Systems, method and apparatus for reducing impurities in electrolysis cells

Abstract

Systems, methods and apparatus for reducing impurities in electrolysis cells are disclosed. In one approach, a method includes feeding a particulate fines feed stream to a tank, mixing particulate fines (PF) with liquid, the liquid having a first liquid and a second liquid, and separating at least some of the first liquid from at least some of the second liquid. The particulate fines (PF) may include inlet carbon fines (CF I ) and inlet recyclable fines (RF I ). The first liquid may include a recovered recyclable fines portion (RF 1 ), and the second liquid may include a waste carbon fines portion (CF 1 ). The mass ratio of the recovered recyclable fines portion (RF 1 ) to the inlet recyclable fines (RN I ) may be at least about 0.5. The mass ratio of the waste carbon fines portion (CF 1 ) to the inlet carbon fines (CF I ) may be at least about 0.1.

1 - 18 . (canceled) 
     
     
         19 . A system comprising:
 (a) a plurality of aluminum electrolysis cells adapted to produce aluminum metal;   (b) a gas treatment center adapted to:
 (i) receive off-gases from the aluminum electrolysis cells; and 
 (ii) discharge a particulate fines stream;
 wherein the particulate fines stream comprises particulate fines having a maximum diameter of not greater than about 45 microns; 
 wherein the particulate fines comprises carbon fines and recyclable fines; and 
 wherein the recyclable fines comprise alumina fines; 
 
   (c) a fines separator adapted to:
 (i) receive the particulate fines stream; 
 (ii) separate at least some of the carbon fines from at least some of the recyclable fines; and 
 (iii) discharge a recyclable fines outlet stream comprising recyclable fines; and 
   (d) an agglomerator adapted to agglomerate the recyclable fines of the recyclable fines outlet stream into an agglomerated product, wherein the agglomerated product has an average diameter of at least about 90 microns.   
     
     
         20 . The system of  claim 19 , wherein the recyclable fines outlet stream comprises bath fines.