CA2073658A1 - Dispersion of iron (iii) oxides using certain dihydroxyaromatic compounds - Google Patents
Dispersion of iron (iii) oxides using certain dihydroxyaromatic compoundsInfo
- Publication number
- CA2073658A1 CA2073658A1 CA002073658A CA2073658A CA2073658A1 CA 2073658 A1 CA2073658 A1 CA 2073658A1 CA 002073658 A CA002073658 A CA 002073658A CA 2073658 A CA2073658 A CA 2073658A CA 2073658 A1 CA2073658 A1 CA 2073658A1
- Authority
- CA
- Canada
- Prior art keywords
- iron
- iii
- ppm
- oxide
- process according
- 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.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
- C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
- C02F5/10—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
- C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
- C02F5/10—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances
- C02F5/12—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing nitrogen
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Organic Chemistry (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method for treating an aqueous system which contains solid particles of iron (III) oxide is disclosed which comprises adding to the system catechol, hydroquinone, their water soluble salts, and mixtures thereof in an amount effective to disperse or suspend iron (III) oxide particles. The aqueous system should have a pH greater than 7 and have low to moderate hardness.
A method for treating an aqueous system which contains solid particles of iron (III) oxide is disclosed which comprises adding to the system catechol, hydroquinone, their water soluble salts, and mixtures thereof in an amount effective to disperse or suspend iron (III) oxide particles. The aqueous system should have a pH greater than 7 and have low to moderate hardness.
Description
2~73~58 Field of the Invention This invention relates to a process of dispersing iron oxides in aq~eous systems using certain dihydroxyaromatic compounds, and more specifically to a method of treating an aqueous system with catechol, hydroquinone, their water soluble salts, or mixtures thereof.
Backqround of the Invention It is known in the prior art that aqueous systems, particularly industrial aqueous systems such as boiler systems, heat exchangers, cooling towers, desalinization equipment, etc., are subject to the accumulation and deposition of solid particles on the internal surfaces of the equipment and pipes. Such deposits are undesirable since they greatly retard the transfer of heat by limiting or reducing the circulation of water and by insulating the surface of the equipment which the circulating water is intended to cool. In addition, serious corrosion may occur on the equipment surfaces below such deposits.
Among the various undesirable deposits that may form and accumulate in aqueous systems are deposits of insoluble iron compounds that are derived from soluble iron which is present in the system. The deposition of iron oxide is of particular concern in today's boiler water treatment programs. It is believed that much of the iron oxide precipitates are comprised of erric oxide and f~rric hydroxide, wherein the ixon is in its oxidation state of three. For purposes of this invention, iron oxide precipitates are hereinafter referred to as iron (III) oxide.
The control or elimination of iron (III) oxide deposits is commonly effected by the addition of 2~73658 -chelants, or chelant/polymer treatments. However, chelants are known to be corrosive, and the excess overfeed of chelants has been known to dissolve and remove large quantities of iron oxides. This is undesirable since the chelant does not distinguish between the objectionable iron oxide deposits and the protective Pilm of magnetite (Fe3O4 - the oxide formed under boiler conditions).
Both catechol and hydroquinone are commercially available materials which have heretofore been used in boiler systems as oxygen scavengers. It was surprising and unexpected that these compounds would also provide effective iron (III) oxide dispersing abilities in aqueous systems, particularly since other dihydroxy-benzene compounds, such as for example, resorcinol, werenot effective at all in dispersing iron (III3 oxide.
Summary of the Invention It is an object of this invention to provide a novel iron (III) oxide dispersing agent.
It is another object of this invention to provide a process for dispersing or suspending solid particles of iron (III) oxide in aqueous systems.
In accordance with the present invention, there have ~5 been provided certain novel iron (III) oxide dispersing agents comprising dihydroxy benzenes selected from the group consisting of catechol, hydroquinone, their water soluble salts, and mixtures thereof~
These and other objects will be apparent from the remaining specification and the appended claims.
Detailed DescriPtion The present invention is directed to the process of using certain dihydroxyaromatic chemicals in aqueous 2~73~8 systems to disperse or suspend solid particles o~ iron (I~I) oxide. It has now been found that the use of catechol, hydroquinone, their water soluble salts and mixtures thereof is very effective in preventing deposition and/or reducing the tendPncy of iron compounds to deposit on the surfaces of aqueous systems. The use of the dispersing agents of this invention has been found to be most advantageous in aqueous systems wherein the pH
of the water is greater than 7, preferably in the xange 8-10, and wherein the hardness of the water is characterized as low to moderate.
Both the catechol and the hydroquinone are generally used in their protonated form. However, it is also possible to use them in the form of a water soluble salt, particularly salts of an alkali metal such as sodium or potassium, as well as ammonium or lower amine salts, although the use of zinc, molybdate or other salts is not excluded.
The dihydroxybenzene compounds of the present invention may be used in various aqueous systems which include, but are not limited to, recirculating water systems such as boiler systems, heat exchangers, cooling towers, desalinization equipment, and the like. In as much as these compounds are stable at high temperatures and pressures, the use of these compounds as iron (III) oxide dispersants is particularly advantageous in high temperature boiler systems. In general, the dispersing agents of this invention should be present in the aqueous system in a concentration between 1 and 100 ppm, preferably between 2 and 50 ppm.
The iron III oxide dispersing agents of this invention may be used in combination with other known water treatment additives which include, but are not limited to, scale inhibitors such as phosphates, 2~736~
phosphonates and the like, corrosion inhibitors, biocides, other iron dispersing agents, oxygen scavengers, neutralizing amines and filming amines, pH
regulating agents, chelants, and mixtures thereof, as will be known by those skilled in the art.
The iron (III) oxide dispersants of this invention may be added to the aqueous system by any of the conventional means such as, for example by conventional bypass feeder using briquettes containing the dispersant, by adding the dispersant either separately or together with the above-described water treatment additives to the water, or it can be fed as a pre-diluted aqueous feed solution containing the treatment components. Without further elaboration, it is believed that one skilled in the art, using the preceding detailed description can utilize the present invention to its fullest extent.
The following examples are provided to illustrate the invention in accordance with the principles of this invention, but are not to be construed as limiting the invention in any way except as indicated in the appended claims. All parts and percentages are by weight unless otherwise indicated.
Example 1 An aqueous solution was prepared containin~ 99 ppm CaSO~, 13 ppm CaCl2, 55 ppm MgS04 and 176 ppm NaHCO3. The pH of the solution was adjusted to 8.1 with an aqueous sodium hydroxide solution. To this solution was added 50 ppm catechol and 1000 ppm iron (III) oxide powder having a particle size range between 1 and 10 microns. This mixture was stirred continuously for 17 hours at 54C and then allowed to settle, undisturbed for 60 minutes. A
sample was then removed at a 50% depth and was analyzed, after acidification with HCl, by atomic absorption. The 20~3658 ~6--concentration of suspended iron in the sample was 270 ppm.
Example ?
The procedure according to Example 1 was repeated except that no catechol was added to the aqueous mixture.
The amount oP suspended iron in the sample was less than ~0 ppm.
Example 3 The procedure according to Example 1 was repeated except that 50 ppm of hydroquinone was substituted in place of the catechol. The amount of suspended iron in the sample was 410 ppm.
1~
Backqround of the Invention It is known in the prior art that aqueous systems, particularly industrial aqueous systems such as boiler systems, heat exchangers, cooling towers, desalinization equipment, etc., are subject to the accumulation and deposition of solid particles on the internal surfaces of the equipment and pipes. Such deposits are undesirable since they greatly retard the transfer of heat by limiting or reducing the circulation of water and by insulating the surface of the equipment which the circulating water is intended to cool. In addition, serious corrosion may occur on the equipment surfaces below such deposits.
Among the various undesirable deposits that may form and accumulate in aqueous systems are deposits of insoluble iron compounds that are derived from soluble iron which is present in the system. The deposition of iron oxide is of particular concern in today's boiler water treatment programs. It is believed that much of the iron oxide precipitates are comprised of erric oxide and f~rric hydroxide, wherein the ixon is in its oxidation state of three. For purposes of this invention, iron oxide precipitates are hereinafter referred to as iron (III) oxide.
The control or elimination of iron (III) oxide deposits is commonly effected by the addition of 2~73658 -chelants, or chelant/polymer treatments. However, chelants are known to be corrosive, and the excess overfeed of chelants has been known to dissolve and remove large quantities of iron oxides. This is undesirable since the chelant does not distinguish between the objectionable iron oxide deposits and the protective Pilm of magnetite (Fe3O4 - the oxide formed under boiler conditions).
Both catechol and hydroquinone are commercially available materials which have heretofore been used in boiler systems as oxygen scavengers. It was surprising and unexpected that these compounds would also provide effective iron (III) oxide dispersing abilities in aqueous systems, particularly since other dihydroxy-benzene compounds, such as for example, resorcinol, werenot effective at all in dispersing iron (III3 oxide.
Summary of the Invention It is an object of this invention to provide a novel iron (III) oxide dispersing agent.
It is another object of this invention to provide a process for dispersing or suspending solid particles of iron (III) oxide in aqueous systems.
In accordance with the present invention, there have ~5 been provided certain novel iron (III) oxide dispersing agents comprising dihydroxy benzenes selected from the group consisting of catechol, hydroquinone, their water soluble salts, and mixtures thereof~
These and other objects will be apparent from the remaining specification and the appended claims.
Detailed DescriPtion The present invention is directed to the process of using certain dihydroxyaromatic chemicals in aqueous 2~73~8 systems to disperse or suspend solid particles o~ iron (I~I) oxide. It has now been found that the use of catechol, hydroquinone, their water soluble salts and mixtures thereof is very effective in preventing deposition and/or reducing the tendPncy of iron compounds to deposit on the surfaces of aqueous systems. The use of the dispersing agents of this invention has been found to be most advantageous in aqueous systems wherein the pH
of the water is greater than 7, preferably in the xange 8-10, and wherein the hardness of the water is characterized as low to moderate.
Both the catechol and the hydroquinone are generally used in their protonated form. However, it is also possible to use them in the form of a water soluble salt, particularly salts of an alkali metal such as sodium or potassium, as well as ammonium or lower amine salts, although the use of zinc, molybdate or other salts is not excluded.
The dihydroxybenzene compounds of the present invention may be used in various aqueous systems which include, but are not limited to, recirculating water systems such as boiler systems, heat exchangers, cooling towers, desalinization equipment, and the like. In as much as these compounds are stable at high temperatures and pressures, the use of these compounds as iron (III) oxide dispersants is particularly advantageous in high temperature boiler systems. In general, the dispersing agents of this invention should be present in the aqueous system in a concentration between 1 and 100 ppm, preferably between 2 and 50 ppm.
The iron III oxide dispersing agents of this invention may be used in combination with other known water treatment additives which include, but are not limited to, scale inhibitors such as phosphates, 2~736~
phosphonates and the like, corrosion inhibitors, biocides, other iron dispersing agents, oxygen scavengers, neutralizing amines and filming amines, pH
regulating agents, chelants, and mixtures thereof, as will be known by those skilled in the art.
The iron (III) oxide dispersants of this invention may be added to the aqueous system by any of the conventional means such as, for example by conventional bypass feeder using briquettes containing the dispersant, by adding the dispersant either separately or together with the above-described water treatment additives to the water, or it can be fed as a pre-diluted aqueous feed solution containing the treatment components. Without further elaboration, it is believed that one skilled in the art, using the preceding detailed description can utilize the present invention to its fullest extent.
The following examples are provided to illustrate the invention in accordance with the principles of this invention, but are not to be construed as limiting the invention in any way except as indicated in the appended claims. All parts and percentages are by weight unless otherwise indicated.
Example 1 An aqueous solution was prepared containin~ 99 ppm CaSO~, 13 ppm CaCl2, 55 ppm MgS04 and 176 ppm NaHCO3. The pH of the solution was adjusted to 8.1 with an aqueous sodium hydroxide solution. To this solution was added 50 ppm catechol and 1000 ppm iron (III) oxide powder having a particle size range between 1 and 10 microns. This mixture was stirred continuously for 17 hours at 54C and then allowed to settle, undisturbed for 60 minutes. A
sample was then removed at a 50% depth and was analyzed, after acidification with HCl, by atomic absorption. The 20~3658 ~6--concentration of suspended iron in the sample was 270 ppm.
Example ?
The procedure according to Example 1 was repeated except that no catechol was added to the aqueous mixture.
The amount oP suspended iron in the sample was less than ~0 ppm.
Example 3 The procedure according to Example 1 was repeated except that 50 ppm of hydroquinone was substituted in place of the catechol. The amount of suspended iron in the sample was 410 ppm.
1~
Claims (6)
1. A process for dispersing or suspending solid particles of iron (III) oxide in an aqueous system having a pH greater than 7 comprising adding o the system a dispersing agent selected from the group consisting of catechol, hydroquinone, their water soluble salts, and mixtures thereof, in an amount effective to disperse or suspend the iron (III) oxide particles.
2. A process according to Claim 1 wherein the dispersing agent is added at a concentration of from 1 ppm to 100 ppm.
3. A process according to Claim 1 wherein the dispersing agent is added at a concentration of from 2 ppm to 50 ppm.
4. A process according to Claim 1 wherein the pH
of the system is between 8 and 10.
of the system is between 8 and 10.
5. A process according to Claim 1 wherein the hardness of the aqueous system is low to moderate.
6. A process according to Claim 1 wherein the dispersing agent is used in combination with a water treatment additive selected from the group consisting of scale inhibitors, corrosion inhibitors, biocides, oxygen scavengers, neutralizing amines, filming amines, pH
regulating agents, chelants, and mixtures thereof.
regulating agents, chelants, and mixtures thereof.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/773,831 US5223146A (en) | 1991-10-09 | 1991-10-09 | Dispersion of iron (III) oxides using certain dihydroxaromatic compounds |
| US773,831 | 1991-10-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2073658A1 true CA2073658A1 (en) | 1993-04-10 |
Family
ID=25099449
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002073658A Abandoned CA2073658A1 (en) | 1991-10-09 | 1992-07-10 | Dispersion of iron (iii) oxides using certain dihydroxyaromatic compounds |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US5223146A (en) |
| AU (1) | AU644969B2 (en) |
| CA (1) | CA2073658A1 (en) |
| ZA (1) | ZA925047B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2303848B (en) * | 1992-08-17 | 1997-04-16 | Grace W R & Co | Inhibition of oxygen corrosion in aqueous systems |
| US5698250A (en) | 1996-04-03 | 1997-12-16 | Tenneco Packaging Inc. | Modifield atmosphere package for cut of raw meat |
| US6395195B1 (en) | 1996-08-08 | 2002-05-28 | Pactiv Corporation | Oxygen scavenger accelerator |
| US5928560A (en) | 1996-08-08 | 1999-07-27 | Tenneco Packaging Inc. | Oxygen scavenger accelerator |
| US6054153A (en) | 1998-04-03 | 2000-04-25 | Tenneco Packaging Inc. | Modified atmosphere package with accelerated reduction of oxygen level in meat compartment |
| US6231905B1 (en) | 1998-10-08 | 2001-05-15 | Delduca Gary R. | System and method of making a modified atmosphere package comprising an activated oxygen scavenger for packaging meat |
| CA2368445C (en) | 1999-03-26 | 2008-02-12 | Calgon Corporation | Rust and scale removal composition and process |
| US6321509B1 (en) | 1999-06-11 | 2001-11-27 | Pactiv Corporation | Method and apparatus for inserting an oxygen scavenger into a modified atmosphere package |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2396938A (en) * | 1944-01-22 | 1946-03-19 | Martin Dennis Company | Method of treating boilers |
| US3898037A (en) * | 1972-06-01 | 1975-08-05 | Betz Laboratories | Acrylamido-sulfonic acid polymers and their use |
| FR2297814A1 (en) * | 1975-01-20 | 1976-08-13 | Ugine Kuhlmann | METHOD FOR THE SEQUESTRATION OF OXYGEN DISSOLVED IN WATER AND COMPOSITIONS USED FOR THIS PURPOSE |
| US4278635A (en) * | 1979-10-12 | 1981-07-14 | Chemed Corporation | Method for deoxygenation of water |
| US4728497A (en) * | 1980-12-15 | 1988-03-01 | Betz Laboratories, Inc. | Use of aminophenol compounds as oxygen scavengers in an aqueous medium |
| JPS5881494A (en) * | 1981-11-11 | 1983-05-16 | Toagosei Chem Ind Co Ltd | Composition for water purifying agent |
| FR2522522A1 (en) * | 1982-01-27 | 1983-09-09 | Leuna Werke Veb | PROCESS FOR IMPROVING THE INITIAL ACTIVITY OF ACTIVATED HYDRAZINE |
| JPS58133382A (en) * | 1982-02-03 | 1983-08-09 | Katayama Chem Works Co Ltd | Corrosion inhibitor for calcium chloride brine |
| CA1210930A (en) * | 1984-04-18 | 1986-09-09 | Harvey W. Thompson | Composition and method for deoxygenation |
| US4687592A (en) * | 1985-02-19 | 1987-08-18 | The Procter & Gamble Company | Detergency builder system |
| GB8606065D0 (en) * | 1986-03-12 | 1986-04-16 | Ici Plc | Corrosion inhibition |
| US4762621A (en) * | 1986-11-13 | 1988-08-09 | The B. F. Goodrich Company | Itaconate ester copolymers as scale inhibitors |
| US4734203A (en) * | 1987-03-03 | 1988-03-29 | Nalco Chemical Company | Copper chelants/dispersants and their applications for boiler internal treatment |
| US5094814A (en) * | 1990-06-15 | 1992-03-10 | Nalco Chemical Company | All-volatile multi-functional oxygen and carbon dioxide corrosion control treatment for steam systems |
-
1991
- 1991-10-09 US US07/773,831 patent/US5223146A/en not_active Expired - Fee Related
-
1992
- 1992-07-01 AU AU19333/92A patent/AU644969B2/en not_active Ceased
- 1992-07-07 ZA ZA925047A patent/ZA925047B/en unknown
- 1992-07-10 CA CA002073658A patent/CA2073658A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| ZA925047B (en) | 1993-04-13 |
| US5223146A (en) | 1993-06-29 |
| AU644969B2 (en) | 1993-12-23 |
| AU1933392A (en) | 1993-04-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |