Patent ID: 7264729

Claim:
A process for reducing contaminants in contaminated condensate resulting from the refining of aluminum, which comprises: (a) adding from 1 ppm to 1,000 ppm of a cationic melamine formaldehyde coagulant having a having a mean diameter of from about 1 micron to about 25 microns to the condensate to be treated; (b) then adding from 1 ppm to 1,000 ppm of a cationic mannich-tannin coagulant having a mean diameter of from about 40 microns to about 200 microns; (c) filtering said condensate with a continuous-backwash, fluidized bed upflow filter wherein the media of the fluidized bed develops a negative charge, and the temperature of the treated condensate is from 80° C. to 100° C., to reduce said contaminants in said condensate.