Waste Water Treatment after Removal of Thermic Oxides from Stainless Steel Welding Joints. (23rd November 2009)

• Record Type: Journal Article
• Authors: Alar, V.; Runje, B.; Alar, Ž.
• Is Part Of: SRX engineering. Volume 2010(2010)
• Publication Date: 2009-11-23
• Subjects: Engineering -- Periodicals; 620
• DOI: 10.3814/2010/261423
• Languages: English
• ISSNs: 2090-1097

Abstract

Abstract : This work describes chemical methods of removal of thermic oxides from stainless steel welding joints, as well as waste water treatment. Thermal oxides were removed from the stainless steel surface using chemical and electrochemical procedures. A pickling paste that contains HNO 3 and HF in different ratios was used for chemical cleansing of thermal oxides (A, B, and C). Electrochemical removal was done using an apparatus Magic Cleaner, and as electrolyte a solution H 2 SO 4 + H 3 PO 4 was used. Concentrations of chromium, nickel, and iron in the waste water have been determined using Method of Atomic Absorption Spectrophotometrics (AAS). Measured concentrations of Cr, Ni, and Fe are higher than allowed according to legal regulations of the Republic of Croatia. Therefore, an ionic exchange treatment of the waste water is recommended.