US3661510A - Light bulk density sodium perborate - Google Patents

Light bulk density sodium perborate Download PDF

Info

Publication number
US3661510A
US3661510A US806979A US3661510DA US3661510A US 3661510 A US3661510 A US 3661510A US 806979 A US806979 A US 806979A US 3661510D A US3661510D A US 3661510DA US 3661510 A US3661510 A US 3661510A
Authority
US
United States
Prior art keywords
sodium perborate
crystals
sodium
crystallizer
hydrogen peroxide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US806979A
Other languages
English (en)
Inventor
Donald Charles Winkley
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
FMC Corp
Original Assignee
FMC Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by FMC Corp filed Critical FMC Corp
Application granted granted Critical
Publication of US3661510A publication Critical patent/US3661510A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • C01B15/055—Peroxyhydrates; Peroxyacids or salts thereof
    • C01B15/12—Peroxyhydrates; Peroxyacids or salts thereof containing boron
    • C01B15/126—Dehydration of solid hydrated peroxyborates to less hydrated or anhydrous products
    • 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
    • C01B15/055—Peroxyhydrates; Peroxyacids or salts thereof
    • C01B15/12—Peroxyhydrates; Peroxyacids or salts thereof containing boron

Definitions

  • sodium perborate can be produced by the reaction of sodium metaborate and hydrogen peroxide, and that this compound can be utilized in detergent products.
  • Many of these detergent formulations contain spray-dried ingredients having means particle sizes of from about 30 to about 40 mesh and bulk densities of about 0.3 g./cc.; these are produced by spraying a liquid solution or slurry through a heated zone and recovering discrete particles of detergent ingredients.
  • spray-dried particles are dry mixed with sodium perborate to form the detergent formulations
  • conventional perborate compounds segregate from the formulation because normally they have a higher bulk density (0.70-0.85 g./cc.) and further because of their extremely small particle size, normally below 60 mesh. This situation is further aggravated by the high friability of certain of these perborate products. That is, the particles break down during processing and handling to yield even finer particles, which further increases the segregation problem.
  • a unique form of sodium perborate crystals can be produced having a bulk density of from about 0.3 to about 0.6 g./cc. and a size larger than 60 mesh, said crystals being in the form of prismatic crystals having a lengthzwidth ratio of from 3:1 to 10:1 and radially clustered in a group having a common center with their ends protruding beyond the common center in a star"-appcaring pattern.
  • This unique, sodium perborate, star-shaped product is produced by reacting together, at -45 C., hydrogen peroxide and sodium metaborate in a molar ratio of H O :BO of 1:1 in the presence of externally prepared, preformed seed crystals of sodium perborate tetrahydrate having a lengthzwidth ratio of at least 3:1, and seperating the resulting sodium perborate crystals from their mother liquor.
  • FIG. 2 is a photomicrograph (15X magnification) of a sample of the star-shaped sodium perborate of the present invention, prepared by the process set forth in Example 3, Run A.
  • an aqueous sodium metaborate solution must first be prepared.
  • the sodium metaborate solution can be made up from sodium hydroxide and either borax or boric acid.
  • borax boric acid
  • the final solution normally is purified by filtration or by other known means to remove impurities.
  • concentration of the sodium metaborate in the aqueous solution is not critical; however, high concentrations, and preferably metaborate solutions which are saturated at the equivalent of 50-60 C., are preferred, since they reduce the quantity of water which must be removed in a subsequent, vacuum crystallization step.
  • the second ingredient, hydrogen peroxide can be used in any concentration desired with 30-70% H 0 being preferred, since this reduces the amount of water which has to be removed during a subsequent crystallization step.
  • the hydrogen peroxide may have therein stabilizers of various types, such as magnesium, stannate, silicate or organic stabilizers, such as ethylene diamine tetraacetic acid. These stabilizers, which may be present at levels of 10 to 1,000 ppm, do not adversely affect the use of such stabilized hydrogen peroxide in the present process.
  • a conventional, vacuum crystallizing apparatus is charged with a saturated solution of sodium perborate, and preferably a solution which also contains some sodium metaborate, e.g., 0.3 sodium metaborate, which acts to reduce the solubility of the sodium perborate in solution.
  • the sodium perborate can be prepared by simply mixing sodium metaborate and hydrogen peroxide or by simply dissolving conventional sodium perborate in water up to the limit of its solubility. This solution is maintained at a temperature of from 25-45 C. and is used as the mother liquor from which the desired sodium perborate is crystallized.
  • the seeding rate is 20 percent. In general, the seeding rate is maintained between 5 and 30 percent, with a preferred seeding rate of 10 to 25 percent being employed.
  • the reactants which are present in the crystallizer namely sodium metaborate and hydrogen peroxide, are present in substantially a 1:1 molar ratio of H O :BO except for a slight excess sodium metaborate which is maintained in the mother liquor to decrease the solubility of the product, sodium perborate, in the final reaction medium.
  • the concentration of sodium metaborate in the crystallizer solution can be expressed as grams per liter of excess sodium metaborate; that is, that amount of sodium metaborate which is in excess of the stoichiometric amount which will react with any hydrogen peroxide present to form sodium perborate.
  • the slurry density of the mixture in the crystallizer is defined as the weight (in grams) of sodium perborate crystals per 100 ml. of slurry.
  • the precise, slurry density necessary to obtain particles within the desired mesh size will depend on the product production rate and the seeding rate. For example, at a seeding rate of 20 percent and a production rate of 100 g./hr. of the star"-like product, a slurry density of 5 was found to produce satisfactory product. However, at a percent seeding rate, a slurry density of was required to prepare the same good quality product.
  • the sodium perborate star"-shaped crystals are prepared at a rate of between 50300 g./hr. per liter of active crystallizer volume, with a rate of 100 g./hr. per liter being preferred; the active crystallizer volume is the volume of slurry in the crystallizer wherein the crystals are uniformly distributed throughout the mother liquor. This production rate is obtained by regulating the amounts of the reactants which are added continuously to the crystallizer.
  • the reaction to form the sodium perborate is carried out in the crystallizer at temperatures of between 25-45 C. Temperatures below 25 C. tend to form finer size particles than desired, while temperatures above 45 C. cause excessive decomposition. By operating at temperatures of 25 C. or slightly above, commercial operation of this process is simplified because refrigerated cooling water does not have to be used to condense the water evaporated in commercial vacuum crystallizers normally employed in crystallizing the sodium perborate.
  • the reaction liquor in the crystallizer is maintained at a fixed temperature-to precipitate the crystals of sodium perborate under either atmospheric pressures or reduced pressures.
  • Reduced pressures are preferred in order to facilitate evaporation of water from the reaction liquor in the crystallizer, and to aid in controlling the temperature of the reaction liquor.
  • the removal of some water is desired to maintain the volume of reaction liquor constant, thereby obviating the need to sewer excess liquor containing reactants.
  • preformed seed crystals of sodium perborate tetrahydrate having a prismatic form and having a length:width ratio of at least 3:1 must be added to the crystallizer, along with the hydrogen peroxide and sodium metaborate.
  • These seed crystals are produced, in either a batch or a continuous crystallization operation, by adding concentrated sodium metaborate (about 5 M) and hydrogen peroxide having a concentration of from 15-70 percent to a saturated sodium perborate mother liquor having a temperature of from 25-45 C.; the preferred temperature for making the seed crystals is about 35 C.
  • the crystals precipitate from solution at a rate of 25-300 g./hr. per liter and are separated from their mother liquor by filtering or by other known separating techniques.
  • stoichiometric amounts of hydrogen peroxide and sodium metaborate solution are added to an agitator-equipped tankor crystallizer containing a saturated solution of sodium perborate.
  • additional hydrogen peroxide and metaborate solution are added to the crystallizer, perborate crystals precipitate, and some of these crystals are removed continuously for use as seed.
  • the rate for producing sodium perborate seeds is between 25--300 g./l. per hour, with 150 g./l. per hour being preferred. This rate, i.e., 150 g./l. per hour, refers to the grams of seed crystals that are crystallized from one liter of active crystallizer volume each hour.
  • the slurry density of the crystallizer liquor can range from 5-40. Generally, a high slurry density is preferred in order to obtain high production rates. For example, in order to obtain a 100 g./l. per hour production rate, a slurry density of 10-20 is preferred, i.e., 10 to 20 grams of sodium perborate per 100 ml. of active crystallizer volume.
  • both the sodium metaborate solution and hydrogen peroxide are added continuously.
  • the crystallization takes place constantly with the constant addition of reactants, and the production rate varies, depending on the amounts of ingredients added. These should be regulated to yield from 25-300 g., and preferably 150 g. of seed crystals per hour per liter of active crystallizer volume.
  • this addition time should range from 45 minutes to 2 k hours to permit the crystallization of abatch over this period of time.
  • the seed crystals are long, needle-like crystals, i.e., prismatic crystals, having a lengthzwidth ratio of between 3: 1-10: 1.
  • These crystals can be individual, prismatic crystals or may be grouped together in clusters having a common center with protruding ends to form small, star"-shape configurations.
  • the number of rectangular, needle-like crystals which make up these star"-shaped clusters can range from between 2 and 20.
  • Sodium perborate crystals were removed every 15 minutes during the run at a rate corresponding to 100 g./l. per hour.
  • the product was isolated by passing the mother liquor slurry through a vacuum filtration stage where the sodium perborate crystals were separated and then returning the filtered mother liquor back to the crystallizer. Sufficient water was evaporated in the vacuum crystallizer to maintain the level of mother liquor constant so that no mother liquor was discarded during the run.
  • the resulting sodium perborate tetrahydrate seed crystals were found to hem the form of prismatic crystals having a length:width ratio of above 3:1. Many of these small crystals were clustered around a common center having protruding ends beyond the common center and giving a star"-like appearance. The bulk density of these sodium perborate crystals was 0.36 g./cc. and the range of particle size was 34-91 mesh. These sodium perborate tetrahydrate crystals were used as seed crystals in subsequent example 3, Run A.
  • the resulting crystals had a bulk density of 0.45 g./cc.
  • the crystals were prismatic, needle-like crystals having a lengthzwidth ratio of above 3:]. While a few of the crystals were single, prismatic crystals, the major form was clusters of from 2 to of these needle-like crystals having common centers and the ends protruding beyond the common center to yield a star"1ike structure. These crystals were used as seed crystals in example 4.
  • EXAMPLE 3 RUN A PREPARATION OF STAR- SHAPED SODIUM PERBORATE TETRAI-IYDRATE CRYSTALS USING CONTINUOUSLY PREPARED SEEDS
  • a 3 A liter, vacuum crystallizer was charged with a saturated, aqueous solution of sodium perborate having a temperature of 35 C.
  • the saturated solution which had a volume of about 3 B liters also contained 0.8 g./l. of borax and 16 g./l. of excess sodium metaborate (sodium metaborate in amounts beyond the stoichiometric amounts required to produce sodium perborate with any hydrogen peroxide which is present in solution).
  • aqueous solution containing 35 percent hydrogen peroxide and an aqueous solution of 5.4 M sodium metaborate were both added continuously to the crystallizer at a rate sufficient to produce 100 g. of sodium perborate tetrahydrate per hour per liter of slurry in the crystallizer.
  • Sodium perborate tetrahydrate seed crystals prepared in example were also added continuously with the sodium metaborate and the hydrogen peroxide solutions so as to achieve a seeding rate of 16.7 percent. This required adding 20 g. of seeds per hour per liter of slurry.
  • the seeding rate is the weight of sodium perborate tetrahydrate seeds which are added per hour divided by the weight of the final product which is produced per hour from a crystallizer. Accordingly, for every 100 g./hr. of sodium perborate tetrahydrate product recovered, 16.7 g./hr. of seeds were added to the crystallizer.
  • the sodium perborate tetrahydrate product was removed from the crystallizer at a rate of about 120 g./hr. per liter of slurry in the crystallizer. This was done by constantly passing the mother liquor and crystal slurry through a vacuum filter, separating the crystals from the mother liquor and returning the mother liquor back to the crystallizer.
  • the slurry density (weight in grams of crystals per 100 ml. of slurry) of the liquor in the crystallizer was 10, and sufiicient water was removed under vacuum to maintain the volume of the mother liquor constant throughout the run.
  • the crystallizer was operated for several hours until a steady state had been reached.
  • the resulting sodium perborate tetrahydrate product which was recovered was found to have a bulk density of about 0.47 g./cc., a mean particle size of 29 mesh and to be in the form of prismatic crystals with a lengthzwidth ratio of 3:1 to 6:1.
  • the prismatic crystals were clustered into groups having common centers with protruding ends beyond the common centers to give a star"-like appearance. These crystals are shown in FIG. 2 of the drawings which are photomicrographs of the crystals under a 15x magnification.
  • FIG. 1 of the drawings illustrates photomicrographs of conventional sodium perborate crystals prepared by mixing together hydrogen peroxide and sodium metaborate at substantially room temperature, except that no sodium perborate tetrahydrate seeds of the type described in the present invention were added to the crystallizing solution. Rather, the product was separated from its mother liquor, and the motherliquor simply recycled back to the crystallizer. As will be readily apparent, these are in the shape of small, irregular, squat, columnar crystals having a bulk density of from about 0.7 to about 0.8 g./cc.
  • EXAMPLE 4 PRODUCTION OF STAR-SI-IAPED SODIUM PERBORATE TETRAHYDRATE CRYSTALS USING BATCH-WISE PREPARED SEEDS
  • the procedure of example 3 was repeated, except that the seed crystals which were added were those prepared as set forth in example 2.
  • the seed crystals were added in the I amount of 20 g./hr. to yield a seeding rate of 16.7 percent.
  • the slurry density in the crystallizer was 15 instead of 10 as in example 3.
  • the solution of mother liquor in the crystallizer analyzed 35 g./l. of sodium perborate, 16 g./l. of excess sodium metaborate (the amount in excess of the stoichiometric amount required to react with any hydrogen peroxide to produce sodium perborate) and 0.8 g./l. of borax.
  • a state of steady operation was reached in the crystallizer after about 2 to 3 hours, and the sodium perborate tetrahydrate product which was recovered had a bulk density of 0.45 g./cc., a mean particle size of 21 mesh and a friability of 8 percent.
  • the friability is determined as follows: 20 g.
  • the final sodium perborate tetrahydrate product was made up of prismatic crystals having a lengthzwidth ratio of 3:1 to 7:1; clusters of from 4 to 20 of these prismatic crystals were grouped together about a common center with protruding ends beyond the common center to yield a star"-like cluster.
  • EXAMPLE 5 To produce a star"-shaped sodium perborate monohydrate product the following procedure was utilized. A 100 gram sample of the star"-shaped sodium perborate tetrahydrate product produced from example 3, Run A was suspended on a screen in a container and forced, dry, heated air was passed through the container and through the sample on the screen for about 30 minutes until the sample was completely dehydrated to the monohydrate. The temperature of the sample during the conversion was about 50 C. The resulting, star-shaped sodium perborate monohydrate had the same gross morphology as the precursor crystals and its bulk density was 0.39 g./cc.
  • the star"-shaped sodium perborate tetrahydrate can also be converted into other sodium perborate products, such as effervescent sodium perborate, which has the property of giving off gaseous oxygen on contacting water.
  • This conversion was carried out as follows: a 100 gram sample of "starshaped sodium perborate tetrahydrate product produced as set forth in example 3, Run A was placed in a vertical tube and dry, hot air was passed upward through the tube at a superficial, linear velocity of about 2 feet per second. The sample was suspended by the air stream and while suspended was heated to 150 C.
  • a starshaped sodium perborate product can be produced in the form of tetrahydrate or monohydrate crystals or as a sodium perborate product containing active oxygen and/or gaseous oxygen. It is intended that the term sodium perborate, as used in the specification and claims, includes all hydrates of sodium perborate containing from 1 to 4 waters of crystallization, and mixtures thereof, as well as sodium perborate that contains active oxygen and/or gaseous oxygen (as defined in US, Pat. No. 3,421,842).
  • sodium perborate prismatic crystals having a lengthzwidth ratio of 3:1 to 10:1, said crystals grouped together in clusters have a common center with ends protruding from said common center to form star"-shaped clusters, said clusters having a size greater than 60 mesh and a bulk density of from about 0.3 to about 0.6 g./cc, prepared by the process of claim 2.
  • Process of producing sodium perborate in the form of prismatic crystals having a lengthzwidth ratio of 3:1 to 10:], said crystals being radially clustered about a common center in a star-shaped cluster having a size larger than 60 mesh and a bulk density of 0.3-0.6 g./cc. which comprises reacting together at 25-45 C., in an aqueous medium, hydrogen peroxide and sodium metaborate in a mole ratio of H,O,:BO, of 1:1 in the presence of externally prepared, preformed seed crystals of sodium perborate tetrahydrate having a smaller size than the desired product and a lengthzwidth ratio of at least 3:] and separating the resultant sodium perborate crystals from their mother liquor.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Detergent Compositions (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
US806979A 1969-03-13 1969-03-13 Light bulk density sodium perborate Expired - Lifetime US3661510A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US80697969A 1969-03-13 1969-03-13

Publications (1)

Publication Number Publication Date
US3661510A true US3661510A (en) 1972-05-09

Family

ID=25195277

Family Applications (1)

Application Number Title Priority Date Filing Date
US806979A Expired - Lifetime US3661510A (en) 1969-03-13 1969-03-13 Light bulk density sodium perborate

Country Status (8)

Country Link
US (1) US3661510A (enrdf_load_stackoverflow)
JP (1) JPS4820719B1 (enrdf_load_stackoverflow)
BE (1) BE747092A (enrdf_load_stackoverflow)
BR (1) BR7017364D0 (enrdf_load_stackoverflow)
DE (1) DE2008776A1 (enrdf_load_stackoverflow)
ES (1) ES377461A1 (enrdf_load_stackoverflow)
FR (1) FR2045270A5 (enrdf_load_stackoverflow)
NL (1) NL7003578A (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3985862A (en) * 1972-09-02 1976-10-12 Deutsche Gold- Und Silber-Scheideanstalt Vormals Roessler Process for the production of sodium perborate
US4185960A (en) * 1977-04-08 1980-01-29 Interox Super-oxidized solid sodium perborate and processes for its manufacture
GB2188914A (en) * 1986-04-08 1987-10-14 May Helan Vivien Production of sodium perborate
WO2002036085A1 (en) * 2000-11-03 2002-05-10 Chemlink Laboratories, Llc Expanded perborate salt, use, and method of production

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2004158C3 (de) * 1970-01-30 1979-04-05 Kali-Chemie Ag, 3000 Hannover Verfahren zur Herstellung eines rieselfähigen abriebfesten Natriumperborattetrahydrats mit niedrigem Schüttgewicht
JPS5562285U (enrdf_load_stackoverflow) * 1978-10-24 1980-04-28
JPS55100589U (enrdf_load_stackoverflow) * 1979-01-08 1980-07-12

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2223903A (en) * 1940-12-03 Method of producing a perborate of
US2257461A (en) * 1940-03-23 1941-09-30 Du Pont Sodium perborate product
US2828183A (en) * 1954-12-21 1958-03-25 Du Pont Production of sodium perborate
US2947602A (en) * 1955-08-29 1960-08-02 Shell Oil Co Production of sodium perborate in stable form
FR1436629A (fr) * 1965-02-17 1966-04-29 Electrochimie Soc Nouveau perborate de sodium et procédé de préparation
US3348907A (en) * 1963-04-13 1967-10-24 Kali Chemie Ag Process for preparing a highly porous sodium perborate

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2223903A (en) * 1940-12-03 Method of producing a perborate of
US2257461A (en) * 1940-03-23 1941-09-30 Du Pont Sodium perborate product
US2828183A (en) * 1954-12-21 1958-03-25 Du Pont Production of sodium perborate
US2947602A (en) * 1955-08-29 1960-08-02 Shell Oil Co Production of sodium perborate in stable form
US3348907A (en) * 1963-04-13 1967-10-24 Kali Chemie Ag Process for preparing a highly porous sodium perborate
FR1436629A (fr) * 1965-02-17 1966-04-29 Electrochimie Soc Nouveau perborate de sodium et procédé de préparation
GB1142304A (en) * 1965-02-17 1969-02-05 Electro Chimie Metal Sodium perborate and process for its preparation

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3985862A (en) * 1972-09-02 1976-10-12 Deutsche Gold- Und Silber-Scheideanstalt Vormals Roessler Process for the production of sodium perborate
US4185960A (en) * 1977-04-08 1980-01-29 Interox Super-oxidized solid sodium perborate and processes for its manufacture
GB2188914A (en) * 1986-04-08 1987-10-14 May Helan Vivien Production of sodium perborate
GB2188914B (en) * 1986-04-08 1990-04-11 May Helan Vivien Improvements in or relating to the production of sodium perborate
WO2002036085A1 (en) * 2000-11-03 2002-05-10 Chemlink Laboratories, Llc Expanded perborate salt, use, and method of production
US6491947B2 (en) * 2000-11-03 2002-12-10 Chemlink Laboratories, Llc Expanded perborate salt, use, and method of production

Also Published As

Publication number Publication date
DE2008776A1 (de) 1970-09-24
BE747092A (fr) 1970-08-17
JPS4820719B1 (enrdf_load_stackoverflow) 1973-06-22
BR7017364D0 (pt) 1973-06-07
FR2045270A5 (enrdf_load_stackoverflow) 1971-02-26
NL7003578A (enrdf_load_stackoverflow) 1970-09-15
ES377461A1 (es) 1973-02-01

Similar Documents

Publication Publication Date Title
US5194238A (en) Process for the production of highly pure concentrated slurries of sodium hypochlorite
EP0513167B1 (en) Process for the production of highly pure concentrated solutions of potassium hypochlorite
US2986448A (en) Preparation of sodium percarbonate
US2174614A (en) Method of producing polyphosphates and polyphosphate mixtures
US3035056A (en) Potassium dichloroisocyanurate
US4606843A (en) Process for producing a dried, stable mixture of alkali metal or alkaline earth metal ferrate (VI) compounds with hydroxides and carbonates
US3661510A (en) Light bulk density sodium perborate
US3035054A (en) Cross kbl-tklihul
JPS596801B2 (ja) 過炭酸ソ−ダの製造法
US2541733A (en) Production of alkali metal carbonate perhydrates
US2887360A (en) Purification of sodium carbonate monohydrate
US3251647A (en) Process for producing calcium hypochlorite of high purity and available chlorine content
US3369866A (en) Production of solid potassium metabisulfite
CA1070084A (en) Continuous crystallization process for preparing sodium carbonate peroxide
US4118466A (en) Process for the production of compact, coarse sodium percarbonate
US4906778A (en) Process for the production of aminoguanidine bicarbonate
US3644089A (en) Preparation of sodium carbonate
US2616783A (en) Process for the preparation of solid chlorite
US3801706A (en) Preparation of sodium percarbonate
US4579725A (en) Potassium monopersulfate compositions and process for preparing them
US4590058A (en) Process for producing high purity solutions of alkali metal hydrosulfites
US3384453A (en) Process for preparing highly crystalline alpha strontium acid phosphate
US3300281A (en) Method for manufacture of cyanamide
CA1045341A (en) Continuous process for the production of calcium hypochlorite
US3270017A (en) Method for producing stable salts of dichloroisocyanuric acid