US2858198A - Recovery of material from aluminum reduction cell lining - Google Patents

Recovery of material from aluminum reduction cell lining Download PDF

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Publication number
US2858198A
US2858198A US463214A US46321454A US2858198A US 2858198 A US2858198 A US 2858198A US 463214 A US463214 A US 463214A US 46321454 A US46321454 A US 46321454A US 2858198 A US2858198 A US 2858198A
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United States
Prior art keywords
lining
sodium
fluoride
recovery
pot
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Expired - Lifetime
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US463214A
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English (en)
Inventor
James P Mcgeer
Vladimir V Mirkovich
Norman W F Phillips
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Alcan Research and Development Ltd
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Aluminium Laboratories Ltd
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Publication date
Priority to DENDAT1065625D priority Critical patent/DE1065625B/de
Application filed by Aluminium Laboratories Ltd filed Critical Aluminium Laboratories Ltd
Priority to US463214A priority patent/US2858198A/en
Priority to GB29194/55A priority patent/GB813834A/en
Priority to FR1137666D priority patent/FR1137666A/fr
Application granted granted Critical
Publication of US2858198A publication Critical patent/US2858198A/en
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F7/00—Compounds of aluminium
    • C01F7/48—Halides, with or without other cations besides aluminium
    • C01F7/50—Fluorides
    • C01F7/54—Double compounds containing both aluminium and alkali metals or alkaline-earth metals

Definitions

  • the aluminum metal collects in molten form in the bottom of the cell, being drawn o from time to time. Fresh quantities of alumina for reduction are progressively added, and likewise as necessary additional cryolite or other fluoride to maintain the desired molten and other characteristics of the electroylte.
  • the innermost lining of such cells, directly receiving the molten bath, is conventionally composed essentially of carbon, e. g. as may be derived from appropriately pure or puriiied coke and carbonaceous binders such as tar or pitch, in a layer of substantial thickness, such as l() to inches.
  • the carbon lining may be and in modern practice invariably is surrounded by an outer layer of material having thermal insulating properties, e. g., insulating brick or granular ⁇ alumina, bauxite or magnesio, the inner carbon lining being originally deposited or constructed as a coherent, solid mass, and the insulating layer in a manner appropriate to the particular ymaterial used.
  • the carbon lining and insulation are contained in an appropriate steel or other shell.
  • the lining material which is commonly "arent O ICC called pot lining and may sometimes be so identied herein, must rst be comminuted to a very tine state, e. g. usually smaller than mesh, in order to obtain reasonably satisfactory dissolution of the luoride material in the leach liquor.
  • actual recovery of such fluoride from the liquor is difficult or inconvenient, for example in requiringevaporation or other treatment to precipitate the lluoride as cryolite. ⁇
  • the cryolite precipitate is usually in an inconveniently fine state of subdivision and may carry with it considerable impurity which was also leached from the pot lining. Some purification steps are then often necessary. Eventual drying and calcining of the separated fluoride material is required if it is to be reintroduced to the aluminum producing process.
  • the present invention embraces the discovery that such material, especially the desired liuorides, may be recovered by distillation, specifically by breaking up the old lining into -coarse pieces and then heating it in an appropriate crucible or furnace to an elevated but conveniently attained temperature, viz. in the neghbcrhood of 1000 and preferably upwards thereof, under subatmospheric pressure.
  • a particularly important feature of the invention is the discovery that by such process the produced vapor contains not only the volatilized tluorides, but generally also metallic sodium in vapor form.
  • the procedure more specically comprises the conduction of the-vapors, i. e. of fluorides and sodium, through the condensing region where successively lower temperatures are maintained, along the path of vapor travel.
  • the pot lining need not be crushed or ground to any fine state of sub division; relatively coarse or even very large piecescan be eciently treated, so that the expensive grinding step of the prior wet method is avoided.l
  • the -desired uorides are recovered in a highly pure form and in an entirely dry, water-free state, A higher actual recovery of iluorine from the pot lining has been found; achievable than with the usual wet processes.
  • the separate recovery of substantially pure sodium metal represents a particularly new aspect of the process', thequantities of sodium thus produced being relatively substantial and suitable for use or sale.
  • the pot lining may exhibit numerous small cracks and fissures which permit rapid ⁇ escape. of volatile materials from relatively large-lumps n i while in other cases the pot lining may be relatively dense, thus requiring crushing to a smaller size to permit the same rate of removal of volatiles.
  • the particle size may be many times that required by the wet extraction method and in general need never be smaller than an average diameter of about 2 inches.
  • the lining may be treated in blocks of a foot or more in each dimension. Fine crushing can be employed if desired, but evidence indicates that there is ordinarily no advantage in so doing and, owing to the expense of crushing, the size used will ordinarily be the largest which will give an adequate rate of vaporization.
  • the pot lining In its broken-up state, the pot lining is introduced into a suitable furnace, which is closed except for connection to a condenser.
  • the system has appropriate means for maintaining a sub-atmospheric pressure, as with a suitable vacuum pump connected to the remote or furthest end of the condenser whereby the pressure in the entire system, including the heating Zone of the furnace, is kept at the desired value and the desired con duction of vapors from the furnace into and along the condenser is achieved.
  • the pot lining material is then heated in the furnace in any of various ways, e. g. by electrical induction, or by passing electric current through the charge between electrodes extending into it, or by combustion of suitable fuel in regions surrounding the Crucible or the like in which the charge may be placed.
  • the pressure to be maintained for effective volatilization depends on the vapor pressure of the materials being distilled and thus varies with temperature, being about 0.001 atmosphere when the charge is only heated to about 1000 C., and ranging up to 0.1 atmosphere for distillations at about 1400" C. (being of the order of 0.01 atmosphere for operations at 1200), somewhat higher pressures, but still preferably subatmosphen'c, being usable at higher temperatures, such as 1500 C., or above. 'Ihus it will be understood that at increasing temperatures, higher vapor pressures are achieved and more rapid vaporization results. However, energy losses are excessive at high temperatures and uoride materials are corrosive to practically all construction materials.
  • the total time of treatment for production of the desired vapor i. e. in order to secure optimum recovery of fluoride, varies somewhat with the temperature and pressure conditions, longer times being usually required at lower temperatures. 1n general, distillation times of the order of one-half hour to several hours appear en tirely adequate. From the furnace, where the described vapors are evolved throughout the heating period, such vapor is passed, e. g. by simple conduction under the influence of the exhaust pump, into and through a condensing region, which may consist of an elongate-d chamber having appropriately cooled walls and having its effective length, if desired, increased by appropriate balies or the like.
  • temperature conditions in the condenser are suitably correlated with the temperature of volatilization and the pressure, so as to achieve the desired condensation of the vapor, essentially in its entirety.
  • the condenser is conveniently arranged so that throughout the iirst part of its wall and other structure traversed by the gas, say about one-half of the total extent, the iuorides are condensed but essentially none of the sodium.
  • the temperature is kept considerably lower (though in most cases preferably above the melting point of sodium, 98 C., with resulting condensation of the metallic sodium.
  • the condenser is opened and the distillates removed, that in the first zone is generally found to consist essentially of cryolite (sodium aluminum fluoride) and sodium iiuoride, the complex fluoride usually predominating in amount.
  • the metallic sodium is removed from the further region of the condenser, with appropriate precautions ⁇ to keep it dry and avoid excessive contact with air.
  • Actual removal of the distillates can be accomplished in any suitable way as by mechanical scraping or the like.
  • the recovery process may be made continuous by provision of means well known in themselves, such as pressure locks, for the addition of pot lining to the furnace and for the removal of spent pot lining and recovered iiuorides and sodium, without interruption of distillation.
  • the thermal insulating portions outside the heavy carbon layer it would appear that there is suflicient carbon present from the original association with the carbon layer, or alternatively or perhaps additionally sucient carbide present (in the alumina layer), in order to achieve the stated reduction. Indeed during the life of a reduction cell, if reasonably long, the insulating layer tends to lose its identity and to form a more or less monolithic block with the carbon layer, characterized by some mutual penetration of the respective materials. Thus while a large concentration of carbon usually remains adjacent the inner surface, certain amounts of carbon are almost certain to be present even in lining portions near the outer surface.
  • the furnace charge may consist of either one of those portions alone, or alternatively may consist of an unsorted mixture of the parts of the lining, e. g. such ⁇ as might be -obtained by appropriately breaking up the entire lining of a single pot into a unitary mass of unclassified pieces.
  • refractory brick of a silica-containing type, or other silica-containing material is employed for cell lining purposes, e. g. in regions of thermal insulation outside the necessary interior carbon lining.
  • bottom insulation ⁇ for aluminum reduction cells has been made of such refractorybrick instead of alumina-type material, e. g. bauxite or pure alumina.
  • silica contamination of the fluoride distillate is somewhat reduced from that found in using the refractory brick material alone, the presence ⁇ of silica in material to be treated is generally to be avoided.
  • Such silica-containing material can ordinarily be segregated by simple mechanical means.
  • the figure is a diagrammatic illustration, as in vertical section, of one arrangement of a crucible, including evaporator and condensing section, that has been successfully employed.
  • the apparatus essentially comprises an upright, cylindrical, inner shell or vessel ⁇ having a cup-shaped evaporator section 11 at the bottom and openings 12 at the top for withdrawing permanent gas, i.- e. gases that may be present or may be released by the treated material and that are not condensed at normal temperature and pressure, such as hydrogen, oxygen, carbon dioxide or the like.
  • permanent gas i.- e. gases that may be present or may be released by the treated material and that are not condensed at normal temperature and pressure, such as hydrogen, oxygen, carbon dioxide or the like.
  • the vessel 10 is enclosed within an appropriate outer housing 14, the space between the latter and the ⁇ inner shell 10 being lled with insulating material 15, say -of a refractory nature such as granular zirconia, or other divided or cohered refractory material.
  • the openings 12 communicate with a head chamber 16, having a connection I7 to a vacuum pump (not shown) by which air may be exhausted from the system and the desired, reduced pressure maintained during operation.
  • the reduction cell lining material 18 ⁇ to be treated is disposed inthe evaporator 11. Heat is applied by suitable means such as electrical induction; for instance, the lower part ofthe apparatus maybe surrounded by a water-cooled coil 19 through which high frequency electric current is conducted from an appropriate source (not shown).
  • the, interior 4of the vessel 10, above ⁇ the evaporator 11, may have a number of horizontal baffles 20,21, apertured to afford a tortuous path for the vapor drawn from the material 18.
  • mechanical ⁇ scraping devices or the like may be permanently installed for periodic collection of distillate from the interior surfaces of ⁇ the condenser
  • simple forms of the apparatus may be appropriately designed, as in a number of sections, to permit disassembly for recovery of the deposited material.
  • the bathe ⁇ plates 20, 21 and appropriate spacing sleeves between them can be made to ⁇ be removable, when the vessel is,opened.
  • apparatus tion 10 were made of steel.
  • the evaporator 11 In operation, the evaporator 11 is charged with appropriate pieces of pot lining, and heat is applied by induction from the coil 19. Under ⁇ the influence of the vacuum pump, airis essentially removed from the system, and as and after ⁇ the temperature for ⁇ evaporation is reached, continued pumping removes permanent gases which are evolved, and maintains the. ⁇ selected low..pressure in the system.
  • Temperatures stated hereinbelow generally representy the approximate temperature ⁇ of the charge itself ⁇ during ⁇ evaporation, i. e. as measured bythermocouple extending into the charge. Thermocouple ⁇ measurements ⁇ at the bottom of the steel evaporator section 11 showed somewhat higher temperatures ⁇ in all cases, i. e.. usually about- 60 ⁇ to 80 C. more. i
  • the percentage recovery of lluorine measured as percent of the total in the original pot lining, and actually obtained in the form of cryolite (3NaF.AlF3) and sodium iluoride (NaF), varied considerably, from values in the neighborhood of 75% up to 99%, the average being about 90%, and thus considerably better than the average recovery of about 78% that was obtainable from samples of the same pot linings by utilizing a standard wet method, i. e. the conventional caustic leach.
  • 100 gram portions of pot lining derived from the carbon bottom of a seven-year-old pot, and containing 17.9% lluorine was heated to 11.35 C. (for fluoride vaporization) for periods varying from to 60 minutes, and showed iluorine recovery of 8l to 85.5%, these being apparently samples from which iluorine was rather diillcultly releasable.
  • compositions of the distillates were further investigated, utilizing material from the same pot linings, and performing distillations at temperatures from 1050 to 1200 C.
  • the apparatus was of the larger size mentioned above, utilizing the steel condensing section.
  • the distillation times were recorded as varying from 2 to 5 or 6 hours, but included all of the time beginning with the attainment of a temperature of 950 C. in the course of heating up the apparatus. ln every case there was at least one-half hour of operation at the maximum temperature selected, viz. 1050", 1100, 1150 or 1200", in different cases. In these tests, the
  • tion of sodium iluoride appears to increase relative to the cryolite, and in general the greatest concentrations of sodium fluoride appear to occur in lthe side insulation .and at the .carbon cornerat the collector bar level, the least concentrations being in the carbon directly under the bath.
  • values of 45.5% cryolite and 54.5% sodium lluoride were obtained and in another instance proportions as low as 39.9% cryolite and 61.1% sodium fluoride, but in many cases the cryolite considerably exceeded the sodium lluoride, up to situ-- ations where the proportion of cryolite to sodium fluoride was approximately 90% to 10% rand even higher, e. g. of the -order of 97% to 3%.
  • the total weight of thef fluoride condensate appeared to average about of the weight of the lining treated, ranging as low as 12% and as high as 58% among the various samples used.
  • llourine recovery ranged as high as 98 to 99% in many cases and averaged about 90% or better, thus agreeing with the operations described above.
  • ⁇ Item D is the percentage of the total lluorine, in the lining, which was removed in vapor. Measured on the iluorine thus distilled, item E represents the percentage condensed.
  • the table also gives (item F) the composition of the condensed fluoride material, in specific compounds. While it will be appreciated that in some of these and other runs the fluorine recovery was appreciably below a number of the above and still other tests showed recoveries 4well beyond such figure, which represents the average Although the localities of the condensates varied considerably among the tests, typical positions for the fluoride and sodium fractions are indicated respectively at 24 and 25 in the drawing.
  • a method for the recovery of valuable fluoride material -from used aluminum reduction cell lining comprising heating the lining at a temperature in the range of about 1000 C. to about 1500" C. and under pressure reduced below atmospheric, to volatilize fluoride material from the lining into vapor condensable as fluoride material of the class consisting of cryolite and sodium uoride, conducting the resulting vapor to a condensing region and there condensing uoride material of said class from the vapor.
  • a method for producing fluoride material of the class consisting of cryolite and sodium iluoride comprising heating used aluminum reduction cell lining at a temperature in the range of about 1000 C. to about 1500 C., under suitable subatmospheric pressure in the vrange of 0.001 atmosphere and above and for a suflicient time to vaporize fluoride material therefrom, and condensin'g fluoride from said vapor, consisting essentially of uoride material of the aforesaid class.
  • a method for the recovery of valuable material from used aluminum reduction cell lining comprising volatilizing metallic sodium and fluoride condensable as fluoride material of the class consisting of cryolite and sodium fluoride, from said lining, by heating the lining at a temperature in the range of about 1000o C. to about 1500 C. and under pressure reduced below atmospheric, conducting the produced vapor into and along a condensing path which is characterized by decrease of temperature along it, and condensing said fluoride material and metallic sodium from the vapor respectively at successive regions of decreasing temperature along said path.
  • a method 'for the recovery of valuable material from used aluminum reduction cell lining comprising volatilizing uoride material and metallic sodium from the lining by heating the lining at a temperature in the range of about 1000 C. to about 1500 C. and under suitable subatmospheric pressure in the range of 0.001 atmosphere and above, to produce vapor containing fluoride material condensable as material of the class consisting of cryolite and sodium fluoride, and metallic sodium, conducting said vapor into and along a condensing path which is characterized by decrease of temperature along it, and condensing fluoride material of said class and metallic sodium from the vapor respectively at successive regions of decreasing temperature along said path.
  • a method for producing fluoride material and metallic sodium, said lluoride material being of the class consisting of cryolite and sodium uoride comprising heating used aluminum reduction cell lining at a temperature in the range of about 1000 C. to about 1500 C., under suitable subatmospheric pressure and for a suilicient length of time to vaporize fluoride material and metallic sodium therefrom, conducting the produced vapor into and along a condensing path which is characterized by decrease of temperature along it, and condensing fluoride and metallic sodium from the vapor respectively at successive regions of decreasing temperature along said path, said uoride condensate consisting essentially of uoride material of the aforesaid class.
US463214A 1954-10-19 1954-10-19 Recovery of material from aluminum reduction cell lining Expired - Lifetime US2858198A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
DENDAT1065625D DE1065625B (de) 1954-10-19 Rückgewinnung von Fluoriden aus gebrauchten Aus kleidungen von Alumimumreduktionszellen
US463214A US2858198A (en) 1954-10-19 1954-10-19 Recovery of material from aluminum reduction cell lining
GB29194/55A GB813834A (en) 1954-10-19 1955-10-13 Recovery of fluoride material from used aluminum reduction cell lining
FR1137666D FR1137666A (fr) 1954-10-19 1955-10-18 Récupération d'un fluorure à partir de revêtements usés de cellule d'aluminium

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DE (1) DE1065625B (fr)
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GB (1) GB813834A (fr)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3073676A (en) * 1960-07-29 1963-01-15 Electro Chimie Metal Process of recovering fluorine from solid residues by pyrohydrolysis
US3114611A (en) * 1959-06-04 1963-12-17 Nat Distillers Chem Corp Apparatus for refining metal chlorides in molten salts
US3151934A (en) * 1961-06-12 1964-10-06 Kaiser Aluminium Chem Corp Method of recovering lithium values
US3198600A (en) * 1960-08-10 1965-08-03 Electro Chimie Metal Process for recovering fluorine
US4597953A (en) * 1985-02-20 1986-07-01 Aluminum Company Of America Halogen recovery
US4889695A (en) * 1985-02-20 1989-12-26 Aluminum Company Of America Reclaiming spent potlining
US5558847A (en) * 1991-02-05 1996-09-24 Kaaber; Henning Process for recovering aluminium and fluorine from fluorine containing waste materials
US20110081284A1 (en) * 2009-10-02 2011-04-07 Mark Weaver Treatment of bauxite residue and spent pot lining
CN102574173A (zh) * 2009-09-23 2012-07-11 Sgl碳欧洲股份公司 用于处理含碳块状材料的方法和反应器
CN105088274A (zh) * 2015-08-24 2015-11-25 沈阳北冶冶金科技有限公司 一种处理及回收铝电解固体废料的装置
WO2017031798A1 (fr) * 2015-08-24 2017-03-02 沈阳北冶冶金科技有限公司 Appareil de traitement et de recyclage de déchets solides d'électrolyse d'aluminium
CN106868246A (zh) * 2017-03-21 2017-06-20 山东南山铝业股份有限公司 一种环保型磷生铁添加剂、其制备方法及磷生铁增碳脱硫方法
CN108275684A (zh) * 2017-05-19 2018-07-13 上海彭浦特种耐火材料厂有限公司 由铝电解槽产生的废氮化硅结合碳化硅砖回收利用方法
US20180274083A1 (en) * 2017-03-22 2018-09-27 University Of Delaware Centrifugal evaporation sources
CN109047285A (zh) * 2018-08-01 2018-12-21 湘潭大学 一种铝电解槽废阴极炭块中含钠、含氟化合物的转化方法与系统
CN109108050A (zh) * 2018-08-01 2019-01-01 湘潭大学 一种铝电解大修渣中含钠、含氟化合物的转化方法与系统
CN109127655A (zh) * 2018-08-01 2019-01-04 湘潭大学 一种铝电解废炭渣中含钠、含氟化合物的转化方法与系统
WO2020063345A1 (fr) * 2018-09-29 2020-04-02 沈阳北冶冶金科技有限公司 Dispositif de séparation et de récupération de déchets solides électrolytiques d'aluminium et de désulfuration à haute température de coke de pétrole

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CN106423578A (zh) * 2016-09-21 2017-02-22 红河学院 一种通过浮选法将脱氟废槽衬蒸馏残渣中成分分离的方法

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US2117497A (en) * 1937-08-27 1938-05-17 Dow Chemical Co Method of purifying carbon or graphite
US2260746A (en) * 1938-09-02 1941-10-28 Dow Chemical Co Method of treating carbon or graphite
US2624698A (en) * 1947-09-08 1953-01-06 Great Lakes Carbon Corp Method of producing a purified coke
US2732283A (en) * 1951-02-23 1956-01-24 O minutes

Patent Citations (4)

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Publication number Priority date Publication date Assignee Title
US2117497A (en) * 1937-08-27 1938-05-17 Dow Chemical Co Method of purifying carbon or graphite
US2260746A (en) * 1938-09-02 1941-10-28 Dow Chemical Co Method of treating carbon or graphite
US2624698A (en) * 1947-09-08 1953-01-06 Great Lakes Carbon Corp Method of producing a purified coke
US2732283A (en) * 1951-02-23 1956-01-24 O minutes

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3114611A (en) * 1959-06-04 1963-12-17 Nat Distillers Chem Corp Apparatus for refining metal chlorides in molten salts
US3073676A (en) * 1960-07-29 1963-01-15 Electro Chimie Metal Process of recovering fluorine from solid residues by pyrohydrolysis
US3198600A (en) * 1960-08-10 1965-08-03 Electro Chimie Metal Process for recovering fluorine
US3151934A (en) * 1961-06-12 1964-10-06 Kaiser Aluminium Chem Corp Method of recovering lithium values
US4597953A (en) * 1985-02-20 1986-07-01 Aluminum Company Of America Halogen recovery
US4889695A (en) * 1985-02-20 1989-12-26 Aluminum Company Of America Reclaiming spent potlining
US5558847A (en) * 1991-02-05 1996-09-24 Kaaber; Henning Process for recovering aluminium and fluorine from fluorine containing waste materials
CN102574173A (zh) * 2009-09-23 2012-07-11 Sgl碳欧洲股份公司 用于处理含碳块状材料的方法和反应器
US20120251434A1 (en) * 2009-09-23 2012-10-04 Hubert Jaeger Method and reactor for treating bulk material containing carbon
US20110081284A1 (en) * 2009-10-02 2011-04-07 Mark Weaver Treatment of bauxite residue and spent pot lining
CN105088274A (zh) * 2015-08-24 2015-11-25 沈阳北冶冶金科技有限公司 一种处理及回收铝电解固体废料的装置
WO2017031798A1 (fr) * 2015-08-24 2017-03-02 沈阳北冶冶金科技有限公司 Appareil de traitement et de recyclage de déchets solides d'électrolyse d'aluminium
CN106868246A (zh) * 2017-03-21 2017-06-20 山东南山铝业股份有限公司 一种环保型磷生铁添加剂、其制备方法及磷生铁增碳脱硫方法
CN106868246B (zh) * 2017-03-21 2019-01-04 山东南山铝业股份有限公司 一种磷生铁增碳脱硫方法
US20180274083A1 (en) * 2017-03-22 2018-09-27 University Of Delaware Centrifugal evaporation sources
CN108275684A (zh) * 2017-05-19 2018-07-13 上海彭浦特种耐火材料厂有限公司 由铝电解槽产生的废氮化硅结合碳化硅砖回收利用方法
CN108275684B (zh) * 2017-05-19 2022-07-26 上海彭浦特种耐火材料厂有限公司 由铝电解槽产生的废氮化硅结合碳化硅砖回收利用方法
CN109047285A (zh) * 2018-08-01 2018-12-21 湘潭大学 一种铝电解槽废阴极炭块中含钠、含氟化合物的转化方法与系统
CN109108050A (zh) * 2018-08-01 2019-01-01 湘潭大学 一种铝电解大修渣中含钠、含氟化合物的转化方法与系统
CN109127655A (zh) * 2018-08-01 2019-01-04 湘潭大学 一种铝电解废炭渣中含钠、含氟化合物的转化方法与系统
CN109127655B (zh) * 2018-08-01 2021-05-07 湘潭大学 一种铝电解废炭渣中含钠、含氟化合物的转化方法与系统
CN109047285B (zh) * 2018-08-01 2021-05-07 湘潭大学 一种铝电解槽废阴极炭块中含钠、含氟化合物的转化方法与系统
CN109108050B (zh) * 2018-08-01 2021-05-07 湘潭大学 一种铝电解大修渣中含钠、含氟化合物的转化方法与系统
WO2020063345A1 (fr) * 2018-09-29 2020-04-02 沈阳北冶冶金科技有限公司 Dispositif de séparation et de récupération de déchets solides électrolytiques d'aluminium et de désulfuration à haute température de coke de pétrole

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DE1065625B (de) 1959-09-17
FR1137666A (fr) 1957-06-03
GB813834A (en) 1959-05-27

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