Treatment of the Effluent Generated from the Pickling Method and to Remove their Toxic Property to Make it Eco-friendly

Abstract

Pickling is one of the effective processes of Cold Rolled Coil processing. The theory of pickling is based upon acid wash treatment by 6 to 8% of hydrochloric acid (HCl) to remove the iron scales from the coils. As the result Fe⁺², Fe⁺³ iron salts & acid are liberated as effluents. Those effluents need a proper treatment to remove their toxic properties & make them eco-environment friendly. In this industry the effluent is treated with a large effluent treatment plant where acid and iron is removed satisfactorily. After the treatment acid part is evaluated by the help of pH meter resulting generally 6 to 8 range which follow the National Institute for Occupational Safety and Health but due to some methodological problems iron part is not evaluated which need an efficient system. The major objective of this theme is to make the monitoring & remove the remaining iron part in the ultimate water, which is discharged after effluent treatment, & resulting an efficient regeneration & reuse of that water. In the present paper case study has been conducted where this pickling method is used in Tata Ryerson, which is a joint venture between Tata Steel & Ryerson Tull, USA. It has a state-of-the art Cold Rolled coil processing line in Bara, Jamshedpur. The coils are cut to lengths as per requirements & packed in wooden crates for dispatch to various locations. The machine at Tata Ryerson has facilities like eleven roll levelers that are capable of providing dead flat surfaces(10 I Units) with close tolerances(+/- 1 mm.) on the length.