CA1167235A - Process for the preparation of alkali metal or alkaline earth metal peroxides - Google Patents
Process for the preparation of alkali metal or alkaline earth metal peroxidesInfo
- Publication number
- CA1167235A CA1167235A CA000351249A CA351249A CA1167235A CA 1167235 A CA1167235 A CA 1167235A CA 000351249 A CA000351249 A CA 000351249A CA 351249 A CA351249 A CA 351249A CA 1167235 A CA1167235 A CA 1167235A
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- Prior art keywords
- process according
- hydroxide
- oxide
- suspension
- hydrogen peroxide
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B15/00—Peroxides; Peroxyhydrates; Peroxyacids or salts thereof; Superoxides; Ozonides
- C01B15/04—Metal peroxides or peroxyhydrates thereof; Metal superoxides; Metal ozonides; Peroxyhydrates thereof
- C01B15/043—Metal peroxides or peroxyhydrates thereof; Metal superoxides; Metal ozonides; Peroxyhydrates thereof of alkali metals, alkaline earth metals or magnesium or beryllium or aluminium
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
- Agricultural Chemicals And Associated Chemicals (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Fertilizers (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Disclosed is a process for the preparation of an alkali metal or alkaline earth metal peroxide, comprising the steps of mixing a concentrated aqueous suspension comprising an alkali metal oxide or hydroxide or an alkaline earth metal oxide or hydroxide with an aqueous solution containing hydrogen peroxide to obtain a peroxide suspension; agitating the peroxide suspension for a period of time sufficient to substantially complete the reaction between the hydrogen peroxide and the oxide or hydroxide; and subjecting the substantially completed reaction mixture to spray drying. Also disclosed is an improved product resulting from this process.
Disclosed is a process for the preparation of an alkali metal or alkaline earth metal peroxide, comprising the steps of mixing a concentrated aqueous suspension comprising an alkali metal oxide or hydroxide or an alkaline earth metal oxide or hydroxide with an aqueous solution containing hydrogen peroxide to obtain a peroxide suspension; agitating the peroxide suspension for a period of time sufficient to substantially complete the reaction between the hydrogen peroxide and the oxide or hydroxide; and subjecting the substantially completed reaction mixture to spray drying. Also disclosed is an improved product resulting from this process.
Description
1 167~35 PROCESS FOR THE PREPARATION OF ALKALI METAL
OR ALRA~IYE L~ AL PEROXIDES
~OI/ND 0~ ~r Ill~
The present invention pertains to a process for the preparation of alkali metal or alkaline earth metal peroxides.
Alkali metal and alkaline earth metal peroxides are increasingly used in industry. Thus, for example 7 alkaline earth metal peroxides are used for medical and pharmacological purposes. Recently~ CaO2 has been gaining in importance because it serves to improve the growth of culti~ated plants~ The slow release of oxygen by peroxide ' compounds is utili~ed in s~wage treatment technology.
Alkali metal and alkaline earth metal peroxides ar~ prepared, in general, by producing peroxide-containing reaction mixtures from aqueous solutions of their salts, oxides or hydroxides by means of conversion with an aqueous ¦
hydrogen peroxide solu~ion~ centrifuging or filtering the reaction mixtures and drying them on tray driers. The dry material is convent~onally ground and optionally screened~
DE-OS No. 15 42 642 discloses a process for the pxoduction of CaO2 wherein a highly diluted solution of hydrogen peroxide is reacted with an excess of calcium -`
hydroxide at temperatures under 30C to form calcium peroxideoctahydrate, which is ~hen converted in a sub-sequent drying step into anhydrous peroxide.
, 723~
OR ALRA~IYE L~ AL PEROXIDES
~OI/ND 0~ ~r Ill~
The present invention pertains to a process for the preparation of alkali metal or alkaline earth metal peroxides.
Alkali metal and alkaline earth metal peroxides are increasingly used in industry. Thus, for example 7 alkaline earth metal peroxides are used for medical and pharmacological purposes. Recently~ CaO2 has been gaining in importance because it serves to improve the growth of culti~ated plants~ The slow release of oxygen by peroxide ' compounds is utili~ed in s~wage treatment technology.
Alkali metal and alkaline earth metal peroxides ar~ prepared, in general, by producing peroxide-containing reaction mixtures from aqueous solutions of their salts, oxides or hydroxides by means of conversion with an aqueous ¦
hydrogen peroxide solu~ion~ centrifuging or filtering the reaction mixtures and drying them on tray driers. The dry material is convent~onally ground and optionally screened~
DE-OS No. 15 42 642 discloses a process for the pxoduction of CaO2 wherein a highly diluted solution of hydrogen peroxide is reacted with an excess of calcium -`
hydroxide at temperatures under 30C to form calcium peroxideoctahydrate, which is ~hen converted in a sub-sequent drying step into anhydrous peroxide.
, 723~
- 2 -All of these processes are affected by a series of disadvantages. For example~ they are expensive because it is necessary to separate the product from the mother li~uor by centrifuging and then to grind the tray-dried product. Furthermore, the economy of the processes is achievable only to a limited extent, because appreciable losses of peroxide are caused by the decomposition of hydrogen peroxide in the large volumes of liquor resulting from the relatively dilute suspensions and by the long retention time in the drying procedure.
In addition, large volumes of water must be unnecessarily transported because of J he high dilution of the reaction mixture and then removed in an energy-inten-sive drying stage~ Supplemental control devices to control the temperature and additional process steps to eliminate the excess calcium hydroxide are also required. A further disadvantage resides in a certain inhomogeneity of the final product, caused by decomposition during drying and during the subsequent grinding process.
, It is therefore an object of the present invention to provide an improvea process for the preparation of an alkali metal or alkaline earth metal peroxide.
Another object of the present invention resides in providing a process for the preparation of an alkali metal or alkaline earth metal peroxide which is economical to operate and consumes lower amounts of energy.
A further object of the invention i5 to provide such a process in which only small losses in peroxide occur during processing, Still another object of the invention resides in providing a process which produces an improved peroxide product and in providing such an improved product.
~1~
~7~3~ ~
In addition, large volumes of water must be unnecessarily transported because of J he high dilution of the reaction mixture and then removed in an energy-inten-sive drying stage~ Supplemental control devices to control the temperature and additional process steps to eliminate the excess calcium hydroxide are also required. A further disadvantage resides in a certain inhomogeneity of the final product, caused by decomposition during drying and during the subsequent grinding process.
, It is therefore an object of the present invention to provide an improvea process for the preparation of an alkali metal or alkaline earth metal peroxide.
Another object of the present invention resides in providing a process for the preparation of an alkali metal or alkaline earth metal peroxide which is economical to operate and consumes lower amounts of energy.
A further object of the invention i5 to provide such a process in which only small losses in peroxide occur during processing, Still another object of the invention resides in providing a process which produces an improved peroxide product and in providing such an improved product.
~1~
~7~3~ ~
- 3 -In accomplishing the foregoing objects, there has been provided in accordance with the present invention a process for the preparation of an alkali metal or alkaline earth metal peroxide, comprising the steps of mixing a concentrated aqueous suspension comprising an alkali metal oxide or hydroxide or an alkaline earth metal oxide or hydroxide with an a~ueous solution con~aining hydrogen peroxide, to obtain a peroxide suspension; agitating the peroxide suspension for a period of time sufficient to substantially complete the reaction between the hydrogen peroxide and the oxide or hydroxide, and subjecting the substantially completed reaction mixture to spray drying.
Optionally, the process further comprises ~he steps o~
recycling a portion of the reaction mixture to the mixing step, and/or removing part of the water content from th~
reaction mixtllre prior to the spray drying step, and/or cooling the mixture of oxide or hydroxide and hydrogen peroxide after the mixing step and/or concurrently with said agitating step.
In accoxdance with another object of the invention, there has been provided an improved alkali metal or alkaline earth metal peroxide produced in accordance with the pro-cess defined above.
Further objects, features and advantages of the present invention will become apparent to a person of ordinary skill in the art from the detailed description of preferred embodiments which follows.
.. . ..
~7~3~
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
~ ."", According to the invention, a concentrated aqueous alkali metal or alkaline earth me~al oxide or hydroxide suspension is mixed, preferably accompanied by cooling, with an aqueous hydrogen peroxide solution, and the peroxide suspension obtained, preferably with further cooling and with agitation up until the completion of the reaction, i5 subjected to spray drying.
Surprisingly, it has been discovered that the disadvantages of the known processes may be overcome by working with suspensions which are concentrated as highly as possible and by drying thes~ suspensions directly and carefully. The oxide or hydroxide suspension to be used should have a high solids content. Optimally, a suspension just capable of being pumped is used. The solids content of the suspension is determined by the oxide or hydroxide to be utilized, but normally is higher than about 200 g/l, preferably higher than about 300 g/l.
The suspension to be used may be prepared, for 2~ example, by the simultaneous metered addition of water and a commercially available oxide or hydroxide powder wi~h agitation in a mixing vessel. In a pref~rred embodi-ment of the process, the suspension which is internally heated by the exothermic solution process is mixed directly, without any interim cooling, with hydrogen peroxide.
Commercially avail~ble products may be used as the hydrogen peroxide solution; it may also contain one or more known active oxygen stabilizers. It is preferred to use a H2O2 concentration of higher than 50~ by weight, most preferably higher than 65% by weight, so that the re-action mixture will not be excessively diluted.
The process according to the invention may be carried out as follows:
The corresponding oxide or hydroxide is sus-pended in a volume of water which is as small as possible,optionally with cooling. The oxide or hydroxide suspension ci7~35 -- 5 -- .
obtained is mixed with an aqueous solution of hydrogen peroxide in an intensive mixing apparatus~ The peroxide suspension formed is subsequently treated -- optionally with further cooling -- to the completion of the conversion in a kneader, and the paste is then pumped to a spray-drier~ wherein the product is atomized via a rotating disk in a ~low of warm air.
As the intensive mixing apparatus there may be used, for.ex~mple, a rapidly rotating excentric pump or a plough share mixer, optionally equipped with a cooling jacket. It i5 of advan~age to remove a portion of the water content of the reaction mixture after combining and intermixing of the reaction components, preferably, to a content of approximately 40~ by weight t with re-spect to the reaction mixture. For the treatment of thereaction mixture up until the point of complete conversion, there may be used, for example, a conical screw mixer.
In this mixer, the reaction mixture may be kneaded for a period of from about 0 to 3 hours, preferably from about 0 to 0.5 hours, i.e., to the end of the reaction or to the optimum degree of conversion. In the process according to the invention, the paste may be transported by means of a screw pump. For drying ~he product of the invention, an atomi7.ing dxyer with a rapidly rotating disk has been found appropriate. Other types of conveying and spray-drying equipment can also be used.
The following advantages distinguish the process according to the invention from the state of the art:
a) by means of the stoichiometric charging of the reactants and operation with concentrated reaction mixtures, the proportion of the ballast (water, excess reactant) is held to a minimum;
b) expensive separation and purification stages are eliminated by the direct spray drying of the reaction mixture. Furthermore, the product.is obtained in the form of a freely flowing granulate and does not require final treatment in auxiliary comminuting installations;
and ~.
I~
23~ii c) the process may be operated both discon-tinously or continuously.
The product obtained by the process of the in-vention is distinguished by the following advantages from the state of the art:
a) the avoidance of local decomposition re-actions insures good homogeneity of the product;
b) spray-drying provides good flowability, uniform crystal structure and a narrow, uniform grain size range; and c) because of the intensive drying, peroxides free of water of cxystallization are obtained.
The process is schematically illustrated by the diagram in Figure 1. The reference numeral 1 re-presents the mixing apparatus for the preparation ofthe oxide or hydroxide suspension, while the H2O2 solu-tion is held in readiness in vessel 2O The charge solutions are combined in the intensive mixing apparatus 3 and transported by way of the cooler 4 to the conical screw mixer 5. The retention time in mixer 5 may amount from about 0 to 3 hours, preferably from about O to 0.5 hours, depending on process design. By means of a screw pump 6, the reaction product is withdrawn continuously from mixer 5 and transported to the spray-dryer 7 for spray-drying~ In a special alternate embodiment of the process according to the invention, it is possible to remove part of the re-action mixture by means of a bypass 8 prior to its entry into the cooler 4 and to recycle it for an accelerated initiation of the reaction to the mixing apparatus 3.
The mixing apparatus 1 and 3 may be equipped additionally with cooling devices.
The process according to the invention will be explained but not restricted by the examples which follow hereinafter.
.
~"~ ' ' ~ 7~23~
- 7 - !
. .
In a mixing vessel (l) a Ca(OH)2 suspension is prepared by means of the simultaneous metered addition of water and Ca(OH)2 powder under agitation; the suspension contains 50% by weight Ca(OH)2. In a storage vessel, a 70% by weight aqueous H2O2 solution is held in readiness;
the solution is stabilized with 300 mg PO4 /l. With a screw pump, 660 kg/h of the Ca(OH)2 suspension from (l) and with a metering piston pump 186 l/h of the H2O2 - -solution from (2) are passed reactingly through a rapidly rotating mixing pump (Supraton 2.07) (3). In this manner, 900 kg/h of a CaO2 slurry are formed with the simultaneous release of heat.
The slurry is cooled in a thin film heat ex-changer (4) -- a vertically arranged water-cooled double cylinder, wherein the slurry to be cooled is thrown by means of agitators onto the cooling surfaces where it is cooled and then flow3in the downward direction -- to 308K; it then flows freely into a screw mi~er (5)O
From the screw mixer (5), the CaO2 slurry is fed by means of a screw pump (6) to a spray~dryer ~7) for dryingO The dryiny temperatures are set for the con-tinuous flow of the product and equal to 473K at the inlet of the dryer and 348~K at its outlet. The product obtained in this manner (324 kg/h) contains 76.4% by weight CaO2. The scanning electron microscope image (Figure 2) shows that the average particle diameter is around about 5 ~ and that approximately 90~ of the particles have diameters ketween about 2 and 7 ~.
_ _ In a manner similar to the method described in Example l, 496 kg/h of a 25% by weight MgO suspension and 60 l/h of a 70~ by weight H~O2 solution are reactingly processed.
Subsequently to the mixing pump a partial flow (30~ by volume) is recycled by way of a bypass (8) into the mixer pump to accelerate the onset of the reaction;
the Mgo2 slurry (573 kg/h) is cooled -- as described in ~i7235 ~ 8 --Example 1 -- intermixed in a screw mixer and dried in an atomizing drier.
The product obtained in this manner (122 g/h) contains 45~8% by weight MgO2.
~ . . .
In a manner similar to the operating mode in Example 1, 132 kg/h of a 41% by weight LioH suspension and 47 l/h of a 70~ by weight H20~ solution are processed reactingly. 193 kg/h of a Li~02 slurry are formed, with the release of heat.
Processing according to Example 1 yields a product (52 kg/h) containing 89% Li202.
In a variant o the process, the CaO2 slurry pre pared according to Example 1 is fed from the mixing pump into a decanter centrifuge, where it is dehydrated to a total water content of approximately 40% by weight. From there, it is fed into a screw pump, which transports the concentrated slurry to a spray-dryer with an atomizing disk. In the directly heated atomizer, the slurry is dried by the heated air, wh~rein the temperature of the incoming air is approximately 773K and that of the out-going air is approximately 383K.
The dry, free-10wing product in the form of a powder leaving the dryer contains 75% by weight CaO2 and is practically free of water of crystallization. It may be directly fed to a storage silo or packaged after cooling, without grinding~
It should be emphasized that,in spite of the use of industrial grades of Ca(OH)2, products having good stability are obtained; hey may be stored undPr normal storage conditions for months without substantial loss of active oxygen.
Optionally, the process further comprises ~he steps o~
recycling a portion of the reaction mixture to the mixing step, and/or removing part of the water content from th~
reaction mixtllre prior to the spray drying step, and/or cooling the mixture of oxide or hydroxide and hydrogen peroxide after the mixing step and/or concurrently with said agitating step.
In accoxdance with another object of the invention, there has been provided an improved alkali metal or alkaline earth metal peroxide produced in accordance with the pro-cess defined above.
Further objects, features and advantages of the present invention will become apparent to a person of ordinary skill in the art from the detailed description of preferred embodiments which follows.
.. . ..
~7~3~
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
~ ."", According to the invention, a concentrated aqueous alkali metal or alkaline earth me~al oxide or hydroxide suspension is mixed, preferably accompanied by cooling, with an aqueous hydrogen peroxide solution, and the peroxide suspension obtained, preferably with further cooling and with agitation up until the completion of the reaction, i5 subjected to spray drying.
Surprisingly, it has been discovered that the disadvantages of the known processes may be overcome by working with suspensions which are concentrated as highly as possible and by drying thes~ suspensions directly and carefully. The oxide or hydroxide suspension to be used should have a high solids content. Optimally, a suspension just capable of being pumped is used. The solids content of the suspension is determined by the oxide or hydroxide to be utilized, but normally is higher than about 200 g/l, preferably higher than about 300 g/l.
The suspension to be used may be prepared, for 2~ example, by the simultaneous metered addition of water and a commercially available oxide or hydroxide powder wi~h agitation in a mixing vessel. In a pref~rred embodi-ment of the process, the suspension which is internally heated by the exothermic solution process is mixed directly, without any interim cooling, with hydrogen peroxide.
Commercially avail~ble products may be used as the hydrogen peroxide solution; it may also contain one or more known active oxygen stabilizers. It is preferred to use a H2O2 concentration of higher than 50~ by weight, most preferably higher than 65% by weight, so that the re-action mixture will not be excessively diluted.
The process according to the invention may be carried out as follows:
The corresponding oxide or hydroxide is sus-pended in a volume of water which is as small as possible,optionally with cooling. The oxide or hydroxide suspension ci7~35 -- 5 -- .
obtained is mixed with an aqueous solution of hydrogen peroxide in an intensive mixing apparatus~ The peroxide suspension formed is subsequently treated -- optionally with further cooling -- to the completion of the conversion in a kneader, and the paste is then pumped to a spray-drier~ wherein the product is atomized via a rotating disk in a ~low of warm air.
As the intensive mixing apparatus there may be used, for.ex~mple, a rapidly rotating excentric pump or a plough share mixer, optionally equipped with a cooling jacket. It i5 of advan~age to remove a portion of the water content of the reaction mixture after combining and intermixing of the reaction components, preferably, to a content of approximately 40~ by weight t with re-spect to the reaction mixture. For the treatment of thereaction mixture up until the point of complete conversion, there may be used, for example, a conical screw mixer.
In this mixer, the reaction mixture may be kneaded for a period of from about 0 to 3 hours, preferably from about 0 to 0.5 hours, i.e., to the end of the reaction or to the optimum degree of conversion. In the process according to the invention, the paste may be transported by means of a screw pump. For drying ~he product of the invention, an atomi7.ing dxyer with a rapidly rotating disk has been found appropriate. Other types of conveying and spray-drying equipment can also be used.
The following advantages distinguish the process according to the invention from the state of the art:
a) by means of the stoichiometric charging of the reactants and operation with concentrated reaction mixtures, the proportion of the ballast (water, excess reactant) is held to a minimum;
b) expensive separation and purification stages are eliminated by the direct spray drying of the reaction mixture. Furthermore, the product.is obtained in the form of a freely flowing granulate and does not require final treatment in auxiliary comminuting installations;
and ~.
I~
23~ii c) the process may be operated both discon-tinously or continuously.
The product obtained by the process of the in-vention is distinguished by the following advantages from the state of the art:
a) the avoidance of local decomposition re-actions insures good homogeneity of the product;
b) spray-drying provides good flowability, uniform crystal structure and a narrow, uniform grain size range; and c) because of the intensive drying, peroxides free of water of cxystallization are obtained.
The process is schematically illustrated by the diagram in Figure 1. The reference numeral 1 re-presents the mixing apparatus for the preparation ofthe oxide or hydroxide suspension, while the H2O2 solu-tion is held in readiness in vessel 2O The charge solutions are combined in the intensive mixing apparatus 3 and transported by way of the cooler 4 to the conical screw mixer 5. The retention time in mixer 5 may amount from about 0 to 3 hours, preferably from about O to 0.5 hours, depending on process design. By means of a screw pump 6, the reaction product is withdrawn continuously from mixer 5 and transported to the spray-dryer 7 for spray-drying~ In a special alternate embodiment of the process according to the invention, it is possible to remove part of the re-action mixture by means of a bypass 8 prior to its entry into the cooler 4 and to recycle it for an accelerated initiation of the reaction to the mixing apparatus 3.
The mixing apparatus 1 and 3 may be equipped additionally with cooling devices.
The process according to the invention will be explained but not restricted by the examples which follow hereinafter.
.
~"~ ' ' ~ 7~23~
- 7 - !
. .
In a mixing vessel (l) a Ca(OH)2 suspension is prepared by means of the simultaneous metered addition of water and Ca(OH)2 powder under agitation; the suspension contains 50% by weight Ca(OH)2. In a storage vessel, a 70% by weight aqueous H2O2 solution is held in readiness;
the solution is stabilized with 300 mg PO4 /l. With a screw pump, 660 kg/h of the Ca(OH)2 suspension from (l) and with a metering piston pump 186 l/h of the H2O2 - -solution from (2) are passed reactingly through a rapidly rotating mixing pump (Supraton 2.07) (3). In this manner, 900 kg/h of a CaO2 slurry are formed with the simultaneous release of heat.
The slurry is cooled in a thin film heat ex-changer (4) -- a vertically arranged water-cooled double cylinder, wherein the slurry to be cooled is thrown by means of agitators onto the cooling surfaces where it is cooled and then flow3in the downward direction -- to 308K; it then flows freely into a screw mi~er (5)O
From the screw mixer (5), the CaO2 slurry is fed by means of a screw pump (6) to a spray~dryer ~7) for dryingO The dryiny temperatures are set for the con-tinuous flow of the product and equal to 473K at the inlet of the dryer and 348~K at its outlet. The product obtained in this manner (324 kg/h) contains 76.4% by weight CaO2. The scanning electron microscope image (Figure 2) shows that the average particle diameter is around about 5 ~ and that approximately 90~ of the particles have diameters ketween about 2 and 7 ~.
_ _ In a manner similar to the method described in Example l, 496 kg/h of a 25% by weight MgO suspension and 60 l/h of a 70~ by weight H~O2 solution are reactingly processed.
Subsequently to the mixing pump a partial flow (30~ by volume) is recycled by way of a bypass (8) into the mixer pump to accelerate the onset of the reaction;
the Mgo2 slurry (573 kg/h) is cooled -- as described in ~i7235 ~ 8 --Example 1 -- intermixed in a screw mixer and dried in an atomizing drier.
The product obtained in this manner (122 g/h) contains 45~8% by weight MgO2.
~ . . .
In a manner similar to the operating mode in Example 1, 132 kg/h of a 41% by weight LioH suspension and 47 l/h of a 70~ by weight H20~ solution are processed reactingly. 193 kg/h of a Li~02 slurry are formed, with the release of heat.
Processing according to Example 1 yields a product (52 kg/h) containing 89% Li202.
In a variant o the process, the CaO2 slurry pre pared according to Example 1 is fed from the mixing pump into a decanter centrifuge, where it is dehydrated to a total water content of approximately 40% by weight. From there, it is fed into a screw pump, which transports the concentrated slurry to a spray-dryer with an atomizing disk. In the directly heated atomizer, the slurry is dried by the heated air, wh~rein the temperature of the incoming air is approximately 773K and that of the out-going air is approximately 383K.
The dry, free-10wing product in the form of a powder leaving the dryer contains 75% by weight CaO2 and is practically free of water of crystallization. It may be directly fed to a storage silo or packaged after cooling, without grinding~
It should be emphasized that,in spite of the use of industrial grades of Ca(OH)2, products having good stability are obtained; hey may be stored undPr normal storage conditions for months without substantial loss of active oxygen.
Claims (17)
1. A process for the preparation of an alkali metal or alkaline earth metal peroxide, comprising the steps of:
mixing a concentrated aqueous suspension comprising an alkali metal oxide or hydroxide or an alkaline earth metal oxide or hydroxide with an aqueous solution containing hydrogen peroxide to obtain a peroxide suspension;
agitating the peroxide suspension for a period of time sufficient to substantially complete the reaction between the hydrogen peroxide and the oxide or hydroxide; and subjecting the substantially completed reaction mixture to spray drying.
mixing a concentrated aqueous suspension comprising an alkali metal oxide or hydroxide or an alkaline earth metal oxide or hydroxide with an aqueous solution containing hydrogen peroxide to obtain a peroxide suspension;
agitating the peroxide suspension for a period of time sufficient to substantially complete the reaction between the hydrogen peroxide and the oxide or hydroxide; and subjecting the substantially completed reaction mixture to spray drying.
2. A process according to Claim 1, wherein said suspension of oxide or hydroxide is concentrated to the extent that it just remains capable of being pumped.
3. A process according to Claim 2, wherein the solids content of the oxide or hydroxide suspension is greater than about 200 g/l.
4. A process according to Claim 3, wherein the solids content of the oxide or hydroxide suspension is greater than about 300 g/l.
5. A process according to Claim 1, wherein the aqueous hydrogen peroxide solution contains more than about 50% by weight of H2O2.
6. A process according to Claim 1, wherein the aqueous hydrogen peroxide solution contains more than about 65% by weight of H2O2.
7. A process according to Claim 1, wherein the oxide or hydroxide reactant and the hydrogen peroxide are combined in approximately stoichiometric amounts.
8. A process according to Claim 1, wherein said agitation step is carried out for a period of time up to about 3 hours.
9. A process according to Claim 8, wherein said agitation step is carried out for a period of time up to about 0.5 hours.
10. A process according to Claim 1, wherein a concentrated aqueous suspension of lithium oxide or hydroxide is mixed with said aqueous solution containing hydrogen peroxide.
11. A process according to Claim 1, wherein a concentrated aqueous suspension of magnesium oxide or hydroxide or calcium oxide or hydroxide is mixed with said aqueous solution containing hydrogen peroxide.
12. A process according to Claim 1, further com-prising the step of recycling a portion of the reaction mixture to said mixing step after said portion has left said mixing step.
13. A process according to Claim 1, further com-prising the step of removing part of the water content from the reaction mixture prior to said spray drying step.
14. A process according to Claim 13, wherein the water content of the reaction mixture is reduced to a residual water content of about 40% by weight based on the reaction mixture.
15. A process according to Claim 14, wherein said water removal step comprises centrifuging.
16. A process according to Claim 1, further comprising the step of cooling the mixture of oxide or hydroxide and hydrogen peroxide after said mixing step.
17. A process according to Claim 1, further comprising the step of cooling concurrently with said agitating step.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19792918137 DE2918137A1 (en) | 1979-05-05 | 1979-05-05 | METHOD FOR PRODUCING ALKALINE OR ALKALINE EARTH PEROXIDES |
| DEP2918137.1 | 1979-05-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1167235A true CA1167235A (en) | 1984-05-15 |
Family
ID=6069996
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000351249A Expired CA1167235A (en) | 1979-05-05 | 1980-05-05 | Process for the preparation of alkali metal or alkaline earth metal peroxides |
Country Status (13)
| Country | Link |
|---|---|
| JP (1) | JPS55149107A (en) |
| AT (1) | AT382139B (en) |
| AU (1) | AU541584B2 (en) |
| BE (1) | BE883079A (en) |
| BR (1) | BR8002696A (en) |
| CA (1) | CA1167235A (en) |
| DE (1) | DE2918137A1 (en) |
| ES (1) | ES489620A1 (en) |
| FR (1) | FR2456069B1 (en) |
| GB (1) | GB2048842B (en) |
| IT (1) | IT1140860B (en) |
| LU (1) | LU82328A1 (en) |
| NL (1) | NL189083C (en) |
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|---|---|---|---|---|
| US5186165A (en) * | 1991-06-05 | 1993-02-16 | Brookdale International Systems Inc. | Filtering canister with deployable hood and mouthpiece |
| US5394867A (en) * | 1991-06-05 | 1995-03-07 | Brookdale International Systems Inc. | Personal disposable emergency breathing system with dual air supply |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3163044D1 (en) * | 1980-05-15 | 1984-05-17 | Interox Chemicals Ltd | The production of alkali metal or alkaline earth metal peroxides and peroxides when so produced |
| DE3025682A1 (en) * | 1980-07-07 | 1982-02-11 | Peroxid-Chemie GmbH, 8023 Höllriegelskreuth | METHOD FOR PRODUCING PEROXIDES OF TWO-VALUE METALS |
| JPS5773607A (en) * | 1980-10-24 | 1982-05-08 | Dainippon Printing Co Ltd | Calibration system of lithographic-plate pattern area rate meter |
| DE3105584A1 (en) * | 1981-02-16 | 1982-10-28 | Peroxid-Chemie GmbH, 8023 Höllriegelskreuth | METHOD FOR CONTINUOUSLY DETERMINING ALKALI HYPEROXIDE |
| JPH02120478U (en) * | 1989-03-17 | 1990-09-28 | ||
| DE4219459A1 (en) * | 1992-06-13 | 1993-12-16 | Huels Chemische Werke Ag | Process for the preparation of 2,2,6,6-tetramethylpiperidine-N-oxyl and its derivatives substituted in the 4-position |
| DE19650686A1 (en) * | 1996-12-06 | 1998-06-10 | Solvay Interox Gmbh | Alkaline earth metal peroxide product |
| DE10035287A1 (en) | 2000-07-18 | 2002-01-31 | Solvay Interox Gmbh | Coated metal peroxides |
| DE10248652A1 (en) | 2002-10-18 | 2004-04-29 | Solvay Interox Gmbh | Process for the production of dust-free alkaline earth peroxides |
| EP1988974B1 (en) * | 2006-02-28 | 2011-12-21 | Swissdent Cosmetics AG | Toothpaste |
| CN114634165B (en) * | 2022-01-20 | 2023-08-29 | 常熟理工学院 | Method for preparing calcium peroxide by utilizing waste incineration fly ash |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2415443A (en) * | 1944-11-28 | 1947-02-11 | Albert Pavlik | Strontium peroxide and method of making the same |
| US2695217A (en) * | 1952-05-22 | 1954-11-23 | Shell Dev | Purification of hydrogen peroxide |
| US3120997A (en) * | 1961-08-25 | 1964-02-11 | Gen Dynamics Corp | Process for producing alkali metal superoxides |
| US3134646A (en) * | 1962-01-15 | 1964-05-26 | Lithium Corp | Preparation of lithium peroxide |
| US3446588A (en) * | 1967-03-02 | 1969-05-27 | Foote Mineral Co | Method for preparing lithium peroxide |
| JPS5039078B1 (en) * | 1971-02-22 | 1975-12-13 | ||
| US3907506A (en) * | 1972-03-17 | 1975-09-23 | Air Liquide | Apparatus for the preparation of alkaline hyperoxide |
| FR2175652B1 (en) * | 1972-03-17 | 1974-08-02 | Air Liquide | |
| JPS5146520B2 (en) * | 1972-11-10 | 1976-12-09 |
-
1979
- 1979-05-05 DE DE19792918137 patent/DE2918137A1/en active Granted
-
1980
- 1980-03-03 NL NLAANVRAGE8001274,A patent/NL189083C/en not_active IP Right Cessation
- 1980-03-17 ES ES489620A patent/ES489620A1/en not_active Expired
- 1980-04-03 LU LU82328A patent/LU82328A1/en unknown
- 1980-04-15 IT IT21372/80A patent/IT1140860B/en active
- 1980-04-17 AU AU57553/80A patent/AU541584B2/en not_active Expired - Fee Related
- 1980-04-29 GB GB8014089A patent/GB2048842B/en not_active Expired
- 1980-04-30 BR BR8002696A patent/BR8002696A/en not_active IP Right Cessation
- 1980-05-02 BE BE1/9804A patent/BE883079A/en not_active IP Right Cessation
- 1980-05-05 AT AT0238280A patent/AT382139B/en not_active IP Right Cessation
- 1980-05-05 FR FR8010024A patent/FR2456069B1/en not_active Expired
- 1980-05-05 CA CA000351249A patent/CA1167235A/en not_active Expired
- 1980-05-06 JP JP5876380A patent/JPS55149107A/en active Granted
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5186165A (en) * | 1991-06-05 | 1993-02-16 | Brookdale International Systems Inc. | Filtering canister with deployable hood and mouthpiece |
| US5315987A (en) * | 1991-06-05 | 1994-05-31 | Brookdale International Systems Inc. | Filtering canister with deployable hood and mouthpiece |
| US5394867A (en) * | 1991-06-05 | 1995-03-07 | Brookdale International Systems Inc. | Personal disposable emergency breathing system with dual air supply |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2918137A1 (en) | 1980-11-20 |
| AU5755380A (en) | 1980-11-13 |
| ES489620A1 (en) | 1980-09-16 |
| BR8002696A (en) | 1980-12-16 |
| IT8021372A0 (en) | 1980-04-15 |
| AT382139B (en) | 1987-01-12 |
| AU541584B2 (en) | 1985-01-10 |
| NL189083B (en) | 1992-08-03 |
| ATA238280A (en) | 1986-06-15 |
| JPS55149107A (en) | 1980-11-20 |
| NL8001274A (en) | 1980-11-07 |
| GB2048842B (en) | 1983-02-23 |
| FR2456069B1 (en) | 1985-10-11 |
| JPS6356166B2 (en) | 1988-11-07 |
| FR2456069A1 (en) | 1980-12-05 |
| NL189083C (en) | 1993-01-04 |
| IT1140860B (en) | 1986-10-10 |
| BE883079A (en) | 1980-11-03 |
| LU82328A1 (en) | 1980-07-02 |
| GB2048842A (en) | 1980-12-17 |
| DE2918137C2 (en) | 1988-06-09 |
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