US3203883A - Method of refining molten metals by electrolyzing molten slag under arc discharge - Google Patents
Method of refining molten metals by electrolyzing molten slag under arc discharge Download PDFInfo
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- US3203883A US3203883A US177884A US17788462A US3203883A US 3203883 A US3203883 A US 3203883A US 177884 A US177884 A US 177884A US 17788462 A US17788462 A US 17788462A US 3203883 A US3203883 A US 3203883A
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- 238000007670 refining Methods 0.000 title claims description 38
- 229910052751 metal Inorganic materials 0.000 title claims description 30
- 239000002184 metal Substances 0.000 title claims description 30
- 239000002893 slag Substances 0.000 title claims description 29
- 238000000034 method Methods 0.000 title claims description 19
- 238000010891 electric arc Methods 0.000 title claims description 11
- 150000002739 metals Chemical class 0.000 title description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 16
- 230000000694 effects Effects 0.000 claims description 9
- 229910052742 iron Inorganic materials 0.000 claims description 8
- 239000003792 electrolyte Substances 0.000 claims description 7
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 229910001018 Cast iron Inorganic materials 0.000 claims description 4
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 4
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 4
- 229910052918 calcium silicate Inorganic materials 0.000 claims description 4
- 239000000378 calcium silicate Substances 0.000 claims description 4
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 claims description 4
- 150000001875 compounds Chemical class 0.000 claims description 4
- 229910001021 Ferroalloy Inorganic materials 0.000 claims description 3
- 229910052783 alkali metal Inorganic materials 0.000 claims description 3
- 150000001340 alkali metals Chemical class 0.000 claims description 3
- 238000005868 electrolysis reaction Methods 0.000 description 18
- 238000006243 chemical reaction Methods 0.000 description 16
- 229910000831 Steel Inorganic materials 0.000 description 14
- 239000010959 steel Substances 0.000 description 14
- 239000000047 product Substances 0.000 description 8
- 229910045601 alloy Inorganic materials 0.000 description 7
- 239000000956 alloy Substances 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 7
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical class [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 238000006477 desulfuration reaction Methods 0.000 description 5
- 230000023556 desulfurization Effects 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- -1 aluminum halides Chemical class 0.000 description 3
- 239000011575 calcium Substances 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 150000004820 halides Chemical class 0.000 description 2
- 229910052736 halogen Inorganic materials 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 229910000599 Cr alloy Inorganic materials 0.000 description 1
- 229910017082 Fe-Si Inorganic materials 0.000 description 1
- 229910017133 Fe—Si Inorganic materials 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000005255 carburizing Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000000788 chromium alloy Substances 0.000 description 1
- UPHIPHFJVNKLMR-UHFFFAOYSA-N chromium iron Chemical compound [Cr].[Fe] UPHIPHFJVNKLMR-UHFFFAOYSA-N 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 125000005843 halogen group Chemical group 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 238000011081 inoculation Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 235000000396 iron Nutrition 0.000 description 1
- 230000002101 lytic effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 150000004760 silicates Chemical class 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/52—Manufacture of steel in electric furnaces
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0075—Treating in a ladle furnace, e.g. up-/reheating of molten steel within the ladle
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/076—Use of slags or fluxes as treating agents
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B4/00—Electrothermal treatment of ores or metallurgical products for obtaining metals or alloys
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
- C22B9/16—Remelting metals
- C22B9/18—Electroslag remelting
-
- 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
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/134—Reduction of greenhouse gas [GHG] emissions by avoiding CO2, e.g. using hydrogen
-
- 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
Definitions
- the present invention relates to a method of refining molten metals by electrolyzing molten slag under are discharge at ambient pressure characterized in that molten slag consisting of calcium silicate containing one or more of halides of alkaline earth metals, or in addition therewith aluminum oxides or aluminum halides is used as the electrolyte and electrolyzed by applying direct current high potential between the molten metal as a cathode and an anode suspended above the electrolyte, thereby effecting deoxidation of the molten metal.
- the principal object of the invention is to effect strong refining of steels, pig irons, ferro-alloys and non-ferrous metals in the molten state and more patrieularly to efiect intensitive deoxidizing refining.
- the electrolytic refining by high potential arc discharge of the invention has the following specialities if compared with an ordinary electrolysis using dipped electrode wherein an anode is dipped into the electrolyte and the electrolysis is carried out at a comparatively low voltage.
- the temperature of molten slag, molten metal or alloy during the electrolytic refining can be easily maintained by the heat of arc.
- the fluidity of the molten slag can be maintained at a suitable degree.
- the temperature of the molten metal can be easily maintained by the heat of arc and the powerful reduction refining which has heretofore been considered difiicult is rendered possible so that it can be applied to the production of steel, and moreover, the time required for the reduction is made substantially equal to that of ordinary processes or can be shortened even less than that. Accordingly, the cost of melting refining in the electrolytic refining under high potential arc discharge is substantially same as that of melting refining in ordinary refining method and the cost of the direct current electrolyzing device can be compensated by the improvement in the yield of the product.
- a large merit obtainable in carrying out the method of the invention is to produce a melt of refined metals due to the extreme deoxidation and desulfurization for eliminating impurities and improving the yield of the product and its .limit varies according to the kinds of metals, yet the deoxidation as described hereafter by an example results in 20 to 60% improvement compared with ordinary refining and the yield is improved for 1 to 4%.
- the deoxidation and desulfurization mechanism of the electrolytic refining using arc discharge is as follows:
- the reaction of electrolytic refining of the molten slag proceeds 1) by the electrochemical reaction and (2) thermo-dynamic reaction.
- Electrochemical reacti0n.2CaO'SiO and CaX are taken as a slag to be deoxidized and desulfurized for example.
- thermo-dynamic reaction (1) T hermo-dynamic reaction.-Assuming the activities of S and Fe in the molten iron be expressed by aS and aFe respectively and the activities of 8 and Fe in the molten slag be aS and 'aFe respectively and the equilibrium constant between them be L S, then the following thermo-dynamic relation is established.
- both of aS and aFe are reduced by the reaction between two poles and accordingly, in order to maintain the equilibrium, FeS in the molten iron must proceed into the molten slag to efiect the deoxidation refining reaction simultaneously to the desulfurization.
- the reaction occurs on the surface of the molten metal (interface between the molten slag) the reaction product (alumina) is consumed by the molten slag at once so that it cannot be retained in the molten metal as non-metallic inclusions and refined metal may be obtained.
- the excessive precipitated aluminum serves to produce fine grained structure and to toughen the steel entering into the steel in case of refining.
- FIG. 1 is a diagrammatic sectional view of low voltage dipped electrode electrolytic device
- FIG. 2 is a similar diagrammatic sectional view to FIG. 1 illustrating the location of an anode in a high potential are discharge electrolytic refining device.
- Example 1 In stainless steels containing 0.16% C and 13% Cr, the comparison of ordinary refining, low potential dipped electrode electrolysis and are discharge electrolysis is shown in the following table:
- the furnace used is 1 ton Hroult type electrolytic furnace.
- Example 2 In low carbon steels, such as stainless steel containing less than 0.12% C and 13% Cr, even if very low carbon materials are used as charging raw material the carbon content of the molten steel becomes higher than 0.15% in the low voltage dipped electrode electrolysis so that the electrolysis under high voltage are discharge must be used necessarily and the result is as shown in the following:
- the furnace used is 1 ton Hroult type electrolytic furnace.
- Example 3 Fromthe results of test carried out similarly to cast iron, high voltage are discharge electrolysis is not only smoothly carried out its operation if compared with low voltage dipped electrode electrolysis but also the effect of deoxidation and desulfurization are increased. So that the nodularization of graphite due to inoculation can be made easy.
- the furnace used is 1 ton Hroult type electrolytic furnace.
- Example 4 The next table illustrates an example of the method of the invention as applied to pure copper. It is apparent that the pure copper of very high quality (oxygen free copper) was obtained.
- the furnace used was kg. high frequency electrolytic furnace.
- Example 5 Iron-chromium alloys and Fe-Si alloy are subjected to the high potential are discharge electrolytic refining and as its results the oxygen content in the alloy was slag by are discharge and to effect electro-chemical dcoxidation and desulphurization refining.
- a method of are discharge electrolytic refining of a molten metal, wherein said metal is selected from the f steel cast iron ferro-alloys and coprcdueed to $6 to $6 and when the refined alloy ts used 5 group .mslsung 2 for the melting of iron and steel, refined steel and iron which compnsc.s f f metal be refined comainingkss oxygen was obtained.
- the extent of the deoxidation refining according to the pound sflcctcd from group cons'slmg of compqunds method of the invention depends on the kinds of metals of alkali metals, alkaline earth metals, tron and aluminum and in higher alloy steels it is sometimes better than 10 5 an elcctmlye above surface of smd slag suspeng' vacuum smcmng. mg an anode and applying a D.C.
- the present method has advantages and metal be refined at f pressure that if compared with ordinary method of smelting the to clcctmlyu the 5.138 are dlscharge p products of high purity can be obtain at the Sam: or effect electrochemical deoxldatton and desulphurization less costs owing to the extremely strong deoxidation. 15 mfimng' What we claim is: References Cited by the Examiner 1.
- a method of arc-discharge, clCCtrolytic X'Cfining Of a molten metal wherein said metal is selected from the group consisting of steel, cast iron, terroalloys, and cop- 800'984 10/05 Chance 204-140 per, which comprises covering said metal to be refined 2,787,592 4/ 57 Burkhal'dl 204- with a molten calcium silicate slag containing a compound selected from the group consisting of compounds of alkali metals, alkaline earth metals, iron and aluminum as an electrolyte, above the surface of said slag, suspending an anode and applying a D.C. voltage between said anode and said metal to be refined to electrolyze the molten FOREIGN PATENTS 741,567 12/55 Great Britain.
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- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Manufacturing & Machinery (AREA)
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- Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
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Description
g- 1965 TOHEI OTOTANI ET AL 3,203,883
METHOD OF REFINING MOLTEN METALS BY ELECTROLYZING MOLTEN SLAG UNDER ARC DISCHARGE Filed March 6, 1962 F15 1 PRm/e ART molten sla q molten metal moltenslgg molten metal Unitcd States Patent 3,203,883 METHOD 0F REFENTNG MOLTEN METALS BY ELECTROLYZENG MULTEN SLAG UNDER ARC DISCHARGE Tohei Ototani, Masuteru Maruyarna, Jiro Matsumoto,
and Sumio lzumi, Sendai, Japan, assignors to The Research Institute for Iron, Steel and Other Metals of the Tohoku University, Sendai, Japan Filed Mar. 6, 1962, Ser. No. 177,884 Claims priority, application Japan, July 1, 1961, 36/233550 2 Claims. (Cl. 204-149) The present invention relates to a method of refining molten metals by electrolyzing molten slag under are discharge at ambient pressure characterized in that molten slag consisting of calcium silicate containing one or more of halides of alkaline earth metals, or in addition therewith aluminum oxides or aluminum halides is used as the electrolyte and electrolyzed by applying direct current high potential between the molten metal as a cathode and an anode suspended above the electrolyte, thereby effecting deoxidation of the molten metal.
The principal object of the invention is to effect strong refining of steels, pig irons, ferro-alloys and non-ferrous metals in the molten state and more patrieularly to efiect intensitive deoxidizing refining.
The electrolytic refining by high potential arc discharge of the invention has the following specialities if compared with an ordinary electrolysis using dipped electrode wherein an anode is dipped into the electrolyte and the electrolysis is carried out at a comparatively low voltage.
(1) The temperature of molten slag, molten metal or alloy during the electrolytic refining can be easily maintained by the heat of arc.
(2) The fluidity of the molten slag can be maintained at a suitable degree.
(3) Even if the anodic current density becomes large the phenomenon of lowering the efficiency ofclectrolysis such as an anode effect does not absolutely occur.
(4) Since the carbon electrode is not dipped in the molten metal or alloy the electrolytic refining of low carbon metals and alloys is possible. Contrary to the present method it is diflicult in the former electrolytic refining with dipped electrode, for' instance, in steels to obtain the product of less than 0.15% carbon due to the carburizing phenomena.
(5 The more intensitive deoxidation refining can 'be effected if compared with the electrolysis using dipped electrodes since the load voltage is high and a high basicity slag having higher resistance may be used as electrolyte.
As above described, according to the electrolytic refining using arc discharge of the invention the temperature of the molten metal can be easily maintained by the heat of arc and the powerful reduction refining which has heretofore been considered difiicult is rendered possible so that it can be applied to the production of steel, and moreover, the time required for the reduction is made substantially equal to that of ordinary processes or can be shortened even less than that. Accordingly, the cost of melting refining in the electrolytic refining under high potential arc discharge is substantially same as that of melting refining in ordinary refining method and the cost of the direct current electrolyzing device can be compensated by the improvement in the yield of the product.
A large merit obtainable in carrying out the method of the invention is to produce a melt of refined metals due to the extreme deoxidation and desulfurization for eliminating impurities and improving the yield of the product and its .limit varies according to the kinds of metals, yet the deoxidation as described hereafter by an example results in 20 to 60% improvement compared with ordinary refining and the yield is improved for 1 to 4%.
The deoxidation and desulfurization mechanism of the electrolytic refining using arc discharge is as follows:
The reaction of electrolytic refining of the molten slag proceeds 1) by the electrochemical reaction and (2) thermo-dynamic reaction.
(1) Electrochemical reacti0n.2CaO'SiO and CaX are taken as a slag to be deoxidized and desulfurized for example.
The reaction between two poles is as follows:
2CaO SiO 22Ca +SiO CaX e Ca 2X- (X represents halogen) Cathode reaction:
2Ca +4e- 2Ca Ca [O] CaO Ca [S] e CaS Anode reaction:
SiO SiO +4e SiO SiO 2O 20+2C- 2C0 2X 2X +2e As seen from the above the deoxidation and desulfur rization refining proceed by the cathode reaction of the active element produced by the electrolysis.
(2) T hermo-dynamic reaction.-Assuming the activities of S and Fe in the molten iron be expressed by aS and aFe respectively and the activities of 8 and Fe in the molten slag be aS and 'aFe respectively and the equilibrium constant between them be L S, then the following thermo-dynamic relation is established.
When DC. potential is applied to molten iron-molten slag which are in such condition of equilibrium the following relation proceeds between two poles.
That is, both of aS and aFe are reduced by the reaction between two poles and accordingly, in order to maintain the equilibrium, FeS in the molten iron must proceed into the molten slag to efiect the deoxidation refining reaction simultaneously to the desulfurization.
Even though the reaction of electrolytic refining proceeds by either of the above mechanisms oxygen or halogen gases are produced at the anode which controls the speeds of reaction of the electrolytic refining.
When the anode is dipped into the molten slag the generated gases are attracted by the anode surface to form non-conductive monomolecular film and multimolecular film which interrupt the flow of electric cur- G rents and considerably reduce a speed of electrolytic reaction.
On the contrary, in case of high potential are discharge the anode is suspended above the molten slag so that the generated gases are not attracted by the anode surface and even though there might form a gaseous film on the surface of the molten slag it is broken at a high temperature of arc and ion or electron bombardment so that the speed of anode reaction is considerably accelerated to highly advance the desulfurization reaction. When aluminum oxides and halides are contained in the molten slag which is the electrolyte in the present method the aluminum electrolytically reduced by the high voltage are discharge and precipitates under the active condition on the interface of molten metal and molten slag to cause strong deoxidizing reaction. In this case, since the reaction occurs on the surface of the molten metal (interface between the molten slag) the reaction product (alumina) is consumed by the molten slag at once so that it cannot be retained in the molten metal as non-metallic inclusions and refined metal may be obtained.
Moreover, the excessive precipitated aluminum serves to produce fine grained structure and to toughen the steel entering into the steel in case of refining.
For a better understanding of the invention, reference is taken to the accompanying drawings, in which FIG. 1 is a diagrammatic sectional view of low voltage dipped electrode electrolytic device, and
FIG. 2 is a similar diagrammatic sectional view to FIG. 1 illustrating the location of an anode in a high potential are discharge electrolytic refining device.
The method of the invention will be explained further in detail by the examples:
Example 1 In stainless steels containing 0.16% C and 13% Cr, the comparison of ordinary refining, low potential dipped electrode electrolysis and are discharge electrolysis is shown in the following table:
The furnace used is 1 ton Hroult type electrolytic furnace.
Low voltage Arc dis- Ordidipped charge nary electrode electrorefining electrolytic lytic refining refining Condition of electrolysis:
Composition of slag (percent) OaO 67. 27 70. 29 69. 30 SiOL- 25. 99 23. 58 24. 62 Mg 1.22 1.06 1.43 A1 0 2. 08 0. 98 0. 45 FeO 1. 24 0. 60 0. 40 D.C load volt 17. 8 55. 3 DD. load current (A) 2, 900 2, 500 Duration of electrolysis (minutes) 25 25 Test results of products: Impurities (percent)- 0. 0077 0. 0057 0- 0045 Purity by point counting process (percent) Sulfides, silicates 0. 004 0 0 Alumina 0. 006 0 0 Granular oxide 0.072 0. 041 0. 029 Yield of product in weight to the weight of steel ingot (percent). 73.0 73. 9 74. 3
Example 2 In low carbon steels, such as stainless steel containing less than 0.12% C and 13% Cr, even if very low carbon materials are used as charging raw material the carbon content of the molten steel becomes higher than 0.15% in the low voltage dipped electrode electrolysis so that the electrolysis under high voltage are discharge must be used necessarily and the result is as shown in the following:
The furnace used is 1 ton Hroult type electrolytic furnace.
Air discharge Ordinary electrolytic refining refining Condition of electrolysis:
Composition of slag (percent) FeO D.C. load voltage (V D.C. load current (A)..-
Duration of electrolysis Test results of products:
Carbon content (percent) 0.09 0. 09 Impurities (pcrccnt) S 0. 004 0. 008 0 0. 0029 0. 0058 Purity by point counting process (percei Sulfide, silicate 0 O 008 Alumina 0 0 Granular oxide 0.0035 0. 0045 As seen from the above example the effect of deoxidation refining of steels by the high potential are discharge electrolysis is very large.
Example 3 Fromthe results of test carried out similarly to cast iron, high voltage are discharge electrolysis is not only smoothly carried out its operation if compared with low voltage dipped electrode electrolysis but also the effect of deoxidation and desulfurization are increased. So that the nodularization of graphite due to inoculation can be made easy. The furnace used is 1 ton Hroult type electrolytic furnace.
Example 4 The next table illustrates an example of the method of the invention as applied to pure copper. It is apparent that the pure copper of very high quality (oxygen free copper) was obtained.
The furnace used was kg. high frequency electrolytic furnace.
Condition of electrolysis:
Arc discharge composltlon of slag (p electrolytic refining 59 l CaO NaCl 10.08 CaF 28.43 D.C. load voltage (V) 60.4 D.C. load current (A) 1,250 Duration of electrolysis (minutes) 22 Product:
Impurities, percent (the value in bracket shows that before electrolysis)- O 0.0008 (0.0015) S 0.002 (0.006) As 0.001 (0.004)
Example 5 Iron-chromium alloys and Fe-Si alloy are subjected to the high potential are discharge electrolytic refining and as its results the oxygen content in the alloy was slag by are discharge and to effect electro-chemical dcoxidation and desulphurization refining.
2. A method of are discharge electrolytic refining of a molten metal, wherein said metal is selected from the f steel cast iron ferro-alloys and coprcdueed to $6 to $6 and when the refined alloy ts used 5 group .mslsung 2 for the melting of iron and steel, refined steel and iron which compnsc.s f f metal be refined comainingkss oxygen was obtained. with a molten calcium silicate s ag containing a com- The extent of the deoxidation refining according to the pound sflcctcd from group cons'slmg of compqunds method of the invention depends on the kinds of metals of alkali metals, alkaline earth metals, tron and aluminum and in higher alloy steels it is sometimes better than 10 5 an elcctmlye above surface of smd slag suspeng' vacuum smcmng. mg an anode and applying a D.C. voltage hctween said As above described the present method has advantages and metal be refined at f pressure that if compared with ordinary method of smelting the to clcctmlyu the 5.138 are dlscharge p products of high purity can be obtain at the Sam: or effect electrochemical deoxldatton and desulphurization less costs owing to the extremely strong deoxidation. 15 mfimng' What we claim is: References Cited by the Examiner 1. A method of arc-discharge, clCCtrolytic X'Cfining Of a molten metal, wherein said metal is selected from the group consisting of steel, cast iron, terroalloys, and cop- 800'984 10/05 Chance 204-140 per, which comprises covering said metal to be refined 2,787,592 4/ 57 Burkhal'dl 204- with a molten calcium silicate slag containing a compound selected from the group consisting of compounds of alkali metals, alkaline earth metals, iron and aluminum as an electrolyte, above the surface of said slag, suspending an anode and applying a D.C. voltage between said anode and said metal to be refined to electrolyze the molten FOREIGN PATENTS 741,567 12/55 Great Britain.
5 JOHN H. MACK, Primary Examiner.
JOHN R. SPECK, Examiner.
Claims (1)
- 2. A METHOD OF ARC DISCHARGE ELECTROLYTIC REFINING OF A MOLTEN METAL, WHEREIN SAID METAL IS SELECTED FROM THE GROUP CONSISTING OF STEEL, CAST IRON, FERRO-ALLOYS, AND COPPER, WHICH COMPRISES COVERING SAID METAL TO BE REFINED WITH A MOLTEN CALCIUM SILICATE SLAG CONTAINING A COMPOUND SELECTED FROM THE GROUP CONSISTING OF COMPOUNDS OF ALKALI METALS, ALKALINE EARTH METALS, IRON AND ALUMINUM AS AN ELECTROLYTE, ABOVE THE SURFACE OF SAID SLAG SUSPENDING AN ANODE AND APPLYING A D.C. VOLTAGE BETWEEN SAID ANODE AND SAID METAL TO BE REFINED AT AMBIENT PRESSURE TO ELECTROLYZE THE MOLTEN SLAG BY ARC DISCHARGE AND TO EFFECT ELECTROCHEMICAL DEOXIDATION AND DESULPHURIZATION REFINING.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2338061 | 1961-07-01 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3203883A true US3203883A (en) | 1965-08-31 |
Family
ID=12108909
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US177884A Expired - Lifetime US3203883A (en) | 1961-07-01 | 1962-03-06 | Method of refining molten metals by electrolyzing molten slag under arc discharge |
Country Status (4)
Country | Link |
---|---|
US (1) | US3203883A (en) |
DE (1) | DE1608738B1 (en) |
GB (1) | GB994378A (en) |
SE (1) | SE318117B (en) |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4246023A (en) * | 1977-07-01 | 1981-01-20 | Dso "Charna Metalurgia" | Method and apparatus for the refining of iron-based melts |
FR2517328A1 (en) * | 1981-12-01 | 1983-06-03 | Iso Metalurgkomplekt | METHOD AND DEVICE FOR TREATING AND REFINING LIQUID METAL ALLOYS BY DIRECT CURRENT ELECTRIC ARC HEATING |
WO1988009388A1 (en) * | 1987-05-26 | 1988-12-01 | The University Of Toronto Innovations Foundation | Process for treating liquid metals |
US4875985A (en) * | 1988-10-14 | 1989-10-24 | Brunswick Corporation | Method and appparatus for producing titanium |
US4964973A (en) * | 1988-10-14 | 1990-10-23 | Brunswick Corporation | Method and apparatus for producing titanium |
WO1993017132A1 (en) * | 1992-02-28 | 1993-09-02 | Massachusetts Institute Of Technology | Process for improving metal production in iron and steelmaking processes |
WO1996022395A1 (en) * | 1995-01-20 | 1996-07-25 | Massachusetts Institute Of Technology | Method for enhancing reaction rates in metals refining, extraction, and recycling operations involving melts containing ionic species such as slags, mattes, fluxes and the like |
WO1997016572A1 (en) * | 1995-10-30 | 1997-05-09 | Massachusetts Institute Of Technology | Accelerated decarburization of iron-carbon melts |
US20070215483A1 (en) * | 2006-03-10 | 2007-09-20 | Elkem As | Method for electrolytic production and refining of metals |
WO2007106709A3 (en) * | 2006-03-10 | 2007-11-29 | Elkem As | Method for electrolytic production and refining of metals |
WO2009028924A1 (en) * | 2007-08-29 | 2009-03-05 | Jack Victor Nyrup Aguilar | Ionising compound serving as an electric arc stabiliser |
CN101658901A (en) * | 2008-03-10 | 2010-03-03 | 王宇新 | Processing method and special casting equipment for preventing ductile iron liquor from generating spheroidization recession and reducing casting temperature in process of casting |
US20130228469A1 (en) * | 2010-11-02 | 2013-09-05 | I'msep Co., Ltd. | Production method for metal microparticle |
CN105385857A (en) * | 2015-11-06 | 2016-03-09 | 攀钢集团成都钢钒有限公司 | Method for smelting slag used for electroslag ingot resmelting and provided with P increase prevention function |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2396087A1 (en) * | 1977-09-02 | 1979-01-26 | Tscherna Metalurgia | Electrochemically refining iron-based alloys in ladle - by applying a DC arc using submerged anode |
SE461048B (en) * | 1987-03-02 | 1989-12-18 | Gyproc Ab | PERFORED, SOUND-ABSORBING DISC |
Citations (3)
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US800984A (en) * | 1905-06-02 | 1905-10-03 | Henry M Chance | Process of purifying metals. |
GB741567A (en) * | 1952-01-10 | 1955-12-07 | Guszstahlwerk Bochumer Ver Ag | A method of making high-grade steel |
US2787592A (en) * | 1948-10-01 | 1957-04-02 | Ver Deutsche Metallwerke Ag | Method for the treatment of metal |
-
1962
- 1962-03-06 US US177884A patent/US3203883A/en not_active Expired - Lifetime
- 1962-03-16 GB GB10112/62A patent/GB994378A/en not_active Expired
- 1962-04-19 SE SE4473/62A patent/SE318117B/xx unknown
- 1962-06-08 DE DE19621608738 patent/DE1608738B1/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US800984A (en) * | 1905-06-02 | 1905-10-03 | Henry M Chance | Process of purifying metals. |
US2787592A (en) * | 1948-10-01 | 1957-04-02 | Ver Deutsche Metallwerke Ag | Method for the treatment of metal |
GB741567A (en) * | 1952-01-10 | 1955-12-07 | Guszstahlwerk Bochumer Ver Ag | A method of making high-grade steel |
Cited By (25)
Publication number | Priority date | Publication date | Assignee | Title |
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US4246023A (en) * | 1977-07-01 | 1981-01-20 | Dso "Charna Metalurgia" | Method and apparatus for the refining of iron-based melts |
FR2517328A1 (en) * | 1981-12-01 | 1983-06-03 | Iso Metalurgkomplekt | METHOD AND DEVICE FOR TREATING AND REFINING LIQUID METAL ALLOYS BY DIRECT CURRENT ELECTRIC ARC HEATING |
US4462878A (en) * | 1981-12-01 | 1984-07-31 | Iso "Metalurgkomplekt" | Method of treating and refining liquid metal alloys by direct current electric arc heating |
WO1988009388A1 (en) * | 1987-05-26 | 1988-12-01 | The University Of Toronto Innovations Foundation | Process for treating liquid metals |
JPH03500304A (en) * | 1987-05-26 | 1991-01-24 | ユニバーシティ・オブ・トロント・イノベーションズ・ファウンデーション | How to process liquid metal |
US4875985A (en) * | 1988-10-14 | 1989-10-24 | Brunswick Corporation | Method and appparatus for producing titanium |
WO1990004043A3 (en) * | 1988-10-14 | 1990-05-03 | Brunswick Corp | Method of producing titanium |
US4964973A (en) * | 1988-10-14 | 1990-10-23 | Brunswick Corporation | Method and apparatus for producing titanium |
WO1993017132A1 (en) * | 1992-02-28 | 1993-09-02 | Massachusetts Institute Of Technology | Process for improving metal production in iron and steelmaking processes |
WO1996022395A1 (en) * | 1995-01-20 | 1996-07-25 | Massachusetts Institute Of Technology | Method for enhancing reaction rates in metals refining, extraction, and recycling operations involving melts containing ionic species such as slags, mattes, fluxes and the like |
US5700308A (en) * | 1995-01-20 | 1997-12-23 | Massachusetts Institute Of Technology | Method for enhancing reaction rates in metals refining extraction, and recycling operations involving melts containing ionic species such as slags, mattes, fluxes |
WO1997016572A1 (en) * | 1995-10-30 | 1997-05-09 | Massachusetts Institute Of Technology | Accelerated decarburization of iron-carbon melts |
US20070215483A1 (en) * | 2006-03-10 | 2007-09-20 | Elkem As | Method for electrolytic production and refining of metals |
WO2007106709A3 (en) * | 2006-03-10 | 2007-11-29 | Elkem As | Method for electrolytic production and refining of metals |
JP2009529607A (en) * | 2006-03-10 | 2009-08-20 | エルケム アクシエセルスカプ | Electrolytic production of metal and scouring method |
AU2007226754B2 (en) * | 2006-03-10 | 2011-01-20 | Elkem As | Method for electrolytic production and refining of metals |
US7901561B2 (en) | 2006-03-10 | 2011-03-08 | Elkem As | Method for electrolytic production and refining of metals |
WO2009028924A1 (en) * | 2007-08-29 | 2009-03-05 | Jack Victor Nyrup Aguilar | Ionising compound serving as an electric arc stabiliser |
CN101658901A (en) * | 2008-03-10 | 2010-03-03 | 王宇新 | Processing method and special casting equipment for preventing ductile iron liquor from generating spheroidization recession and reducing casting temperature in process of casting |
US20110005351A1 (en) * | 2008-03-10 | 2011-01-13 | Yuxin Wang | Method for treating spheroidal graphite iron and pouring device thereof |
US8419821B2 (en) * | 2008-03-10 | 2013-04-16 | Yuxin Wang | Method for treating spheroidal graphite iron and pouring device thereof |
US8767793B2 (en) | 2008-03-10 | 2014-07-01 | Yuxin Wang | Method for treating spheroidal graphite iron and pouring device thereof |
US20130228469A1 (en) * | 2010-11-02 | 2013-09-05 | I'msep Co., Ltd. | Production method for metal microparticle |
US9562296B2 (en) * | 2010-11-02 | 2017-02-07 | I'msep Co., Ltd. | Production method for silicon nanoparticles |
CN105385857A (en) * | 2015-11-06 | 2016-03-09 | 攀钢集团成都钢钒有限公司 | Method for smelting slag used for electroslag ingot resmelting and provided with P increase prevention function |
Also Published As
Publication number | Publication date |
---|---|
DE1608738B1 (en) | 1972-01-05 |
SE318117B (en) | 1969-12-01 |
GB994378A (en) | 1965-06-10 |
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