Abstract
Iron solubilities in spent pickling (HF-HNO3-H2O) solutions were determined as a function of HF and HNO3 acid concentrations. A chemical analysis of the industrial pickling solutions and sludges was performed. The stable phases observed in the sludges are FeF3·3H2O and (FeCr)F3·3H2O. Pure Fe metal, AISI 316 stainless steel and AISI 416 stainless steel were used in this study. The results show that the solubility of Fe increased as the concentrations of HF increased in the pickling solution at a fixed concentration of HNO3. A reasonable agreement between the experimental solubility data and the theoretical calculated data was obtained. X-ray diffraction analysis showed that the solid solubility product formed in the ternary solution containing pure Fe is mainly at a high pH value, FeO(OH) compounds and, at a low pH value, FeF33H2O compounds.
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SME nonmeeting paper 92-639.
Discussion of this peer-reviewed and approved paper is invited and must be submitted, in duplicate, prior to Aug. 31, 1993.
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Reddy, R.G., Wang, S. & Chen, B. Solubility of iron in spent pickling solutions. Mining, Metallurgy & Exploration 10, 102–107 (1993). https://doi.org/10.1007/BF03403009
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DOI: https://doi.org/10.1007/BF03403009