Process for the preparation of absorbent materials

Abstract

Methods are provided for preparing absorbent material, comprising providing non-broken down and uncut recycled fiber sludge having a moisture content of greater than about 40%; pelletizing said recycled fiber sludge to form wet pellets; and drying said wet pellets. The absorbent material is particularly useful as an industrial-grade waste liquid absorbent and/or an animal litter.

What is claimed is:  
     
         1 . A method for preparing an absorbent material comprising: 
 (a) providing non-broken down and uncut recycled fiber sludge having a moisture content of greater than about 40%;    (b) pelletizing said recycled fiber sludge to form wet pellets; and    (c) drying said wet pellets.    
     
     
         2 . A process according to  claim 1  wherein said recycled fiber sludge has a moisture content of greater than about 40% to about 70%.  
     
     
         3 . A process according to  claim 2  wherein said recycled fiber sludge has a moisture content of about 42% to less than about 70%.  
     
     
         4 . A process according to  claim 3  wherein said recycled fiber sludge has a moisture content of from about 50% to about 66%.  
     
     
         5 . A process according to  claim 1  comprising pelletizing said recycled fiber sludge with a die-roller pelletizer device.  
     
     
         6 . A process according to  claim 1  wherein said wet pellets remain substantially motionless relative to each other while drying.  
     
     
         7 . A process according to  claim 6  wherein comprising drying said pellets with a conveyor dryer.  
     
     
         8 . A method for preparing an absorbent material comprising: 
 (a) providing recycled fiber sludge having a moisture content of greater than about 50% to less than about 70%;    (b) pelletizing said sludge to form wet pellets; and    (c) drying said wet pellets.    
     
     
         9 . A method according to  claim 8  comprising providing recycled fiber sludge from a tissue-grade deinking mill.  
     
     
         10 . An absorbent material which is prepared by a process comprising: 
 (a) providing non-broken down and uncut recycled fiber sludge having a moisture content of greater than about 40%;    (b) pelletizing said sludge to form wet pellets; and    (c) drying said wet pellets.    
     
     
         11 . An absorbent material according to  claim 10  which is selected from the group consisting of an industrial-grade waste liquid absorbent and an animal litter.  
     
     
         12 . An absorbent material according to  claim 11  wherein said animal litter is a cat litter.  
     
     
         13 . An absorbent material according to  claim 10  wherein said recycled fiber sludge has an ash content of less than about 80%.  
     
     
         14 . An absorbent material which is prepared from uncut and non-broken down recycled fiber sludge and which comprises a bulk density of less than about 36 lb/ft 3  and a liquid absorbing capacity of at least about 1.1.  
     
     
         15 . An absorbent material according to  claim 14  which is selected from the group consisting of an industrial-grade waste liquid absorbent and an animal litter.  
     
     
         16 . An absorbent material according to  claim 15  wherein said animal litter is a cat litter.  
     
     
         17 . An absorbent material according to  claim 14  which comprises pellets having a diameter of about {fraction (3/32)} inch to about ¼ inch, and a length of about ⅛ inch to about ½ inch.  
     
     
         18 . An absorbent material according to  claim 17  wherein said pellets have a diameter of about ⅛ inch to about {fraction (3/16)} inch, and a length of about {fraction (3/16)} inch to about {fraction (5/16)} inch.  
     
     
         19 . A method of absorbing a liquid comprising contacting the liquid with an absorbent material which is prepared by a process comprising: 
 (a) providing non-broken down and uncut recycled fiber sludge having a moisture content of greater than about 40%;    (b) pelletizing said sludge to form wet pellets; and    (c) drying said wet pellets.    
     
     
         20 . A method according to  claim 19  wherein said liquid is selected from the group consisting of solvents, aqueous liquids and petroleum-based liquids.  
     
     
         21 . A method according to  claim 20  wherein said aqueous liquid comprises an animal waste liquid.  
     
     
         22 . A method according to  claim 21  wherein said animal waste liquid comprises urine.  
     
     
         23 . A method according to  claim 20  wherein said petroleum-based liquid comprises oil or grease.