathodic.
  • a five pound batch of chopped wire requires about one hundred amperes'at five volts.
  • the time for each cycle may .vary, but five minutes anodic followed by ten minutes cathodic proved to be preferred.
  • the preferred method of removing the dr'agout from the workpiece in this case is by subjecting the workpiece to the action of live steam.
  • the workpiece is now better conditioned for Water quenching, since it has, by the steam, been slowly cooled, and the chance of any violent reaction when the workpiece is water quenched, is nil.
  • the thinly coated copper wire was stripped of lead and tin with a straight cathodic (reducing) cycle alone.
  • a reducing-oxidizing-reducing sequence, or a series of oxidizing-reducing couplets proved to be preferred.
  • the salvaged copper wire was fairly bright after water quenching, but did evidence a somewhat mottled appearance with some adhering salt.
  • the workpiece was, after treatment, contacted with a hot water soak to dissolve residual salt, followed by a bright d ip. This bright dip involved: at room. temperature, contacting the workpiece with a sulfuric-dichromate mix (three percent sodium or potassium dichromate in ten percent sulfuric acid). This converts the matted mass of heterogeneous wire into a uniform bright golden texture.
  • the assay of the reclaimed Cu was 99.5 percent.
  • the workpiece was made cathodic for five minutes at one hundred amperes, and 4.4 volts; then was made anodic for fiv'e minutes at one hundred amperes and 4.6 volts.
  • the basket was raised from the salt, allowed 7 to drain for a few seconds, then quenched in cold water and rinsed free of salt in hot wa ter. There was no visible evidence of any lead or tin remaining on any of the copper wires.
  • Example 3 Stripping of Lead and Tin The same conditions, batch size, basket and pot as in Example '2. The process included five minutes of oxidizing (anodic at onehundred amperes at 4.5 volts), plus ten minutes reduction (cathodic) one hundred amperes at 4.6 volts), plus water quench followed by a hot water soak. No evidence of lead or tin, but slightly mottled (non-uniform) copper color on surface.
  • Example 5 Stripping of Lead and Tin The same conditions-as in Example 4 wherein a five pound batch of wire was deposited in the basket and processed for fifteen minutes of straight reduction only (cathodic one hundred amperes, 4.6 volts), plus water quench, followed by a hot water soak. No evidence of lead or tin, but not particularly bright finish on the copper.
  • Example 6 S tripping of Lead and Tin Repeated the process of Example 5 followed by a bright dip for forty-five seconds in a sulfuric acid-dichromate composition at room' temperature, rinsed and dried. A bright, clean product resulted with no evidence of lead or tin remaining.
  • Example 7 Slripping of Lead and Tin Same process as in Example 2, followed by a bright dip, forty-five seconds in sulfulric acid-dichromate mixture, at room temperature. A very clean, bright golden finish was achieved with no trace of lead or tin.
  • Example 8 Stripping of T in- Aone and three-quarter inch strip was cut from a tin can; the strip was six inches in diameter and was suspended from the hoist. This strip was made cathodic for two minutes at eighty amperes and 7.0 volts. It was quenched in water, followed by a hot water rinse; it was one hundred percent detinned clean steel.
  • Example 9 Slripping of Tin From a tin can, a strip four and three-quarter inches by six inches in diameter was suspended into the melt as it was in Example 8. It was made cathodic for two minutes at eighty amperes and 6.0 volts. The results were one hundred percent detinned clean steel.
  • Example 10 Stripping of Phosphate Coating
  • a three by five inch 1010 steel panel, used in thi'stest was coated with a light, brown to blue clear phosphate coating known as SRP-35 Iron. This panel contained from 10.2 to 16.5 milligrams of iron phosphate. Initial weight of the panel was 6115741 grams. Connection was made to a source of direct current and the panel was made negative. Sensitive ammeter and voltmeter was included in the circuit at the point of use (that is, at the salt). Salt composition was: NaOH, fifty to ninety-five percent; Na PO five to ten percent; Na SnO two to five percent; KCl, zero to ten percent; Na CO .2 to twenty-five percent. Salt temperature was nine hundred degrees Fahrenheit. The following data was obtained:
  • Example 12 Stripping of Oxides A panel of 1010 steel, seven-eighths of an inch by two and one-half inches, with a blued protective oxide film, was connected to the source of direct current and made the cathode in the circuit through the salt composi tion of Example 11 and to the pot wall serving as an anode. Salt temperature was nine hundred and fifty degrees Fahrenheit. Current used was ten amperes at 1.8 volts, for five minutes. This was a current density of three hundred and twenty-nine amperes per square foot. The panel was removed, quenched, washed, dried and examined. It was bright, clean, metallic iron-the blue oxide was completely stripped from the surface.
  • Example 13 Stripping of Oxides A panel of eighty percent nickel steel, coated with a thin, tenacious, black protective oxide, was connected as cathode in a DC. circuit using the pot as anode. The three by six inch panel was processed as in Example 12 in the same salt, ten amperes at 2.4 volts for five minutes. This was a current density of forty amperes per square foot. After quenching and drying, panel was examined and found to be brilliantly bright and metallic, with no trace of the black oxide coating.
  • Example 14 Stripping of Oxides A dull, black oxide-coated brass nozzle, two inches in diameter and five inches long, was hung from a hook connected to a source of direct current as cathode in a circuit through a salt composition as in Example 10 to the steel pot wall as anode. A current of ten amperes at 2.5 volts for five minutes was employed, at which point the nozzle was removed and quenched in cold water, rinsed in hot water, and dried. Current density over the whole surface was estimated to be 30.0 amperes per square foot. The nozzle exhibited its bright, golden metallic appearance, without any trace of the original black oxide coating. It was completely stripped.
  • a method of stripping a surface coating from a metallic workpiece which comprises contacting a coated workpiece with an electrolyte in an electrochemical system said electrolyte consisting essentially of a molten bath for the electrolytic stripping of surface coatings from the metal resulting from fusing together at least 50 percent of an alkali metal hydroxide with 1 to 50 percent of a substance selected from the group consisting of sulfates, stannates, zincates, plumbates, silicates, molybdates, titanates, zirconates fluotitanates fluozirconates, and mixtures thereof, and being substantially non-reactive with said workpiece.
  • the base metal of the workpiece is a metal selected from the group consisting of steel, copper, copper alloys and mixtures thereof.
  • said surface coating is a substance selected from the group consisting of lead, tin, phosphates, chromates, oxides, and mixtures thereof.
  • a method of stripping a surface coating from a metallic workpiece which comprises contacting a coated workpiece with an electrolyte in an electrochemical system, said electrolyte consisting essentially of a molten bath for the electrolytic stripping of surface coatings from metal resulting from fusing together about percent by weight of sodium hydroxide, about 5 percent by weight of trisodium phosphate, and about 10 percent by weight of potassium chloride.
  • a method of stripping a surface coating from a metallic workpiece which comprises contacting a coated workpiece with an electrolyte in an electrochemical system, said electrolyte consisting essentially of a molten bath for the electrolytic stripping of surface coatings from metal resulting from fusing together at least 50 percent of an alkali metal hydroxide with l to 50 percent of a substance selected from the group consisting of sulfates, stannates, zincates, plumbates, silicates, molybdates, titanates, zirconates, fluotitanates, fiuozirconates, and mixtures thereof, and being substantially non-reactive with said workpiece, said electrochemical system comprising in addition to said electrolyte anode means and cathode means, said anode means comprising said workpiece; and reversing the current, whereby said workpiece is made cathodic and said cathode means is made anodic.
  • the method of stripping a lead coating from a copper basis which comprises contacting the lead coated copper basis with an electrolyte in an electrochemical system, said electrolyte consisting essentially of a molten bath for the electrolytic stripping of surface coatings from metal resulting from fusing together about eightyfive percent by weight of sodium hydroxide, about five percent by weight of trisodium phosphate, and about ten percent by weight of potassium chloride.
  • the method of stripping a tin coating from a copper basis which comprises contacting the tin coated copper basis with an electrolyte in an electrochemical system, said electrolyte consisting essentially of a molten bath for the electrolytic stripping of surface coatings from metal resulting from fusing together about eighty-five percent by weight of sodium hydroxide, about five percent by weight of trisodium phosphate, and about ten percent by Weight of potassium chloride.
  • a nonoxidizing composition adapted for use as a molten bath for the electrolytic stripping of surface coatings from metal which consists essentially of the product resulting from fusing together at least fifty percent of an alkali metal hydroxide with' 1 to 50 percent'of a substance selected from the group consisting of sulfates, stannates, zincates, plumbates, silicates, molybdates, titanates, zirconates, fluotitanates, fluozirconates and mixtures thereof.
  • composition of claim 10 wherein said alkali metal hydroxide is sodium hydroxide.
  • a composition for use as a molten bath for the electrolytic ;stripping of surface coatings from metal which consists essentially of the product resulting from fusing together about 35.0 percent sodium hydroxide, about 44.0 percent potassium hydroxide, about 5.0 percent trisodium phosphate, about 5.0 percent sodium stannate, about 10.0 percent potassium chloride, and about 1.0 percent sodium carbonate.v

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electroplating Methods And Accessories (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
  • Coating With Molten Metal (AREA)
US140925A 1961-09-26 1961-09-26 Composition and method for electrolytic stripping of coatings from metals Expired - Lifetime US3257299A (en)

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Application Number Priority Date Filing Date Title
BE622847D BE622847A (US07709020-20100504-C00068.png) 1961-09-26
NL124986D NL124986C (US07709020-20100504-C00068.png) 1961-09-26
NL283267D NL283267A (US07709020-20100504-C00068.png) 1961-09-26
US140925A US3257299A (en) 1961-09-26 1961-09-26 Composition and method for electrolytic stripping of coatings from metals
GB35539/62A GB1020592A (en) 1961-09-26 1962-09-18 Improvements in stripping coatings from metal surfaces
FR910444A FR1334293A (fr) 1961-09-26 1962-09-25 Procédé et dispositif pour retirer le revêtement superficiel d'une pièce métallique
DE19621421994 DE1421994A1 (de) 1961-09-26 1962-09-25 Verfahren,Einrichtung und Mittel zur Reinigung von Metalloberflaechen

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GB (1) GB1020592A (US07709020-20100504-C00068.png)
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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3492210A (en) * 1967-10-16 1970-01-27 Hamilton Cosco Inc Electrolytic stripping of nonferrous metals from a ferrous metal base
US4100044A (en) * 1977-07-15 1978-07-11 The United States Of America As Represented By The Secretary Of The Air Force Procedure for removing aluminum from an Al-Al3 Ni two-phase matrix
US4246083A (en) * 1978-08-31 1981-01-20 Johnson, Matthey & Co., Limited Removal of surface material
US4287033A (en) * 1980-04-14 1981-09-01 Calspan Corporation Electrochemical method for removing metallic sheaths
DE3318598A1 (de) * 1982-05-27 1983-12-01 Occidental Chemical Corp., 48089 Warren, Mich. Bad und verfahren fuer die elektrolytische entfernung von ueberzuegen aus kupfer, kupferlegierung oder chrom von einem eisenhaltigen grundmetall
US20030132416A1 (en) * 2001-10-11 2003-07-17 Shipley Company, L.L.C. Stripping solution
US20100101963A1 (en) * 2007-02-16 2010-04-29 Nippon Mining & Metals Co., Ltd. Method of Recovering Valuable Metal from Scrap Conductive Oxide
US20100101964A1 (en) * 2007-02-16 2010-04-29 Nippon Mining & Metals Co., Ltd. Method of Recovering Valuable Metal from Scrap Containing Conductive Oxide
US20100282615A1 (en) * 2008-02-12 2010-11-11 Nippon Mining & Metals Co., Ltd. Method of Recovering Valuable Metals from IZO Scrap
US20100288645A1 (en) * 2008-03-06 2010-11-18 Nippon Mining & Metals Co., Ltd. Method of Recovering Valuable Metals from IZO Scrap
US20100288646A1 (en) * 2008-02-12 2010-11-18 Nippon Mining & Metals Co., Ltd. Method of Recovering Valuable Metals from IZO Scrap

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US948681A (en) * 1908-04-16 1910-02-08 Edwin M Chance Electrolytic separation of metal.
GB419819A (en) * 1933-05-12 1934-11-12 Mond Nickel Co Ltd Improvements relating to the dissolving of metals of the platinum group
US2655473A (en) * 1948-07-20 1953-10-13 Metal & Thermit Corp Electrolytic detinning
US2738294A (en) * 1951-09-13 1956-03-13 Diamond Alkali Co Salt bath system and method for treating metals
US2826539A (en) * 1956-12-05 1958-03-11 Allegheny Ludlum Steel Method of cleaning metal strip
US2920023A (en) * 1955-04-04 1960-01-05 Chrysler Corp Electrolytic cleaning of metal and composition therefor
US2936270A (en) * 1957-11-12 1960-05-10 Kolene Corp Methods for cleaning and descaling titanium
US2936278A (en) * 1955-03-07 1960-05-10 Kolene Corp Molten salt bath apparatus for electrolytic cleaning of metals
US3096261A (en) * 1959-05-25 1963-07-02 Hooker Chemical Corp Salt bath for electrolytic cleaning of metals

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US948681A (en) * 1908-04-16 1910-02-08 Edwin M Chance Electrolytic separation of metal.
GB419819A (en) * 1933-05-12 1934-11-12 Mond Nickel Co Ltd Improvements relating to the dissolving of metals of the platinum group
US2655473A (en) * 1948-07-20 1953-10-13 Metal & Thermit Corp Electrolytic detinning
US2738294A (en) * 1951-09-13 1956-03-13 Diamond Alkali Co Salt bath system and method for treating metals
US2936278A (en) * 1955-03-07 1960-05-10 Kolene Corp Molten salt bath apparatus for electrolytic cleaning of metals
US2920023A (en) * 1955-04-04 1960-01-05 Chrysler Corp Electrolytic cleaning of metal and composition therefor
US2826539A (en) * 1956-12-05 1958-03-11 Allegheny Ludlum Steel Method of cleaning metal strip
US2936270A (en) * 1957-11-12 1960-05-10 Kolene Corp Methods for cleaning and descaling titanium
US3096261A (en) * 1959-05-25 1963-07-02 Hooker Chemical Corp Salt bath for electrolytic cleaning of metals

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3492210A (en) * 1967-10-16 1970-01-27 Hamilton Cosco Inc Electrolytic stripping of nonferrous metals from a ferrous metal base
US4100044A (en) * 1977-07-15 1978-07-11 The United States Of America As Represented By The Secretary Of The Air Force Procedure for removing aluminum from an Al-Al3 Ni two-phase matrix
US4246083A (en) * 1978-08-31 1981-01-20 Johnson, Matthey & Co., Limited Removal of surface material
US4287033A (en) * 1980-04-14 1981-09-01 Calspan Corporation Electrochemical method for removing metallic sheaths
DE3318598A1 (de) * 1982-05-27 1983-12-01 Occidental Chemical Corp., 48089 Warren, Mich. Bad und verfahren fuer die elektrolytische entfernung von ueberzuegen aus kupfer, kupferlegierung oder chrom von einem eisenhaltigen grundmetall
US20030132416A1 (en) * 2001-10-11 2003-07-17 Shipley Company, L.L.C. Stripping solution
US8685225B2 (en) * 2007-02-16 2014-04-01 Jx Nippon Mining & Metals Corporation Method of recovering valuable metal from scrap conductive oxide
US20100101963A1 (en) * 2007-02-16 2010-04-29 Nippon Mining & Metals Co., Ltd. Method of Recovering Valuable Metal from Scrap Conductive Oxide
US20100101964A1 (en) * 2007-02-16 2010-04-29 Nippon Mining & Metals Co., Ltd. Method of Recovering Valuable Metal from Scrap Containing Conductive Oxide
US8734633B2 (en) * 2007-02-16 2014-05-27 Jx Nippon Mining & Metals Corporation Method of recovering valuable metal from scrap containing conductive oxide
US20100282615A1 (en) * 2008-02-12 2010-11-11 Nippon Mining & Metals Co., Ltd. Method of Recovering Valuable Metals from IZO Scrap
US8308932B2 (en) 2008-02-12 2012-11-13 Jx Nippon Mining & Metals Corporation Method of recovering valuable metals from IZO scrap
US8308933B2 (en) 2008-02-12 2012-11-13 Jx Nippon Mining & Metals Corporation Method of recovering valuable metals from IZO scrap
US20100288646A1 (en) * 2008-02-12 2010-11-18 Nippon Mining & Metals Co., Ltd. Method of Recovering Valuable Metals from IZO Scrap
US8308934B2 (en) 2008-03-06 2012-11-13 Jx Nippon Mining & Metals Corporation Method of recovering valuable metals from IZO scrap
US20100288645A1 (en) * 2008-03-06 2010-11-18 Nippon Mining & Metals Co., Ltd. Method of Recovering Valuable Metals from IZO Scrap

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DE1421994A1 (de) 1969-04-03
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