Recovery of Heavy Metals by Crystallization in the Pelletreactor

Summary

Since 1980 DHV Consulting Engineers has been involved in the development of a new system for the recovery of heavy metals (Zn, Ni, Cu, Co, Cd, Mn, Ba, Sr, Pb and Hg) from waste water of the electro-plating industry (plating baths, drag-out baths, pickling baths, passivating baths, rinsing water). Since 1985 the Catholic University of Leuven has been involved in the fundamental research of the crystallization of heavy metal carbonates. Contrary to conventional waste water treatment methods (hydroxide precipitation) no sludge is produced but pure pellets of metalcarbonate. These pellets can be reused in the electro-plating industry, a.o. for the preparation of a new plating bath.

The plant is very compact, relatively cheap and can be used to treat various baths separately.

Pilot-plant research has yielded very favourable results for Zn, Ni and Cu. The financial possibilities of the system look very bright. In a subsequent project in 1986/87, the implementation of the system will be worked out in cooperation with a partner from the electro-plating industry.

The project is financially supported by the Dutch government.