Menetelmä syövytysliuoksen käsittelemiseksi ja uudelleenkäyttämiseksi

• Main Authors: WECKMAN,ANDERS, JOKINEN,JUHA
• Format: Patent
• Language: Finnish; Swedish
• Published: 14.10.2008
• Subjects: CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; 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; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; 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; PRINTED CIRCUITS

In the method, the spent stripper solution for tin or a tin mixture is treated to precipitate dissolved or suspended metal compounds. On the one hand chemicals for reuse, and on the other hand metals such as copper, tin, lead and/or iron are recovered from the waste water streams. Efficiency of the precipitation is improved by heating of the stripping solution at elevated temperatures, and by the addition of a precipitating reagent. Once the precipitate is removed, the remaining liquid may be reused, typically as an admixture with a fresh solution. In the production method of a regenerated stripping solution for tin comprising at least one inorganic acid, ferric ions, at least one organic acid, and at least one organic additive, the stripping solution is heated at elevated temperatures, precipitating reagent is added, precipitated matter is separated and removed, and one or some of the acids or additives mentioned are added for the recovery of the desired tin stripping capacity.