Solid Molded Sulfite-Based Oxygen Scavenger Composition and Method of Manufacutre

Abstract

A thermally stable, solid sulfite-based treatment composition for treating water systems, particularly heated water systems, to reduce corrosion. A treatment composition comprises (1) a sulfite salt that may provide at least 50% weight active sulfite and (2) a second inorganic salt hydrate that may have a melting point of 45? C. or higher. The treatment composition does not physically degrade or experience melting when stored at temperatures of 35? C.-40? C. The treatment composition is made by mixing water and a sulfite salt at an elevated temperature, then adding a second inorganic salt while maintaining the elevated temperature until a homogenous mixture is formed, then pouring the mixture in a mold and allowing it to cure at room temperature. A preferred sulfite salt is sodium metabisulfite. A preferred second inorganic salt is dipotassium phosphate.

Claims

1. A solid sulfite-based composition comprising: a first inorganic salt; and a hydrate of a second inorganic salt; wherein the first inorganic salt is a sulfite; and wherein the solid sulfite-based composition is thermally stable at temperatures between 35? C.-40? C.

2. The solid sulfite-based composition according to claim 1 wherein the solid sulfite-based composition comprises at least 50% active sulfite as SO.sub.3 by weight.

3. The solid sulfite-based composition according to claim 1 wherein the second inorganic salt is a phosphate.

4. The solid sulfite-based composition according to claim 3 wherein the phosphate is dipotassium phosphate.

5. The solid sulfite-based composition according to claim 4 wherein the hydrate of the second inorganic salt is dipotassium heptahydrate.

6. The solid sulfite-based composition according to claim 1 wherein the sulfite is sodium metabisulfite.

7. The solid sulfite-based composition according to claim 1 wherein the hydrate has a melting point of at least 40? C.

8. The solid sulfite-based composition according to claim 1 wherein the hydrate has a melting point of at least 48? C.

9. The solid sulfite-based composition according to claim 1 further comprising a catalyst or a decharacterization additive or both.

10. The solid sulfite-based composition according to claim 9 wherein the catalyst comprises sodium erythorbate or cobalt sulfate heptahydrate or both; and wherein the decharacterization additive comprises a lignosulfonate.

11. The solid sulfite-based composition according to claim 10 wherein the lignosulfonate comprises sodium lignosulfonate.

12. The solid sulfite-based composition according to claim 1 wherein the solid sulfite-based composition is in a molded form and maintains the molded form at temperatures between 35? C.-40? C. for at least 5 days.

13. A sulfite-based composition for treating heated water systems to reduce corrosion, the sulfite-based composition comprising the following ingredients: 60 to 80% by weight of a first inorganic salt; 5 to 30% by weight of a second inorganic salt; and 10 to 30% by weight of deionized water; wherein the first inorganic salt is a sulfite; and wherein the second inorganic salt is capable of forming a hydrate having a melting point of at least 40? C.

14. The sulfite-based composition according to claim 13 wherein the sulfite-based composition comprises at least 50% active sulfite (as SO3) by weight.

15. The sulfite-based composition according to claim 13 wherein the second inorganic salt is dipotassium phosphate and wherein the hydrate has a melting point of at least 48? C.

16. The sulfite-based composition according to claim 15 wherein the sulfite is sodium metabisulfite.

17. The sulfite-based composition according to claim 13 further comprising a catalyst or a decharacterization additive or both.

18. The sulfite-based composition according to claim 17 wherein the catalyst comprises 0 to 3% sodium erythorbate or 0 to 1% cobalt sulfate heptahydrate or both; and wherein the decharacterization additive comprises 0 to 5% sodium lignosulfonate.

19. A method of making a solid sulfite-based composition, the method comprising: heating water to a first temperature range; adding and mixing a first inorganic salt to the water after heating the water to form a first mixture; adding and mixing a second inorganic salt to the first mixture to form a second mixture; pouring the second mixture into a mold; curing the second mixture in the mold until it is solid; wherein the first inorganic salt is a sulfite salt; and wherein the solid sulfite-based composition is thermally stable at temperatures between 35? C.-40? C.

20. The method according to claim 19 wherein the first temperature range is around 65 to 70? C.

21. The method according to claim 19 further comprising adding a catalyst or a decharacterization additive or both prior to adding and mixing the sulfite salt.

22. The method according to claim 21 wherein the catalyst comprises sodium erythorbate or cobalt sulfate heptahydrate or both; and wherein the decharacterization additive comprises sodium lignosulfonate.

23. The method according to claim 20 further comprising heating during adding and mixing the first inorganic salt until the first mixture is within the first temperature range.

24. The method according to claim 23 wherein adding and mixing the second inorganic salt comprises slowly adding the second inorganic salt in a manner in which the second mixture stays within 5? C. of the first temperature range.

25. The method according to claim 23 wherein adding and mixing the second inorganic salt comprises adding 5 to 30% of the second inorganic salt by weight of the solid sulfite-based composition and mixing until the second mixture is homogenous.

26. The method according to claim 23 wherein curing the second mixture comprises allowing the second mixture to sit in the mold at a second temperature range for at least 16 hours.

27. The method according to claim 26 wherein the second temperature range is around 15 to 30? C.

28. The method according to claim 20 wherein the solid sulfite-based composition comprises around 60 to 80% of the first inorganic salt and around 5 to 30% of the second inorganic salt by weight.

29. The method according to claim 20 further comprising heating during adding and mixing the first inorganic salt until the first mixture is within the first temperature range; wherein the first temperature range is around 65 to 70? C.; wherein adding and mixing the second inorganic salt comprises slowly adding the second inorganic salt in a manner in which the second mixture stays within 5? C. of the first temperature range; wherein curing the second mixture comprises allowing the second mixture to sit in the mold at a second temperature range for at least 16 hours; wherein the second temperature range is around 15 to 30? C.; wherein the solid sulfite-based composition comprises around 60 to 80% of the first inorganic salt and around 5 to 30% of the second inorganic salt by weight; wherein the first inorganic salt is sodium metabisulfite; and wherein the second inorganic salt is dipotassium phosphate.

30. A method of treating a water system comprising: adding a sulfite-based composition to the water system, the sulfite-based composition comprising (1) first inorganic salt, and (2) a hydrate of a second inorganic salt; wherein the first inorganic salt is a sulfite; wherein the sulfite-based composition is in a solid form prior to adding the sulfite-based composition to the water system, wherein the solid form is thermally stable at temperatures between 35? C.-40? C.; and wherein the water system is a heated water system or boiler system.

31. The method of claim 30 further comprising dissolving the solid form prior to adding the sulfite-based composition to the water system.

32. The method of claim 30 wherein the sulfite-based composition provides an active sulfite concentration as SO.sub.3 in the water system of at least 10,000 ppm.

33. The method of claim 30 wherein the sulfite-based composition comprises at least 50% active sulfite as SO.sub.3 by weight.

34. The method of claim 30 wherein the second inorganic salt is a phosphate.

35. The method of claim 34 wherein the phosphate is dipotassium phosphate.

36. The method of claim 35 wherein the hydrate of the dipotassium phosphate is dipotassium heptahydrate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The composition and method of the invention are further described and explained in relation to the following figures wherein:

[0021] FIG. 1 contains a photograph showing a bottle of prior art HandiPak 900+ after exposure to a temperature of 40? C. for 6 days, where a liquid layer above a soft slurry;

[0022] FIG. 2 contains a photograph showing the stable solid form of a treatment composition of Example 1 according to an embodiment herein after exposure to a temperature of 40? C. for five days.

DETAILED DESCRIPTION OF EMBODIMENTS

[0023] In some embodiments, a sulfite-based treatment composition may comprise the following ingredients by weight: around 50 to 90% of a sulfite salt, around 5 to 30% of a second inorganic salt, and around 10 to 30% water (preferably deionized water, which does not interfere with the hydrate formation). More preferably, a solid sulfite-based treatment composition comprises the following ingredients by weight: around 55 to 80% of a sulfite, around 15 to 25% of a second inorganic salt, and around 15 to 25% water (preferably deionized water, which does not interfere with the hydrate formation). Most preferably, a sulfite-based treatment composition comprises the following ingredients by weight: around 60 to 65% of a sulfite, around 15 to 22% of a second inorganic salt, and around 18 to 24% water (preferably deionized water, which does not interfere with the hydrate formation). When mixed together and allowed to cure, preferably according to a method as described herein, these ingredients will form a thermally stable, solid sulfite-based treatment composition comprising a sulfite salt hydrate and a salt hydrate of the second inorganic salt.

[0024] Treatment compositions according to some embodiments herein do not include any neutralizing amine (such cyclohexylamine or morpholine) or any polymer, but may include any combination of these ingredients.

[0025] According to some embodiments, a sulfite-based treatment composition further comprises one or more optional ingredients. One type of optional ingredient is a catalyst. In some embodiments, a catalyst comprises cobalt sulfate heptahydrate, or sodium erythorbate, or both. If a cobalt sulfate heptahydrate catalyst is used, it may be in an amount of 0% to around 1% by weight, more preferably around 0.05 to around 0.5% by weight, and most preferably around 0.08% to around 0.13% by weight. If a sodium erythorbate catalyst is used, it may be in an amount of 0 to around 3% by weight, more preferably around 1% to 2% by weight, and most preferably around 1.3% to 1.8% by weight. Other forms of these catalysts, such as ethorybic acid, may also be used. In some embodiments, any sulfite catalyst suitable for use in a heated water system or boiler, including those listed in 21 CFR 173.310, may also be used. In other embodiments, only sulfite catalysts listed in 21 CFR 173.310 may be used. If more than one catalyst is used, a total amount of catalyst may be in an amount of 0 to around 4% by weight, more preferably around 1.0% to around 2.5% by weight, and more preferably around 1.3% to around 2.1% by weight.

[0026] Another type of optional ingredient is a decharacterization additive. In some embodiments, a decharacterization additive comprises lignosulfonic acid or a lignosulfonate, preferably sodium lignosulfonate, or lignin. If a decharacterization additive is used, it may be in an of 0 to around 5% by weight, more preferably around 2% to around 4% by weight, and most preferably around 2.5% to around 3.5% by weight.

[0027] In some embodiments, the sulfite salt in the composition is most preferably sodium metabisulfite, but other metabisulfites, such as potassium metabisulfite may also be used. According to other embodiments, other sulfite salts, such as sodium sulfite or potassium sulfite may also be used; however, in still other embodiments, these sulfite salts are excluded and not used.

[0028] In some embodiments, the second inorganic salt is one that will form a hydrate with a melting point of 35? C. or higher, more preferably 40? C. or higher, and most preferably of 48? C. or higher. The second inorganic salt is most preferably a phosphate, which is useful in inhibiting corrosion in the water system, but other inorganic salts may also be used. The phosphate is most preferably dipotassium phosphate, but other phosphates, such as sodium phosphate, potassium phosphate, and disodium phosphate may also be used. Dipotassium phosphate forms dipotassium heptahydrate, which has a melting point of around 48? C. Other inorganic salts that form hydrates, such as Trisodium Phosphate Dodecahydrate (65? C. melting point); Sodium Acetate trihydrate (58? C. melting point); Sodium Thiosulfate Pentahydrate (48? C. melting point); Disodium Phosphate Heptahydrate (48? C. melting point); Sodium Pyrophosphate Decahydrate (76? C. melting point); Trisodium Phosphate Dodecahydrate (65? C. Melting point); Sodium Acetate trihydrate (58? C. melting point); Sodium Thiosulfate Pentahydrate (48? C. melting point); Disodium Phosphate Heptahydrate (48? C. melting point); and Sodium Pyrophosphate Decahydrate (76? C. melting point) may also be used as the second inorganic salt.

[0029] In some embodiments, the salts do not include any divalent cations, which could interfere with solubility in the water being treated. Most preferably, the ingredients used will favor formation of a potassium heptahydrate (which has a higher melting point) over a sulfite heptahydrate (which would have a melting point below 33.4? C.). A phosphate heptahydrate is preferably formed to achieve a higher melting point and stability for the composition.

[0030] In some embodiments, a thermally stable, solid sulfite-based treatment composition preferably comprises no sulfite salt hydrate or less than around 10% of the sulfite salt hydrate by weight. It also preferably comprises around 10 to around 50%, more preferably around 15 to around 40%, and most preferably around 16 to around 35% of the dipotassium heptahydrate by weight.

[0031] The treatment compositions are most preferably fed into the water system using a solid product feeder that dissolves the composition into a solution that is discharged into the water system. Such dissolvers are as described in U.S. Patent Application Publication No. 20110293481 or the commercially available Ultra-B and Ultra-M dissolvers from Chem-Aqua. The use of a product feeder that pre-dissolves the treatment composition is preferred, since it gives the ease of mixing with the water in the water system found in a liquid formula with the shipping and handling advantages of a solid formula. When dissolved on site at the point of use, the solid treatment composition added to the water system in an amount as needed to achieve the desired active sulfite concentration in the water system, which is preferably at least 10,000 ppm, more preferably at least 20,000 ppm, most preferably around 30,000 ppm.

[0032] Solid sulfite-based compositions according to embodiments herein are thermally stable at temperatures of at least 33? C., more preferably of at least 35? C., and most preferably of at least 40? C. The treatment composition would most likely be stored and used near a heating or boiler water system in a non-climate controlled environment, which is unlikely to experience ambient temperatures above 50? C. or even 45? C. Although treatment compositions according to embodiments herein may be thermally stable at temperatures above 45? C., they do not need to be stable above this temperature. As used herein, thermally stable means the compositions remain in a solid form and without physical and/or chemical deterioration, degradation, or instability when held at temperatures above the specified temperature for at least 1 day, more preferably at least 3 days, and most preferably at least 5 days. Physical and/or chemical deterioration or degradation may be shown by one or more of the following characteristics: (i) formation of a soft slurry; (ii) separation into visible layers; (iii) presence of liquid water; and/or (iv) failure of the composition to properly dissolve in a dissolution device/feeder (such as clogging or jamming the feeder and/or breaking off in chunks that do not fully dissolve prior to discharge from the feeder, and/or otherwise resulting in incorrect feed amounts or incorrect active concentrations in the dissolved solution for the desired sulfite treatment product that are above or below a target range.

[0033] In some embodiments, a method of making or manufacturing a thermally stable, solid sulfite-based treatment composition (preferably a composition according to an embodiment herein) comprises the following steps: (1) adding deionized water to a mixing tank; (2) heating the water to a first temperature range; (3) adding a sulfite salt to the mixing tank; (4) stirring or mixing the sulfite salt with the water to create a slurry and continuing until the temperature of the mixture returns to the first temperature range; (5) slowly adding the second inorganic salt in manner in which the temperature of the mixture stays within the first temperature range or near the first temperature range (preferably within 5? C. of the first temperature range); (6) stirring or mixing during step 5 until all of the second inorganic salt has been added and the mixture is homogenous; (7) pouring the mixture into a mold; and (8) allowing the mixture to cool and cure at room temperature (preferably around 15? C. to 25? C.) for around 16 to 24 hours to form the thermally stable, solid sulfite-based treatment composition. The amounts of water, sulfite salt, and second inorganic salt added are preferably according to the amounts of ingredients for compositions according to embodiments as described herein or amounts that will result in the amounts for the salt hydrates formed as described above.

[0034] In some embodiments, a method of making or manufacturing a thermally stable, solid sulfite-based treatment composition (preferably a composition according to an embodiment herein) comprises the above steps except that the second inorganic salt is added in step (3) and the sulfite salt is added in step (5). When the second inorganic salt is a phosphate, the mixture when added in this order can be thicker. To achieve a more homogenous mixture, the phosphate is preferably added in step (5) after the sulfite is added in step (3).

[0035] According to still other embodiments, one or more optional ingredients are added as part of a method of making or manufacturing a thermally stable, solid sulfite-based treatment composition (preferably a composition according to an embodiment herein). In these embodiments, a method comprises the steps in the preceding paragraphs and further comprises adding and stirring or mixing the one or more optional ingredients between steps (1) and (2). In some embodiments, one or more optional ingredients may be (i) added prior to step (1) or (ii) during step (1) or (iii) after step (3) or (iv) during step (3). Most preferably, when one or more optional ingredients comprises a catalyst and/or a decharacterization additive, the optional ingredients are added prior to adding the sulfite (in either step (3) or step (5)).

[0036] The first temperature range may be around 10 to 20? C. higher than the melting point of the second inorganic salt hydrate that will be formed. As an example, if the second inorganic salt hydrate is sodium acetate trihydrate, which has a melting point of 58? C., then the first temperature range may be 68 to 78? C. Most preferably, the first temperature range is around 65 to 75? C., more preferably around 68 to 72? C., and most preferably around 70? C. The curing time in step 8 will vary depending on the size of the mold and the temperature, but usually at least 16 hours is needed to complete the cure. In some embodiments, curing at cooler temperatures or in refrigeration may also be used; but most preferably, room temperature cooling is used to save on costs and to avoid potential issues with formation of the crystal structures during the curing, which may be negatively impacted by refrigeration temperatures.

[0037] An example product according to an embodiment of a treatment composition herein, Example 1, was made according to a method of manufacture herein using the above method steps and the following ingredient amounts: 20% deionized water, 60% sodium metabisulfite, and 20% dipotassium phosphate by weight. This Example 1 product did not include any catalysts or decharacterization additives. After curing, the example product was stored in a 40? C. oven for 5 days to test its thermal stability. The example product at the end of the 5 day is shown in FIG. 2. Unlike the prior art product in FIG. 1, which separated and layered at a temperature of around 33? C., the example product in FIG. 2 remained in a solid form and did not show any physical degradation. The example product was then tested in an Ultra-B dissolver (a commercially available device to dissolve solid treatments into a solution to be added to a water system being treated). This test was to confirm the example product dissolved correctly and would provide a treatment solution with the required sulfite activity, both of which were confirmed. This testing showed that no chemical instabilities occurred while in the 5 day 40? C. environment.

[0038] Three other example products according to embodiments of a treatment composition herein were made according to embodiments of a method of manufacture using the above method steps and the ingredients and amounts (% w/w) as indicated below in Table 1. These Examples 2-4 included a catalyst or a decharacterization additive.

TABLE-US-00001 TABLE 1 Example Products Example No. Ingredient Example 2 Example 3 Example 4 Water (deionized) 21.9 23.5 22.0 Sulfite salt 60.0 60.0 60.0 (sodium metabisulfite) Second inorganic 18.0 15.0 15.0 salt (dipotassium phosphate) Catalyst (sodium N/A 1.5 N/A erythorbate) Catalyst (cobalt 0.1 N/A N/A sulfate heptahydrate) Decharacterization N/A N/A 3.0 Additive (sodium lignosulfonate)

[0039] After curing, each of Examples 2-4 were stored in a 40? C. oven for 5 days to test thermal stability. Each of Examples 2-4 at the end of the 5 day heated test was similar in appearance to Example 1 as shown in FIG. 2, with each remaining in a solid form and without showing any physical degradation. Each of Examples 2-4 were then tested in an Ultra-B dissolver (a commercially available device to dissolve solid treatments into a solution to be added to a water system being treated). These tests were to confirm each example product dissolved correctly and would provide a treatment solution with the required sulfite activity, both of which were confirmed for Examples 2-4. This testing showed that no chemical instabilities occurred while in the 5 day 40? C. environment when a catalyst or decharacterization additive were included.

[0040] It will be appreciated that treatment compositions and/or methods disclosed herein may include one or more of the following embodiments:

[0041] Embodiment 1. A solid sulfite-based composition comprising: a first inorganic salt; and a hydrate of a second inorganic salt; wherein the first inorganic salt is a sulfite; and wherein the solid sulfite-based composition is thermally stable at temperatures between 35? C.-40? C.

[0042] Embodiment 2. The solid sulfite-based composition according to Embodiment 1 wherein the solid sulfite-based composition comprises at least 50% active sulfite as SO3 by weight.

[0043] Embodiment 3. The solid sulfite-based composition according to any one of Embodiments 1-2 wherein the second inorganic salt is a phosphate.

[0044] Embodiment 4. The solid sulfite-based composition according to Embodiment 3 wherein the phosphate is dipotassium phosphate.

[0045] Embodiment 5. The solid sulfite-based composition according to any one of Embodiments 1-4 wherein the hydrate of the second inorganic salt is dipotassium heptahydrate.

[0046] Embodiment 6. The solid sulfite-based composition according to any one of Embodiments 1-5 wherein the sulfite is sodium metabisulfite.

[0047] Embodiment 7. The solid sulfite-based composition according to any one of Embodiments 1-6 wherein the hydrate has a melting point of at least 40? C.

[0048] Embodiment 8. The solid sulfite-based composition according to any one of Embodiments 1-6 wherein the hydrate has a melting point of at least 48? C.

[0049] Embodiment 9. The solid sulfite-based composition according to any one of Embodiments 1-8 further comprising a catalyst or a decharacterization additive or both.

[0050] Embodiment 10. The solid sulfite-based composition according to Embodiment 9 wherein the catalyst comprises sodium erythorbate or cobalt sulfate heptahydrate or both; and wherein the decharacterization additive comprises a lignosulfonate.

[0051] Embodiment 11. The solid sulfite-based composition according to Embodiment 10 wherein the lignosulfonate comprises sodium lignosulfonate.

[0052] Embodiment 12. The solid sulfite-based composition according to any one of Embodiments 1-11 wherein the solid sulfite-based composition is in a molded form that is thermally stable and maintains the molded form at temperatures between 35? C.-40? C. for at least 5 days.

[0053] Embodiment 13. A sulfite-based composition for treating heated water systems to reduce corrosion, the sulfite-based composition comprising the following ingredients: 60 to 80% by weight of a first inorganic salt; 5 to 30% by weight of a second inorganic salt; and 10 to 30% by weight of deionized water; wherein the first inorganic salt is a sulfite; and wherein the second inorganic salt is capable of forming a hydrate having a melting point of at least 40? C.

[0054] Embodiment 14. The sulfite-based composition according to Embodiment 13 wherein the sulfite-based composition comprises at least 50% active sulfite (as SO3) by weight.

[0055] Embodiment 15. The sulfite-based composition according to any one of Embodiments 13-14 wherein the second inorganic salt is dipotassium phosphate and wherein the hydrate has a melting point of at least 48? C.

[0056] Embodiment 16. The sulfite-based composition according to any one of Embodiments 13-15 wherein the sulfite is sodium metabisulfite.

[0057] Embodiment 17. The sulfite-based composition according to any one of Embodiments 13-16 further comprising a catalyst or a decharacterization additive or both.

[0058] Embodiment 18. The sulfite-based composition according to Embodiment 17 wherein the catalyst comprises 0 to 3% sodium erythorbate or 0 to 1% cobalt sulfate heptahydrate or both; and wherein the decharacterization additive comprises 0 to 5% sodium lignosulfonate.

[0059] Embodiment 19. A method of making a solid sulfite-based composition, the method comprising: heating water to a first temperature range; adding and mixing a first inorganic salt to the water after heating the water to form a first mixture; adding and mixing a second inorganic salt to the first mixture to form a second mixture; pouring the second mixture into a mold; curing the second mixture in the mold until it is solid; wherein the first inorganic salt is a sulfite salt; and wherein the solid sulfite-based composition is thermally stable at temperatures between 35? C.-40? C.

[0060] Embodiment 20. The method according to Embodiment 19 wherein the first temperature range is around 65 to 70? C.

[0061] Embodiment 21. The method according to any one of Embodiments 19-20 further comprising adding a catalyst or a decharacterization additive or both prior to adding and mixing the sulfite salt.

[0062] Embodiment 22. The method according to Embodiment 21 wherein the catalyst comprises sodium erythorbate or cobalt sulfate heptahydrate or both; and wherein the decharacterization additive comprises sodium lignosulfonate.

[0063] Embodiment 23. The method according to any one of Embodiments 19-22 further comprising heating during adding and mixing the first inorganic salt until the first mixture is within the first temperature range.

[0064] Embodiment 24. The method according to any one of Embodiments 19-23 wherein adding and mixing the second inorganic salt comprises slowly adding the second inorganic salt in a manner in which the second mixture stays within 5? C. of the first temperature range.

[0065] Embodiment 25. The method according to any one of Embodiments 19-24 wherein adding and mixing the second inorganic salt comprises, or further comprises, adding 5 to 30% of the second inorganic salt by weight of the solid sulfite-based composition and mixing until the second mixture is homogenous.

[0066] Embodiment 26. The method according to any one of Embodiments 19-25 wherein curing the second mixture comprises allowing the second mixture to sit in the mold at a second temperature range for at least 16 hours.

[0067] Embodiment 27. The method according to Embodiment 26 wherein the second temperature range is around 15 to 30? C.

[0068] Embodiment 28. The method according to any one of Embodiments 19-27 wherein the solid sulfite-based composition comprises around 60 to 80% of the first inorganic salt and around 5 to 30% of the second inorganic salt by weight.

[0069] Embodiment 29. The method according to any one of Embodiments 19-28 further comprising heating during adding and mixing the first inorganic salt until the first mixture is within the first temperature range; wherein the first temperature range is around 65 to 70? C.; wherein adding and mixing the second inorganic salt comprises slowly adding the second inorganic salt in a manner in which the second mixture stays within 5? C. of the first temperature range; wherein curing the second mixture comprises allowing the second mixture to sit in the mold at a second temperature range for at least 16 hours; wherein the second temperature range is around 15 to 30? C.; wherein the solid sulfite-based composition comprises around 60 to 80% of the first inorganic salt and around 5 to 30% of the second inorganic salt by weight; wherein the first inorganic salt is sodium metabisulfite; and wherein the second inorganic salt is dipotassium phosphate.

[0070] Embodiment 30. The method according to any one of Embodiments 19-29 wherein the solid sulfite-based composition is according to any one of Embodiments 1-12.

[0071] Embodiment 31. The method according to any one of Embodiments 19-29 wherein the solid sulfite-based composition is the sulfite-based composition according to any one of Embodiments 13-18.

[0072] Embodiment 32. A method of treating a water system comprising: adding a sulfite-based composition to the water system, the sulfite-based composition comprising (1) first inorganic salt, and (2) a hydrate of a second inorganic salt; wherein the first inorganic salt is a sulfite; wherein the sulfite-based composition is in a solid form prior to adding the sulfite-based composition to the water system, wherein the solid form is thermally stable at temperatures between 35? C.-40? C.; and wherein the water system is a heated water system or boiler system.

[0073] Embodiment 33. The method of Embodiment 32 further comprising dissolving the solid form prior to adding the sulfite-based composition to the water system.

[0074] Embodiment 34. The method of any one of Embodiments 32-33 wherein the sulfite-based composition provides an active sulfite concentration as SO3 in the water system of at least 10,000 ppm.

[0075] Embodiment 35. The method of any one of Embodiments 32-34 wherein the sulfite-based composition comprises at least 50% active sulfite as SO3 by weight.

[0076] Embodiment 36. The method of any one of Embodiments 32-35 wherein the second inorganic salt is a phosphate.

[0077] Embodiment 37. The method of Embodiment 36 wherein the phosphate is dipotassium phosphate.

[0078] Embodiment 38. The method of Embodiment 37 wherein the hydrate of the dipotassium phosphate is dipotassium heptahydrate.

[0079] Embodiment 39. The method according to any one of Embodiments 32-38 wherein the sulfite-based composition is made according to any one of Embodiments 19-31.

[0080] Embodiment 40. The method according to any one of Embodiments 32-34 wherein the sulfite-based composition is the solid sulfite-based composition according to any one of Embodiments 1-12.

[0081] Embodiment 41. The method according to any one of Embodiments 32-34 wherein the sulfite-based composition is according to any one of Embodiments 13-18.

[0082] All numerical values, ratios, or percentages indicated herein as a range include each individual amount, numerical value, or ratio within those ranges and any and all subset combinations within ranges, including subsets that overlap from one range (or one preferred range) to another range (or a more preferred range). References to about or around with respect to numerical values generally mean(1)+/?1 for values expressed as whole numbers (without a decimal, e.g., around 15% means 14-16%); (2)+/?0.1 for values expressed with a single decimal place (for example, around 9.5% means 9.4-9.6%; and (3)+/?0.01 for values expressed with two or more decimal places (for example, around 0.02 means 0.01-0.03, each of the foregoing excluding values that would result in a negative number. References to ranges expressed as at least means greater than or equal to the value, including each individual value, up to 100% when the value is expressed as a percentage. For example, at least 50% means 50-100%, including all individual amounts and subranges therein. References to ranges expressed as more than a value means greater than the value, up to 100% when the value is expressed as a percentage. For example, more than 50% means 50.0001-100%, including all individual amounts and subranges therein. References to ranges expressed as no more than means less than or equal to the value, down to 0 when the value is expressed as a weight, volume, concentration. For example, no more than 16% means 0-16%, including all individual amounts and subranges therein. References to ranges expressed as less than or below means all values that are less than the value, down to 0 when the value is expressed as a weight, volume, concentration. For example, less than 16% means 0-15.9999%, including all individual amounts and subranges therein.

[0083] References herein to water (without any modifier) as an ingredient in a treatment composition include potable water, distilled water, deionized water, or other forms of purified, filtered, or cleaned water. These forms of water may be substituted for references herein to deionized water, other than in the claims.

[0084] With respect to the discussion of various embodiments according to the disclosure, references herein to thermally stable, solid sulfite-based treatment compositions, solid sulfite-based compositions, treatment compositions, and similar phrases are used to refer to any of the composition embodiments herein.

[0085] Any ingredient or method steps of an embodiment herein may be used with any other ingredients, features, components, or steps of other embodiments even if not specifically described with respect to that embodiment, unless such combination is explicitly excluded herein. Any ingredient or amount of an ingredient, or method steps described as excluded with any particular embodiment herein may similarly be excluded with any other embodiment herein even if not specifically described with such embodiment. Any treatment composition embodiment herein may comprise, consist essentially of, or consist of any combination of ingredients described herein. Any specific treatment composition ingredient described herein as one that may be included or may be optionally included in any embodiment herein, such as sodium phosphate as the specific second inorganic salt, may also be excluded from any embodiment herein.

[0086] Those of ordinary skill in the art will appreciate upon reading this specification, including the examples contained herein, that modifications and alterations to the composition and methodology for making the composition may be made within the scope of the invention and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventor is legally entitled.