MACO Pilot – Optimisation of the mixed-acid online monitoring and control in stainless steel pickling plants

Initial situation

• Economic pressure on European steel sector demands high flexible and favourable production
• Especially the pickling step is of high importance for stainless steel production
• High process flexibility needs a fast adjustment of defined concentrations in industrial mixed-acid pickling baths for achieving consistently high product qualities and plant productivity.
• Within the RFCS project FLEXPROMUS an innovative method for continuous HF-HNO₃-mixed-acid online analysis was successfully developed
• First prototype tests at stainless steel strip pickling lines showed very promising results

Project objectives

• Optimisation of online-measuring-technique for continuous concentration monitoring in HNO₃-HF-mixed acids
• Optimisation of concentration monitoring and control at stainless steel pickling facilities
• Online-measuring technique prototype test installations at stainless steel strip and wire rod pickling plants and acid regeneration plant

Innovative process approaches

• Continuous online-concentration monitoring of mixed acid pickling solutions by means of model based measuring technique
• Development of a „closed loop“-concentration control model for stainless steel strip pickling lines on basis of online-concentration data
• Development of a pickling programme management model for wire-rod pickling plants
• Concept development for improvement of existing European mixed acid pickling plants by online monitoring and control

Current results (as of 12/2017)

• Further optimisation of online-concentration measuring system set-up
• Database enhancement for online concentration calculation model
• Realisation of operational prototype online-measuring system installations
• Development of „closed-loop“-concentration control model for strip pickling line

Outlook

• Operational testing and further optimisation of prototype online-measuring system installations at stainless pickling plants
• Test and optimisation of the „closed-loop“ concentration control model
• Development and testing of pickling-programme management model for wire-rod pickling plants

• concentration monitoring
• control
• HNO3-HF
• mixed acid
• online
• pickling
• stainless steel