System and process for battery recycling

Abstract

In a method of recycling sealed batteries, the batteries are shredded to form a shredded feedstock. The shredded feedstock is heated above ambient temperature and rolled to form a dried material. The dried material is screen separating into a coarse fraction and a powder fraction and the powder fraction is output. A system for recycling sealed cell batteries comprises an oven with a first conveyor extending into the oven. A rotatable tunnel extends within the oven from an output of the first conveyor. The tunnel has a spiral vane depending from its inner surface which extends along a length of the tunnel. A second conveyor is positioned below an output of the rotatable tunnel.

1 . A method of recycling sealed batteries, comprising:
 shredding said batteries to form a shredded feedstock;   heating said shredded feedstock above ambient temperature while rolling said shredded feedstock to form a dried material;   screen separating said dried material into a coarse fraction and a powder fraction; and   outputting said powder fraction.   
     
     
         2 . The method of  claim 1  wherein said batteries are alkaline batteries containing mercury, said heating comprises heating said shredded feedstock above ambient temperature and below the boiling point of mercury, said heating while rolling evaporates a portion of said mercury from said feedstock, and wherein said powder fraction comprises zinc oxide, manganese dioxide, and potassium hydroxide. 
     
     
         3 . The method of  claim 2  further comprising drawing air through said shredded material during said heating and rolling to draw off mercury vapour from said shredded feedstock. 
     
     
         4 . The method of  claim 3  further comprising sequestering said mercury in a scrubber. 
     
     
         5 . The method of any one of  claim 1  to  claim 4  further comprising swirling said air drawn from said shredded material to drop out any particulates from said air and returning said particulates to said shredded material. 
     
     
         6 . The method of any one of  claim 1  to  claim 5  further comprising magnetically separating said coarse fraction into a magnetic component and a non-magnetic component. 
     
     
         7 . The method of  claim 6  further comprising immersing said magnetic component in a first water bath and passing water from said first water bath through a screen to separate magnetic solids, and outputting said magnetic solids. 
     
     
         8 . The method of  claim 7  further comprising separating said magnetic solids based on their specific gravity prior to said outputting said magnetic solids and wherein said outputting said magnetic solids comprises outputting separated constituents of said magnetic solids. 
     
     
         9 . The method of  claim 7  or  claim 8  further comprising immersing said non-magnetic component in a second water bath and passing water from said second water bath through a screen to separate fluff, and outputting said fluff. 
     
     
         10 . The method of  claim 9  further comprising separating said fluff based on specific gravity of constituents of said fluff prior to said outputting said fluff and wherein said outputting said fluff comprises outputting separated constituents of said fluff. 
     
     
         11 . The method of  claim 9  or  claim 10  further comprising using at least a portion of said fluff as a combustible in said heating step. 
     
     
         12 . The method of any one of  claim 9  to  claim 11  further comprising combining water from said first water bath and said second water bath as a water component and filtering said water component to recover a powder component. 
     
     
         13 . The method of  claim 12  further comprising adding said powder component to said shredded material. 
     
     
         14 . A method of recycling sealed batteries containing mercury, comprising:
 shredding said batteries to form a shredded feedstock;   heating said shredded feedstock above ambient temperature and below the boiling point of mercury while rolling said shredded feedstock to evaporate a portion of said mercury from said feedstock to form a mercury reduced dried material;   screen separating said dried material into a coarse fraction and a powder fraction; and   outputting said powder fraction.   
     
     
         15 . A system for recycling sealed cell batteries, comprising:
 an oven;   a first conveyor extending into said oven;   a rotatable tunnel with a spiral vane depending from an inner surface of said tunnel extending along a length of said tunnel, said rotatable tunnel disposed within said oven and extending from an output of said first conveyor;   a second conveyor below an output of said rotatable tunnel.   
     
     
         16 . The system of  claim 15  further comprising a sieve downstream of an output of said second conveyor. 
     
     
         17 . The system of  claim 15  or  claim 16  further comprising a shredder upstream of an input of said first conveyor. 
     
     
         18 . The system of any one of  claim 15  to  claim 17  further comprising a leveller associated with said first conveyor. 
     
     
         19 . The system of any one of  claim 15  to  claim 18  further comprising a cyclone and a scrubber above said oven, and means for moving air upwardly through said oven, said cyclone and said scrubber. 
     
     
         20 . The system of  claim 19  further comprising at least one particulate filter between said oven and said scrubber.