Innovative Pickling Process for Stainless Steels With High Positive Impact both on Operational Costs and on Environmental Issues
(Room 307)
16 May 16
11:30 AM
-
12:00 PM
Tracks:
Pickling, Plant Upgrades & New Equipment Developments
Pickling operations are very important in the process for manufacturing stainless steel. Pickling is carried out in one or more reactors and involves several reactions and represents one of the most pollutant and costly chemical process in the steel industry.
The most largely used process includes electrochemical and chemical operations to remove oxides scale as well as Chromium-depleted layer generated on the strip surface during high temperature steel annealing process.
Both in the Hot rolled as well as for Cold rolled coils different acids are normally used in a multistep process; the impact of these chemicals in the environment is heavy due to the presence of the high corrosive acids and the hazardous substances as Hexavalent Chromium and NOx.
Tenova in the recent years addressed its research activities to develop new pickling technologies aimed to sensibly reduce the pollutants effects of the chemicals used in this process and to reduce as well the overall process operational costs.
After some years of intense research activities at CSM laboratories, a new pickling process has been successfully developed and tested up to pilot scale and industrial case in Italy. This new process has not only a reduced environmental impact but also much lower operational costs thanks to a dramatic reduction of consumptions of expensive acids (as HF and HNO3) and, as a consequence, the energy and fuel consumptions the treatments of relevant wastes.
The overall pickling cost saving is ranging from 4 to 6 USD/ton of product for a Cold Rolled Coils Annealing & Pickling Line.