Today in Europe, a galvanisation workshop can have annual cost of waste treatment from 40 000 to 120 000 Euro depending on the size of the industry and the country. All galvanisation workshops are confronted with the problem of elimination of pickling bath chemicals. The valorisation of these baths presents the most favourable solution.
The aim of the project was the pilot scale implementation of a new process in hot dip galvanisation workshops in order to demonstrate its efficiency and technical-economical viability, according to the earlier successful results of a CRAFT project. This project looked at the environmental problems of this industry through waste minimisation and proposed a clean technology compared to the traditional solutions.
The objectives of the project were to:
- improve the pickling process, introduce new concepts such as stirring and temperature control and optimise the management of the baths.
- avoid the cross contamination of Zn and Fe in both the pickling and the etching baths.
- produce valorizable wastes with the following characteristics: a bigger concentration of the metals iron and zinc in the bath; and no contamination of iron in the bath of zinc and vice versa.
The final result of the project were an optimised process based on existing pickling procedures. Most of the existing facilities and infrastructure in the hot dip galvanisation workshops could be used and some modifications will be needed. The final process will be based mainly on methodology and good practice without interference in the organisation and in the good quality of the galvanised materials being produced.