ELECTRODIALYSIS METHOD FOR PURIFYING OF SILICATE-CONTAINING POTASSIUM HYDROXIDE ETCHING SOLUTION

• Main Authors: CHANG, GOANGNG, YANG, WEI-LIANG, DOVE, CURTIS DOUGLAS
• Format: Patent
• Language: English; French
• Published: 29.01.2013
• Subjects: APPARATUS THEREFOR; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY ORREFINING OF METALS; SEPARATION; TRANSPORTING

An electrodialysis method for the treatment of silicate-containing potassium hydroxide etching waste solution is provided. The method comprises: providing a reaction tank including a cathode, an anode, and two cation dialysis membranes, wherein the reaction tank is divided by the cation dialysis membranes into a cathode chamber, an anode chamber and a waste solution disposing chamber located therebetween; filling a sulfuric acid solution into the anode chamber; filling a potassium hydroxide solution into the cathode chamber; introducing a silicate-containing potassium hydroxide etching waste solution into the waste solution disposing chamber; and applying a voltage and a current density to each of the chambers to render potassium ions to transport from the waste solution chamber through the cation dialysis membrane to the cathode chamber.