15/06/2022 – Surface treatment
Pickling in a sustainable way
Agenda 2030 lists 17 interconnected goals for the sustainable development to protect the planet, end poverty and improve the lives of everyone, everywhere. In particular, goal 12 requires to “Ensure sustainable consumption and production patterns” This point affects very much the chemical metal surface treatment sector where a consolidated waste of resources is perpetrated.
Starting from the belief that this “modus operandi” will have soon to evolve to join the growing common feeling, Condoroil has been developing recovery technologies starting from the early 90’s. With the Condoroil approach, the chemical solutions, dumped from the metal surface treatments, are no more considered wastes but an economical resource to be exploited.
The resource consumption does not follow any more the production load and a decoupling of the economic growth from environmental depredation could be achieved.
When they consider a pickling process, we have to consider the production of two different waste streams, as to say the spent pickling solution and rinse water, contaminated by the pickling solution itself. With the use of the green technologies proposed by Condoroil it is today possible to pickle with zero discharge and resources consumption. In particular, the complete system would consist of a regeneration unit for the solution treatment and a water recycling unit.
The regeneration process would vary according to the processed metal and the used acid mix but the final target would not change, as to say the acid is recovered in the pickling operation while the metal is recovered as secondary raw material.
Different molecular separation technologies are used to get to the point, for example acid retardation resins + electrodialysis are used for the mix acids in the stainless-steel pickling, crystallization in the sulphuric acid carbon steel treatment and electrowinning in the copper alloys pickling.
When they consider rinse waters, the answer comes from the improvement of the chemical resistance of the reverse osmosis membranes. With a reverse osmosis concentration unit, it is in fact today possible to concentrate back the dragged solution producing demineralized water. The water can be recycled at the rinsing stages while the concentrated solution can be recovered in the pickling tank.
Condoroil Stainless srl
wire/Tube 2022, hall 7a booth D 19
Tel.: +39 0332 945212