Galvanotechnics

Development of an environmentally friendly technology for metal chemistry and electroplating

In metal chemistry and surface coating technologies, the drag-in and drag-out of process solutions in the course of rinsing processes is a significant source of wastewater production. The application of new technologies and surface finishes for transport containers allows a significant reduction in the carry-over of these materials. For example, a regeneration process has been developed for a combined Zn/Ni electrolyte which will allow the completion of the material cycle in this subprocess. 

Summary

In electroplating, the adhesion of fluids to solid components associated with the carry-over of process fluids to work pieces, drums and racks results in the substantial loss of source chemicals, which will then need to be replenished.

Downstream baths are contaminated by this ingress of materials, and by unwanted reaction products, and will consequently need to be replaced or treated, together with rinsing water, once a given contamination limit has been reached.

Under the terms of an overall research project, the common objective has been the development of processes for the minimisation of carry-over.  The influence of surface condition upon carry-over has also been investigated and evaluated.

Results:

  • Although physical treatment processes for the reduction of carry-over have been investigated, these have not been shown to have any influence.
  • However, a clear reduction in carry-over losses can be achieved by the optimisation of the surface finish and geometries of support structures and transport containers for components.  No modification to the existing installation will be required.
  • A regeneration process has been developed for a special zinc-nickel electrolyte which will allow the virtual completion of the material cycle in this subprocess.  By means of evaporation, the complete separation of useful materials from degradation products (contaminants) can be achieved.
  • Control and instrumentation technology for this process has been developed and implemented on an operational scale.  A basis has also been established for the transfer of this process to other electrolytes with a significant organic content.

More Project Informations

Project title:  Development of an environmentally friendly technology for metal chemistry and electroplating

Project number:  01RW0203 (Teilvorhaben 1 und Anschlussvorhaben), 01RW0002 (Teilvorhaben 2), 01RW0003 (Teilvorhaben 3), 01RW0004 (Teilvorhaben 4)

Project period:  2000 - 2003

Project region:  Germany (Saxony)

Project contact:

Herr Prof. Stelter

This email address is being protected from spambots. You need JavaScript enabled to view it.

++ 49/3731/39-2015

++ 49/3731/39-2268

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Source: German National Library of Science and Technology Hannover (TIB)