EP0099948B1 - Verfahren zur Herstellung von Aluminium hoher Reinheit - Google Patents

Verfahren zur Herstellung von Aluminium hoher Reinheit Download PDF

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Publication number
EP0099948B1
EP0099948B1 EP19820303995 EP82303995A EP0099948B1 EP 0099948 B1 EP0099948 B1 EP 0099948B1 EP 19820303995 EP19820303995 EP 19820303995 EP 82303995 A EP82303995 A EP 82303995A EP 0099948 B1 EP0099948 B1 EP 0099948B1
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Prior art keywords
aluminum
molten aluminum
boron
cooling body
impurities
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EP19820303995
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English (en)
French (fr)
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EP0099948A1 (de
Inventor
Hideo Shingu
Kozo Showa Aluminum Corporation Arai
Masashi Showa Aluminum Corporation Sakaguchi
Toshio Showa Aluminum Corporation Nishide
Osamu Showa Aluminum Corporation Watanabe
Yasushi Showa Aluminum Corporation Tashiro
Ryotatsu Showa Aluminum Corporation Otsuka
Kenji Showa Aluminum Corporation Tsukamoto
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Showa Aluminum Can Corp
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Showa Aluminum Corp
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Priority to DE8282303995T priority Critical patent/DE3274369D1/de
Priority to EP19820303995 priority patent/EP0099948B1/de
Publication of EP0099948A1 publication Critical patent/EP0099948A1/de
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    • 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
    • C22B21/00—Obtaining aluminium
    • C22B21/06—Obtaining aluminium refining

Definitions

  • the present invention relates to a process for producing aluminum having high purity, and more particularly to a process for treating aluminum containing eutectic impurities, such as Fe, Si, Cu and Mg, and also peritectic impurities, such as Ti, V and Zr, by resorting to segregation solidification to obtain aluminum having lower contents of eutectic impurities and peritectic impurities and a higher purity than the original aluminum.
  • eutectic impurities such as Fe, Si, Cu and Mg
  • peritectic impurities such as Ti, V and Zr
  • eutectic impurities refers to the impurities which undergo a eutectic reaction with aluminum
  • peritectic impurities refers to the impurities which undergo a peritectic reaction with aluminum
  • the impurity concentration Cs of the resulting solid aluminum fraction is theoretically represented by the following equation.
  • ko is the distribution coefficient
  • Co is the impurity concentration of the original aluminum
  • fs is the ratio of the solid fraction.
  • the above equation shows that when the distribution coefficient ko is smaller than 1, the impurity concentration Cs of the solid fraction is smaller than the impurity concentration Co of the original aluminum and that when the distribution coefficient ko is larger than 1, the impurity concentration Cs of the solid fraction is greater than the impurity concentration Co of the original aluminum.
  • the resulting solid fraction is lower in the concentration of eutectic impurities but higher in the concentration of peritectic impurities than the original aluminum.
  • Aluminum containing both eutectic impurities and peritectic impurities is therefore usually treated by adding boron to a melt of such aluminum in a container to cause the boron to react with Ti, V, Zr and like peritectic impurities and form insoluble metallic borides such as TiB 2 , VB 2 , ZrB 2 , etc., allowing the mixture to stand for a long period of time, for example, for more than 1 hour to settle the metallic borides, placing the molten aluminum into another container as separated from the borides, and selectively drawing off pro-eutectic aluminum only from the container. This process is inefficient since the settlement of the metallic borides requires much time.
  • Such aluminum has alternatively been treated by rotation of a cooling body within the molten aluminum as described in JP-A-56-127735.
  • the object of the present invention is to overcome the above drawback and to provide a process for treating aluminum containing both eutectic impurities and peritectic impurities by segregation solidification to remove the impurities of both types from the aluminum to the greatest possible extent and obtain aluminum having a higher purity than the original aluminum.
  • a process for producing high-purity aluminum comprising the steps of melting the aluminum to be purified and containing both eutectic impurities and peritectic impurities to obtain molten aluminum, and rotating a cooling body when immersed in the molten aluminum while introducing a cooling fluid to the interior of the cooling body to crystallize high-purity aluminum on the surface of the body, characterised by placing the molten aluminum into a holding container and controlling the temperature of the molten aluminum, adding boron to the molten alumimum within the container, and rotating the cooling body at a predetermined speed when immersed in the molten aluminum containing boron and dispersed borides of peritectic impurities resulting from the boron addition.
  • the boron reacts with the peritectic impurities to form metallic borides, which are moved away from the cooling body and dispersed throughout the liquid phase by the centrifugal force produced by the rotation of the cooling body. Accordingly an aluminum fraction having lower contents of eutectic impurities and peritectic impurities than the original aluminum can be crystallized on the surface of the cooling body, giving high-purity aluminum.
  • the present process does not involve the necessity of settling the metallic borides and therefore can be practiced within a shortened period of time.
  • the amount of boron to be used which is determined in accordance with the Ti, V, Zr and like contents of the aluminum to be purified, is a predetermined amount larger than the amount needed for forming the above metallic borides.
  • the boron may be added in the form of an Al-B master alloy or NaBF4 or like salt.
  • the impurity concentration of the solid phase is governed by the effective distribution coefficient k E considering the thickness of the concentrated layer (hereinafter referred to as "diffusion layer").
  • the impurity concentration Cs of the solid phase is represented by Equation (1) wherein k E is used in place of ko, i.e. by the following equation.
  • the effective distribution coefficient k E is represented by the following equation. wherein R is the solidification velocity, 6 is the thickness of the diffusion layer formed in the vicinity of the liquid-solid interface, and D is the diffusion coefficient of the eutectic impurities in the liquid phase. It therefore follows that the effective distribution coefficient k E can be made approximate to the distribution coefficient ko effectively by decreasing the solidification velocity R and the thickness of the diffusion layer, 6, and increasing the diffusion coefficient D. Of these variables, the diffusion coefficient D is considered to be a constant which is dependent on the kind of the eutectic impurity generally when the liquid phase has a constant temperature, so that it is difficult to vary the diffusion coefficient D. It is therefore effective to decrease the solidification velocity R and the thickness of the diffusion layer, 6, for making the effective distribution coefficient k, approximate to the distribution coefficient ko.
  • dendrites are formed at the interface. It is well known that when such dendrites grow, the impurities released into the liquid phase in the vicinity of the liquid-solid interface are trapped, as they are or in the form of eutectic crystals of several microns, in the interstices of the dendrites. This phenomenon is undesirable for the purification of aluminum.
  • the growth of dendrites occurs when the actual temperature of the liquid phase is lower than the temperature of the equilibrium liquidus in the vicinity of the liquid-solid interface. This phenomenon is referred to as constitutional undercooling.
  • the growth of dendrites is promoted when the difference (degree of undercooling) AT between the temperature of the equilibrium liquidus and the actual liquid phase temperature increases. Accordingly the growth of dendrites can be inhibited effectively by decreasing the difference ⁇ T.
  • To decrease AT there is the need to increase the temperature gradient of the melt in the vicinity of the liquid-solid interface. Ideally, the temperature gradient should be smaller than the temperature gradient of the equilibrium liquidus to make AT smaller than 0.
  • the thicknesses of the diffusion layer and the boundary layer in the temperature distribution can be decreased by increasing the speed of rotation of the cooling body, in other words, the speed of the relative movement between the cooling body and the molten aluminum.
  • the speed of the relative movement is within the range of 400 to 8,000 mm/sec because if the speed is lower than 400 mm/sec, the diffusion layer will not be made thinner effectively, whereas if it is higher than 8,000 mm/sec, the increased centrifugal force will lead to reduced productivity.
  • the cooling body When the cooling body is in the form of a cylinder having a diameter of 160 mm, for example, the body can be rotated at 50 to 1,000 r.p.m., but especially good results are obtained at 200 to 700 r.p.m. Further improved results can be achieved if the direction of rotation of the body is reversed with suitable frequency. Since boron undergoes a eutectic reaction with aluminum, the excess of boron other than the amount of boron forming metallic borides with the peritectic impurities is removed in the same manner as Fe, Si, Cu, Mg and like eutectic impurities.
  • the high-purity aluminum deposited on the surface of the cooling body on crystallization is recovered, for example, by melting the high-purity fraction or by scraping off the fraction.
  • a process for producing high purity aluminum comprising the steps of melting the aluminum to be purified and containing both eutectic impurities and peritectic impurities to obtain molten aluminum, and rotating a cooling body when immersed in the molten aluminum while introducing a cooling fluid to the interior of the cooling body to crystallize high-purity aluminum on the surface of the body, characterised by placing the molten aluminum into a boron adding vessel and controlling the temperature of the molten aluminum, adding boron to the molten aluminum within the vessel, continuously agitating the boron-containing molten aluminum, continuously causing the boron-containing molten aluminum to be forwarded to a plurality of purifying tanks from tank to tank and to be discharged from the last tank, and rotating a cooling body at a predetermined speed when immersed in the molten aluminum containing boron and dispersed borides of peritectic impurities resulting from the boron addition within each of the tanks.
  • This process affords a large quantity of high-purity aluminum efficiently by a continuous operation.
  • the boron adding vessel and the purifying tanks are prepared, for example, by dividing a single large container into a plurality of sections by partitions each having a communication opening, one of the sections serving as the vessel and the other sections as the tanks.
  • a plurality of crucibles may be arranged in a row, with each crucible communicating with another through a trough, such that one of the crucibles serves as the boron adding vessel and the others as the purifying tanks.
  • Boron is placed into the vessel continuously so that the molten aluminum therein has a constant boron concentration during operation.
  • the molten aluminum in the vessel is agitated to accelerate the reaction between the boron and the peritectic impurities.
  • a cooling body is immersed in the molten aluminum in each of the purifying tanks.
  • the supply of the melt to the purifying tanks is so adjusted that the amount of the melt in each tank remains unchanged during operation.
  • the temperature of the molten aluminum, the speed of rotation and cooling capacity of the cooling bodies are suitably controlled.
  • the eutectic impurity concentration of the molten aluminum in the purifying tanks progressively increases from tank to tank away from the melting furnace.
  • the average impurity concentration of all the aluminum fractions obtained is variable by varying the ratio of the total amount of aluminum fractions recovered by the cooling bodies to the total amount of the melt supplied. (The ratio will be referred to as "recovery ratio"). The smaller the recovery ratio, the lower is the average impurity concentration. Accordingly aluminum having a constant purity which is higher than the purity of the original aluminum supplied from the melting furnace for purification can be obtained by rendering the recovery ratio constant. Further at the same recovery ratio, the purity of the aluminum obtained increases with the increase in the number of purifying tanks.
  • the aluminum to be purified and containing both eutectic impurities and peritectic impurities is melted and placed in a molding container comprising a crucible 2.
  • the molten aluminum 1 is heated and maintained at a temperature exceeding the solidifying temperature thereof.
  • Boron is added to the molten aluminum 1, and the mixture is agitated for at least 5 minutes.
  • a cooling body 3 is thereafter immersed in the melt 1.
  • the cooling body 3 is in the form of a hollow cylinder having closed opposite ends and is movable upward and downward.
  • a hollow rotary shaft 4 extends upward from the upper end of the body 3. The interior of the hollow rotary shaft 4 is in communication with the interior of the cooling body 3.
  • a cooling fluid supply pipe 5 extends through the shaft 4 into the cooling body 3.
  • the rotary shaft 4 is provided at its upper end with a drive device (not shown), by which the shaft 4 and the body 3 are rotated.
  • the top and bottom of the body 3 and the portion of the shaft 4 to be exposed to the melt 1 are preferably covered with a heat insulating material 6 so as not to permit aluminum to crystallize on these portions. This is due to the reason that since the effect produced by the rotation of the body 3 is lower at these portions than at the periphery of the body 3, aluminum, if crystallizing on these portions will have a lower purity than the aluminum crystallizing on the periphery.
  • the cooling body 3 is rotated while introducing a cooling fluid, such as air, nitrogen or argon, from the pipe 5 into the body 3 at an adjusted rate so that the portion of the melt 1 around the body 3 will be cooled slowly.
  • a cooling fluid such as air, nitrogen or argon
  • Pro-eutectic aluminum having a high purity then starts to crystallize on the periphery of the body 3. After a specified quantity of aluminum has been deposited on the body 3, the body is raised and withdrawn from the melt 1, and the high-purity aluminum obtained is collected.
  • a melting furnace 11 for melting the aluminum to be purified and containing both eutectic impurities and peritectic impurities.
  • a large container 12 in the form of a horizontally elongated rectangular parallelepiped is disposed on the right side of the furnace 11.
  • the container 12 is divided into five sections by partitions 13. Of these sections, the one at the left end serves as a boron adding vessel 14, and the other four sections serve as purifying tanks 15 to 18.
  • the partitions 13 are formed at their upper ends with openings 19 through which the vessel 14 and the tanks 15 to 18 communicate with one another.
  • the vessel 14 has an agitator 20 in its interior.
  • the agitator 20 comprises a vertical rotary shaft 21, a propeller- shaped stirring blade 22 attached to the lower end of the shaft 21 and unillustrated drive means.
  • Each of the tanks 15 to 18 is provided with a cooling body 23 which is movable upward and downward.
  • the body 23 is in the form of a downwardly tapered hollow cylinder having closed opposite ends and a hollow rotary shaft 24 extending upward from its top.
  • the interior of the shaft 24 is in communication with the interior of the body 23.
  • a cooling fluid supply pipe 26 extending through the shaft 24 into the body 23 has a large number of cooling fluid outlets 25 in its peripheral wall.
  • the upper end peripheral portion and the bottom of the cooling body 23 are covered with heat insulating members 27 and 28 respectively.
  • the aluminum to be purified and containing both eutectic impurities and peritectic impurities is melted in the furnace 11, and the molten aluminum 30 is first placed into the vessel 14, in which boron is added to the melt 30.
  • the mixture is agitated by the agitator 20.
  • the boron reacts with Ti, V, Zr and like peritectic impurities, forming TiB 2 , VB 2 , ZrB 2 and like insoluble metallic borides.
  • the molten aluminum containing the eutectic impurities, insoluble metallic borides and an excess of boron flows into the tanks 15 to 18 through the communication openings 19.
  • the cooling body 23 is lowered and immersed in the melt, with the upper heat insulating member 27 in contact with the melt 30 and with the lower edge of the member 27 located within the mass of the melt 30 at such a position that it will not be influenced by the temperature of the atmosphere.
  • the upper end peripheral portion of the body 23 is covered with the insulating member 27, and the body is so immersed in the melt 30 that the member 27 is in contact with the surface of the melt 30 with its lower edge at a position where it is free of the influence of the atmospheric temperature, for the following reason.
  • the portion of the melt 30 near the surface thereof exposed to the atmosphere has a lower temperature than the other portion by being affected by the atmospheric temperature and is therefore liable to solidify on the periphery of the body 23 in the vicinity of the above surface. Consequently aluminum solidifies at a higher velocity at this portion than at the other portion of the periphery of the body 23, with the result that the aluminum fraction deposited on this portion has a lower purity than the fraction on the other portion and becomes mixed with the latter fraction when the purified aluminum is removed from the outer periphery of the body 23 for collection after the completion of the purifying operation. This results in a reduced overall purifying efficiency.
  • the bottom of the cooling body 23 is covered with the heat insulating member 28 because the rotation of the body 23 will not produce a satisfactory effect at the bottom, such that the aluminum fraction deposited on the bottom of the body 23 has a lower purity than the other fraction on the periphery of the body.
  • the cooling body 23 in this state is rotated while injecting a cooling fluid into the body through the inlets 25 of the supply pipe 26.
  • This causes aluminum to crystallize on the portion of the peripheral surface of the body 23 which is immersed in the melt 30 and which is not covered with the insulating members 27 and 28. Since the metallic borides contained in the melt 30 are centrifugally forced away from the body 23 by the rotation thereof, the aluminum deposited on the periphery of the body 23 is free from such borides. The excess of boron, which forms a eutectic with aluminum, is removed like the eutectic impurities.
  • the temperature of the molten aluminum, and the speed of rotation and cooling capacity of the bodies 23 are so controlled that equal amounts of aluminum will be deposited on the peripheral surfaces of the bodies in the purifying tanks 15 to 18, while the supply and discharge of molten aluminum are controlled so that the tanks 15 to 18 contain equal amounts of melt with the recovery ratio maintained at a constant value.
  • the ratio of the eutectic impurity concentration of the melt in each of the tanks 15 to 18 to C0 namely the ratio CN/CO where N is 1 to 4 increases with the start of the operation but levels off when the amount of aluminum deposit on the periphery of the cooling body 23 reaches a value as shown in Fig. 4.
  • the total amount of eutectic impurities, Ms, in the aluminum recovered by the cooling bodies 23 plus the amount of eutectic impurities, Mn, in the molten aluminum discharged from the tank 18 at the right end is always equal to the amount of eutectic impurities, Mo, in the aluminum to be purified. Accordingly, if the eutectic impurity concentration and the effective distribution coefficient of the eutectic impurities of the molten aluminum in each of the tanks 15 to 18 are known, high-purity aluminum can be obtained with the desired eutectic impurity concentration when the recovery ratio is set to a definite value.
  • the purity of the aluminum to be obtained can be determined by varying the recovery ratio.
  • the eutectic impurity concentration of the molten aluminum discharged increases with the increase of the number of purifying tanks as seen in Fig. 5, enabling the cooling bodies 23 to afford aluminum of higher purity.
  • Fig. 1 The apparatus shown in Fig. 1 was used.
  • Aluminum containing 0.08 wt.% of Fe, 0.05 wt.% of Si, 0.0015 wt.% of Ti, 0.004 wt.% of V and 0.0005 wt.% of Zr was melted, and the molten aluminum 1 was maintained at 670°C in the crucible 2.
  • AI-3 wt.% B master alloy was added to the alumimum 1 so that the resulting melt had a boron concentration of 0.004 wt.%.
  • the mixture was agitated for 5 minutes after the addition of the alloy.
  • the body 3 was rotated for 10 minutes and thereafter withdrawn from the melt 1 by raising.
  • the body 3 was found to have aluminum deposited on its periphery in an amount of 20 wt.% based on the amount of the original aluminum.
  • the cast aluminum block was found to contain 0.008 wt.% of Fe, 0.012 wt.% of Si, less than 0.0001 wt.% of Ti, 0.0002 wt.% of V, less than 0.0002 wt.% of Zr and 0.0003 wt.% of B.
  • Fig. 1 The apparatus shown in Fig. 1 was also used.
  • Aluminum containing 0.08 wt.% of Fe, 0.05 wt.% of Si, 0.002 wt.% of Ti, 0.008 wt.% of V and 0.001 wt.% of Zr was melted, and the molten aluminum 1 was maintained at 670°C in the crucible 2.
  • AI-3 wt.% B master alloy was added to the aluminum 1 so that the resulting melt had a boron concentration of 0.008 wt.%.
  • the mixture was agitated for 5 minutes after the addition of the alloy.
  • the body 3 was withdrawn from the melt.
  • the body 3 was found to have aluminum deposited on its periphery in an amount of 20% based on the amount of the original aluminum.
  • the cast aluminum block was found to contain 0.005 wt.% of Fe, 0.009 wt.% of Si, less than 0.0001 wt.% of Ti and V, less than 0.0002 wt.% of Zr and 0.0005 wt.% of B.
  • the apparatus shown in Figs. 2 and 3 was used.
  • the cooling bodies 23 were held raised.
  • Aluminum containing 0.08 wt.% of Fe, 0.05 wt.% of Si. 0.002 wt.% of Ti and 0.008 wt.% of V was melted in the furnace 11, and the molten aluminum was supplied to the boron adding vessel 14. Boron was added to the aluminum so that the resulting melt had a boron concentration of 0.008 wt.% at all times.
  • the mixture was agitated by the agitator 20.
  • each cooling body 23 having a diameter of 200 mm at the portion thereof covered with the heat insulating member 27 was lowered into the molten aluminum 30.
  • the body 30 was rotated at 400 r.p.m. while supplying a cooling fluid into its interior from the pipe 26.
  • the molten aluminum was continuously supplied from the furnace 11 to the vessel 14 and tanks 15 to 18 so as to fill up these containers to a constant level. Boron was also continuously placed into the vessel 14 to maintain the boron concentration at 0.008 wt.% at all times.
  • the eutectic impurity concentrations C1, C2, C3 and C4 of the melt portions in the tanks 15 to 18 remained in the relation of C1, C2, C3, C4 from the start of the operation, and a steady state was established after the amount of aluminum deposit on the body 23 reached a specified amount.
  • the effective distribution coefficient of iron was 0.1 at a recovery ratio of 0.7
  • the operation was continued in this state.
  • the resulting cast aluminum blocks were found to contain 0.008 wt.% of Fe, 0.008 wt.% of Si, 0.0001 wt.% of Ti, 0.0002 wt.% of V and 0.0006 wt.% of B on the average.
  • Example 3 The operation of Example 3 was repeated under the same conditions except that the recovery ratio was 0.4. The operation was continued in a steady state. All the aluminum blocks obtained were found to have average impurity concentrations of: 0.005 wt.% Fe, 0.006 wt.% Si, 0.0001 wt.% Ti, 0.0002 wt.% V and 0.0005 wt.% B.
  • Example 3 The operation of Example 3 was repeated under the same conditions as in Example 3 except that eight purifying tanks were used in place of the four tanks. The operation was continued in a steady state.
  • the aluminum blocks obtained were found to have the following average impurity concentrations: 0.0065 wt.% Fe, 0.007 wt.% Si, 0.0001 wt.% Ti, 0.0002 wt.% V, 0.0005 wt.% B.
  • the aluminum had a higher purity than that obtained in Example 3 with use of the four purifying tanks and was produced at twice the speed therein.

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Claims (6)

1. Verfahren zum Herstellen von hochreinem Aluminium, bei dem das zu reinigende und sowohl eutektische Verunreinigungen als auch peritektische Verunreinigungen enthaltende Aluminium zum Erhalt von geschmolzenem Aluminium geschmolzen wird und bei dem ein in das geschmolzene Aluminium eingetauchter Kühlkörper rotiert wird, während man ein Kühlfluid in das Innere das Kühlkörpers einführt, damit sich hochreines Aluminium an der Oberfläche des Körpers kristallisiert, dadurch gekennzeichnet, daß man das geschmolzene Aluminium in einen Haltebehälter (2) einbringt und die Temperatur des geschmolzenen Aluminiums steuert, Bor zu dem geschmolzenen Aluminium innerhalb des Behälters (2) hinzufügt und den Kühlkörper (3) mit einer vorbestimmten Geschwindigkeit rotiert, wenn er in das aufgrund der Borzugabe Bor und dispergierte Boride von peritektischen Verunreinigungen enthaltende geschmolzene Aluminium eingetaucht ist.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß die Geschwindigkeit der Relativbewegung zwischen dem Kühlkörpers (3) und dem geschmolzenen Aluminium etwa 400 bis etwa 8000 mm/sec beträgt, wenn der Kühlkörpert rotiert wird.
3. Verfahren zum Herstellen von hochreinem Aluminium, bei dem das zu reinigende und sowohl eutektische Verunreinigungen als auch peritektische Verunreinigungen enthaltende Aluminium zum Erhalt von geschmolzenem Aluminium geschmolzen wird und bei dem ein in das geschmolzene Aluminium eingetauchter Kühlkörper rotiert wird, während man ein Kühlfluid in das Innere des Kühlkörpers einführt, damit sich hochreines Aluminium an der Oberfläche des Körpers kristallisiert, dadurch gekennzeichnet, daß man das geschmolzene Aluminium in ein Borzugabegefäß (14) einbringt und die Temperatur des geschmolzenen Aluminiums steuert, Bor zu dem geschmolzenen Aluminium innerhalb des Gefäßes (14) hinzufügt, das Bor enthaltende geschmolzene Aluminium kontinuierlich in Bewegung hält, das Bor enthaltende geschmolzene Aluminium kontinuierlich zu einer Mehrzahl von Reinigungstanks (15 bis 18) von Tank zu Tank vorfördert und aus dem letzten Tank
(18) entnimmt und innerhalb jedes Tanks (15 bis 18) einen Kühlkörper (23) mit einer vorbestimmten Geschwindigkeit rotiert, wenn er in das aufgrund der Borzugabe Bor und dispergierte Boride von peritektischen Verunreinigungen enthaltende geschmolzene Aluminium eingetaucht ist.
4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß das Zuführen und das Abführen des geschmolzenen Aluminiums in der Art gesteuert werden, daß die Mengen geschmolzenen Aluminiums in den Reinigungstanks (15 bis 18) während des Betriebs unverändert bleiben, und daß die Kühlkörper (23) derart gesteuert werden, daß an den Oberflächen der Kühlkörper (23) gleiche Mengen von hochreinem Aluminium kristallisiert werden.
5. Verfahren nach einem der Ansprüche 3 oder 4, dadurch gekennzeichnet, daß die Geschwindigkeit der Relativbewegung zwischen dem Kühlkörper (23) und dem geschmolzenem Aluminium etwa 400 bis etwa 8000 mm/sec beträgt, wenn der Kühlkörper rotiert wird.
EP19820303995 1982-07-28 1982-07-28 Verfahren zur Herstellung von Aluminium hoher Reinheit Expired EP0099948B1 (de)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE8282303995T DE3274369D1 (en) 1982-07-28 1982-07-28 Process for producing high-purity aluminum
EP19820303995 EP0099948B1 (de) 1982-07-28 1982-07-28 Verfahren zur Herstellung von Aluminium hoher Reinheit

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EP19820303995 EP0099948B1 (de) 1982-07-28 1982-07-28 Verfahren zur Herstellung von Aluminium hoher Reinheit

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EP0099948B1 true EP0099948B1 (de) 1986-11-20

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Cited By (2)

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DE10127753A1 (de) * 2001-06-07 2002-12-12 Bayerische Motoren Werke Ag Reinigung von Aluminium-Gusslegierungen
DE10157722A1 (de) * 2001-11-24 2003-06-05 Bayerische Motoren Werke Ag Reinigung von Aluminium-Gusslegierungen

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GB8317243D0 (en) * 1983-06-24 1983-07-27 Alcan Int Ltd Producing aluminium boride
JP2949512B2 (ja) * 1990-05-28 1999-09-13 昭和アルミニウム株式会社 電子材料用アルミニウム材の製造方法
US6156092A (en) * 1997-08-08 2000-12-05 Sumitomo Chemical Company, Limited Method for producing high purity aluminum
US6454832B1 (en) 1999-11-15 2002-09-24 Pechiney Rhenalu Aluminium alloy semi-finished product manufacturing process using recycled raw materials
FR2801060B1 (fr) * 1999-11-15 2001-12-21 Pechiney Rhenalu Procede de fabrication de demi-produits en alliages d'aluminium utilisant des matieres recyclees
EP1264903B1 (de) * 2001-06-07 2006-09-20 Bayerische Motoren Werke Aktiengesellschaft Reinigung von Aluminium-Gusslegierungen mittels Zugabe von Bor
NL1019105C2 (nl) 2001-10-03 2003-04-04 Corus Technology B V Werkwijze en inrichting voor het beheersen van het aandeel kristallen in een vloeistof-kristalmengsel.
EP1380658A1 (de) 2002-07-05 2004-01-14 Corus Technology BV Verfahren zur fraktionierten Kristallisation von Metallschmelze
EP1380659A1 (de) 2002-07-05 2004-01-14 Corus Technology BV Verfahren zur fraktionierten Kristallisation von Metall
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ES2304009T3 (es) 2004-03-19 2008-09-01 Aleris Switzerland Gmbh Metodo para la purificacion de un metal fundido.
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