CA1049743A - Casting of copper anodes - Google Patents
Casting of copper anodesInfo
- Publication number
- CA1049743A CA1049743A CA210,982A CA210982A CA1049743A CA 1049743 A CA1049743 A CA 1049743A CA 210982 A CA210982 A CA 210982A CA 1049743 A CA1049743 A CA 1049743A
- Authority
- CA
- Canada
- Prior art keywords
- molds
- slurry
- copper
- mold
- casting
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C3/00—Selection of compositions for coating the surfaces of moulds, cores, or patterns
Abstract
ABSTRACT OF THE DISCLOSURE
In the coating of interior surfaces of copper molds with a slurry of a release material prior to the casting thereinto of molten impure copper for the production of anodes for use in the electrolytic refining of such impure copper, the improvement wherein the slurry is heated to a temperature of from about, 150° to about 200°F. prior to its being applied, resulting in greatly increasing the operating life of the molds.
In the coating of interior surfaces of copper molds with a slurry of a release material prior to the casting thereinto of molten impure copper for the production of anodes for use in the electrolytic refining of such impure copper, the improvement wherein the slurry is heated to a temperature of from about, 150° to about 200°F. prior to its being applied, resulting in greatly increasing the operating life of the molds.
Description
Case: K-0399-KCC
~049743 The lnvention relates to the production of copper anodes for use in the electrolytic refining of impure copper by castin~ molten im~ure copper into molds made of copper.
Copper anodes used in electrolytic copper refining are cast in solid copper molds weighing up to 6,000 or more pounds. It is common practice totreat the interior surfaces of such a mold be~ore each pour with a slurry ~ade up of a finely divided inorganic release material, such as silica, suspended in a liquid medium, such as water. The liquid medlum is vaporized by the heat of the mold, resulting in the deposition of a coating of the release material on the interior surfaces of the mold. The temperature of the mold during the treatment with the slurry is normally between about 200F.
and 1000F. Molten copper, at a temperature of ~OOO~F.
or more is introduced into the treated mold and the mold is then cooled until the molten metal has solidified. The cast copper anode is removed, and the mold is a~ain treated with the slurry for the subsequent pour. Cracking of the molds is a serious problem that has long plagued the casting ~0 operation. Small cracks develop in a mold after about a week of use, and the small cracks rapidly enlarge to an extent that makes it necessary to take the mold out of service and replace it with a new mold. The cracking problem has long been considered to be a difficulty that simply had to be tolerated, and molds have customarily been replaced after only short intervals of use.
It has now been found that the cracking problem can be reduced or eliminated by the process of this invention.
In accordance with the present invention, the slurry that is ~0 normally applied at room temperature or below to the interior
~049743 The lnvention relates to the production of copper anodes for use in the electrolytic refining of impure copper by castin~ molten im~ure copper into molds made of copper.
Copper anodes used in electrolytic copper refining are cast in solid copper molds weighing up to 6,000 or more pounds. It is common practice totreat the interior surfaces of such a mold be~ore each pour with a slurry ~ade up of a finely divided inorganic release material, such as silica, suspended in a liquid medium, such as water. The liquid medlum is vaporized by the heat of the mold, resulting in the deposition of a coating of the release material on the interior surfaces of the mold. The temperature of the mold during the treatment with the slurry is normally between about 200F.
and 1000F. Molten copper, at a temperature of ~OOO~F.
or more is introduced into the treated mold and the mold is then cooled until the molten metal has solidified. The cast copper anode is removed, and the mold is a~ain treated with the slurry for the subsequent pour. Cracking of the molds is a serious problem that has long plagued the casting ~0 operation. Small cracks develop in a mold after about a week of use, and the small cracks rapidly enlarge to an extent that makes it necessary to take the mold out of service and replace it with a new mold. The cracking problem has long been considered to be a difficulty that simply had to be tolerated, and molds have customarily been replaced after only short intervals of use.
It has now been found that the cracking problem can be reduced or eliminated by the process of this invention.
In accordance with the present invention, the slurry that is ~0 normally applied at room temperature or below to the interior
2 ~
~049743 surfaces of a copper anode mold is heated, before application, to a temperature of from about 150 to about 200F and is applied to the mold within that temperature range.
Thus, according to one aspect of the invention there is provided in the casting of copper anodes wherein copper molds are successively filled with molten copper and the solidified anodes are successively removed therefrom on a cyclic basis, and coatings of an inorganic release material are applied as a slurry thereof in a liquid medium capable of being volatilized within the range of 200F to about 1000F to the internal surfaces of the respective molds prior to the introduction of the molten copper thereinto, the improvement wherein the slurry is heated and applied to the interior surfaces of said molds at a temperature of from about 150F. to about 200F.
The release agent may be selected from the group consisting of silica, bone ash, alumina, clay, ganister, lime, and graphite, and is slurried with a liquid medium capable of being volatilized at the temperature of the mold, i.e. from about 200 to 1000F. In accordance with conventional practice, the release agent is finely divided sllica and the liquid medium is water. The heated slurry is applied to the interior surfaces of the mold by convent-ional means, usually by spraying, but other methods of applying it may be used, e.g. painting, splashing, or otherwise allowing the slurry to flow over the surfaces of the mold to form a coating thereon. The residual heat remaining in the mold from pour to pour vaporizes the liquid medium from the slurry coating, leaving a residual coating of the release agent on the interior surfaces of the mold.
In accordance with the invention, undesirable cracking of a mold is greatly reduced. Operating life of the mold 1049~3 is significan-tly longer -than has been the case in the past.
Conventional casting procedures are preferably followed in carrying out the invention. Thus, the usual casting l.~hich is normally employed, with the molten copper being poured sequentially from the usual ladle into a series of solid copper molds carried circumferentially of the wheel.
The only difference over conventional practice is the heating of the usual slurry prior to its application to the interior surfaces of the molds.
1~ Heating of the slurry may be accomplished in any suitable manner, bu-t is conveniently carried out by injecting steam into the reservoir of slurry maintained at the usual mold-coating station.
The sequence of steps involved in conventional casting operations comprises pouring mol~en copper into the mold, cooling the mold, removing the solidified copper casing from the mold, and applying a coating of the slurry to the interior surfaces of the empty molds. The empty molds are then returne,1 to the pour step and the sequence is repeated.
The slurry comprises a finely divided release material suspended in a liquid medium. The residual heat remaining in the mold from pour to pour vaporizes the liquid rnedium from the slurry coating, leaving a coating of -the release material on the interior surfaces of the mold. The molds can be cycled through tha sequence of steps as a group, or, preferably, they are cycled therethrough sequentially in a continuous series.
The inorganic release ma-ter 1 contained in the slurry includes such materials as silica, bone ash, alumina, clay, ganister, lime and graphite, preferably silica. The liquid ~ ~ -104g743 medium is preferably water. The slurry itself may vary in the concentration of solids present depending upon the method of applying the slurry to the surfaces of the molds. For spraying operations, the solids concentration may be as low as 2~o to 5~ by weight, but generally will be between about 10% and 25~ by weight. In splashing and other methods of applying the slurry to the mold surfaces, the solids concen-tration may be as high as ~0% by weight. The particle si~e of the solids in the slurry can also vary over a wide range 1~ depending upon the method of applying the slurry to the surfaces of the molds. For spraying operations, the particle size is preferably such that the dry solids are capable of passing through a 200 mesh screen. For other methods of applying the slurry to the mold surfaces, the particle size of the solids is not criticall the only requirements being that a homogeneous slurry be maintained, and that the coating of solids applied to the mold surfaces is uniform. Generally, the solids will have a particle size capable of passing through a 200 mesh screen.
The temperature of the mold during the application of the slurry thereto is generally between about 200Fo and 1000F.
The residual heat remaining in the molds from pour to pour, as mentioned hereinbefore, vaporizes the liquid medium from the slurry coating, leaving a residual coating of the release rnaterial on the interior surfaces of the mold.
Cooling of the mold following a pour can be accomp-lished by circulating water through internal passageways if the molds are constructed with such passageways. Generally, however, the molds are not provided with internal passageways, ~0 and are simply allowed to cool in the ambient air and/or .
spra~red with water.
The invention is furthe,r described by reference to the following example which is given for purposes of illus~
tration only and wi-~hout any in-tention that the invention be limited thereto.
EXAMPLE
A comparison test was run using the apparatus of a conventional, operating facility for producing cast copper anodes. The apparatus comprised a castin~ wheel which supported a series of copper molds, each mold ~eighing approximately 6,000 pounds. F,ach mold was capable of casting, a 700 pound copper anode. As the casting wheel rotated, each of the molds supported thereon progressively advanced from a filling station wherein molten copper was charged to the molds, to an anode discharge station where the anodes, which had cooled and solidified during their travel between the filling station and the discharge station, were removed from the molds. The empty molds then rnoved past a mold wash station wherein a slurry of silica in water 2~ was applied as a coating to the interior surfaces of the mold.
The temperature of the molds during the application of the silica generally was between about 300F. and 1000F., and the heat content of the molds rapidly vaporized the water content of the slurry coating, leaving only a coating of silica on the sur~aces of the moldO The molds were then returned to the filling station.
This casting c~cle had been operated commercially for several years using a slurry comprising approximately 500 pounds of silica to S gallons of water. The silica used .
had a particle size capable o~` passing through a ~00 mesh screen. The temperature of the silica solution as it was applied to the molds was appro~imately that of the a~bient atmosphere, i.e., between about 50F. and about lOO~F.
Experience with this process indicated that small cracks developed in the molds after about one week of use, and the small cracks would rapidly increase in size to where the mold had to be discarded.
In the comparison test, all of the molds on the 1o casting wheel, with the exception of one, were replaced with new molds. One old mold, which had developed one small crack, was left in place on the casting wheel. The procedure used in casting anodes with the new molds was exactly as given hereinabove with the single exception that the silica siurry was heated to a temperature between about 150F. and 200F.
prior to its being applied to the surface of the empty molds.
Following a two months' period in which these molds were continuously used in casting copper anodes, not a single crack develo,ped in any of the new molds which had been ~ installed on the casting wheel. The one old mold, which had a small crack therein at the start of the two months' test, still had only one crack therein, and that one crack was o~ the same size that it had been at the beginning of the two months' test.
Whereas, there is here described a certain preferred procedure which is presently regarded as the best mode of carrying out the invention, it should be understood that various changes may be made and other procedures adopted without departing from the disclosed inventive concepts ~0 particularly pointed out and claimed hereinafter.
.
.
~049743 surfaces of a copper anode mold is heated, before application, to a temperature of from about 150 to about 200F and is applied to the mold within that temperature range.
Thus, according to one aspect of the invention there is provided in the casting of copper anodes wherein copper molds are successively filled with molten copper and the solidified anodes are successively removed therefrom on a cyclic basis, and coatings of an inorganic release material are applied as a slurry thereof in a liquid medium capable of being volatilized within the range of 200F to about 1000F to the internal surfaces of the respective molds prior to the introduction of the molten copper thereinto, the improvement wherein the slurry is heated and applied to the interior surfaces of said molds at a temperature of from about 150F. to about 200F.
The release agent may be selected from the group consisting of silica, bone ash, alumina, clay, ganister, lime, and graphite, and is slurried with a liquid medium capable of being volatilized at the temperature of the mold, i.e. from about 200 to 1000F. In accordance with conventional practice, the release agent is finely divided sllica and the liquid medium is water. The heated slurry is applied to the interior surfaces of the mold by convent-ional means, usually by spraying, but other methods of applying it may be used, e.g. painting, splashing, or otherwise allowing the slurry to flow over the surfaces of the mold to form a coating thereon. The residual heat remaining in the mold from pour to pour vaporizes the liquid medium from the slurry coating, leaving a residual coating of the release agent on the interior surfaces of the mold.
In accordance with the invention, undesirable cracking of a mold is greatly reduced. Operating life of the mold 1049~3 is significan-tly longer -than has been the case in the past.
Conventional casting procedures are preferably followed in carrying out the invention. Thus, the usual casting l.~hich is normally employed, with the molten copper being poured sequentially from the usual ladle into a series of solid copper molds carried circumferentially of the wheel.
The only difference over conventional practice is the heating of the usual slurry prior to its application to the interior surfaces of the molds.
1~ Heating of the slurry may be accomplished in any suitable manner, bu-t is conveniently carried out by injecting steam into the reservoir of slurry maintained at the usual mold-coating station.
The sequence of steps involved in conventional casting operations comprises pouring mol~en copper into the mold, cooling the mold, removing the solidified copper casing from the mold, and applying a coating of the slurry to the interior surfaces of the empty molds. The empty molds are then returne,1 to the pour step and the sequence is repeated.
The slurry comprises a finely divided release material suspended in a liquid medium. The residual heat remaining in the mold from pour to pour vaporizes the liquid rnedium from the slurry coating, leaving a coating of -the release material on the interior surfaces of the mold. The molds can be cycled through tha sequence of steps as a group, or, preferably, they are cycled therethrough sequentially in a continuous series.
The inorganic release ma-ter 1 contained in the slurry includes such materials as silica, bone ash, alumina, clay, ganister, lime and graphite, preferably silica. The liquid ~ ~ -104g743 medium is preferably water. The slurry itself may vary in the concentration of solids present depending upon the method of applying the slurry to the surfaces of the molds. For spraying operations, the solids concentration may be as low as 2~o to 5~ by weight, but generally will be between about 10% and 25~ by weight. In splashing and other methods of applying the slurry to the mold surfaces, the solids concen-tration may be as high as ~0% by weight. The particle si~e of the solids in the slurry can also vary over a wide range 1~ depending upon the method of applying the slurry to the surfaces of the molds. For spraying operations, the particle size is preferably such that the dry solids are capable of passing through a 200 mesh screen. For other methods of applying the slurry to the mold surfaces, the particle size of the solids is not criticall the only requirements being that a homogeneous slurry be maintained, and that the coating of solids applied to the mold surfaces is uniform. Generally, the solids will have a particle size capable of passing through a 200 mesh screen.
The temperature of the mold during the application of the slurry thereto is generally between about 200Fo and 1000F.
The residual heat remaining in the molds from pour to pour, as mentioned hereinbefore, vaporizes the liquid medium from the slurry coating, leaving a residual coating of the release rnaterial on the interior surfaces of the mold.
Cooling of the mold following a pour can be accomp-lished by circulating water through internal passageways if the molds are constructed with such passageways. Generally, however, the molds are not provided with internal passageways, ~0 and are simply allowed to cool in the ambient air and/or .
spra~red with water.
The invention is furthe,r described by reference to the following example which is given for purposes of illus~
tration only and wi-~hout any in-tention that the invention be limited thereto.
EXAMPLE
A comparison test was run using the apparatus of a conventional, operating facility for producing cast copper anodes. The apparatus comprised a castin~ wheel which supported a series of copper molds, each mold ~eighing approximately 6,000 pounds. F,ach mold was capable of casting, a 700 pound copper anode. As the casting wheel rotated, each of the molds supported thereon progressively advanced from a filling station wherein molten copper was charged to the molds, to an anode discharge station where the anodes, which had cooled and solidified during their travel between the filling station and the discharge station, were removed from the molds. The empty molds then rnoved past a mold wash station wherein a slurry of silica in water 2~ was applied as a coating to the interior surfaces of the mold.
The temperature of the molds during the application of the silica generally was between about 300F. and 1000F., and the heat content of the molds rapidly vaporized the water content of the slurry coating, leaving only a coating of silica on the sur~aces of the moldO The molds were then returned to the filling station.
This casting c~cle had been operated commercially for several years using a slurry comprising approximately 500 pounds of silica to S gallons of water. The silica used .
had a particle size capable o~` passing through a ~00 mesh screen. The temperature of the silica solution as it was applied to the molds was appro~imately that of the a~bient atmosphere, i.e., between about 50F. and about lOO~F.
Experience with this process indicated that small cracks developed in the molds after about one week of use, and the small cracks would rapidly increase in size to where the mold had to be discarded.
In the comparison test, all of the molds on the 1o casting wheel, with the exception of one, were replaced with new molds. One old mold, which had developed one small crack, was left in place on the casting wheel. The procedure used in casting anodes with the new molds was exactly as given hereinabove with the single exception that the silica siurry was heated to a temperature between about 150F. and 200F.
prior to its being applied to the surface of the empty molds.
Following a two months' period in which these molds were continuously used in casting copper anodes, not a single crack develo,ped in any of the new molds which had been ~ installed on the casting wheel. The one old mold, which had a small crack therein at the start of the two months' test, still had only one crack therein, and that one crack was o~ the same size that it had been at the beginning of the two months' test.
Whereas, there is here described a certain preferred procedure which is presently regarded as the best mode of carrying out the invention, it should be understood that various changes may be made and other procedures adopted without departing from the disclosed inventive concepts ~0 particularly pointed out and claimed hereinafter.
.
.
Claims (4)
PROPERTY OF PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In the casting of copper anodes wherein copper molds are successively filled with molten copper and the solidified anodes are successively removed therefrom on a cyclic basis, and coatings of an inorganic release material are applied as a slurry thereof in a liquid medium capable of being volatilized within the range of 200°F to about 1000°F to the internal surfaces of the respective molds prior to the introduction of the molten copper thereinto, the improvement wherein the slurry is heated and applied to the interior surfaces of said molds at a temperature of from about 150°F. to about 200°F.
2. A method in accordance with Claim 1, wherein the liquid medium is water.
3. A method in accordance with Claim 1 or Claim 2, wherein the release agent is silica, and the temperature of the mold during the application of the release agent thereto is within the range of about 200°F. to about 1000°F.
4. A method in accordance with Claim 1, wherein the release agent is a member selected from the group con-sisting of silica, bone ash, alumina, clay, ganister, lime, and graphite.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US430740A US3867977A (en) | 1974-01-04 | 1974-01-04 | Method of casting copper anodes using a preheated mold coating |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1049743A true CA1049743A (en) | 1979-03-06 |
Family
ID=23708824
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA210,982A Expired CA1049743A (en) | 1974-01-04 | 1974-10-08 | Casting of copper anodes |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US3867977A (en) |
| CA (1) | CA1049743A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4178981A (en) * | 1978-06-29 | 1979-12-18 | Kerr-Mcgee Corporation | Copper casting method using titanium dioxide release method |
| CN102989997B (en) * | 2012-10-31 | 2014-07-16 | 高金菊 | Preparation method of releasing agent for iron casting machine |
| RU2614508C2 (en) * | 2013-09-23 | 2017-03-28 | Смс Меер Гмбх | Method and plant for copper semi-finished product production, as well as method and device for mold paint application |
| CN104226896B (en) * | 2014-09-17 | 2016-08-24 | 云南铜业股份有限公司 | A kind of copper anode casting compound releasing agent and preparation method thereof |
| CN110479955B (en) * | 2019-09-11 | 2020-05-05 | 邓跃武 | Release agent for copper anode plate casting and preparation method and use method thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3126294A (en) * | 1964-03-24 | Mold release material | ||
| US1662354A (en) * | 1925-01-10 | 1928-03-13 | Gen Motors Res Corp | Process of coating molds and product thereof |
| US3515201A (en) * | 1967-11-14 | 1970-06-02 | Amsted Ind Inc | Method of casting |
-
1974
- 1974-01-04 US US430740A patent/US3867977A/en not_active Expired - Lifetime
- 1974-10-08 CA CA210,982A patent/CA1049743A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US3867977A (en) | 1975-02-25 |
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