CA2262186A1 - Copper dissolver process - Google Patents
Copper dissolver process Download PDFInfo
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- CA2262186A1 CA2262186A1 CA 2262186 CA2262186A CA2262186A1 CA 2262186 A1 CA2262186 A1 CA 2262186A1 CA 2262186 CA2262186 CA 2262186 CA 2262186 A CA2262186 A CA 2262186A CA 2262186 A1 CA2262186 A1 CA 2262186A1
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
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Abstract
A method for dissolving copper metal comprising circulating an aqueous solution of monoethanolamine through a bed of copper metal, and simultaneously passing a source of oxygen through the bed of copper metal; an apparatus for dissolving copper metal comprising a receptacle for containing copper metal, a receptacle for containing an aqueous solution of monoethanolamine, means for pumping the monoethanolamine from the receptacle containing the monoethanolamine to the receptacle containing the copper metal, and pressure means for providing air to the receptacle containing the copper metal; and a process for preserving wood wherein the wood is infiltrated with gaseous carbon disulfide, and impregnated with an aqueous solution of copper ions and dimethylamine, are disclosed.
Description
Docket No. 028948-257 PATENT
COPPER DISSOLVER PROCESS
BACKGROUND OF THE INVENTION
This invention relates to a process for dissolving copper metal in a dilute solution of monoethanolamine (MEA) and to the apparatus for efficiently carrying out the process. The invention is particularly useful as a source of copper in the treatment of wood.
The treatment of wood against decay and insect infestation and to provide color preservation of wood is well known. A particularly effective wood preservative is copper dimethyldithiocarbamate. Commonly assigned U.S. Pat.
Application No. 08/786,823, filed January 21, 1997 i(presently allowed) is directed to a process for the in situ formation of copper dimethyldithiocarbamate directly in the wood matrix by reacting carbon disulfide, dimethylamine and a water-soluble source of copper, such as copper hydroxide solubilized by a complexing agent such as monoethanolamine, in the wood being treated. One step of the process involves rinsing the wood with an aqueous solution containing about 2.5 weight percent monoethanolamine (MEA). A portion of the rinse solution is charged with cupric ion to produce a solution enriched in copper content for use in another process step. Typically, the source of the copper ion is copper hydroxide. However, the cost of copper hydroxide is relatively high and an alternative source of copper ion is therefore desirable.
. U.S. Pat. No. 4,808,407 to Hein discloses a multi step process for preparing soluble copper salts of Docket No. 028948-257 carboxylic acids wherein a source of copper, such as copper metal, is reacted with a carboxylic acid and an alkanolamine is a first step and the mixture is subsequently treated with oxygen at an elevated temperature of about 70-95°C (158-203°F) until the desired copper salt is obtained.
SUMMARY OF THE INVENTION
The present invention involves a process wherein copper metal is dissolved in an aqueous solution of monoethanolamine (MEA) at ambient temperature to provide a copper-monoethanolamine complex wherein the complex consists of at least one mole monoethanolamine per mole of copper.
Typically, the complex contains two moles monoethanolamine per mole of copper. In accordance with the process, the monoethanolamine solution and air are passed through a reactor bed containing copper metal, such as shredded copper wire, at a solution-circulation rate and an aeration rate sufficient to effect the formation of copper-MEA complex.
The apparatus for carrying out the process comprises a column which contains the bed of copper metal, a tank which holds the monoethanolamine solution, a centrifugal pump for pumping the monoethanolamine solution through the bed of copper metal, and an air compressor for forcing air upward through the bed of copper metal.
Accordingly, it is an object of this present invention to provide a process for dissolving copper metal in an aqueous solution of monoethanolamine in a single step.
It is another object of the present invention to provide an apparatus for use in dissolving copper metal in an aqueous solution of monoethanolamine.
Docket No. 028948-257 It is yet another object of the present invention to provide a relatively inexpensive source of copper ions for use in a process for preserving wood.
These and other objects and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram of a pilot plant illustrating the process of the present invention;
FIG. 2 is a graph illustrating the effect of temperature on the dissolution of copper in the present invention;
FIG. 3 is a graph illustrating the effect of circulation rate of monoethanol-amine solution on the dissolution of copper in the present invention;
FIG. 4 is a graph illustrating the effect of flow rate of air on the dissolution of copper in the present invention;
FIG. 5 is a graph illustrating the effect of oxygen content on the dissolution of copper in the present invention; and FIG. 6 is a graph illustrating the effect of the amount of copper in the bed on the dissolution of copper in the present invention.
COPPER DISSOLVER PROCESS
BACKGROUND OF THE INVENTION
This invention relates to a process for dissolving copper metal in a dilute solution of monoethanolamine (MEA) and to the apparatus for efficiently carrying out the process. The invention is particularly useful as a source of copper in the treatment of wood.
The treatment of wood against decay and insect infestation and to provide color preservation of wood is well known. A particularly effective wood preservative is copper dimethyldithiocarbamate. Commonly assigned U.S. Pat.
Application No. 08/786,823, filed January 21, 1997 i(presently allowed) is directed to a process for the in situ formation of copper dimethyldithiocarbamate directly in the wood matrix by reacting carbon disulfide, dimethylamine and a water-soluble source of copper, such as copper hydroxide solubilized by a complexing agent such as monoethanolamine, in the wood being treated. One step of the process involves rinsing the wood with an aqueous solution containing about 2.5 weight percent monoethanolamine (MEA). A portion of the rinse solution is charged with cupric ion to produce a solution enriched in copper content for use in another process step. Typically, the source of the copper ion is copper hydroxide. However, the cost of copper hydroxide is relatively high and an alternative source of copper ion is therefore desirable.
. U.S. Pat. No. 4,808,407 to Hein discloses a multi step process for preparing soluble copper salts of Docket No. 028948-257 carboxylic acids wherein a source of copper, such as copper metal, is reacted with a carboxylic acid and an alkanolamine is a first step and the mixture is subsequently treated with oxygen at an elevated temperature of about 70-95°C (158-203°F) until the desired copper salt is obtained.
SUMMARY OF THE INVENTION
The present invention involves a process wherein copper metal is dissolved in an aqueous solution of monoethanolamine (MEA) at ambient temperature to provide a copper-monoethanolamine complex wherein the complex consists of at least one mole monoethanolamine per mole of copper.
Typically, the complex contains two moles monoethanolamine per mole of copper. In accordance with the process, the monoethanolamine solution and air are passed through a reactor bed containing copper metal, such as shredded copper wire, at a solution-circulation rate and an aeration rate sufficient to effect the formation of copper-MEA complex.
The apparatus for carrying out the process comprises a column which contains the bed of copper metal, a tank which holds the monoethanolamine solution, a centrifugal pump for pumping the monoethanolamine solution through the bed of copper metal, and an air compressor for forcing air upward through the bed of copper metal.
Accordingly, it is an object of this present invention to provide a process for dissolving copper metal in an aqueous solution of monoethanolamine in a single step.
It is another object of the present invention to provide an apparatus for use in dissolving copper metal in an aqueous solution of monoethanolamine.
Docket No. 028948-257 It is yet another object of the present invention to provide a relatively inexpensive source of copper ions for use in a process for preserving wood.
These and other objects and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram of a pilot plant illustrating the process of the present invention;
FIG. 2 is a graph illustrating the effect of temperature on the dissolution of copper in the present invention;
FIG. 3 is a graph illustrating the effect of circulation rate of monoethanol-amine solution on the dissolution of copper in the present invention;
FIG. 4 is a graph illustrating the effect of flow rate of air on the dissolution of copper in the present invention;
FIG. 5 is a graph illustrating the effect of oxygen content on the dissolution of copper in the present invention; and FIG. 6 is a graph illustrating the effect of the amount of copper in the bed on the dissolution of copper in the present invention.
w Docket No. 028948-257 DETAILED DESCRIPTION OF THE INVENTION
In accordance with the invention an aqueous solution of monoethanolamine and air are passed through a bed of copper metal to provide a solution of copper-mono-ethanolamine. In a preferred aspect of the invention, the process for dissolving copper metal in monoethanolamine is effective for providing a source of copper ion useful in the preservation of wood, particularly, in the process described in the above mentioned commonly assigned, U.S. Pat.
Application No. 08/786,823, where copper hydroxide is disclosed as the source of cupric ion. The copper metal of the present invention is economically more attractive as the source of copper ion than the relatively expensive copper hydroxide. The present process is especially favorable since the copper ions may be obtained from scrap copper.
Copper dissolution in the MEA solution typically is a three step process, mechanistically involving:
(1) oxygen dissolution at the gas-liquid interface;
(2) oxygen transfer to the copper surface; and (3) a reaction at the copper surface with oxygen and MEA.
At any point in time, the rates of the three processes are equal. The rate of copper dissolution per unit volume of bed = kla [Poz/Hoz-Coz] =Kiwi [Coz-Cozsl =KrapCozs CMEA (1) where:
Coz - Oz concentration in the bulk solution (moles/liter) C02s - Oz concentration at the copper surface (moles/liter) Poz - Partial pressure of Oz in air Docket No. 028948-257 Hoz - Henrys Law constant for Oz in solution aP - surface area of copper packing per unit volume of bed al - effective area of packing for liquid - solid mass transfer klal - volumetric mass transfer coefficient at air -liquid interface (1/time) klsal - volumetric mass transfer coefficient between solution and copper kr - rate constant for copper dissolution. If the expression krapCozSCM~, has dimensions of (gm-atoms) /liter-time) , and aP = (SP/VP) (1-a) has dimensions of cm2/cm3 (where 1-E is the packing volume fraction in the bed) , then kr = (cm-liter)/gmmole-time) El iminating Coz and Cozs f rom equat ion ( 1 ) in terms of Poz/Hoz the rate - [k apCM~p,Po2/Hoz] / [1+kraPCMEA/klsal+krapCMEA/kla] (2) r ~y material balance, the rate of disappearance of MEA per unit volume of copper bed equals twice the rate of copper dissolution per unit volume of copper bed. Therefore: The rate=-dCMEA/dt=2KrCMeA(Poz/Hoz) (Ub/US) (3) where : Kr - kraP/ [1+kraPCM~,/klsal+krapCM~"/kla]
Vb - volume of the copper bed (including voidage) VS - volume of the solution If one can assume that all terms except CMEA are essentially constant throughout the reaction process, then one can easily integrate (3) to obtain the following expression:
In accordance with the invention an aqueous solution of monoethanolamine and air are passed through a bed of copper metal to provide a solution of copper-mono-ethanolamine. In a preferred aspect of the invention, the process for dissolving copper metal in monoethanolamine is effective for providing a source of copper ion useful in the preservation of wood, particularly, in the process described in the above mentioned commonly assigned, U.S. Pat.
Application No. 08/786,823, where copper hydroxide is disclosed as the source of cupric ion. The copper metal of the present invention is economically more attractive as the source of copper ion than the relatively expensive copper hydroxide. The present process is especially favorable since the copper ions may be obtained from scrap copper.
Copper dissolution in the MEA solution typically is a three step process, mechanistically involving:
(1) oxygen dissolution at the gas-liquid interface;
(2) oxygen transfer to the copper surface; and (3) a reaction at the copper surface with oxygen and MEA.
At any point in time, the rates of the three processes are equal. The rate of copper dissolution per unit volume of bed = kla [Poz/Hoz-Coz] =Kiwi [Coz-Cozsl =KrapCozs CMEA (1) where:
Coz - Oz concentration in the bulk solution (moles/liter) C02s - Oz concentration at the copper surface (moles/liter) Poz - Partial pressure of Oz in air Docket No. 028948-257 Hoz - Henrys Law constant for Oz in solution aP - surface area of copper packing per unit volume of bed al - effective area of packing for liquid - solid mass transfer klal - volumetric mass transfer coefficient at air -liquid interface (1/time) klsal - volumetric mass transfer coefficient between solution and copper kr - rate constant for copper dissolution. If the expression krapCozSCM~, has dimensions of (gm-atoms) /liter-time) , and aP = (SP/VP) (1-a) has dimensions of cm2/cm3 (where 1-E is the packing volume fraction in the bed) , then kr = (cm-liter)/gmmole-time) El iminating Coz and Cozs f rom equat ion ( 1 ) in terms of Poz/Hoz the rate - [k apCM~p,Po2/Hoz] / [1+kraPCMEA/klsal+krapCMEA/kla] (2) r ~y material balance, the rate of disappearance of MEA per unit volume of copper bed equals twice the rate of copper dissolution per unit volume of copper bed. Therefore: The rate=-dCMEA/dt=2KrCMeA(Poz/Hoz) (Ub/US) (3) where : Kr - kraP/ [1+kraPCM~,/klsal+krapCM~"/kla]
Vb - volume of the copper bed (including voidage) VS - volume of the solution If one can assume that all terms except CMEA are essentially constant throughout the reaction process, then one can easily integrate (3) to obtain the following expression:
w Docket No. 028948-257 In [CMEAo/CMEA~t>~ =2krap (Poz/Hoz) (Vb/VS) t-krap [1/ki5ai+1/kia]
[CMEFIo/CMEA~t~ ~ (4 ) where: CMEAo = initial MEA concentration of the solution CMEA~t~ - MEA concentration of solution at time t t - time (hr) Equation (4) can be rearranged to solve for t:
t = In [CMEAo/CMEA~t) ] + krap [1/klsal+1/kla] [CMSao-CMer.~c) ] (5) [2krap (Po2/Ho2) (vb/vs) ]
Equation (5) describes how various parameters affect the rate of dissolution of copper in the system. To increase the rate of dissolution of copper (minimize t), one can increase the temperature of the solution (increase Kr), increase the surface area of the copper metal (increase ap), increase the flowrate of the solution through the copper bed ( increase klsal ) , increase the f lowrate of air ( oxygen) through the column (increase kla), increase the content of oxygen in the air passing through the bed (increase Poz), increase the amount of copper in the column (increase Vb), and decrease the amount of solution in the batch (decrease VS ) .
The copper-dissolving reaction of the present invention is carried out using a monoethanolamine solution temperature of about ambient to about 120°F. Typically, the solution temperature is at ambient temperature (about 65-75°F).
The aqueous monoethanolamine solution typically has a monoethanolamine concentration of about 1% to 50%, and w Docket No. 028948-257 preferably about 15% to 25%, and most preferably about 20 weight percent. The circulation rate of the monoethanolamine solution upward through the copper bed is about 20 to 40 gpm/sq. ft. (gallons per crossectional sq.
ft. of the column) and preferably about 35 to 40 gpm/sq. ft.
The flow rate of air upward through the copper bed is about 5 to 30 cfm/sq. ft., and preferably about 20 to 25 cfm/sq. ft. Generally, atmospheric air is sufficient for use in the present invention; however, air enriched with oxygen tends to produce a slight increase in the rate of dissolution of the copper.
The copper metal useful in the invention may be new copper or scrap copper and is present in a reaction column as a packed bed of copper metal. The bed is supported by a porous structure such as a screen. Preferably, the copper is in the form of shredded copper wire, typically about 10 to 20 gauge is effective to provide the desired results.
The amount of copper metal employed in the process is dependent upon the concentration of the monoethanolamine solution, the circulation rate of the MEA solution, the flow rate of air, and the temperature of the reaction.
While the process is most preferably directed to the use of aqueous solutions of monoethanolamine, aqueous solutions of other amines, such as alkylamines, alkanolamines, particularly other monoalkanolamines, may be used, to the extent of their solubility in water and their ability to complex with copper metal, in carrying out the invention.
[CMEFIo/CMEA~t~ ~ (4 ) where: CMEAo = initial MEA concentration of the solution CMEA~t~ - MEA concentration of solution at time t t - time (hr) Equation (4) can be rearranged to solve for t:
t = In [CMEAo/CMEA~t) ] + krap [1/klsal+1/kla] [CMSao-CMer.~c) ] (5) [2krap (Po2/Ho2) (vb/vs) ]
Equation (5) describes how various parameters affect the rate of dissolution of copper in the system. To increase the rate of dissolution of copper (minimize t), one can increase the temperature of the solution (increase Kr), increase the surface area of the copper metal (increase ap), increase the flowrate of the solution through the copper bed ( increase klsal ) , increase the f lowrate of air ( oxygen) through the column (increase kla), increase the content of oxygen in the air passing through the bed (increase Poz), increase the amount of copper in the column (increase Vb), and decrease the amount of solution in the batch (decrease VS ) .
The copper-dissolving reaction of the present invention is carried out using a monoethanolamine solution temperature of about ambient to about 120°F. Typically, the solution temperature is at ambient temperature (about 65-75°F).
The aqueous monoethanolamine solution typically has a monoethanolamine concentration of about 1% to 50%, and w Docket No. 028948-257 preferably about 15% to 25%, and most preferably about 20 weight percent. The circulation rate of the monoethanolamine solution upward through the copper bed is about 20 to 40 gpm/sq. ft. (gallons per crossectional sq.
ft. of the column) and preferably about 35 to 40 gpm/sq. ft.
The flow rate of air upward through the copper bed is about 5 to 30 cfm/sq. ft., and preferably about 20 to 25 cfm/sq. ft. Generally, atmospheric air is sufficient for use in the present invention; however, air enriched with oxygen tends to produce a slight increase in the rate of dissolution of the copper.
The copper metal useful in the invention may be new copper or scrap copper and is present in a reaction column as a packed bed of copper metal. The bed is supported by a porous structure such as a screen. Preferably, the copper is in the form of shredded copper wire, typically about 10 to 20 gauge is effective to provide the desired results.
The amount of copper metal employed in the process is dependent upon the concentration of the monoethanolamine solution, the circulation rate of the MEA solution, the flow rate of air, and the temperature of the reaction.
While the process is most preferably directed to the use of aqueous solutions of monoethanolamine, aqueous solutions of other amines, such as alkylamines, alkanolamines, particularly other monoalkanolamines, may be used, to the extent of their solubility in water and their ability to complex with copper metal, in carrying out the invention.
' Docket No. 028948-257 EXPERIMENTAL
A pilot plant was constructed to measure the rate of dissolution of copper in accordance with the present invention. As illustrated in Fig. 1, the pilot plant 10 consisted of a glass column 12 (2" in diameter) filled with shredded scrap copper wire 14 (10-14 gauge). The copper wire 14 was supported by a heavy gauge stainless steel screen 16. An aqueous solution of 2.5 wt.% monoethanolamine was pumped from a holding tank 18 to the column 12 via conduit 20 using a Wilden m. 025 diaphragm centrifugal pump 22 where the solution passed upwards through the bed of copper wire 14. The solution containing copper-monoethanolamine overflowed from the column 12 back to the holding tank 18 via conduit 24. Simultaneously, air was passed into column 12 and upwards through the bed of copper wire 14 via conduit 28 using compressor 26. After passing through the bed of copper wire 14, the air was released to the atmosphere through opening 30.
Several runs were made in the pilot plant for determining the effects of (1) temperature of the solution;
(2) flow rate of the monoethanolamine solution; (3) oxygen content of the air passed through the copper bed; and (4) the amount of copper in the bed. The results of the runs accord with equation (5).
Runs 1, 2 and 3 were made with solution temperatures of 70°F, 100°F and 120°F, respectively. Runs 4 and 5 were made ' at temperatures of 70°F and 95°F, respectively and, in runs Docket No. 028948-257 4 and 5, 50 SCFH air was passed through the copper bed. As seen in Fig. 2 an increase in temperature of the solution from ambient only slightly increased the rate of dissolution of copper. Any increase in Kr attained by increasing the temperature of the solution, however, is largely negated by a decrease in the solubility of oxygen (Po2/Ho2) since the solubility of oxygen decreases with increasing temperature.
Furthermore, it was noted that, as the temperature of the solution was increased, a black insoluble precipitate formed on the elements of the heater.
Runs 6 and 7 were made varying the circulation rate of the monoethanolamine solution. As seen in Fig. 3, an increase in the circulation of the monoethanolamine solution through the copper bed increases the rate of dissolution of copper by increasing the mass transfer coefficient klSa1-Runs 8, 9, 10 and 11 were made varying the flow rate of air through the copper bed. As seen in Fig. 4, an increase in the flow rate of air passing upward through the copper bed significantly increases the rate of dissolution of copper by increasing the mass transfer coefficient kla. As the flow rate of air increases through the copper bed for a given circulation rate of the solution, the hydrodynamic conditions in the copper bed approach pluse-flow regime in which the copper bed is near fluidization.
Runs 12 and 13 were made varying the oxygen content of air passed through the copper bed. As seen in Fig. 5, the addition of oxygen to the air passing through the copper bed at atmospheric pressure produces only a slight increase in the rate of dissolution of copper.
A pilot plant was constructed to measure the rate of dissolution of copper in accordance with the present invention. As illustrated in Fig. 1, the pilot plant 10 consisted of a glass column 12 (2" in diameter) filled with shredded scrap copper wire 14 (10-14 gauge). The copper wire 14 was supported by a heavy gauge stainless steel screen 16. An aqueous solution of 2.5 wt.% monoethanolamine was pumped from a holding tank 18 to the column 12 via conduit 20 using a Wilden m. 025 diaphragm centrifugal pump 22 where the solution passed upwards through the bed of copper wire 14. The solution containing copper-monoethanolamine overflowed from the column 12 back to the holding tank 18 via conduit 24. Simultaneously, air was passed into column 12 and upwards through the bed of copper wire 14 via conduit 28 using compressor 26. After passing through the bed of copper wire 14, the air was released to the atmosphere through opening 30.
Several runs were made in the pilot plant for determining the effects of (1) temperature of the solution;
(2) flow rate of the monoethanolamine solution; (3) oxygen content of the air passed through the copper bed; and (4) the amount of copper in the bed. The results of the runs accord with equation (5).
Runs 1, 2 and 3 were made with solution temperatures of 70°F, 100°F and 120°F, respectively. Runs 4 and 5 were made ' at temperatures of 70°F and 95°F, respectively and, in runs Docket No. 028948-257 4 and 5, 50 SCFH air was passed through the copper bed. As seen in Fig. 2 an increase in temperature of the solution from ambient only slightly increased the rate of dissolution of copper. Any increase in Kr attained by increasing the temperature of the solution, however, is largely negated by a decrease in the solubility of oxygen (Po2/Ho2) since the solubility of oxygen decreases with increasing temperature.
Furthermore, it was noted that, as the temperature of the solution was increased, a black insoluble precipitate formed on the elements of the heater.
Runs 6 and 7 were made varying the circulation rate of the monoethanolamine solution. As seen in Fig. 3, an increase in the circulation of the monoethanolamine solution through the copper bed increases the rate of dissolution of copper by increasing the mass transfer coefficient klSa1-Runs 8, 9, 10 and 11 were made varying the flow rate of air through the copper bed. As seen in Fig. 4, an increase in the flow rate of air passing upward through the copper bed significantly increases the rate of dissolution of copper by increasing the mass transfer coefficient kla. As the flow rate of air increases through the copper bed for a given circulation rate of the solution, the hydrodynamic conditions in the copper bed approach pluse-flow regime in which the copper bed is near fluidization.
Runs 12 and 13 were made varying the oxygen content of air passed through the copper bed. As seen in Fig. 5, the addition of oxygen to the air passing through the copper bed at atmospheric pressure produces only a slight increase in the rate of dissolution of copper.
w Docket No. 028948-257 Runs 14, 15 and 16 were made varying the amount of copper in the bed. As seen in Fig. 6, increasing the amount of copper.
Based on these experimental runs, the most significant process parameters of a copper dissolution process are the circulation rate of the monoethanolamine solution upward through the copper bed, the air flow rate upward through the copper bed, and the amount and size of the copper metal in the bed.
In a typical reaction scheme, circulation of the monoethanolamine solution (about 2.5o wt. % of MEA) through a packed bed of shredded copper wire (10 to 20 gauge) at a circulation rate of about 37 gpm/sq. ft. of packed copper metal in the bed and with an aeration rate of about 23 cfm/sq. ft. of packed copper, will provide conditions suitable for dissolving the copper metal to provide about 1.0 to 1.2 wt. % of copper-MEA in the monoethanolamine solution at about 70°F.
Having described the invention in detail by reference to preferred aspects thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.
What is claimed is:
Based on these experimental runs, the most significant process parameters of a copper dissolution process are the circulation rate of the monoethanolamine solution upward through the copper bed, the air flow rate upward through the copper bed, and the amount and size of the copper metal in the bed.
In a typical reaction scheme, circulation of the monoethanolamine solution (about 2.5o wt. % of MEA) through a packed bed of shredded copper wire (10 to 20 gauge) at a circulation rate of about 37 gpm/sq. ft. of packed copper metal in the bed and with an aeration rate of about 23 cfm/sq. ft. of packed copper, will provide conditions suitable for dissolving the copper metal to provide about 1.0 to 1.2 wt. % of copper-MEA in the monoethanolamine solution at about 70°F.
Having described the invention in detail by reference to preferred aspects thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.
What is claimed is:
Claims (20)
1. A method for dissolving copper metal comprising:
circulating an aqueous solution of monoethanolamine upward through a bed of copper metal; and simultaneously passing a source of oxygen upward through said bed of copper metal.
circulating an aqueous solution of monoethanolamine upward through a bed of copper metal; and simultaneously passing a source of oxygen upward through said bed of copper metal.
2. The method of claim 1 wherein said aqueous solution contains about 1 to 50 weight percent monoethanolamine.
3. The method of claim 2 wherein said aqueous solution contains about 15 to 25 weight percent monoethanolamine.
4. The method of claim 3 wherein said aqueous solution contains about 20 weight percent monoethanolamine.
5. The method of claim 1 wherein said monoethanolamine solution is circulated through said bed of copper metal at about 20 to 40 gpm/sq. ft.
6. The method of claim 5 wherein said monoethanolamine is circulated through said bed of cooper metal at about 35 to 40 gpm/sq. ft.
7. The method of claim 1 wherein said source of oxygen is air and said air is passed through said bed of copper metal at about 5 to 30 cfm/sq. ft.
8. The method of claim 7 wherein said air is passed through said bed of copper metal at about 20 to 25 cfm/sq.
ft.
ft.
9. The method of claim 1 wherein said aqueous solution of monoethanolamine is at a temperature of about 50 to 120 °F.
10. The method of claim 9 wherein said temperature is about 70°F.
11. The method of claim 1 wherein said air is a mixture of air and oxygen.
12. The method of claim 1 wherein said method is useful for providing copper ion in a process for preserving wood.
13. An apparatus for dissolving copper metal comprising:
a receptacle for containing copper metal;
a receptacle for containing an aqueous solution of monoethanolamine;
means for pumping said monoethanolamine from the receptacle containing the monoethanolamine to the receptacle containing said copper metal; and pressure means for providing air to the receptacle containing said copper metal.
a receptacle for containing copper metal;
a receptacle for containing an aqueous solution of monoethanolamine;
means for pumping said monoethanolamine from the receptacle containing the monoethanolamine to the receptacle containing said copper metal; and pressure means for providing air to the receptacle containing said copper metal.
14. The apparatus for claim 13 wherein said apparatus further comprises a perforated platform upon which the bed of copper metal rests.
15. The apparatus of claim 14 wherein said perforated platform further comprises a pervious support pad.
16. The apparatus of claim 13 wherein said means for pumping said monoethanolamine is a centrifugal pump.
17. The apparatus of claim 13 wherein said pressure means is a compressor.
18. The apparatus of claim 13 wherein said receptacle for containing the copper metal further comprises an exhaust for exhausting said air into the atmosphere.
19. A process for preserving wood wherein said wood is infiltrated with gaseous carbon disulfide, and impregnated with an aqueous solution of a copper source and dimethylamine, wherein said copper source is copper ions generated by a method for dissolving copper metal said method comprising:
circulating an aqueous solution containing about 1 to 50 weight percent monoethanolamine upwardly through a packed bed of copper metal at about 20 to 40 gpm/sq, ft.
simultaneously passing air upwardly through said bed of copper metal at about 5 to 30 cfm/sq. ft.
circulating an aqueous solution containing about 1 to 50 weight percent monoethanolamine upwardly through a packed bed of copper metal at about 20 to 40 gpm/sq, ft.
simultaneously passing air upwardly through said bed of copper metal at about 5 to 30 cfm/sq. ft.
20. The process of claim 19 wherein said aqueous solution contains about 15 to 25 weight percent monoethanolamine and said air is passed upwardly through said bed of copper at about 20 to 25 cfm/sq. ft.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US4981098A | 1998-03-27 | 1998-03-27 | |
| US09/049,810 | 1998-03-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2262186A1 true CA2262186A1 (en) | 1999-09-27 |
Family
ID=21961862
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2262186 Abandoned CA2262186A1 (en) | 1998-03-27 | 1999-02-17 | Copper dissolver process |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2262186A1 (en) |
| NZ (1) | NZ334310A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1490375A2 (en) * | 2002-02-14 | 2004-12-29 | Phibrotech, Inc. | Process for the dissolution of copper metal |
| EP1640463A1 (en) * | 2004-09-10 | 2006-03-29 | Phibro-Tech, Inc. | Process for the dissolution of copper metal |
| US7273944B2 (en) | 2003-11-19 | 2007-09-25 | Arch Chemicals, Inc. | Methods for producing copper ethanolamine solutions |
| WO2019046245A1 (en) | 2017-09-01 | 2019-03-07 | Koppers Performance Chemicals Inc. | Method of preparing copper-containing wood preserving compositions |
| CN113457611A (en) * | 2021-07-06 | 2021-10-01 | 江西鑫铂瑞科技有限公司 | Electrolytic copper foil copper dissolving material process capable of reducing energy consumption |
-
1999
- 1999-02-17 CA CA 2262186 patent/CA2262186A1/en not_active Abandoned
- 1999-02-22 NZ NZ33431099A patent/NZ334310A/en unknown
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1490375A2 (en) * | 2002-02-14 | 2004-12-29 | Phibrotech, Inc. | Process for the dissolution of copper metal |
| US6905531B2 (en) | 2002-02-14 | 2005-06-14 | Phibro Tech, Inc. | Process for the dissolution of copper metal |
| US6905532B2 (en) | 2002-02-14 | 2005-06-14 | Phibro-Tech, Inc. | Process for the dissolution of copper metal |
| EP1490375A4 (en) * | 2002-02-14 | 2006-09-13 | Phibrotech Inc | Process for the dissolution of copper metal |
| US7476371B2 (en) | 2002-02-14 | 2009-01-13 | Phibro-Tech, Inc. | Dissolution of copper metal in aqueous alkanolamine to form copper containing aqueous solution |
| US7273944B2 (en) | 2003-11-19 | 2007-09-25 | Arch Chemicals, Inc. | Methods for producing copper ethanolamine solutions |
| EP1640463A1 (en) * | 2004-09-10 | 2006-03-29 | Phibro-Tech, Inc. | Process for the dissolution of copper metal |
| WO2019046245A1 (en) | 2017-09-01 | 2019-03-07 | Koppers Performance Chemicals Inc. | Method of preparing copper-containing wood preserving compositions |
| CN113457611A (en) * | 2021-07-06 | 2021-10-01 | 江西鑫铂瑞科技有限公司 | Electrolytic copper foil copper dissolving material process capable of reducing energy consumption |
| CN113457611B (en) * | 2021-07-06 | 2022-08-05 | 江西鑫铂瑞科技有限公司 | Electrolytic copper foil copper dissolving material process capable of reducing energy consumption |
Also Published As
| Publication number | Publication date |
|---|---|
| NZ334310A (en) | 2001-01-26 |
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