High active oxygen content granulated sodium perborate product and method of making the same

A method for producing granulated sodium perborate monohydrate with an active oxygen content of 14 to 16% by weight and a dissolution rate of less than 1 minute, measured with a 2% by weight solution at 15.degree. C., comprising the steps of:

• removing spray-dried sodium perborate primary particles from a spray drier;
• introducing said perborate to an intensive mixing zone;
• heating said perborate to a temperature in the range of at least 60.degree. C. to 75.degree. C., and before, during or after said heating, adding an effective amount of powdery sodium perborate tetrahydrate under mixing condition, whereby said perborate tetrahydrate melts from said heating;
• allowing said perborate and said perborate tetrahydrate melt mixture to form the granulated sodium perborate;
• and
• post-drying said granulated sodium perborate.

A method for producing granulated sodium perborate monohydrate with an active oxygen content of 14 to 16% by weight and a dissolution rate of less than 1 minute, measured with a 2% by weight solution at 15.degree. C., a bulk weight greater than 600 g/l and an abrasion index less than 10% based on ISO test 5937, comprising the steps of:

• removing spray-dried sodium perborate monohydrate primary particles from a spray drier;
• introducing said perborate monohydrate to an intensive mixing zone;
• heating said perborate monohydrate to a temperature in the range of at least 60.degree. C. to 75.degree. C., and before, during or after said heating, adding 10 to 15% by weight sodium perborate tetrahydrate relative to the perborate monohydrate content, under mixing condition, whereby said perborate tetrahydrate melts from said heating;
• allowing said perborate monohydrate and said perborate tetrahydrate melt mixture to form the granulated sodium perborate monohydrate;
• and
• post-drying said granulated sodium perborate monohydrate.

A granulated sodium perborate monohydrate with an active oxygen content of 14 to 16% by weight and a dissolution rate of less than 1 minute, measured with a 2% by weight solution at 15.degree. C., a bulk weight greater than 600 g/l and an abrasion index less than 10% based on ISO test 5937, said granulated sodium perborate monohydrate produced by the process comprising the steps of:

• removing spray-dried sodium perborate monohydrate primary particles from a spray drier;
• introducing said perborate monohydrate to an intensive mixing zone;
• heating said perborate monohydrate to a temperature in the range of at least 60.degree. C. to 75.degree. C., and before, during or after said heating, adding 10 to 15% by weight sodium perborate tetrahydrate relative to the perborate monohydrate content, under mixing condition, whereby said perborate tetrahydrate melts from said heating;
• allowing said perborate monohydrate and said perborate tetrahydrate melt mixture to form the granulated sodium perborate monohydrate;
• and
• post-drying said granulated sodium perborate monohydrate.