Hydrochloric acid pickling is a common practice in steel manufacturing industry. During the process, acidis consumed to dissolve surface oxides and metals ions are accumulated in the solution, which becomesless effective with time. In addition, the costly and risky waste acid disposal is another issue affecting thehot-dip galvanizing industry.In this work, a novel sustainable waste acid recovery process from pickling solutions based on circularapproach is proposed to tackle these issues. The innovative system allows (i) the continuous regenerationof pickling solutions to enhance process rate and performance and (ii) minimise the highly expensive andenvironmentally risky wastewater disposal. In this way, refilling pickling baths with fresh acid, as done inconventional operation, can be avoided and can be carried out continuously under optimal workingconditions. Moreover, the recovery of valuable substances (e.g. metal hydroxide or salts solution) can beobtained as an additional benefit. Continuous treatment and regeneration of pickling solution can beaccomplished by coupling diffusion dialysis (DD) and membrane distillation (MD) technologies with areactive precipitation unit where iron ions can be separated from the zinc-rich solution, in order torecover valuable products.To this purpose, a steady state process simulator was developed to predict the operation of the proposedintegrated process.
|Numero di pagine||13|
|Rivista||JOURNAL OF CLEANER PRODUCTION|
|Stato di pubblicazione||Published - 2019|
All Science Journal Classification (ASJC) codes