CA1144378A - Process for decreasing the contaminant content of aluminium melts and aluminium alloy melts - Google Patents
Process for decreasing the contaminant content of aluminium melts and aluminium alloy meltsInfo
- Publication number
- CA1144378A CA1144378A CA000345308A CA345308A CA1144378A CA 1144378 A CA1144378 A CA 1144378A CA 000345308 A CA000345308 A CA 000345308A CA 345308 A CA345308 A CA 345308A CA 1144378 A CA1144378 A CA 1144378A
- Authority
- CA
- Canada
- Prior art keywords
- aluminium
- gas
- melts
- melt
- content
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- 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
- C22B21/064—Obtaining aluminium refining using inert or reactive gases
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
ABSTRACT OF THE
DISCLOSURE
The invention relates to a process for decreasing the contaminant content of aluminium melte or of aluminium alloy melts, in the first line their content of alkali metal, of hydrogen gas and of solid non-metallic contaminants, especially oxides in a way that an inert gas of a pressure below 2 atmospheres, preferably nitrogen gas containing a powder which develops chlorine gas is led into the aluminium melt or aluminium alloy melt isolated from the air, at a temperature of 670 - 860 °C.
DISCLOSURE
The invention relates to a process for decreasing the contaminant content of aluminium melte or of aluminium alloy melts, in the first line their content of alkali metal, of hydrogen gas and of solid non-metallic contaminants, especially oxides in a way that an inert gas of a pressure below 2 atmospheres, preferably nitrogen gas containing a powder which develops chlorine gas is led into the aluminium melt or aluminium alloy melt isolated from the air, at a temperature of 670 - 860 °C.
Description
The invention relates -to a process for decreasing the contaminant content of aluminium melts or of aluminium alloy melts, characterized by leading into the aluminium melt or aluminium alloy melt isolated from the air an inert gas of a pressure below 2 atmospheres, and at a temperature of 670-860C.
Various processes are known for the purification of metals. Of these processes, the more effective ones are carried out with use of an active gas: chlorine gas or salts which develop chlorine gas: halogenides. By means of rinsing with chlorine gas (Tomany, J. P.: The control of aluminium chloride fumes. - Light Metal Age, 1968. 26, No. 9-10, p. 19-20) the content of gaseous hydrogen, of oxide and of alkali metal of most alloys is decreased but at the same time most part of the gas (introduced into the melt through graphite pipes or steel pipes protected by resistant coat) does not participate in the purification process and causes severe problems of neutralisation and absorption. In the workshops of the plants where chlorine gas is used, the iron structures are exposed to corrosion, and in the course of the handling, storage and neutralisation of chlorine gas, the hazard of intoxication is continuous (N~lting, P.: Betriebliche Erfahrungen mit der Chlorbehandlung von Aluminiumlegierungen.
Giesserei. 61, 1974. No. 1, p. 7-10).
Solutions of this problem are known where the gas blown-.~
~1~4~78 - 3 _ -~n for rinsing consists of a mixture of chlorine gas and nitrogen gas or of one of the noble gases: argonJ! helium~
neon,J krypton,! xenon alone or of a mixture of these noble gases.
Also nitrogen is a gas which does not react with alu-minium.
The generally used composition of chlorine-nitrogen gas mixtures isi:
10~35 % by volume of chlorine gas ~ 65-90 % by volume of nitrogen gas.
The hydrogen-gas removing effect of this gas mixture is lower than ~hat of pure chlorine gas but higher than that of pure nitrogen gas tPrescheO~ P. ~ Wulmstrof~! N.~ sehandlun9 von Aluminiumschmelzen mit Gasgemischen. Aluminium. 48. 1972. No.
10. p. 677_678). Of $he gases inert towards aluminiumrl argon decreases the hydrogen content of the melt more effec~ively than nitrogen ~Ginsberg.j H. - Agrawal~, A.N.: ~berprufung der Wirkungsweise gebrauchlicher Entgasungsmethoden fur Metall-schmelzen aus Reinaluminium und Aluminium-Magnesium-Legierungen unter Anwendung der neuen Gasbestimmùngsapparaturen. III~
Aluminium. 41~ 1965. No. 11. p. 683-687). At the same time argon and the other noble gases are rather expensive~i and thus their use has not been introduced into the aluminium industryO
By the liquefaction and separation of air great amounts of nitrogen gas can be produced cheaply. However~l rinsing with nitrogen gas has the drawbaclc that in case of melts of alloyed aluminium the degree of degasification is low~! and at the same time on the surface of the metal bath a slag containing 1~ ~4378 ~ 4 --a relatively high amount of metals and hardly treatable is formed and this increases the loss of metal. Nitrogen gas does not decrease the content of alkali metals of the melt,l either,J and thus nitrogen alone is not suitable for the purifi-cation of melts contaminated by alkali metals,J and it must be applied only when mixed up with chlorine gas ~Szél<ely~
A.G.,: The Removal of solid particles from Molten Aluminium in the Spinning No~zle Inert Flotation Process. Metallurgical Transactions. 7B. 1976. p. 259-270). Sodium content is decreased the most effectively by chlorine gas ~Lagowski, S.~: Magnesium loss during chlorination of aluminium melts~
Les Plaines III.~J Trans. Amer. FoundrymenJ!s Soc. 77. 1969.
p. 206-207).
On t~e effect of chlorine gas introduced into the melt AlC13 is formed,3 and thus sodium is bound:
AlC13 + 3 Na ~ 3 NaCl + Al NaCl + AlC13 ---~ tAlC13.NaCl)~
Of the gas-developing salts~j the chlorides e.g. manganese chloride and zinc chloride are reacting with liquid aluminium and they form aluminium chloride which latter is in a gaseous state at the temperature of the treatment (Marienbakh~ L.M. -- Sokolovskii.J L. 0.: Plavka slavov tsvetnykh metallov dlya fasonnogo litya. Moscow~j 1967~ p. 184-189~.
3 MeC12 + 2 Al --~ 2 AlC13 1 3 Me Aluminium chloride in a gaseous state decreases also the sodium contamina~ion of the melt.
Aiso hexachloroethane is used for decreasing the content of contaminants in aluminium mel~ or aluminium alloy 11~43~78 melts ~Marienbalch~l L.M. - Sokolovskii~l L.O.: Plavka slavov tsvetnykh metallov dlya fasonnogo litya. Moscow. 1967. p.
184_189).
Reactions of hexachloroethane in the aluminium melt are as followslO
3 C2C16 _ 3 C2C14 ~ 3 C12
Various processes are known for the purification of metals. Of these processes, the more effective ones are carried out with use of an active gas: chlorine gas or salts which develop chlorine gas: halogenides. By means of rinsing with chlorine gas (Tomany, J. P.: The control of aluminium chloride fumes. - Light Metal Age, 1968. 26, No. 9-10, p. 19-20) the content of gaseous hydrogen, of oxide and of alkali metal of most alloys is decreased but at the same time most part of the gas (introduced into the melt through graphite pipes or steel pipes protected by resistant coat) does not participate in the purification process and causes severe problems of neutralisation and absorption. In the workshops of the plants where chlorine gas is used, the iron structures are exposed to corrosion, and in the course of the handling, storage and neutralisation of chlorine gas, the hazard of intoxication is continuous (N~lting, P.: Betriebliche Erfahrungen mit der Chlorbehandlung von Aluminiumlegierungen.
Giesserei. 61, 1974. No. 1, p. 7-10).
Solutions of this problem are known where the gas blown-.~
~1~4~78 - 3 _ -~n for rinsing consists of a mixture of chlorine gas and nitrogen gas or of one of the noble gases: argonJ! helium~
neon,J krypton,! xenon alone or of a mixture of these noble gases.
Also nitrogen is a gas which does not react with alu-minium.
The generally used composition of chlorine-nitrogen gas mixtures isi:
10~35 % by volume of chlorine gas ~ 65-90 % by volume of nitrogen gas.
The hydrogen-gas removing effect of this gas mixture is lower than ~hat of pure chlorine gas but higher than that of pure nitrogen gas tPrescheO~ P. ~ Wulmstrof~! N.~ sehandlun9 von Aluminiumschmelzen mit Gasgemischen. Aluminium. 48. 1972. No.
10. p. 677_678). Of $he gases inert towards aluminiumrl argon decreases the hydrogen content of the melt more effec~ively than nitrogen ~Ginsberg.j H. - Agrawal~, A.N.: ~berprufung der Wirkungsweise gebrauchlicher Entgasungsmethoden fur Metall-schmelzen aus Reinaluminium und Aluminium-Magnesium-Legierungen unter Anwendung der neuen Gasbestimmùngsapparaturen. III~
Aluminium. 41~ 1965. No. 11. p. 683-687). At the same time argon and the other noble gases are rather expensive~i and thus their use has not been introduced into the aluminium industryO
By the liquefaction and separation of air great amounts of nitrogen gas can be produced cheaply. However~l rinsing with nitrogen gas has the drawbaclc that in case of melts of alloyed aluminium the degree of degasification is low~! and at the same time on the surface of the metal bath a slag containing 1~ ~4378 ~ 4 --a relatively high amount of metals and hardly treatable is formed and this increases the loss of metal. Nitrogen gas does not decrease the content of alkali metals of the melt,l either,J and thus nitrogen alone is not suitable for the purifi-cation of melts contaminated by alkali metals,J and it must be applied only when mixed up with chlorine gas ~Szél<ely~
A.G.,: The Removal of solid particles from Molten Aluminium in the Spinning No~zle Inert Flotation Process. Metallurgical Transactions. 7B. 1976. p. 259-270). Sodium content is decreased the most effectively by chlorine gas ~Lagowski, S.~: Magnesium loss during chlorination of aluminium melts~
Les Plaines III.~J Trans. Amer. FoundrymenJ!s Soc. 77. 1969.
p. 206-207).
On t~e effect of chlorine gas introduced into the melt AlC13 is formed,3 and thus sodium is bound:
AlC13 + 3 Na ~ 3 NaCl + Al NaCl + AlC13 ---~ tAlC13.NaCl)~
Of the gas-developing salts~j the chlorides e.g. manganese chloride and zinc chloride are reacting with liquid aluminium and they form aluminium chloride which latter is in a gaseous state at the temperature of the treatment (Marienbakh~ L.M. -- Sokolovskii.J L. 0.: Plavka slavov tsvetnykh metallov dlya fasonnogo litya. Moscow~j 1967~ p. 184-189~.
3 MeC12 + 2 Al --~ 2 AlC13 1 3 Me Aluminium chloride in a gaseous state decreases also the sodium contamina~ion of the melt.
Aiso hexachloroethane is used for decreasing the content of contaminants in aluminium mel~ or aluminium alloy 11~43~78 melts ~Marienbalch~l L.M. - Sokolovskii~l L.O.: Plavka slavov tsvetnykh metallov dlya fasonnogo litya. Moscow. 1967. p.
184_189).
Reactions of hexachloroethane in the aluminium melt are as followslO
3 C2C16 _ 3 C2C14 ~ 3 C12
2 Al ~ 8 C12 --- 2 AlC13
3 C2C16 ~ 2 Al ~-~ 3 C2C14 ~ 2 AlC13 Owing to the violence of the reactions taking place and to the hazard of explosion the amount of treating material reguired to attain the desired effect canno~ be added at once to ~e liquid metal. Some processes are known wherein hexachloroethane is added in smaller portions into the melt.
This means surplus costs~ and at the same time the powder packed in ~oils or capsules or the compressed compact tablets must be-introduced into the melt by means of dipper bells by a tlresome manual operation which cannot be mechanizedD
In case of furnace units having a large bath ~urface 20 the feeding will not be uniform and thus the degree o~ utiliza-tion of hexachloroethane is low and a significant portion of the treating material is lost quite unused with the waste gases.
Also the vacuum treatment is applied for the purifica~
25 tion of the liquid metal ~Alker,~ K.~ Aluminiumentgasen im Vakuum. Vakuumbehandlung be~riebssicher und umweltfreund~
licher als Chlorierungsverfahren. VDl~Nachrichten 27~ 1973.
No. 22~ p~ 12)o The drawback of this process is that only ~ 7 8 the upper part of the melt layer is degasified ~Mal<arov~
G~S.: Zalconomernosti udaleniya vodoroda pri vakuumnoi obrabotlce rasplavlennogo alyuminiya. Tekhn. Legk. Splavov.
1970. No. 4,, p. 37-42)~ The process is expensive because the construction and operation of the vacuum furnaces require high investment and maintenance COStS-Also the ultrasonic treatment belongs to the physicalprocesses by which the hydrogen content can be decreased ~Livanov,J V.A. et al.: Rafinirovaniye alyuminiya i ego splavov ul~ltrazvul<ovymi kelebaniyami. Tsvetnye Metally~ 19680 No. 60 p. 82-84). The process has not been applied on an industrial scale.
A common drawback of the physical processes is that they do not decrease the all<ali metal content of the aluminium melt.
In the last 15 years the equipments for carrying out the treatment of metals in a continuous operation outside the furnace passed through a significant development. These equipments are being described below.
The equipment of the trade nanie FILD of the firm Gautschi combines the rinsing with nitrogen gas by filtra-tion through activated alumina balls ~Entgasung und Reinigung von Aluminiumschmelzen. Gautsch folder. Aluminium 50. 19740 No~ 4,~ p. 297).
The firni BASF applies a continuous equipmen~ based on petroleum coke. This equipment combines the rinsing with neutral gases by filtration through a surfactant mechanical filter bed (Bohm,l G0 Das Filtrieren und Entgasen von Alumi~
~ 37 8 niumsch~elzen im Durchlaufverfahren. ~luminium. 1973. No.
11. p. 743-747)-In the equipment produced by the firm Carborundum the main filter element ~8 an inser~ecl filter composed of porous 6 tubes o~ the trade-mark AloxitO Thls inserted filter is locat-ed in a filter ves~el equipped with an electric roof heater ln a way that the metal inflltrates on the effsct of the mstflllostatic pressure through the mantle o~ the tubes and belongs into a collector space ~hesfi~J C. Mangalick: The Rlgid Medls Filter - Princlples and Appllcations. Manuscript presented on the 102nd Annual Meeting of the AIM~. Chicago.
1972).
The firm Unio~ Carbide Corporation uses a flotation process instead of f1ltration ~or the separation of the solid contaminants while applying a SNIF equipment ~Szbl<ely,J A.G.:
The Removal of Solid Particles from Molten Aluminium in the Spinning Nozzle Inert Flotation Process. Metallurgical Transactions 7~. 1976. p. 259-270).
The equipment developed by the firm Alcoa contains tWO
filter beds through which a mixture of chlorine and argon gases is allowed to pa99 ~Blayden~J L.C. - BrondykeJIi<,~
Alcoa 469. Process. Low costi,J non-polluting,l continuous metal fluxing. 30urnal of Metals. 1974. February. p. 25-28).
The above described processe~ are advantageous in ~5 continuous foundries where the cas~ing period is long and the non~recurrent treatment in the furnace is not sufficient to keep the hydrogen gas content o~ the charge at the desired .
3~8 .
low level till the end of casting. However7l a common draw-back of these processes is that the gaseous reaction products owing to the rather hlgh flow-through outputs ~3-20 t/hour) and to the short residence times~J cannot be lifted cDmpletely to tha surface. To compensa~e this drawbacl<,J reactors with several chambers have been developed~i but the dimensions and the heating system of these are similar to those of the fur-naces and thus they hardly can be fi~ted between the existing foundry and furnace.
-10 The invention is aimed at eliminating the above draw-backs and at developing a continuous process for the decrease of the contaminant content of aluminium melts and aluminium alloy melts by the use of which proces~ the utilization of the treating material is increased to a great exten~ and the purification process becomes weli regulable and controllable.
We were surprised to experience that on introducing into the aluminium melt or aluminium alloy melt7l isolated from the air?l ~ powder which develops chlorine gas~l expedient-ly zinc chlorideJ~ magnesiùm chlorideJ! hexachloroethane or manganese chloride mixed up with an inert gasrl expediently with nitrogen gas~l the amount of the powder developing the chlorine gas required for the removal of a certain amount of contaminant can be decreased in the process according to the invention by about 60 % referred to the processes known up to the present.
The advantages of the process according to the invention are summarized below.
1. By the use of the process according to the invention 378 '`
_ g _ the amount of the powder developing the chlorine gas required fDr the removal of the given amount of contaminants is decreased to a great extent i.e~ the utilization of ma~erial is improved end the amount of non-utilized treat-ing material is reduced. From a~ e~onomical aspect this 1s of quite unest~mable importance.
2. The process according tD the invention can be operated con~inuously and controlled automatically at a high precision. Thus the purification process can be carried out by less physical power in a well controlIable way.
3. Purification is carried out under exclusion of air.J and thus any further oxide contaminations can be eliminat~
~d. Namely,l in the presence of atmospheric oxygen additional oxide contaminants could be formed.
This means surplus costs~ and at the same time the powder packed in ~oils or capsules or the compressed compact tablets must be-introduced into the melt by means of dipper bells by a tlresome manual operation which cannot be mechanizedD
In case of furnace units having a large bath ~urface 20 the feeding will not be uniform and thus the degree o~ utiliza-tion of hexachloroethane is low and a significant portion of the treating material is lost quite unused with the waste gases.
Also the vacuum treatment is applied for the purifica~
25 tion of the liquid metal ~Alker,~ K.~ Aluminiumentgasen im Vakuum. Vakuumbehandlung be~riebssicher und umweltfreund~
licher als Chlorierungsverfahren. VDl~Nachrichten 27~ 1973.
No. 22~ p~ 12)o The drawback of this process is that only ~ 7 8 the upper part of the melt layer is degasified ~Mal<arov~
G~S.: Zalconomernosti udaleniya vodoroda pri vakuumnoi obrabotlce rasplavlennogo alyuminiya. Tekhn. Legk. Splavov.
1970. No. 4,, p. 37-42)~ The process is expensive because the construction and operation of the vacuum furnaces require high investment and maintenance COStS-Also the ultrasonic treatment belongs to the physicalprocesses by which the hydrogen content can be decreased ~Livanov,J V.A. et al.: Rafinirovaniye alyuminiya i ego splavov ul~ltrazvul<ovymi kelebaniyami. Tsvetnye Metally~ 19680 No. 60 p. 82-84). The process has not been applied on an industrial scale.
A common drawback of the physical processes is that they do not decrease the all<ali metal content of the aluminium melt.
In the last 15 years the equipments for carrying out the treatment of metals in a continuous operation outside the furnace passed through a significant development. These equipments are being described below.
The equipment of the trade nanie FILD of the firm Gautschi combines the rinsing with nitrogen gas by filtra-tion through activated alumina balls ~Entgasung und Reinigung von Aluminiumschmelzen. Gautsch folder. Aluminium 50. 19740 No~ 4,~ p. 297).
The firni BASF applies a continuous equipmen~ based on petroleum coke. This equipment combines the rinsing with neutral gases by filtration through a surfactant mechanical filter bed (Bohm,l G0 Das Filtrieren und Entgasen von Alumi~
~ 37 8 niumsch~elzen im Durchlaufverfahren. ~luminium. 1973. No.
11. p. 743-747)-In the equipment produced by the firm Carborundum the main filter element ~8 an inser~ecl filter composed of porous 6 tubes o~ the trade-mark AloxitO Thls inserted filter is locat-ed in a filter ves~el equipped with an electric roof heater ln a way that the metal inflltrates on the effsct of the mstflllostatic pressure through the mantle o~ the tubes and belongs into a collector space ~hesfi~J C. Mangalick: The Rlgid Medls Filter - Princlples and Appllcations. Manuscript presented on the 102nd Annual Meeting of the AIM~. Chicago.
1972).
The firm Unio~ Carbide Corporation uses a flotation process instead of f1ltration ~or the separation of the solid contaminants while applying a SNIF equipment ~Szbl<ely,J A.G.:
The Removal of Solid Particles from Molten Aluminium in the Spinning Nozzle Inert Flotation Process. Metallurgical Transactions 7~. 1976. p. 259-270).
The equipment developed by the firm Alcoa contains tWO
filter beds through which a mixture of chlorine and argon gases is allowed to pa99 ~Blayden~J L.C. - BrondykeJIi<,~
Alcoa 469. Process. Low costi,J non-polluting,l continuous metal fluxing. 30urnal of Metals. 1974. February. p. 25-28).
The above described processe~ are advantageous in ~5 continuous foundries where the cas~ing period is long and the non~recurrent treatment in the furnace is not sufficient to keep the hydrogen gas content o~ the charge at the desired .
3~8 .
low level till the end of casting. However7l a common draw-back of these processes is that the gaseous reaction products owing to the rather hlgh flow-through outputs ~3-20 t/hour) and to the short residence times~J cannot be lifted cDmpletely to tha surface. To compensa~e this drawbacl<,J reactors with several chambers have been developed~i but the dimensions and the heating system of these are similar to those of the fur-naces and thus they hardly can be fi~ted between the existing foundry and furnace.
-10 The invention is aimed at eliminating the above draw-backs and at developing a continuous process for the decrease of the contaminant content of aluminium melts and aluminium alloy melts by the use of which proces~ the utilization of the treating material is increased to a great exten~ and the purification process becomes weli regulable and controllable.
We were surprised to experience that on introducing into the aluminium melt or aluminium alloy melt7l isolated from the air?l ~ powder which develops chlorine gas~l expedient-ly zinc chlorideJ~ magnesiùm chlorideJ! hexachloroethane or manganese chloride mixed up with an inert gasrl expediently with nitrogen gas~l the amount of the powder developing the chlorine gas required for the removal of a certain amount of contaminant can be decreased in the process according to the invention by about 60 % referred to the processes known up to the present.
The advantages of the process according to the invention are summarized below.
1. By the use of the process according to the invention 378 '`
_ g _ the amount of the powder developing the chlorine gas required fDr the removal of the given amount of contaminants is decreased to a great extent i.e~ the utilization of ma~erial is improved end the amount of non-utilized treat-ing material is reduced. From a~ e~onomical aspect this 1s of quite unest~mable importance.
2. The process according tD the invention can be operated con~inuously and controlled automatically at a high precision. Thus the purification process can be carried out by less physical power in a well controlIable way.
3. Purification is carried out under exclusion of air.J and thus any further oxide contaminations can be eliminat~
~d. Namely,l in the presence of atmospheric oxygen additional oxide contaminants could be formed.
4. A further advantage of the process according to the invention is that on applying ~his process the aluminium content of ~he slag formed during the treatment is essen-tially lower than e.g. the aluminium content on treatment with nitrogen gas only.
The process according to the invention is carried, out in the equipment shown schematically in Fig. 1.
The pressurized container denoted in Fig. 1 by (1) which can be filled up after opening the cover ~9) serves as a recipient of the'treating material. The feeder ~4) forwards the treating matenal to the mixing ~pace ~5).'The velocity of feeding can be varied ungradually and it is ' stabilizad by the driving unit ~3) at a high ac'curacy.
The filling~up of the container wlth the treating material .
. .
-- lo --is controlled by a signal induced by the signal device (2).
The carrier gas enters the mixing space ~5) through pressure regulator and stabilizer t7)~ The volume of the gas can be controlled by the flow meter ~6). The mixture of gas and treating material prepared in the mixing ~ace flows through the flexible tube t8) to the treating pipe ~lo). The material of the treating pipe is resistan~ to the effect of the liquid metal. Metal purification by means of a mixture of gas and treating material is applied under plant conditions at the treatment of aluminium and aluminium alloy melts. The treating material is hexachloroethane,J the carrier gas is nitrogen.
The process according to the invention is elucidated in detail by the following non-limiting examples.
Exam ~
An ~luminium_magnesium~silicon alloy melt is treated in a 15 tons tub-type flame furnace by an equipment of ~he type shown in Fig~ 1. The flow by volume of the nitrogen carrier gas used for the treatment is 0.4~0.5 Nm~minute.
Treatment is started at a temperature of 710-720C. In one half of the cases no salt developing chlorine gas is added to the nitrogen gas. The amOunt of applied hexachloroethane is 2 kg/t of melt to. 2 %). The gas content of the melt before and after ~he treatment is shown in Table 1. The gas content is determined by the ,~first bubblei~ method. Nitrogen gas is capable of removing 9-33 % of the hydrogen gas conten~
of ~he melt~ On adding hexachloroethane,l as an agent which develops chlorine yas,l to the ni~rogen gas,! the content of 37~3 hydrogen gas can be reduced by 48-77 %. The formed slag' is drytl powder-lil<e~l having a low aluminium content where-as on treatment with nitrogen gas alone,l the formed slag is puLpy. At ths addi~ion of hexachloroethane the temperature of the melt does not decrease on the effect of the heat of reaction during the treatment. At the treatment with ni~rogen gas alone,J in turn~) the temperature decreased by 15C.
Example ,2 An aluminium~magnesium-silicon alloy melt is treated in the equipment shown in Fig. l in a 15 tons tub-type flame furnace at the parameters specified in Example l. Powdered hexachloroethane'serves as a salt developing chlorine gas.
For the salce of comparison on another occasion tablets of hexachloroethane are introduced into the melt by the dipping bell method. The amount of the treating material is in both cases 2 kg/t of melt. The contents of hydrogen'gas are given in Table 2 for comparison. On feeding in a nitrogen gas current~ owing to the better reaction conditions,J the gas content of the melt decreases by 58-70 %ol a value more than twice as high as the purifying effect attainable by the tablets of hexachloroethane.
The same effect appears in the oxygen content of the melt. Whereas the oxygen conce'ntration of the melt is lO,ppm on blowing~in powdered hexachloroethane,J this value is about q 18 ppm at the treatment with tablets. The variation of oxygen content in case of a treatment with hexachloroethane tablets or with powdered hexachloroethane plus nitrogen gas is shown in Tables 6 and 7.
Example 3 .
The decrease of the content o~ hydrogen gas in an aluminium-magnesium-silic4n alloy melt is investigated as a function of the amount of powdered hexachloroethane introduced as an agent developing chlorine gas~l with the use of an equipment of the type shown in Fig. 1.
Figs. 2 and 3 show the efficiency of purification by comparing the effects of a treatment with tablets of hexa-chloroethane and the effects of a treatment in 15 ton tub--type furnaces with powdered hexachloroethane blown-in by nitrogen gas. In Fig. 2 the hydrogen gas content of the melt (ml/100 g) is shown as a function o~ the specific hexachloro-ethane consumption (l<g calculated for 1 ton of the melt).
In Fig. 3,J in turnr~ the initial hydrogen gas content (denoted as Sk and given in ml/100 9) is shown as a function of ths specific hexachloroethane consumption (given as kg/ton of the melt). Also the hydrogen gas contents at the end of the treatment ~denoted as Sv) are given. The continuous lines refer to a treatment with powdered hexachlooethane plus nitrogen gas whereas the dotted lines relate to a treatment with tablets of hexachloroethane. The efficiency of powdered hexachloro-ethane introduced in a nitrogen gas current exceeds that of the treatment with tablets of hexachloroethane. This is shown in Fig. 3 for an initial hydrogen gas content of 0.3 ml/100 9 and for a final hydrogen gas content of 0.1 ml/100 9. For ob-taining an identical purification effect the decrease in the consumption of hexachloroethane may attain 60 %. On blowing_in powdered hexachloroethane in a nitrogen gas current the oxygen ~ 37 8 - 13 _ content decreesed in the investigated case to 5 ppmO
Ex~ple 4 By the equipment of the type ~hown in Fig. l a 13 ton charge of aluminium~magnesium-silicon alloy melt is treat-ed ~n ~ tub-type flame furnace. Changes in the sodium conten~
occurring on the effect of the blowing-in of 2 kg/ton of melt of powdered hexachloroethane delivering chlorine gas are investigated. In Table 3 the sodium contents before and after the tre~tment ere compared. The decrease is by 27-65 ~.
The efficiency of purification attainable by increas ing the applied amount of the hexachloroethane powder is shown in Fig. 4 wherein the sodium content tppm Na) is shown as a function of the specific hexachloroethane consumption ~kg/ton of melt).
Example 5 .
By the e~uipment of the type shown in FigD 1 an aluminium-magnesium-silicon alloy melt is treated in a 15 ton tub-type flame furnace. The volume flow of the nitrogen gas used for the treatment is 0.4-0.5 Nm3/minute. The tempe~
rature of the treatment is 710-720C.
Table 4 shows the oxygen content of the melt before and ~fter the treatment with nitrogen gas. The oxygen content is determined by the neutron activation method. On average no decrease of-the oxygen content is experienced. On the contraryDJ the oxygen content even increased in the majori~y of cases~
~ . .
In a tub-type flame furnace a 25 ton charge of aluminium-~4437~3 - 14 ~
-magneslum-silicon alloy melt is treated with hexachloro-ethane tabletsO Changes ln the sodium content are regist-rated as a result of mixing up 2 kg/ton tablets of hexachloro-ethane delivering chlorine gas with the melt. The temperature of the treatment is 710_720C.
Sodium contents before and after the trc~ment are given in Table 5 for the sake of comparison. The sodium content deereases by 14-57 %.
T~ble 1 Hydrogen gas content Treatment with N2 Treatment with N2~C2C16 ., , , ,,, - Before After Decrease Before After Decrease t r e a t m e n t t r e a t m e n t ml/100 9 ml/100 9 ml/100 9ml/100 9 Al A1 ~ Al. ^ A1 %
, ... . ~ _ _ _ 0.23 0.21 9 0.20 0.~9 55 0.11 0~08 27 O.z6 0.1~ 62 o.zl 0.14 33 ~.21 0.06 71 0~27 0.24 11 0.23 0.12 48 0.24 0.17 29 0.22 U~05 77 ~ 15 -Tabl~e 2 Hydrogen gas content ~ .... ~
Treatment with C2C16tablets Treatment with N2 ~ powdered . . 2 ~ 6 Before After Dacrease Before After Decreese t r e e t m e n t t r e a t m e n t ml/100 ~ ml/100 9 ml/100 g ml/100 g Al Al % Al Al %
~ . . .._ o.lg 0.16 16 0.20 0.06 70 0.22 0.1~ 14 0.32 0.11 66 0.32 0.23 28 0.23 0.09 61 0.21 Ool9 10 0.2~ o.lo 62 0.32 0.25 22 ¦ b.24 o.lo 5~
Table 3 Sodium content .. . . _ Treatment with N ~ 2 kg/t of powdered C2C16 Before treatmentAfter treatment Decrease ppm ppm I %
~ 16 _ T~ble 4 Oxygen content L ._ -- r _ ~_ _ _ _ Tre~tment with N2 gas Before tre~tment After treE~tment Ch~nge ppm ppm , , ~ lo . 65 ~35 26 38 ~13 43 ~ 1~
3e 30 - 8 , 35 - 5 38 40 ~ 2 2~ 30 ~ 5 O
, ~ 17 -Teble 5 Sodium content . Treatment with 2 kg/t of tablots of C2C16 3efore treatment A~ter treatment Oecrea~e ppm pp~ %
8 5 37.0 3 40.0 7 4 43.0 8 5 37.0 7 3 57.0 6 4 33.0 9 6 33.0 7 6 .14.0 8 20.0 Tab Oxygen content Treetment with C2C16 tablet~
~efore tre~tmentAfter treatment Decrease ppm ppm %
The process according to the invention is carried, out in the equipment shown schematically in Fig. 1.
The pressurized container denoted in Fig. 1 by (1) which can be filled up after opening the cover ~9) serves as a recipient of the'treating material. The feeder ~4) forwards the treating matenal to the mixing ~pace ~5).'The velocity of feeding can be varied ungradually and it is ' stabilizad by the driving unit ~3) at a high ac'curacy.
The filling~up of the container wlth the treating material .
. .
-- lo --is controlled by a signal induced by the signal device (2).
The carrier gas enters the mixing space ~5) through pressure regulator and stabilizer t7)~ The volume of the gas can be controlled by the flow meter ~6). The mixture of gas and treating material prepared in the mixing ~ace flows through the flexible tube t8) to the treating pipe ~lo). The material of the treating pipe is resistan~ to the effect of the liquid metal. Metal purification by means of a mixture of gas and treating material is applied under plant conditions at the treatment of aluminium and aluminium alloy melts. The treating material is hexachloroethane,J the carrier gas is nitrogen.
The process according to the invention is elucidated in detail by the following non-limiting examples.
Exam ~
An ~luminium_magnesium~silicon alloy melt is treated in a 15 tons tub-type flame furnace by an equipment of ~he type shown in Fig~ 1. The flow by volume of the nitrogen carrier gas used for the treatment is 0.4~0.5 Nm~minute.
Treatment is started at a temperature of 710-720C. In one half of the cases no salt developing chlorine gas is added to the nitrogen gas. The amOunt of applied hexachloroethane is 2 kg/t of melt to. 2 %). The gas content of the melt before and after ~he treatment is shown in Table 1. The gas content is determined by the ,~first bubblei~ method. Nitrogen gas is capable of removing 9-33 % of the hydrogen gas conten~
of ~he melt~ On adding hexachloroethane,l as an agent which develops chlorine yas,l to the ni~rogen gas,! the content of 37~3 hydrogen gas can be reduced by 48-77 %. The formed slag' is drytl powder-lil<e~l having a low aluminium content where-as on treatment with nitrogen gas alone,l the formed slag is puLpy. At ths addi~ion of hexachloroethane the temperature of the melt does not decrease on the effect of the heat of reaction during the treatment. At the treatment with ni~rogen gas alone,J in turn~) the temperature decreased by 15C.
Example ,2 An aluminium~magnesium-silicon alloy melt is treated in the equipment shown in Fig. l in a 15 tons tub-type flame furnace at the parameters specified in Example l. Powdered hexachloroethane'serves as a salt developing chlorine gas.
For the salce of comparison on another occasion tablets of hexachloroethane are introduced into the melt by the dipping bell method. The amount of the treating material is in both cases 2 kg/t of melt. The contents of hydrogen'gas are given in Table 2 for comparison. On feeding in a nitrogen gas current~ owing to the better reaction conditions,J the gas content of the melt decreases by 58-70 %ol a value more than twice as high as the purifying effect attainable by the tablets of hexachloroethane.
The same effect appears in the oxygen content of the melt. Whereas the oxygen conce'ntration of the melt is lO,ppm on blowing~in powdered hexachloroethane,J this value is about q 18 ppm at the treatment with tablets. The variation of oxygen content in case of a treatment with hexachloroethane tablets or with powdered hexachloroethane plus nitrogen gas is shown in Tables 6 and 7.
Example 3 .
The decrease of the content o~ hydrogen gas in an aluminium-magnesium-silic4n alloy melt is investigated as a function of the amount of powdered hexachloroethane introduced as an agent developing chlorine gas~l with the use of an equipment of the type shown in Fig. 1.
Figs. 2 and 3 show the efficiency of purification by comparing the effects of a treatment with tablets of hexa-chloroethane and the effects of a treatment in 15 ton tub--type furnaces with powdered hexachloroethane blown-in by nitrogen gas. In Fig. 2 the hydrogen gas content of the melt (ml/100 g) is shown as a function o~ the specific hexachloro-ethane consumption (l<g calculated for 1 ton of the melt).
In Fig. 3,J in turnr~ the initial hydrogen gas content (denoted as Sk and given in ml/100 9) is shown as a function of ths specific hexachloroethane consumption (given as kg/ton of the melt). Also the hydrogen gas contents at the end of the treatment ~denoted as Sv) are given. The continuous lines refer to a treatment with powdered hexachlooethane plus nitrogen gas whereas the dotted lines relate to a treatment with tablets of hexachloroethane. The efficiency of powdered hexachloro-ethane introduced in a nitrogen gas current exceeds that of the treatment with tablets of hexachloroethane. This is shown in Fig. 3 for an initial hydrogen gas content of 0.3 ml/100 9 and for a final hydrogen gas content of 0.1 ml/100 9. For ob-taining an identical purification effect the decrease in the consumption of hexachloroethane may attain 60 %. On blowing_in powdered hexachloroethane in a nitrogen gas current the oxygen ~ 37 8 - 13 _ content decreesed in the investigated case to 5 ppmO
Ex~ple 4 By the equipment of the type ~hown in Fig. l a 13 ton charge of aluminium~magnesium-silicon alloy melt is treat-ed ~n ~ tub-type flame furnace. Changes in the sodium conten~
occurring on the effect of the blowing-in of 2 kg/ton of melt of powdered hexachloroethane delivering chlorine gas are investigated. In Table 3 the sodium contents before and after the tre~tment ere compared. The decrease is by 27-65 ~.
The efficiency of purification attainable by increas ing the applied amount of the hexachloroethane powder is shown in Fig. 4 wherein the sodium content tppm Na) is shown as a function of the specific hexachloroethane consumption ~kg/ton of melt).
Example 5 .
By the e~uipment of the type shown in FigD 1 an aluminium-magnesium-silicon alloy melt is treated in a 15 ton tub-type flame furnace. The volume flow of the nitrogen gas used for the treatment is 0.4-0.5 Nm3/minute. The tempe~
rature of the treatment is 710-720C.
Table 4 shows the oxygen content of the melt before and ~fter the treatment with nitrogen gas. The oxygen content is determined by the neutron activation method. On average no decrease of-the oxygen content is experienced. On the contraryDJ the oxygen content even increased in the majori~y of cases~
~ . .
In a tub-type flame furnace a 25 ton charge of aluminium-~4437~3 - 14 ~
-magneslum-silicon alloy melt is treated with hexachloro-ethane tabletsO Changes ln the sodium content are regist-rated as a result of mixing up 2 kg/ton tablets of hexachloro-ethane delivering chlorine gas with the melt. The temperature of the treatment is 710_720C.
Sodium contents before and after the trc~ment are given in Table 5 for the sake of comparison. The sodium content deereases by 14-57 %.
T~ble 1 Hydrogen gas content Treatment with N2 Treatment with N2~C2C16 ., , , ,,, - Before After Decrease Before After Decrease t r e a t m e n t t r e a t m e n t ml/100 9 ml/100 9 ml/100 9ml/100 9 Al A1 ~ Al. ^ A1 %
, ... . ~ _ _ _ 0.23 0.21 9 0.20 0.~9 55 0.11 0~08 27 O.z6 0.1~ 62 o.zl 0.14 33 ~.21 0.06 71 0~27 0.24 11 0.23 0.12 48 0.24 0.17 29 0.22 U~05 77 ~ 15 -Tabl~e 2 Hydrogen gas content ~ .... ~
Treatment with C2C16tablets Treatment with N2 ~ powdered . . 2 ~ 6 Before After Dacrease Before After Decreese t r e e t m e n t t r e a t m e n t ml/100 ~ ml/100 9 ml/100 g ml/100 g Al Al % Al Al %
~ . . .._ o.lg 0.16 16 0.20 0.06 70 0.22 0.1~ 14 0.32 0.11 66 0.32 0.23 28 0.23 0.09 61 0.21 Ool9 10 0.2~ o.lo 62 0.32 0.25 22 ¦ b.24 o.lo 5~
Table 3 Sodium content .. . . _ Treatment with N ~ 2 kg/t of powdered C2C16 Before treatmentAfter treatment Decrease ppm ppm I %
~ 16 _ T~ble 4 Oxygen content L ._ -- r _ ~_ _ _ _ Tre~tment with N2 gas Before tre~tment After treE~tment Ch~nge ppm ppm , , ~ lo . 65 ~35 26 38 ~13 43 ~ 1~
3e 30 - 8 , 35 - 5 38 40 ~ 2 2~ 30 ~ 5 O
, ~ 17 -Teble 5 Sodium content . Treatment with 2 kg/t of tablots of C2C16 3efore treatment A~ter treatment Oecrea~e ppm pp~ %
8 5 37.0 3 40.0 7 4 43.0 8 5 37.0 7 3 57.0 6 4 33.0 9 6 33.0 7 6 .14.0 8 20.0 Tab Oxygen content Treetment with C2C16 tablet~
~efore tre~tmentAfter treatment Decrease ppm ppm %
5~ 45 1~
3g 30 14 Table 7 Oxygen centent Treatment with N2 ~ powdered C2C16 Before treetmentAfter treatment Decrea~e ppm ppm %
15 - ~0
3g 30 14 Table 7 Oxygen centent Treatment with N2 ~ powdered C2C16 Before treetmentAfter treatment Decrea~e ppm ppm %
15 - ~0
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for decreasing the contaminant content of aluminium melts or of aluminium alloy melts, characterized by leading into the aluminium melt or aluminium alloy melt isolated from the air an inert gas of a pressure below 2 atmospheres, and at a temperature of 670-860°C.
2. A process according to claim 1, for removing alkali metal, hydrogen or solid non-metallic contaminants from aluminium melts or from aluminium alloy melts.
3. A process according to claim 1, for removing solid oxide contaminants from aluminium melts or from aluminium alloy melts.
4. A process according to claim 1, 2 or 3 in which the inert gas is nitrogen gas admixed with chlorine or a compound which develops chlorine gas.
5. A process as claimed in claim 1, 2 or 3 in which the inert gas is nitrogen, admixed with zinc chloride, magnesium chloride, manganese chloride or hexachloroethane, which develops chlorine gas.
6. A process according to claim 1, 2 or 3, in which the inert gas is nitrogen admixed with hexachloroethane.
7. A process according to claim 1, 2 or 3, in which the inert gas is admixed with a compound which develops chlorine gas applied in an amount of 0. 05-10 kg/ton of aluminium melt or aluminium alloy melt.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| HUMA003106 | 1979-02-08 | ||
| HUMA-3106 | 1979-02-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1144378A true CA1144378A (en) | 1983-04-12 |
Family
ID=10999060
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000345308A Expired CA1144378A (en) | 1979-02-08 | 1980-02-08 | Process for decreasing the contaminant content of aluminium melts and aluminium alloy melts |
Country Status (16)
| Country | Link |
|---|---|
| JP (1) | JPS55138033A (en) |
| AU (1) | AU5530780A (en) |
| BE (1) | BE881572A (en) |
| BR (1) | BR8000768A (en) |
| CA (1) | CA1144378A (en) |
| CS (1) | CS216519B2 (en) |
| DD (1) | DD149084A5 (en) |
| DE (1) | DE3004120A1 (en) |
| ES (1) | ES8101649A1 (en) |
| FR (1) | FR2448576A1 (en) |
| GB (1) | GB2041982A (en) |
| IT (1) | IT1150053B (en) |
| LU (1) | LU82135A1 (en) |
| NL (1) | NL8000567A (en) |
| PL (1) | PL221889A1 (en) |
| RO (1) | RO79075A (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4832740A (en) * | 1987-03-30 | 1989-05-23 | Swiss Aluminium Ltd. | Process for removing alkali and alkaline earth elements from aluminum melts |
| IT1229673B (en) * | 1989-04-20 | 1991-09-06 | Protecme S R L | Molten metal, in particular aluminium purificn. device |
| US5769924A (en) * | 1996-08-14 | 1998-06-23 | Eckert; C. Edward | Method of treating aluminum with chlorine produced from chlorocarbon compounds |
| AU2001293540B2 (en) * | 2000-09-12 | 2006-06-29 | Alcan International Limited | Process and rotary device for adding particulate solid material and gas to molten metal bath |
| CN101984099B (en) * | 2010-11-24 | 2012-05-09 | 上海电机学院 | On-line degassing device for aluminium melt |
| CN101984098B (en) * | 2010-11-24 | 2012-07-04 | 上海电机学院 | On-line degassing method for aluminium melt |
| CN102560160B (en) * | 2011-12-29 | 2013-04-24 | 东南大学 | Aluminum alloy vacuum standing, gas removal and smelting device |
| CN114015954B (en) * | 2021-09-08 | 2022-07-01 | 先导薄膜材料有限公司 | Method for reducing oxygen content in aluminum alloy |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR724553A (en) * | 1930-12-24 | 1932-04-29 | Alais & Froges & Camarque Cie | Metal purification process |
| GB603213A (en) * | 1945-07-24 | 1948-06-10 | Foundry Services Ltd | Improvements in or relating to the degassing of metals or metal alloys |
| FR1010723A (en) * | 1948-10-11 | 1952-06-16 | Improvements in processes to remove solid inclusions in metal baths | |
| FR1038557A (en) * | 1950-02-08 | 1953-09-30 | Affinerie De Juvisy | Process and device for treating molten charges with reagents, in particular with gases |
| CH491201A (en) * | 1966-09-02 | 1970-05-31 | Feichtinger Heinrich Ing Dr | Method and device for treating molten metal in containers |
| DE1533078A1 (en) * | 1966-10-21 | 1969-12-04 | Riedelbauch & Stoffregen Dr | Process for low-smoke chlorine degassing from metal melts |
| DE2206722A1 (en) * | 1972-02-12 | 1973-08-16 | Vaw Ver Aluminium Werke Ag | Aluminium melt de-oxidation - by inert gas injection of chlorine emitting salts |
| SE395911B (en) * | 1974-04-16 | 1977-08-29 | Uddeholms Ab | TREATMENT OF METAL MELTS IN CERAMIC REQUIRED REACTION VESSEL |
| FR2305502A1 (en) * | 1975-03-27 | 1976-10-22 | Air Ind | Refining molten metals with chlorine - where surplus chlorine in exhaust gas is absorbed and returned to melt |
| FR2312570A1 (en) * | 1975-05-28 | 1976-12-24 | Servimetal | Aluminium alloy mfr. using prealloyed briquettes - contg. flux which evolves gas, ensuring uniform distribution of alloys in melt |
| NL7612653A (en) * | 1976-11-15 | 1978-05-17 | Delfzijl Aluminium | METHOD OF REDUCING THE POST CONTENT IN AN ALUMINUM-MAGNESIUM ALLOY. |
-
1980
- 1980-01-28 CS CS80586A patent/CS216519B2/en unknown
- 1980-01-30 GB GB8003125A patent/GB2041982A/en not_active Withdrawn
- 1980-01-30 NL NL8000567A patent/NL8000567A/en not_active Application Discontinuation
- 1980-02-04 FR FR8002359A patent/FR2448576A1/en active Pending
- 1980-02-05 LU LU82135A patent/LU82135A1/en unknown
- 1980-02-05 DE DE19803004120 patent/DE3004120A1/en not_active Withdrawn
- 1980-02-06 DD DD80218924A patent/DD149084A5/en unknown
- 1980-02-06 BE BE0/199283A patent/BE881572A/en unknown
- 1980-02-06 RO RO80100105A patent/RO79075A/en unknown
- 1980-02-07 AU AU55307/80A patent/AU5530780A/en not_active Abandoned
- 1980-02-07 IT IT19745/80A patent/IT1150053B/en active
- 1980-02-07 JP JP1426380A patent/JPS55138033A/en active Pending
- 1980-02-07 BR BR8000768A patent/BR8000768A/en unknown
- 1980-02-08 ES ES488417A patent/ES8101649A1/en not_active Expired
- 1980-02-08 CA CA000345308A patent/CA1144378A/en not_active Expired
- 1980-02-08 PL PL22188980A patent/PL221889A1/xx unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DD149084A5 (en) | 1981-06-24 |
| BR8000768A (en) | 1980-10-21 |
| IT1150053B (en) | 1986-12-10 |
| BE881572A (en) | 1980-05-30 |
| IT8019745A0 (en) | 1980-02-07 |
| NL8000567A (en) | 1980-08-12 |
| JPS55138033A (en) | 1980-10-28 |
| ES488417A0 (en) | 1980-12-16 |
| FR2448576A1 (en) | 1980-09-05 |
| DE3004120A1 (en) | 1980-08-21 |
| PL221889A1 (en) | 1980-11-03 |
| CS216519B2 (en) | 1982-11-26 |
| AU5530780A (en) | 1980-08-14 |
| ES8101649A1 (en) | 1980-12-16 |
| LU82135A1 (en) | 1980-05-07 |
| GB2041982A (en) | 1980-09-17 |
| RO79075A (en) | 1982-11-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3737305A (en) | Treating molten aluminum | |
| US3929464A (en) | Desulfurization of molten ferrous metals | |
| US5435982A (en) | Method for dissociating waste in a packed bed reactor | |
| CA1144378A (en) | Process for decreasing the contaminant content of aluminium melts and aluminium alloy melts | |
| US2866701A (en) | Method of purifying silicon and ferrosilicon | |
| US5013532A (en) | Method for recycling electric arc furnace dust | |
| US3137753A (en) | Device for treating metallic melts | |
| CN103266237B (en) | Deslagging smelting flux for smelting casting zinc alloy and preparation method thereof | |
| NL8003815A (en) | Apparatus for introducing gases into metal smelters; METHOD FOR THE OPERATION THEREOF. | |
| US4417920A (en) | Process for eliminating metallic impurities from magnesium by injecting a halogenated derivative or boron | |
| CA2076743A1 (en) | Process for the desulphurization treatment of pig iron melts | |
| US3953579A (en) | Methods of making reactive metal silicide | |
| US4144054A (en) | Process for the removal of impurities from aluminum melts | |
| US4773929A (en) | Method of and device for the simultaneous heating and refining of a metal bath | |
| US4832740A (en) | Process for removing alkali and alkaline earth elements from aluminum melts | |
| US3843354A (en) | Pneumatic refining of pig iron | |
| CA1171663A (en) | Desulphurising agent | |
| US4247324A (en) | Method and apparatus for introducing solid substances into liquid metals | |
| CA1042215A (en) | Method for refining pig iron into steel | |
| US4233064A (en) | Method of scavenging steel | |
| EP0170900B1 (en) | Process for the removal of contaminating elements from pig- iron, steel, other metals and metal alloys | |
| Sasagawa et al. | Removal of Nitrogen by BaO--TiO sub 2 Based Slags | |
| KR910000006B1 (en) | Method of keeping inductor spouts downgates and outlet channels free of deposits in connection with a cast iron melt | |
| GB2078785A (en) | Adding Volatile Refining Agents to Molten Steel | |
| SU438715A1 (en) | Method of steel refining |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |