Patent ID: 7285677
Filing Date: 2007-10-23
Classification: B01J,C07C,C22B,Y02P

Abstract:
1. A method for recovering CTA (crude terephthalic acid) residues and purifying and regenerating catalyst, being used for recovering CTA (crude terephthalic acid) residues generated in a reaction process of oxidation in manufacturing PTA (purified terephthalic acid), said system comprises following steps: water washing CTA (crude terephthalic acid) residues: CTA residues are added with water for stirring in order to resolve catalyst discharged from said process of oxidation of said PAT (purified terephthalic acid) into said water; first time filtering and separating: said catalyst resolved in water is separated from solid organic material; sedimentation: said catalyst resolved in said water is added with inorganic alkali being used as an agent for sedimentation to collect metallic ions in said water, and concentration of said metallic ions in said water is lowered to a level to be adapted for discharging, and metallic salt is generated; second time filtering and separating: said metallic salt is filtered and collected, said catalyst then is purified and regenerated to produce oxidized catalyst from said metallic salt; and said purifying and regenerating catalyst includes steps of cobalt purifying/regenerating and oxidized catalyst producing wherein said cobalt purifying/regenerating step includes: a) an acid solution step; to resolve solid metal by adding inorganic acid solution; b) a neutralization and sedimentation step: to adjust pH value of said liquid to 4 to eliminate iron ions to form solution before extradition; c) a resin treatment step: to remove copper, nickel and chromium ions from said solution before extraction; d) a metal extraction step: to remove zinc and iron ions from said solution before extraction by extraction using organic extractant; and e) an electrolyzing step: to obtain metal cobalt by electrolyzing from liquid after extraction.