US3637508A - Process and composition for dissolving copper oxide - Google Patents

Process and composition for dissolving copper oxide Download PDF

Info

Publication number
US3637508A
US3637508A US17154A US3637508DA US3637508A US 3637508 A US3637508 A US 3637508A US 17154 A US17154 A US 17154A US 3637508D A US3637508D A US 3637508DA US 3637508 A US3637508 A US 3637508A
Authority
US
United States
Prior art keywords
ethylenediamine
acid
weight
water
ammonium hydroxide
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 - Lifetime
Application number
US17154A
Inventor
William B Willsey
Daniel J Brogan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DANIEL J BROGAN
WILLIAM B WILLSEY
Original Assignee
DANIEL J BROGAN
WILLIAM B WILLSEY
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by DANIEL J BROGAN, WILLIAM B WILLSEY filed Critical DANIEL J BROGAN
Application granted granted Critical
Publication of US3637508A publication Critical patent/US3637508A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/14—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G3/00—Compounds of copper
    • 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
    • C22B15/00—Obtaining copper
    • C22B15/0063—Hydrometallurgy
    • 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
    • Y02P10/20—Recycling

Definitions

  • a polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine is mixed with a compound selected from a second group consisting of salicyclic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, a dihydroxybenzoic acid, 5-5-methylenedisalicyclic acid, 3-hydroxy-2-naphthoic acid and salts thereof with an aliphatic polyamine of the first class and with ammonium hydroxide in an alkaline water solution or a salicylate of one of these amines can be used with ammonium hydroxide.
  • the composition can be used cold but will preferably be used in a temperature range between 150 F. and the boiling temperature at the particular pressure.
  • ABSTRACT 17 Claims 12 Drawing Figures CuO S0 LUB LE, gms.
  • ETHYLENEDIAMINE 0.6 g L 1 30.5- CD 3 .J 0 (00-4;
  • the rate of copper oxide dissolution can be accelerated by adding an oxidizing agent such as ammonium persulphate.
  • the process of the invention can be employed effectively to remove cuprous oxide, but it is even more effective on cupric oxide and as cupric oxide is more frequently encountered, the test results are chiefly directed to removal of cupric oxide.
  • concentration of combined ethylenediamine or the like and salicylic acid or the like should be between 0.25 and 100 percent by weight, most desirably between 1 and 50 percent by weight, and under normal conditions concentrations of the order of l5 to 30 percent by weight, the balance in any case being a solvent such as water.
  • the weight ratio of ethylenediamine or the like to salicylic acid or the like should preferably be between about 0.25 and 6, more desirably between 0.50 and 4 and most desirably about 1.4 although if desired greater ratios may be used, with diminishing effectiveness. In other words, it is preferable to have about 3 moles of ethylenediamine to 1 mole of salicylic acid.
  • composition of the invention will include ethylenediamine, salicylic acid and water.
  • ethylenediamine instead of ethylenediamine, however, other aliphatic polyamines may be used, examples of such other polyamines being diethylenetriamine, triethylenetetramine and tetraethylenepentamine.
  • Salicylic acid is of course orthohydroxybenzoic acid. As altematives for salicylic acid, metahydroxybenzoic and parahydroxybenzoic acids may be used.
  • a dihydroxybenzoic acid can also be employed instead of salicylic acid, an example being 2,4-dihydroxybenzoic acid.
  • a disalicyclic acid may also be employed, an example being 5,5 methylenedisalicylic acid which also is known as 4,4- dihydroxydiphenylmethane-3,3 '-dicarboxylic acid.
  • 3-hydroxy-2-naphthoic acid can be used instead of salicylic acid but on the other hand l-hydroxy-Z-naphthoic acid is not effective, apparently because of the different location of the double bond.
  • any one of the acids above referred to can be used in the form of salts with ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine or ammonium hydroxide.
  • examples are ethylenediamine salicylate, diethylenetriamine salicylate, ammonium salicylate, and the ethylenediamine salt of parahydroxybenzoic acid.
  • salts of these acids with metals such as sodium or potassium, of which an example is sodium salicylate are not effective.
  • the particular alternate compound can be used in admixture with the compound for which it is substituting, as for example salicylic acid can be used mixed with parahydroxybenzoic acid.
  • a salicylate of ethylenediamine or one of the other aliphatic polyamines referred to with sufficient ammonium hydroxide to maintain the combination alkaline is an effective composition for dissolving copper oxide and shows to a substantial extent the unusual properties above referred to.
  • compositions of the present invention in water solutions are inherently alkaline by virtue of the strongly alkaline character of the polyamines.
  • Hydroxylamine-type compounds have pronounced oxidation-reduction properties whereas the oxidation-reduction properties of salicylic acid and the other related compounds disclosed by applicants are negligible.
  • An example of this pronounced oxidation-reduction property of hydroxylamine and its salts is that they will react quite vigorously with ferrous ions.
  • the ferrous ion is oxidized to ferric ion and the reaction is accompanied by an undesired excessive exothermic heat of reaction.
  • lf cupric ions are present, they are reduced to cuprous ions or metallic copper which will plate out on metallic and other surfaces.
  • compositions of this invention essentially do not react with ferrous or ferric ions, the corrosion rate for iron, steel and stainless steel is much lower. Also, since the compositions do not react corrosively with iron, the solution may be prepared in an ordinary steel tank. This contrasts with Calls solvent which must be prepared in a plastic-lined tank because it will react violently with iron oxides that may be present in a steel tank.
  • the copper oxide solubility of the compositions of this invention is due to:
  • the copper forms a water soluble complex with the salicylic acid type compound.
  • the complex formed is illustrated below.
  • the present invention relates to processes for dissolving copper oxide, whether cuprous or cupric oxide, and compositions therefor.
  • a purpose of the invention is to remove copper oxide by a composition which is not inherently hazardous and therefore much safer than some of the compositions commonly used for this purpose.
  • a further purpose is to remove copper oxide without leaving any residue except for a small quantity of soluble copper salt which can be removed by washing with water.
  • a further purpose is to reduce the cost of the chemicals required.
  • a further purpose is to reduce the corrosion rate, especially on copper and copper alloys when removing copper oxide.
  • a further purpose is to employ a composition for removing copper oxide which will not react with iron or iron compounds.
  • a further purpose is to avoid objectionable gassing which in some cases in the prior art has produced an explosive type of overflowing.
  • a further purpose is to employ a solution for removing copper oxide which has insignificant exothermic heat of solutron.
  • a further purpose is to avoid plating or depositing copper by a solution which has removed copper oxide.
  • a further purpose is to produce a bright passivated metal surface on copper and copper alloys which is resistant to further oxidation.
  • Copper may be picked up and carried by water or steam in a steam powerplant and deposited as copper oxide on buckets and nozzles of steam turbines, heat exchangers and condensers. It tends to reduce the efficiency of the equipment and therefore must be removed periodically.
  • Copper oxide is present in a vapor phase in high-pressure areas and tends to deposit at lower pressure locations on parts of the steam turbine.
  • Copper oxide also is a problem in feed water heaters for boilers.
  • the composition reacts with iron and iron oxide and increases the corrosion rate on steel, brass and other copper alloys, and this is objectionable.
  • the present invention is concerned with overcoming the difficulties present in the prior art compositions and particularly eliminating the above difficulties referred to in connection with the Call composition.
  • composition of the present invention is inherently not hazardous and is safe to use unlike some of the prior art compositions. It does not dissolve iron or iron oxide and does not undergo any gassing or violent reaction with iron or iron oxide. No substantial exothermic temperature rise occurs during use.
  • composition of the present invention does not have an increased corrosion rate on steel and brass from presence of iron.
  • composition of the invention can simply be used at low temperature for cleaning or polishing copper or copper alloys, and it is quite effective without the difficulties of the prior art compositions used for these purposes such as conventional bright dips.
  • composition of the invention leaves no residue except a small amount of soluble copper salt which can be removed by washing with water.
  • composition of the present invention avoids disassembly of equipment.
  • the process and composition of the invention is less costly than the prior art compositions.
  • composition of the invention leaves the surface of copper alloys passivated and resistant to further oxidation.
  • the widest use of the invention may be in removing copper oxide from the interiors of closed steam generators and associated equipment such as steam turbines, heat exchangers, and condensers.
  • the solution of the invention at a temperature between F. and the boiling point of the solution at the particular pressure. The reason for this is that the action under these circumstances would be much slower if the solution were used cold.
  • the cleaning action in a cold solution can be accelerated by placing the parts on an ultrasonic vibration table in a cleaning bath.
  • the inside of the tubing was cleaned by the foaming technique previously mentioned.
  • Aspercent solution of inhibited hydrochloric acid foam at a 13 to 1 foam-to-liquid ratio was passed through the condenser tubes, followed by a water foam, then by a foam solution of composition 23 at a foam-to-liquid ratio of 9 to l. and finally by a water foam.
  • the outside of the tubing (steam side) was sprayed with a 3 percent solution of inhibited hydrochloric acid, followed by a spray of composition 23, and then a water rinse, which left the metal surface in a bright passivated condition, resistant to oxidation.
  • the entire procedure was carried out at a temperature of about 120 F.
  • Pieces after cleaning with the composition of the present in-' vention and with the bright dip were treated in a mercury strike, were rinsed in water and were then silver plated for half an hour. Visual examination indicated the plating on all of the pieces was of equal quality and on testing by scraping, the adhesion was about equal.
  • the thicknesses of silver plating, as measured with a micrometer, on the brass washers and the copper plate cleaned by the treatment according to the present invention were determined to be satisfactory and about the same as when using the bright dip.
  • the costs of equal volumes of the composition of the present invention and the above bright dip were substantially identical.
  • composition of the present invention has the important advantage over conventional bright dips in that it may be used without the necessity for the special precautions required for the safe use of the strong acids comprised in the bright dips. Accordingly, the composition of the present invention may be applied freely with a brush or as a wash or spray to vertical and under surfaces of permanent structures, or wherever else bright dips could not be used because of the hazard.
  • composition of the invention may be used as a household polish and cleaner for copper and brass.
  • a suitable biocide may be incorporated if desired.
  • Copper switch parts were cleaned with the solution discussed in connection with FIG. 10 for 5 to l0 minutes at room temperature and at l F. Good results were obtained in all cases but the parts treated at elevated temperatures were shiny and those treated at room temperature had a matte finish.
  • FIG. 11 plots cupric oxide soluble in grams as ordinate against time as abscissa for various temperatures shown by various curves as follows;
  • cupric oxide increases rapidly with temperature so that for example as much cupric oxide can be dissolved by the composition in 1 hour at 21 2 F. as can be dissolved in 6 hours at 175 F.
  • FIG. I shows the results obtained in an experiment where 1 gram of cupric oxide was present and the treating solution involved 6.75 grams of ethylenediamine, 42.5 grams of water and various additions of salicylic acid as shown by the abscissa. The experiment was carried on for hours at 200 F., and it will be noted that there is a rapid rise in the quantity of cupric oxide dissolved with additions of salicylic acid up to about 4 grams of salicylic acid.
  • FIG. la for the same experimental conditions plots as abscissa the weight ratio of ethylenediamine to salicylic acid. It is noted that this rises very rapidly and then descends somewhat less rapidly, but there is a hump in the intermediate range which reaches a peak at about a ratio of 1.3.
  • FIG. 2 for the same test conditions otherwise employs 2,4- dihydroxybenzoic acid instead of salicylic acid and plots as abscissa the weight ratio of ethylenediamine to 2,4-dihydroxybenzoic acid. It will be noted again that there is a hump in this case at a weight ration of 1.2.
  • FIG. 3 employs similar test conditions except that the sodium salt of salicylic acid is used and the abscissa is the weight ratio of ethylenediamine to the salicylic acid sodium salt. It will be noted that this is very ineffective and evidently does not have properties similar to the composition of ethylenediamine and salicylic acid.
  • FIG. 4 plots as abscissa the weight ratio of ethylenediamine to 5,55'-methylenedisalicylic acid. This is very effective and shows a hump at about the weight ratio of 1.2. The other conditions in this test are the same as for FIG. 1.
  • FIG. 5 for similar test conditions employs ethylenediamine salicylate and ethylenediamine.
  • the abscissa is the weight ration of ethylenediamine to ethylenediamine salicylate and the curve has a peak at about 1.
  • FIG. 6 is a test performed using a solution having 1 gram of cupric oxide, 42.5 grams of water, and 7.5 grams of sodium hydroxide with various quantities of ethylenediamine salicylate. The test time was 5 hours at 200 F.
  • the abscissa is the weight ratio of sodium hydroxide to ethylenediamine salicylate. It will be noted that this composition is completely ineffective and therefore the good results do not seem to be a matter of alkalinity imparted by ethylenediamine. However, it is necessary that the aqueous compositions of this invention be of alkaline character in order to dissolve the salicylic acid which is essentially insoluble in water which is not alkaline.
  • EDA Ethylenediamine
  • Salicylic triethylenetetramine and tetraethyleneopentamine in place of ethylenediamine, and similarly for their use with salicylic acid or the previously mentioned alternative therefor.
  • FIG. 7 for test results similar to FIG. la has substituted 3- hydroxy-Z-naphthoic acid for salicylic acid.
  • the abscissa is the weight ratio of ethylenediamine to 3-hydroxy-2-naphthoic acid. This composition is quite effective and shows a hump at a weight ratio of about 1.
  • FIG. 8 has test conditions similar to FIG. la except that lhydroxy-2-naphthoic acid has been used instead of salicylic acid and the abscissa is the weight ratio of ethylenediamine to l-hydroxy-2-naphthoic acid. This composition is quite ineffective.
  • FIG. 9 shows results obtained using 3 grams of cupric oxide, 42.5 grams of water, 6.75 grams of ethylenediamine and 5.0 grams of salicylic acid, the abscissa in this case showing time.
  • the quantity of cupric oxide dissolved rises steeply at first and then becomes almost asymptotic to the horizontal.
  • FIG. 10 shows a test made with 1 gram of cupric oxide per 50 grams of solution in the presence of ethylenediamine and salicylic acid held at a weight ratio of 1.4. The test was carried on for 5 hours at 200 F. and the abscissa shows the percentage of ethylenediamine by weight. It will be noted that the curve rises sharply and uniformly. Experiments indicate that this weight ration is the most effective for combinations of ethylenediamine and salicylic acid.
  • a composition of the character described above in reference to FIG. 10 at 12.5 percent of ethylenediamine by weight was used experimentally at a power station to remove copper oxide from four drain coolers which could not be diassembled for mechanical cleaning and had not been cleaned for over 20 years. Approximately 275 pounds of copper oxide were removed from an area totaling 4,500 square feet.
  • composition of the invention was used and comparative pressure gage charts were' obtained comparing cleaning by a cyanide (in this case potassium cyanide) and by composition 23. The results obtained are very comparable showing that the composition of the invention is effective for this service.
  • Corrosion rates were determined for the various alloys in composition 23. Disc lkinches in diameter and one-sixteenth inch thick with a center hole of one-fourth inch were made. Seven hundred fifty ml. of the composition was used at a temperature of 200 F. and the test was run for I66 hours. The composition was placed in a 1,000 ml. glass reaction kettle equipped with a reflux condenser and a thermometer. The kettle was placed on a constant-temperature bath. Various samples were mounted on a vertical glass rod separated by spacers of polytetrafluoroethylene. Three sets of samples were employed. At the end of the test the samples were removed, immersed in a mild detergent in an ultrasonic bath, then rinsed with water followed by acetone and were dried and weighed. Test results are called A.
  • Corrosion rates of various materials and alloys upon con centration and vaporization of the solvent were also determined using the discs.
  • the temperature of 200 F. was maintained until the samples were dry and then the temperature was raised to 500" F.
  • One disc was placed horizontally in a 100 ml heukri 'llunolvclll was introduced and the assembly was tttnlttlnlttrd m 200" l-' until the evaporation ol'the solvent was complete and then the beaker and sample were placed in an oven at 500 F. until complete removal of the residue had occurred after which the samples were evaluated as below described. Test results are designated as D.
  • a process of dissolving copper oxide by applying thereto an alkaline aqueous solution comprising (1) a polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine, (2) a compound selected from a group consisting of salicylic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, a dihydroxybenzoic acid, 5-5'- mcthylcnedisalieylic acid, 3-hydroxy-2-naphthoie acid, salts thereof with a polyamine selected from said first-mentioned group and salts thereof with ammonium hydroxide, and (3) balance water, the total concentration of the polyamine of the first-mentioned group and the compound of the second-mentioned group being between 0.25 and substantially 100 percent by weight, and the ratio by weight of the polyamine of the first-mentioned group to the compound of the second-mentioned group being between about 0.25 and 6, forming
  • a process of claim 1, in which the concentration of the polyamine of the first-mentioned group plus the compound of the second-mentioned group is between 1 and 50 percent by weight.
  • a process of claim 3, in which the ratio of the weight of the polyamine of the first-mentioned group to the compound of the second-mentioned group is between about 0.50 and 4.
  • a process of dissolving copper oxide by applying thereto an alkaline aqueous solution comprising ethylenediamine plus salicylic acid, the balance being water, in a total concentration of ethylenediamine and salicyclic acid between 0.25 and substantially percent by weight and with a weight ratio of ethylenediamine to salicylic acid of between about 0.25 and 6, forming a water-soluble complex with copper ions.
  • a process of dissolving copper oxide by applying thereto an alkaline aqueous solution comprising ethylenediamine plus salicylic acid, the balance being water, the weight ratio of ethylenediamine to salicylic acid being about 1.4 and the concentration of ethylenediamine plus salicylic acid being between 1 and 50 percent by weight, forming a water-soluble complex with copper ions.
  • a process of dissolving copper oxide which comprises applying thereto a solution of ammonium hydroxide and ethylenediamine salicylate, the balance being water, the quantity of ammonium hydroxide plus ethylenediamine salicylate being between 1 and 50 percent by weight and the concentration of ammonium hydroxide being sufficient to maintain the composition alkaline.
  • a process of dissolving copper oxide which comprises applying thereto a solution of ammonium hydroxide in the presence of a salicylate of a polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine, the balance being water, the total quantity of ammonium hydroxide plus the salicylate of the polyamine being between 0.25 and substantially 100 percent by weight, the quantity of ammonium hydroxide being sufficient to maintain the solution alkaline.
  • a salicylate of a polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine
  • a polyamine selectedfrorn a group consisting of ethylenediamine, diethylenetriamine,
  • An alkaline aqueous solution for dissolving copper oxide which essentially consists of a solution of ethylenediamine and salicylic acid in a concentration range of ethylenediamine plus salicylic acid of between 0.25 and substantially 100 percent by weight, the balance being water, in which the weight ratio of ethylenediamine to salicyclic acid is between about 0.25 and 6, forming a water-soluble complex with copper ions.
  • a composition for dissolving copper oxide essentially consisting of ammonium hydroxide, a salicylate of a polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine, the balance being water, the total concentration of ammonium hydroxide plus the salicylate of the polyamine being between 0.25 and substantially 100 percent by weight, the quantity of ammonium hydroxide being sufficient to maintain the composition alkaline.
  • a composition for dissolving copper oxide which essentially consists of ammonium hydroxide, ethylenediamine salicylate and water, the total concentration of ammonium hydroxide being sufficient to maintain the composition alkaline.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Inorganic Chemistry (AREA)
  • Detergent Compositions (AREA)

Abstract

The present invention relates to dissolving copper oxide, whether cuprous or cupric oxide. A polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine is mixed with a compound selected from a second group consisting of salicyclic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, a dihydroxybenzoic acid, 5-5''-methylenedisalicyclic acid, 3hydroxy-2-naphthoic acid and salts thereof with an aliphatic polyamine of the first class and with ammonium hydroxide in an alkaline water solution or a salicylate of one of these amines can be used with ammonium hydroxide. The composition can be used cold but will preferably be used in a temperature range between 150* F. and the boiling temperature at the particular pressure.

Description

United States Patent 1151 3,637,508 Willsey et al. 1 1 Jan. 25, 1972 541 PROCESS AND COMPOSITION FOR 3,173,876 3/1965 Zobrist ..252/152 DISSOLVING COPPER OXIDE 3,218,351 11/1965 Jolly .252/152 3,248,235 4/1966 Pryor et al. 106/3 Inventors: William B. Willsey, 108 Deerfield Drive, Cherry Hill, NJ. 08034; Daniel J. Brogan, 7111 Penarth Ave., Upper Darby, Pa. 19082 Filed: Mar. 6, 1970 Appl. No.: 17,154
Related US. Application Data [63] Continuationin-part of Ser. No. 601,181, Dec. 12,
1966, abandoned.
[56] References Cited UNITED STATES PATENTS 3,003,970 10/1961 Call ..252/152 Primary Examiner Richard D. Lovering Assistant Examinerlrwin Gluck Att0rneyJackson, Jackson & Chovanes The present invention relates to dissolving copper oxide, whether cuprous or cupric oxide. A polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine is mixed with a compound selected from a second group consisting of salicyclic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, a dihydroxybenzoic acid, 5-5-methylenedisalicyclic acid, 3-hydroxy-2-naphthoic acid and salts thereof with an aliphatic polyamine of the first class and with ammonium hydroxide in an alkaline water solution or a salicylate of one of these amines can be used with ammonium hydroxide. The composition can be used cold but will preferably be used in a temperature range between 150 F. and the boiling temperature at the particular pressure.
ABSTRACT 17 Claims, 12 Drawing Figures CuO S0 LUB LE, gms.
PATENTEU JAN 2 51972 3.637.508 SHEET UlUF 12 CONDITIONS l gm. CuO
06 5hrs TIME 6.75 gms. ETHYLENEDIAMINE Q5 42-5 gms. WATER 3 -4 5 SALICYLIC ACID, gms.
CuO SOLUBLE,gms.
PATENIEDJANZSISYZ 3,637508 SHEET OEUF 12 iZg /a.
CONDITIONS I gm. CuO
42.5 gms. WATER 5hrs. TIME 6.75gms. ETHYLENEDIAMINE I 1 I I I I l l l l I l l I J l I 2 8 I0 I I2 I4 WEIGHT RATIO ETHYLENEDIAMINE TO SALICYLIC ACID 7. ATTORNEYS PATENTEUJM25IQY2 3.637.508
SHEET 614 OF 12 Fig.3.
CONDITIONS 1.0- lgm. CuO
425 gms. WATER 5 hrs. TIME 200 F.
- 6.75 gms. ETHYLENEDIAMINE gms.
CuO SOLUBLE I I I l l I I l l I I l I I I I l 2 4 e 8 l0 l2 l4 WEIGHT RATIO ETHYLENEDIAMINE TO SALICYLIC ACID SODIUM SALT ATTORNEYS PATENTEDJANZSBFZ 3.637.508.
CONDITIONS I gm CuO 0.9- 42.5 gm s. WATER 5hrs.TlME
200 F. 6.75gms. ETHYLENEDIAMINE 0.6 g L 1 30.5- CD 3 .J 0 (00-4;
I l l I l I 1 l l 1 l l l I 2 4 e 8 l0 l2 :4 WEIGHT RATIO ETHYLENEDIAMINE TO ETHYLENEDIAMINE SALICYLATE INV TORS Mai/(4745.114! 5 fimwe/J fira zm MQWQQ ATTORNEYS SHEET 08 0F 12 Z/ gZZ CONDITIONS lgm. CuO 0.9 42.5 gms. WATER 5hrs- TIME 6.75gms. ETHYLENEDIAMINE CuO SOLUBLE, gms. p O a v1 1 1 1 1 1 1 1 1 1 1 1 l 1 1 1 1 2 4 6 8 IO l2 l4 WEIGHT RATIO ETHYLENEDIAMINE TO 3-'HYDROXY2'-NAPHTHO|C ACID ATTORNVEYS CuO SOLUBLE, gms.
PATENTEU Jms If}? 3,637. 508 SHEET 09 0F 12 CONDITIONS lgm. CuO
0.9 425 gms, WATER 5 hrs. TIME 200 F. 6-75 gms. ETHYLENEDIAMINE l I l 1 l l I l 1 1 I 2 4 s 8 IO I2 I4 WEIGHT RATIO ETH YLENEDIAMINE TO I-HYDROXY-ZNAPHTHOIC ACID flarzze/ 670 m PATENYEU JAMES [9?2 SHEET 10 U? 5.0 gms. SALICYLIC ACID E W M m D E N S A T N W E m s &
Ds o
O Q. 2 O 7.
A 5 TIME, HOURS 7; .2
m .25 QED-6m 03 n B O Mai/4am VEly/ RS & may Warns/6794 BY r" V \k g ATTORNEYS CuO SOLUBLE gms.
PATENTEDJmsmz 3,637,508
SHEET 11 0F .2
CONDITIONS LOgm. CuO/50gms. SOLUTION 200F 5 hrs. TIME CONSTANT WEIGHT RATIO gms. ETHYLENEDIAMINE gms, SALICYLIC ACID l I I I l I I J I I I I I I I I 4 6 B IO I2 l4 'ETHYLENEDIAMINE '/o BY WEIGHT 1 VENT xs 14444224: a BY flazwe/Jfirgyaa ATTORNEYS The solution used can be static or circulating although circulation improves the results. The solution can also be used as a foam with a suitable gas as described in Brenner et al. US. Pat. No. 3,037,887, granted June 5, 1962, for Foam Cleaning of Surface and in Carroll et al. US. Pat. No. 3,212,762, granted Oct. 12, 1965 for Pump Generator. if the equipment lends itself to pressure or to reflux condensation, this can be used. The addition of foaming agent permits a sevento thirtyfold increase in volume, so that a large space may be filled with a minimum amount of the solvent.
If corrosion of the underlying copper can be tolerated, such as in preparation for silver plating, the rate of copper oxide dissolution can be accelerated by adding an oxidizing agent such as ammonium persulphate.
The process of the invention can be employed effectively to remove cuprous oxide, but it is even more effective on cupric oxide and as cupric oxide is more frequently encountered, the test results are chiefly directed to removal of cupric oxide.
Wide variations in concentration can be employed but preferably the concentration of combined ethylenediamine or the like and salicylic acid or the like should be between 0.25 and 100 percent by weight, most desirably between 1 and 50 percent by weight, and under normal conditions concentrations of the order of l5 to 30 percent by weight, the balance in any case being a solvent such as water.
The weight ratio of ethylenediamine or the like to salicylic acid or the like should preferably be between about 0.25 and 6, more desirably between 0.50 and 4 and most desirably about 1.4 although if desired greater ratios may be used, with diminishing effectiveness. In other words, it is preferable to have about 3 moles of ethylenediamine to 1 mole of salicylic acid.
For many purposes, the composition of the invention will include ethylenediamine, salicylic acid and water. Instead of ethylenediamine, however, other aliphatic polyamines may be used, examples of such other polyamines being diethylenetriamine, triethylenetetramine and tetraethylenepentamine.
Salicylic acid is of course orthohydroxybenzoic acid. As altematives for salicylic acid, metahydroxybenzoic and parahydroxybenzoic acids may be used.
A dihydroxybenzoic acid can also be employed instead of salicylic acid, an example being 2,4-dihydroxybenzoic acid. A disalicyclic acid may also be employed, an example being 5,5 methylenedisalicylic acid which also is known as 4,4- dihydroxydiphenylmethane-3,3 '-dicarboxylic acid.
3-hydroxy-2-naphthoic acid can be used instead of salicylic acid but on the other hand l-hydroxy-Z-naphthoic acid is not effective, apparently because of the different location of the double bond.
Any one of the acids above referred to can be used in the form of salts with ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine or ammonium hydroxide. Examples are ethylenediamine salicylate, diethylenetriamine salicylate, ammonium salicylate, and the ethylenediamine salt of parahydroxybenzoic acid. As later explained in more detail, however, salts of these acids with metals such as sodium or potassium, of which an example is sodium salicylate, are not effective.
In any one of the cases given above, the particular alternate compound can be used in admixture with the compound for which it is substituting, as for example salicylic acid can be used mixed with parahydroxybenzoic acid.
A salicylate of ethylenediamine or one of the other aliphatic polyamines referred to with sufficient ammonium hydroxide to maintain the combination alkaline is an effective composition for dissolving copper oxide and shows to a substantial extent the unusual properties above referred to.
It will be evident that all of the resultant compositions of the present invention in water solutions are inherently alkaline by virtue of the strongly alkaline character of the polyamines.
Because salicylic acid and the other hydroxy-substituted compounds are strictly organic in nature, their chemical properties are vastly different from the inorganic hydroxyl amine mineral acid salts used in the Call composition previously referred to.
Hydroxylamine-type compounds have pronounced oxidation-reduction properties whereas the oxidation-reduction properties of salicylic acid and the other related compounds disclosed by applicants are negligible. An example of this pronounced oxidation-reduction property of hydroxylamine and its salts is that they will react quite vigorously with ferrous ions. The ferrous ion is oxidized to ferric ion and the reaction is accompanied by an undesired excessive exothermic heat of reaction. lf cupric ions are present, they are reduced to cuprous ions or metallic copper which will plate out on metallic and other surfaces.
Not only does the use of salicylic acid or the related compounds disclosed by applicants in combination with ethylenediamine greatly enhance copper oxide solubility, but none of the previously referred to undesirable reactions will occur when ferrous ions are present.
Since the compositions of this invention essentially do not react with ferrous or ferric ions, the corrosion rate for iron, steel and stainless steel is much lower. Also, since the compositions do not react corrosively with iron, the solution may be prepared in an ordinary steel tank. This contrasts with Calls solvent which must be prepared in a plastic-lined tank because it will react violently with iron oxides that may be present in a steel tank.
The theoretical explanation of the remarkable synergism illustrated by the composition of the invention seems to be due to the fact that the salicylic acid reacts with ethylenediamine or the equivalent and the resulting compound is much more effective in dissolving copper oxide than either of the original components. In some cases at least the reaction appears to involve two molecules of salicylic acid reacting with one molecule of ethylenediamine, although in other cases reaction may be in different molecular proportions.
The copper oxide solubility of the compositions of this invention is due to:
l. The copper forms a water soluble complex with the salicylic acid type compound. The complex formed is illustrated below.
H alkaline /CO aqueous O OH solution Cu++ Cu 1110 2. If p-hydroxybenzoic acid is used, the separation of the positions of the OH and COOl-l' groups are too great for the above complex to be formed and the following reaction occurs:
One gram of reagent grade cupric oxide (wire) was placed in an aqueous solution having a volume of 50 ml. in which the amounts and ration of ethylenediamine and salicylic acid were varied. The solution was held in contact with the cupric oxide at F. for 5 hours. At the end of the experiment any undis- PROCESS AND COMPOSITION FOR DISSOLVING COPPER OXIDE This application is a continuation-in-part of our copending application, Ser. No. 601,181, filed Dec. 12, 1966 and now abandoned for Process and Composition for Dissolving Copper Oxide.
The present invention relates to processes for dissolving copper oxide, whether cuprous or cupric oxide, and compositions therefor.
A purpose of the invention is to remove copper oxide by a composition which is not inherently hazardous and therefore much safer than some of the compositions commonly used for this purpose.
A further purpose is to remove copper oxide without leaving any residue except for a small quantity of soluble copper salt which can be removed by washing with water.
A further purpose is to reduce the cost of the chemicals required.
A further purpose is to reduce the corrosion rate, especially on copper and copper alloys when removing copper oxide.
A further purpose is to employ a composition for removing copper oxide which will not react with iron or iron compounds.
A further purpose is to avoid objectionable gassing which in some cases in the prior art has produced an explosive type of overflowing.
A further purpose is to employ a solution for removing copper oxide which has insignificant exothermic heat of solutron.
A further purpose is to avoid plating or depositing copper by a solution which has removed copper oxide.
A further purpose is to produce a bright passivated metal surface on copper and copper alloys which is resistant to further oxidation.
Further purposes appear in the specification and in the claims.
The drawings show curves useful in explaining the inventron.
Copper may be picked up and carried by water or steam in a steam powerplant and deposited as copper oxide on buckets and nozzles of steam turbines, heat exchangers and condensers. It tends to reduce the efficiency of the equipment and therefore must be removed periodically.
This problem is most serious in supercritical turbines and boilers. Copper oxide is present in a vapor phase in high-pressure areas and tends to deposit at lower pressure locations on parts of the steam turbine.
Copper oxide also is a problem in feed water heaters for boilers.
There is also a need to remove copper oxide more effectively from copper catalysts in oxidation bombs used for testing oil.
Particularly in the electrical industry, these are numerous requirements for cleaning copper or copper alloys, particularly prior to silver plating of contacts.
In the prior art, an effective manner of removing copper oxide is by dissolving it in a solution of hydroxylamine salt plus an aliphatic polyamine such as ethylenediamine in water, according to Call U.S. Pat. No. 3,003,970, granted Oct. 10, 1961, for Cleaning Composition and Method of Its Use. This has been employed extensively in cleaning steam turbines to remove copper oxide deposits.
ln employing the process of the Call patent, the following difficulties have developed:
1. The composition reacts with iron and iron oxide and increases the corrosion rate on steel, brass and other copper alloys, and this is objectionable.
2. The composition of the Call patent when it reacts with iron and iron oxide present, produces violent gassing which may cause it to erupt from a tank or the like with a sort of violent expulsion or explosion.
3. The reaction with iron causes rapid development of exothermic heat causing an objectionable rise in temperature.
4. When iron reacts with the Call composition, the corrosion rate on steel and brass or other copper alloys is greatly increased.
5. When iron reacts with the Call composition, it tends to plate out copper and this is objectionable.
The use of the Call solution and some of its difficulties are discussed by E. B. Morris and R. G. Call, Chemical Cleaning of Turbines for Removal of Copper Oxide Deposits," ASME Publication 64-WA/BFS-l.
Among the other prior art compositions are those of Jolly U.S. Pat. No. 3,218,351 which involves a mixture of salicylic acid and a very viscous water-immiscible high molecular weight resin or fatty acid polyamine, and McCoy U.S. Pat. No. 2,540,003, and Holman U.S. Pat. No. 2,700,654, both of which involve the use of ethylenediamine with fatty acids, fatty acid esters, etc. Zobrist U.S. Pat. No. 3,173,876 shows the use of ethylenediamine with an enhancer such as sodium borate or a sodium phosphate. Fatty acid compositions are expensive and difficult to use as they may leave deposits.
The present invention is concerned with overcoming the difficulties present in the prior art compositions and particularly eliminating the above difficulties referred to in connection with the Call composition.
The composition of the present invention is inherently not hazardous and is safe to use unlike some of the prior art compositions. It does not dissolve iron or iron oxide and does not undergo any gassing or violent reaction with iron or iron oxide. No substantial exothermic temperature rise occurs during use.
The composition of the present invention does not have an increased corrosion rate on steel and brass from presence of iron.
There is no tendency to plate out copper using the solution of the invention.
The composition of the invention can simply be used at low temperature for cleaning or polishing copper or copper alloys, and it is quite effective without the difficulties of the prior art compositions used for these purposes such as conventional bright dips.
The composition of the invention leaves no residue except a small amount of soluble copper salt which can be removed by washing with water.
The composition of the present invention avoids disassembly of equipment.
The process and composition of the invention is less costly than the prior art compositions.
One of the elements in the low cost is not only that the chemicals themselves are inexpensive but also that the synergistic action greatly reduces the quantity of chemicals required. This an an example, to dissolve 0.45 grams of cupric oxide took 6.75 grams of ethylenediamine along, but this same quantity of cupric oxide was dissolved by 1.5 grams of ethylenediamine and 1.0 gram of salicylic acid used together.
One favorable result of the composition of the invention is that it leaves the surface of copper alloys passivated and resistant to further oxidation.
It is believed that the widest use of the invention may be in removing copper oxide from the interiors of closed steam generators and associated equipment such as steam turbines, heat exchangers, and condensers. For this use it is best to employ the solution of the invention at a temperature between F. and the boiling point of the solution at the particular pressure. The reason for this is that the action under these circumstances would be much slower if the solution were used cold.
It will also be decidedly preferable to use the solution thus heated in cleaning copper catalysts in oxidation bombs for testing oils. in many cases, however, for general cleaning and polishing, effective results will be obtained by using the solution cold. One example is the removal of copper oxide from copper and copper alloys prior to silver plating contacts.
The cleaning action in a cold solution can be accelerated by placing the parts on an ultrasonic vibration table in a cleaning bath.
recent cleaning the solvent action was accelerated by forcefully circulating the composition at approximately 100 gallons per minute, whereas the original cleaning comprised a static soaking in the same composition. The increased rate of copper oxide removal is evidently attributable to the forced circulation of the composition. 7
To improve the heat transfer performance of the main steam turbine condenser of a l82-megawatt generating unit, the inside of the tubing (water side) was cleaned by the foaming technique previously mentioned. A Spercent solution of inhibited hydrochloric acid foam at a 13 to 1 foam-to-liquid ratio was passed through the condenser tubes, followed by a water foam, then by a foam solution of composition 23 at a foam-to-liquid ratio of 9 to l. and finally by a water foam. The outside of the tubing (steam side) was sprayed with a 3 percent solution of inhibited hydrochloric acid, followed by a spray of composition 23, and then a water rinse, which left the metal surface in a bright passivated condition, resistant to oxidation. The entire procedure was carried out at a temperature of about 120 F.
Experiments were carried on in cleaning brass washers with this composition in comparison with a conventional bright dip comprising an aqueous solution of 56 percent by weight of concentrated sulfuric acid, 8.8 percent by weight of concentrated nitric acid and 0.2 percent by weight of concentrated hydrochloric acid. Copper plate was also cleaned in the solution and in the bright dip. These comparison were made at room temperature. The solution of the present invention was about equal in effectiveness to that of the bright dip, without the use of the inherently hazardous materials comprising the latter.
Pieces after cleaning with the composition of the present in-' vention and with the bright dip were treated in a mercury strike, were rinsed in water and were then silver plated for half an hour. Visual examination indicated the plating on all of the pieces was of equal quality and on testing by scraping, the adhesion was about equal. The thicknesses of silver plating, as measured with a micrometer, on the brass washers and the copper plate cleaned by the treatment according to the present invention were determined to be satisfactory and about the same as when using the bright dip. The costs of equal volumes of the composition of the present invention and the above bright dip were substantially identical.
The composition of the present invention has the important advantage over conventional bright dips in that it may be used without the necessity for the special precautions required for the safe use of the strong acids comprised in the bright dips. Accordingly, the composition of the present invention may be applied freely with a brush or as a wash or spray to vertical and under surfaces of permanent structures, or wherever else bright dips could not be used because of the hazard.
Mixed with a mild abrasive such as powdered alumina, cream of tartar, precipitated chalk, or powdered magnesium carbonate, together with a conventional thickening agent such as starch, tapioca, gum tragacanth, gum dammar, gum arabic and the like to form a paste, the composition of the invention may be used as a household polish and cleaner for copper and brass. A suitable biocide may be incorporated if desired.
Copper switch parts were cleaned with the solution discussed in connection with FIG. 10 for 5 to l0 minutes at room temperature and at l F. Good results were obtained in all cases but the parts treated at elevated temperatures were shiny and those treated at room temperature had a matte finish.
FIG. 11 plots cupric oxide soluble in grams as ordinate against time as abscissa for various temperatures shown by various curves as follows;
In each case a l-gram sample of cupric oxide was introduced into 50 ml. of composition 23.
It will be evident that the ability to dissolve cupric oxide increases rapidly with temperature so that for example as much cupric oxide can be dissolved by the composition in 1 hour at 21 2 F. as can be dissolved in 6 hours at 175 F.
Comparative tests were made using various amines and various acids or acid salts together, and also in some instances using amines or acid salts along.
In each of these tests, 1 gram of reagent grade cupric oxide was placed in 52 grams of a solution consisting of one or more chemicals as listed plus water as a solvent, and the solution was maintained at 200 F. for 5 hours. After the end of the 5 hour test period, the remaining cupric oxide was washed, dried, and reweighed to determine the amount of cupric oxide dissolved. The following table gives the quantities of reagents used and the test results obtained:
QUANTITY OF CUIRIC OXIDE DISSOLVED BY SOLUTIONS HAVING REAUENTS NO'IEI) Weight Weight percent ol percent. of Solution Compo- Compo- Cupric oxide Number Component A nent A Compooent B nent; B (IISSOlVtd 13. 7 None 45. 0 12. 4 o-Hydroxybenzoic acid 9. 2 .19.9 12. 4 m-Hydroxybenzoic acid U. 2 96. 6 12. 4 p-Hydroxybenzoic acid 9. 2 84. 2 14.1 None 53. 3 12. 8 o-Hydroxybenzoie acid 9. 0 89. 8 12. 8 m-Hydroxybenzoic 301d... 1). 0 8S). 0 12.8 p-Hydroxybenzoic acid- J. 0 85. 6 14.7 None 57.6 13. 4 o-Hycroxybenzolc acid 9. 1 86.0 13. 4 m-Hydroxybenzoie acid... 9.1 85. 4 13. 4 pHydroxybenzoie acid- 0. 1 83. 4 15.0 None 411.1 13. 6 o-Hyc'lroxybenzoic acid 9. 1 85.1 13. 6 m'Hydroxybenzoic aG1d-..--. 9. 1 79.1 13. 6 p-Hydroxybenzoie acid... 9.1 84. 4 12. 4 Sodium salicylate 9. 2 59. 7 12. 4 Ammonium salicylatefl nn 9. 2 U9. 8 12. 4 2,4-dihydroxybenzoie acid-.. J. 2 88. 2 12.4 1 hydroxy-2-maphthoic acid. .1. 2 31.4 12.4 3-hydroxy-2naphthoic acid 9.2 117.9 12. 4 4,4dihydroxydiphenyl- 9. 2
n1ethane 3,3-dicarbpxy11e (535Methylenedisaheyclic ac 12. 4 Ethylenediamine salieylate. $1.2 8G. 3 12.4 .do 14.4 .10 U
solved cupric oxide was recovered, washed and dried and reweighed to determine the amount of cupric oxide which had dissolved. The following table shows the results obtained:
Copper oxide solubility (percent by weight Weight ratio,
(percent EDA/SA by weight) E thyleuediamine (percent by weight) 5 IBmCDGOOHHH bhKlioho $M Samples of reagent grade cuprous oxide were placed in 52 grams (50 ml.) solutions of the following composition at 200 The data will be best understood by reference to the curves. All of the curves plot the number of grams of cupric oxide which is soluble as the ordinate, but they have different abscissae.
FIG. I shows the results obtained in an experiment where 1 gram of cupric oxide was present and the treating solution involved 6.75 grams of ethylenediamine, 42.5 grams of water and various additions of salicylic acid as shown by the abscissa. The experiment was carried on for hours at 200 F., and it will be noted that there is a rapid rise in the quantity of cupric oxide dissolved with additions of salicylic acid up to about 4 grams of salicylic acid.
FIG. la for the same experimental conditions plots as abscissa the weight ratio of ethylenediamine to salicylic acid. It is noted that this rises very rapidly and then descends somewhat less rapidly, but there is a hump in the intermediate range which reaches a peak at about a ratio of 1.3.
FIG. 2 for the same test conditions otherwise employs 2,4- dihydroxybenzoic acid instead of salicylic acid and plots as abscissa the weight ratio of ethylenediamine to 2,4-dihydroxybenzoic acid. It will be noted again that there is a hump in this case at a weight ration of 1.2.
FIG. 3 employs similar test conditions except that the sodium salt of salicylic acid is used and the abscissa is the weight ratio of ethylenediamine to the salicylic acid sodium salt. It will be noted that this is very ineffective and evidently does not have properties similar to the composition of ethylenediamine and salicylic acid.
FIG. 4 plots as abscissa the weight ratio of ethylenediamine to 5,55'-methylenedisalicylic acid. This is very effective and shows a hump at about the weight ratio of 1.2. The other conditions in this test are the same as for FIG. 1.
FIG. 5 for similar test conditions employs ethylenediamine salicylate and ethylenediamine. The abscissa is the weight ration of ethylenediamine to ethylenediamine salicylate and the curve has a peak at about 1.
FIG. 6 is a test performed using a solution having 1 gram of cupric oxide, 42.5 grams of water, and 7.5 grams of sodium hydroxide with various quantities of ethylenediamine salicylate. The test time was 5 hours at 200 F. The abscissa is the weight ratio of sodium hydroxide to ethylenediamine salicylate. It will be noted that this composition is completely ineffective and therefore the good results do not seem to be a matter of alkalinity imparted by ethylenediamine. However, it is necessary that the aqueous compositions of this invention be of alkaline character in order to dissolve the salicylic acid which is essentially insoluble in water which is not alkaline.
Tests made at a temperature of approximately 72 F. on a wide range of total concentrations and weight ratios of salicylic acid in aqueous solutions of ethylenediamine showed complete solubility of the salicylic acid and that the solutions were alkaline. The results of these tests are shown in the following table:
pH of Selected Aqueous Solutions of Ethylenediamine (EDA) and Salicylic triethylenetetramine and tetraethyleneopentamine in place of ethylenediamine, and similarly for their use with salicylic acid or the previously mentioned alternative therefor.
FIG. 7 for test results similar to FIG. la has substituted 3- hydroxy-Z-naphthoic acid for salicylic acid. The abscissa is the weight ratio of ethylenediamine to 3-hydroxy-2-naphthoic acid. This composition is quite effective and shows a hump at a weight ratio of about 1.
FIG. 8 has test conditions similar to FIG. la except that lhydroxy-2-naphthoic acid has been used instead of salicylic acid and the abscissa is the weight ratio of ethylenediamine to l-hydroxy-2-naphthoic acid. This composition is quite ineffective.
FIG. 9 shows results obtained using 3 grams of cupric oxide, 42.5 grams of water, 6.75 grams of ethylenediamine and 5.0 grams of salicylic acid, the abscissa in this case showing time. The quantity of cupric oxide dissolved rises steeply at first and then becomes almost asymptotic to the horizontal.
FIG. 10 shows a test made with 1 gram of cupric oxide per 50 grams of solution in the presence of ethylenediamine and salicylic acid held at a weight ratio of 1.4. The test was carried on for 5 hours at 200 F. and the abscissa shows the percentage of ethylenediamine by weight. It will be noted that the curve rises sharply and uniformly. Experiments indicate that this weight ration is the most effective for combinations of ethylenediamine and salicylic acid.
A composition of the character described above in reference to FIG. 10 at 12.5 percent of ethylenediamine by weight was used experimentally at a power station to remove copper oxide from four drain coolers which could not be diassembled for mechanical cleaning and had not been cleaned for over 20 years. Approximately 275 pounds of copper oxide were removed from an area totaling 4,500 square feet.
About 4 years later two of these four drain coolers were again experimentally cleaned, comprising a preliminary application of approximately 5 percent inhibited hydrochloric acid to remove iron oxides, then a water rinse and finally treatment with the same composition used for the original cleaning. Approximately 350 pounds of copper oxide were removed from an area totaling 2,250 square feet, representing substantial improvement in rate of copper oxide removal. For the more Continued QUANTITY OF CUPRIC OXIDE DISSOLVED BY SOLUTIONS HAVING REAGENTS NOTED Weight Weight percent oi-- Solution peasant of c C A d ompoom ou rie oxi e Number Component A nent A Component B non? B dissolved 110 .d 11.9 o-Hy droxybenz oic acid 13.2 37.0 17 do 11.9 Ethylonediamine selicylate. 1'3. 2 77.0 ..d0 11.9 5,5methylenedisalicyclic 13. 2 18.0
acid.
Experiments were carried on using the composition of the H 0.0000 0.0000 0.0000 0.0000 invention for cleaning a copper catalyst of the type employed 1 in an oxidation bomb for determining Oxidation Stability of 1 Special New Mineral Insulating Oils Containing 2,6-d1-tert1ary-buty1- 1mm"; X 0,0002 0.0001 0.0000 0 paracresol by Rotating Bomb, ASTM specification D21 12-62T, and Continuity of Steam-turbine Oil Oxidation Stability by Rotating Bomb, ASTM specification D2272-64T. H Instead of cleaning the catalyst with sodium cyanide solution as specified in these specifications, the composition of the invention was used and comparative pressure gage charts were' obtained comparing cleaning by a cyanide (in this case potassium cyanide) and by composition 23. The results obtained are very comparable showing that the composition of the invention is effective for this service.
Comparative studies were made on the corrosion of various alloys by composition 23 above referred to. The following table shows the analyses of the materials tested.
\ Stress corrosion tests were made using U-bends of average dimensions 3%inches long, one-fourth inch wide and one-sixteenth inch thick, the other procedure being the same except that the rest was run for 161 hours. The U-bends were mounted horizontally on vertical glass supports, each specimen separated from the adjacent one by a glass separator. Due to space limitations only one sample was run of the carbon steel and Code Nos. A and B. Test results are designated B.
Chro- Molybmium Iron Carbon denum Vanadium Nickel Tung- Alusten minum Niobium Others .I bput'ial 111001101X l Maximunn 2 Ti (approximate).
Corrosion rates were determined for the various alloys in composition 23. Disc lkinches in diameter and one-sixteenth inch thick with a center hole of one-fourth inch were made. Seven hundred fifty ml. of the composition was used at a temperature of 200 F. and the test was run for I66 hours. The composition was placed in a 1,000 ml. glass reaction kettle equipped with a reflux condenser and a thermometer. The kettle was placed on a constant-temperature bath. Various samples were mounted on a vertical glass rod separated by spacers of polytetrafluoroethylene. Three sets of samples were employed. At the end of the test the samples were removed, immersed in a mild detergent in an ultrasonic bath, then rinsed with water followed by acetone and were dried and weighed. Test results are called A.
Stress Corrosion Tests B Crevice galvanic corrosion data was run using discs of linches diameter, one-sixteenth inch thick having a center hole of one-fourth inch and end squares lXl inch, one-sixteenth inch thick with a center hole of onefourth inch. The procedure followed was similar except that that the time of test was 168 hours. Three galvanic couples consisting of a disc and a square specimen were mounted on a vertical glass rod, each couple being separated by a polytetrafluoroethylene spacer. Test results are designated C.
Crevice Galvanic Corrosion Tests C.
Corrosion lhs./ft./day
CODE A (square) 0.0130 C (disc) 0.0187 E (square) 0.0134 J (disc) 0.0137 A151 1035 (square) 0.0418 H (disc) 0.0251
Corrosion rates of various materials and alloys upon con centration and vaporization of the solvent were also determined using the discs. The temperature of 200 F. was maintained until the samples were dry and then the temperature was raised to 500" F. One disc was placed horizontally in a 100 ml heukri 'llunolvclll was introduced and the assembly was tttnlttlnlttrd m 200" l-' until the evaporation ol'the solvent was complete and then the beaker and sample were placed in an oven at 500 F. until complete removal of the residue had occurred after which the samples were evaluated as below described. Test results are designated as D.
Concentration and vaporization Tests D Having thus described our invention what we claim as new and desire to secure by Letters Patent is:
1. A process of dissolving copper oxide, by applying thereto an alkaline aqueous solution comprising (1) a polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine, (2) a compound selected from a group consisting of salicylic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, a dihydroxybenzoic acid, 5-5'- mcthylcnedisalieylic acid, 3-hydroxy-2-naphthoie acid, salts thereof with a polyamine selected from said first-mentioned group and salts thereof with ammonium hydroxide, and (3) balance water, the total concentration of the polyamine of the first-mentioned group and the compound of the second-mentioned group being between 0.25 and substantially 100 percent by weight, and the ratio by weight of the polyamine of the first-mentioned group to the compound of the second-mentioned group being between about 0.25 and 6, forming a water-soluble complex with copper ions.
2. A process of claim 1, in which said ratio by weight of the polyamine of the first-mentioned group to the compound of the second-mentioned group is between 0.50 and 4.
3. A process of claim 1, in which the concentration of the polyamine of the first-mentioned group plus the compound of the second-mentioned group is between 1 and 50 percent by weight.
4. A process of claim 3, in which the ratio of the weight of the polyamine of the first-mentioned group to the compound of the second-mentioned group is between about 0.50 and 4.
5. A process of dissolving copper oxide, by applying thereto an alkaline aqueous solution comprising ethylenediamine plus salicylic acid, the balance being water, in a total concentration of ethylenediamine and salicyclic acid between 0.25 and substantially percent by weight and with a weight ratio of ethylenediamine to salicylic acid of between about 0.25 and 6, forming a water-soluble complex with copper ions.
6. A process of dissolving copper oxide, by applying thereto an alkaline aqueous solution comprising ethylenediamine plus salicylic acid, the balance being water, the weight ratio of ethylenediamine to salicylic acid being about 1.4 and the concentration of ethylenediamine plus salicylic acid being between 1 and 50 percent by weight, forming a water-soluble complex with copper ions.
7. A process of dissolving copper oxide, which comprises applying thereto a solution of ammonium hydroxide and ethylenediamine salicylate, the balance being water, the quantity of ammonium hydroxide plus ethylenediamine salicylate being between 1 and 50 percent by weight and the concentration of ammonium hydroxide being sufficient to maintain the composition alkaline.
ii. A process of dissolving copper oxide, which comprises applying thereto a solution of ammonium hydroxide in the presence of a salicylate of a polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine, the balance being water, the total quantity of ammonium hydroxide plus the salicylate of the polyamine being between 0.25 and substantially 100 percent by weight, the quantity of ammonium hydroxide being sufficient to maintain the solution alkaline.
9. An alkaline aqueous solution for dissolving copper oxide,
which essentially consists of l) a polyamine selectedfrorn a group consisting of ethylenediamine, diethylenetriamine,
triethylenetetramine and tetraethylenepentamine, and (2) a compound selected from a group consisting of salicylic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, a dihydroxy-benzoic acid, 55-methylenedisalicylic acid, 3- hydroxy-Z-naphthoic acid, salts thereof with a polyamine selected from said first-mentioned group and salts thereof with ammonium hydroxide, (3) the balance being water, the total concentration of the polyamine of the first-mentioned group plus the compound of the second-mentioned group being between 0.25 and substantially 100 percent by weight, the weight ratio of the polyamine of the first-mentioned group to the compound of the second-mentioned group being about 0.25 and 6, forming a water-soluble complex with copper ions.
10. An alkaline aqueous solution of claim 9, in which the total concentration of the polyamine of the first-mentioned group and the compound of the second-mentioned group is between 1 and 50 percent by weight.
11. An alkaline aqueous solution of claim 9, in which said weight ratio is between 0.50 and 4.
12. An alkaline aqueous solution for dissolving copper oxide, which essentially consists of a solution of ethylenediamine and salicylic acid in a concentration range of ethylenediamine plus salicylic acid of between 0.25 and substantially 100 percent by weight, the balance being water, in which the weight ratio of ethylenediamine to salicyclic acid is between about 0.25 and 6, forming a water-soluble complex with copper ions.
13. A composition of claim 12, including a mild abrasive and a thickening agent, in the form of a paste for cleaning and polishing brass and copper.
14. A composition of claim 12, in combination with a gaseous foaming agent sufficient to produce a foam having a foamto-liquid ratio in the range of from 7 to l to 30 to 1 15. An alkaline aqueous solution of claim 12, in which said weight ratio is about 1.4.
16. A composition for dissolving copper oxide, essentially consisting of ammonium hydroxide, a salicylate of a polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine, the balance being water, the total concentration of ammonium hydroxide plus the salicylate of the polyamine being between 0.25 and substantially 100 percent by weight, the quantity of ammonium hydroxide being sufficient to maintain the composition alkaline.
17. A composition for dissolving copper oxide, which essentially consists of ammonium hydroxide, ethylenediamine salicylate and water, the total concentration of ammonium hydroxide being sufficient to maintain the composition alkaline.

Claims (16)

  1. 2. A process of claim 1, in which said ratio by weight of the polyamine of the first-mentioned group to the compound of the second-mentioned group is between 0.50 and 4.
  2. 3. A process of claim 1, in which the concentration of the polyamine of the first-mentioned group plus the compound of the second-mentioned group is between 1 and 50 percent by weight.
  3. 4. A process of claim 3, in which the ratio of the weight of the polyamine of the first-mentioned group to the compound of the second-mentioned group is between about 0.50 and 4.
  4. 5. A process of dissolving copper oxide, by applying thereto an alkaline aqueous solution comprising ethylenediamine plus salicylic acid, the balance being water, in a total concentration of ethylenediamine and salicyclic acid between 0.25 and substantially 100 percent by weight and with a weight ratio of ethylenediamine to salicylic acid of between about 0.25 and 6, forming a water-soluble complex with copper ions.
  5. 6. A process of dissolving copper oxide, by applying thereto an alkaline aqueous solution comprising ethylenediamine plus salicylic acid, the balance being water, the weight ratio of ethylenediamine to salicylic acid being about 1.4 and the concentration of ethylenediamine plus salicylic acid being between 1 and 50 percent by weight, forming a water-soluble complex with copper ions.
  6. 7. A process of dissolving copper oxide, which comprises applying thereto a solution of ammonium hydroxide and ethylenediamine salicylate, the balance being water, the quantity of ammonium hydroxide plus ethylenediamine salicylate being between 1 and 50 percent by weight and the concentration of ammonium hydroxide being sufficient to maintain the composition alkaline.
  7. 8. A process of dissolving copper oxide, which comprises applying thereto a solution of ammonium hydroxide in the presence of a salicylate of a polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine, the balance being water, the total quantity of ammonium hydroxide plus the salicylate of the polyamine being between 0.25 and substantially 100 percent by weight, the quantity of ammonium hydroxide being sufficient to maintain the solution alkaline.
  8. 9. An alkaline aqueous solution for dissolving copper oxide, which essentially consists of (1) a polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine, and (2) a compound selected from a group consisting of salicylic acid, metahydroxybenzoic acid, parahydroxybenzoic acid, a dihydroxy-benzoic acid, 5-5''-methylenedisalicylic acid, 3-hydroxy-2-naphthoic acid, salts thereof with a polyamine selected from said first-mentioned group and salts thereof with ammonium hydroxide, (3) the balance being water, the total concentration of the polyamine of the first-mentioned group plus the compound of the second-mentioned group being between 0.25 and substantially 100 percent by weight, the weight ratio of the polyamine of the first-mentioned group to the compound of the second-mentioned group being about 0.25 and 6, forming a water-soluble complex with copper ions.
  9. 10. An alkaline aqueous solution of claim 9, in which the total concentration of the polyamine of the first-mentioned group and the compound of the second-mentioned group is between 1 and 50 percent by weight.
  10. 11. An alkaline aqueous solution of claim 9, in which said weight ratio is between 0.50 and 4.
  11. 12. An alkaline aqueous solution for dissolving copper oxide, which essentially consists of a solution of ethylenediamine and salicylic acid in a concentration range of ethylenediamine plus salicylic acid of between 0.25 and substantially 100 percent by weight, the balance being water, in which the weight ratio of ethylenediamine to salicyclic acid is between about 0.25 and 6, forming a water-soluble complex with copper ions.
  12. 13. A composition of claim 12, including a mild abrasive and a thickening agent, in the form of a paste for cleaning and polishing brass and copper.
  13. 14. A composition of claim 12, in combination with a gaseous foaming agent sufficient to produce a foam having a foam-to-liquid ratio in the range of from 7 to 1 to 30 to 1.
  14. 15. An alkaline aqueous solution of claim 12, in which said weight ratio is about 1.4.
  15. 16. A composition for dissolving copper oxide, essentially consisting of ammonium hydroxide, a salicylate of a polyamine selected from a group consisting of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine, the balance being water, the total concentration of ammonium hydroxide plus the salicylate of the polyamine being between 0.25 and substantially 100 percent by weight, the quantity of ammonium hydroxide being sufficient to maintain the composition alkaline.
  16. 17. A composition for dissolving copper oxide, which essentially consists of ammonium hydroxide, ethylenediamine salicylate and water, the total concentration of ammonium hydroxide plus ethylenediamine salicylate being between 0.25 and substantially 100 percent, the quantity of ammonium hydroxide being sufficient to maintain the composition alkaline.
US17154A 1970-03-06 1970-03-06 Process and composition for dissolving copper oxide Expired - Lifetime US3637508A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US1715470A 1970-03-06 1970-03-06

Publications (1)

Publication Number Publication Date
US3637508A true US3637508A (en) 1972-01-25

Family

ID=21781020

Family Applications (1)

Application Number Title Priority Date Filing Date
US17154A Expired - Lifetime US3637508A (en) 1970-03-06 1970-03-06 Process and composition for dissolving copper oxide

Country Status (1)

Country Link
US (1) US3637508A (en)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4093557A (en) * 1976-09-16 1978-06-06 Hercules Incorporated Process for inhibiting corrosion of metals in aqueous systems
US4431457A (en) * 1982-06-29 1984-02-14 Phillips Petroleum Company Process for cleaning metal surfaces of poly(arylene sulfide) deposits
US6627546B2 (en) * 2001-06-29 2003-09-30 Ashland Inc. Process for removing contaminant from a surface and composition useful therefor
US20100065616A1 (en) * 2008-09-15 2010-03-18 Lockheed Martin Corporation Lead solder-free electronics
US20110127464A1 (en) * 2009-11-30 2011-06-02 Lockheed Martin Corporation Nanoparticle composition and methods of making the same
US20110215279A1 (en) * 2010-03-04 2011-09-08 Lockheed Martin Corporation Compositions containing tin nanoparticles and methods for use thereof
US8828979B2 (en) 2012-03-27 2014-09-09 Essential Ingredients, Inc. Salicylic acid gel
US9005483B2 (en) 2012-02-10 2015-04-14 Lockheed Martin Corporation Nanoparticle paste formulations and methods for production and use thereof
US9072185B2 (en) 2009-07-30 2015-06-30 Lockheed Martin Corporation Copper nanoparticle application processes for low temperature printable, flexible/conformal electronics and antennas
US9095898B2 (en) 2008-09-15 2015-08-04 Lockheed Martin Corporation Stabilized metal nanoparticles and methods for production thereof
US9666750B2 (en) 2012-02-10 2017-05-30 Lockheed Martin Corporation Photovoltaic cells having electrical contacts formed from metal nanoparticles and methods for production thereof
US9797032B2 (en) 2009-07-30 2017-10-24 Lockheed Martin Corporation Articles containing copper nanoparticles and methods for production and use thereof
WO2019046245A1 (en) * 2017-09-01 2019-03-07 Koppers Performance Chemicals Inc. Method of preparing copper-containing wood preserving compositions
US10544483B2 (en) 2010-03-04 2020-01-28 Lockheed Martin Corporation Scalable processes for forming tin nanoparticles, compositions containing tin nanoparticles, and applications utilizing same

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3003970A (en) * 1960-05-23 1961-10-10 Dow Chemical Co Cleaning composition and a method of its use
US3173876A (en) * 1960-05-27 1965-03-16 John C Zobrist Cleaning methods and compositions
US3218351A (en) * 1956-11-15 1965-11-16 Sun Oil Co N-naphthenyl polyamine salts
US3248235A (en) * 1961-09-28 1966-04-26 Minnesota Mining & Mfg Anti-tarnish composition for coppercontaining surfaces

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3218351A (en) * 1956-11-15 1965-11-16 Sun Oil Co N-naphthenyl polyamine salts
US3003970A (en) * 1960-05-23 1961-10-10 Dow Chemical Co Cleaning composition and a method of its use
US3173876A (en) * 1960-05-27 1965-03-16 John C Zobrist Cleaning methods and compositions
US3248235A (en) * 1961-09-28 1966-04-26 Minnesota Mining & Mfg Anti-tarnish composition for coppercontaining surfaces

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4093557A (en) * 1976-09-16 1978-06-06 Hercules Incorporated Process for inhibiting corrosion of metals in aqueous systems
US4431457A (en) * 1982-06-29 1984-02-14 Phillips Petroleum Company Process for cleaning metal surfaces of poly(arylene sulfide) deposits
US6627546B2 (en) * 2001-06-29 2003-09-30 Ashland Inc. Process for removing contaminant from a surface and composition useful therefor
US8105414B2 (en) 2008-09-15 2012-01-31 Lockheed Martin Corporation Lead solder-free electronics
US20100065616A1 (en) * 2008-09-15 2010-03-18 Lockheed Martin Corporation Lead solder-free electronics
EP2906027A1 (en) 2008-09-15 2015-08-12 Lockheed Martin Corporation Lead solder-free electronics
US8663548B2 (en) 2008-09-15 2014-03-04 Lockheed Martin Corporation Metal nanoparticles and methods for producing and using same
US9095898B2 (en) 2008-09-15 2015-08-04 Lockheed Martin Corporation Stabilized metal nanoparticles and methods for production thereof
US10701804B2 (en) 2009-07-30 2020-06-30 Kuprion Inc. Copper nanoparticle application processes for low temperature printable, flexible/conformal electronics and antennas
US9797032B2 (en) 2009-07-30 2017-10-24 Lockheed Martin Corporation Articles containing copper nanoparticles and methods for production and use thereof
US9072185B2 (en) 2009-07-30 2015-06-30 Lockheed Martin Corporation Copper nanoparticle application processes for low temperature printable, flexible/conformal electronics and antennas
US20110127464A1 (en) * 2009-11-30 2011-06-02 Lockheed Martin Corporation Nanoparticle composition and methods of making the same
US8486305B2 (en) 2009-11-30 2013-07-16 Lockheed Martin Corporation Nanoparticle composition and methods of making the same
US9378861B2 (en) 2009-11-30 2016-06-28 Lockheed Martin Corporation Nanoparticle composition and methods of making the same
US20110215279A1 (en) * 2010-03-04 2011-09-08 Lockheed Martin Corporation Compositions containing tin nanoparticles and methods for use thereof
US8834747B2 (en) 2010-03-04 2014-09-16 Lockheed Martin Corporation Compositions containing tin nanoparticles and methods for use thereof
US10544483B2 (en) 2010-03-04 2020-01-28 Lockheed Martin Corporation Scalable processes for forming tin nanoparticles, compositions containing tin nanoparticles, and applications utilizing same
US9005483B2 (en) 2012-02-10 2015-04-14 Lockheed Martin Corporation Nanoparticle paste formulations and methods for production and use thereof
US9666750B2 (en) 2012-02-10 2017-05-30 Lockheed Martin Corporation Photovoltaic cells having electrical contacts formed from metal nanoparticles and methods for production thereof
US8828979B2 (en) 2012-03-27 2014-09-09 Essential Ingredients, Inc. Salicylic acid gel
WO2019046245A1 (en) * 2017-09-01 2019-03-07 Koppers Performance Chemicals Inc. Method of preparing copper-containing wood preserving compositions
US11102980B2 (en) 2017-09-01 2021-08-31 Koppers Performance Chemicals Inc. Method of preparing copper-containing wood preserving compositions

Similar Documents

Publication Publication Date Title
US3637508A (en) Process and composition for dissolving copper oxide
US3438811A (en) Removal of copper containing incrustations from ferrous surfaces
US3308065A (en) Scale removal, ferrous metal passivation and compositions therefor
EP0086245B1 (en) Aqueous acid metal cleaning composition and method of use
US5591381A (en) Corrosion inhibiting compositions and methods
US3003970A (en) Cleaning composition and a method of its use
US2846440A (en) Composition for and method of inhibiting corrosion of metals
US3989636A (en) Polymeric composition with chelating properties
JPS616287A (en) Chemically acid cleaning bath for heat resistant alloy product
US3072515A (en) Method and composition for chemically polishing metals
US5529637A (en) Formic-carboxylic acid mixtures for removing iron oxide sclae from steel surfaces
US3506576A (en) Metal cleaning solution of chelating agent and water-soluble sulfide
US3962122A (en) Polyamide corrosion inhibitor
US3507795A (en) Composition for removal of copper and copper oxide scales from boilers
US4670186A (en) Acid inhibitor composition
US4111830A (en) Method of inhibiting corrosion
US5009714A (en) Process for removing copper and copper oxide deposits from surfaces
US4636327A (en) Aqueous acid composition and method of use
EP0239770A1 (en) Adducts of propargyl alcohol and their use as corrosion inhibitors in acidizing systems
US3907699A (en) Composition and process for the removal of copper during acid cleaning of ferrous alloys
US3095862A (en) Scale removal
Keera Inhibition of corrosion of carbon steel in acid solutions by tetratriethanolamine trioleiate
US2951039A (en) Penetrant composition
US3585142A (en) Method of removing copper-containing incrustations from ferrous metal surfaces using an aqueous acid solution of aminoalkyl thiourea
JPS5853072B2 (en) metal corrosion inhibitor