Experimental Chevreul’s Salt Production Methods on Copper Recovery

Authors: Turan Çalban, Oral Laçin, Abdüsselam Kurtbas

Abstract:

Experimental production methods of Chevreul’s salt being an intermediate stage product in copper recovery were investigated on this article. Chevreul’s salt, Cu2SO3.CuSO3.2H2O, being a mixed valence copper sulphite compound, has been obtained by using different methods and reagents. Chevreul’s salt has an intense brick-red color. It is highly stable and expensive. The production of Chevreul’s salt plays a key role in hydrometallurgy. Thermodynamic tendency on precipitation of Chevreul’s salt is related to pH and temperature. Besides, SO2 gaseous is a versatile reagent for precipitating of copper sulphites, Using of SO2 for selective precipitation can be made by appropriate adjustments of pH and temperature. Chevreul’s salt does not form in acidic solutions if those solutions contains considerable amount of sulfurous acid. It is necessary to maintain between pH 2–4.5, because, solubility of Chevreul’s salt increases with decreasing of pH values. Also, the region which Chevreul’s salt is stable can be seen from the potentialpH diagram.

Keywords: Chevreul’s salt, copper recovery, copper sulphite, stage product.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1100641

References:

[1] T. Çalban, S. Çolak and M. Yesilyurt, “Statistical modelling of Chevreul’s salt recovery from leach solutions containing copper”, Chem. Eng. Process., vol. 45, 2006, pp. 168-174.
[2] J.B. de Andrade, L.A. da Silva, “Isomorphic series of double sulfites of the Cu2SO3.MSO3·2H2O (M= Cu, Fe, Mn, and Cd) type,” J. Braz. Chem. Sci., vol. 15, 2004, pp. 170-177.
[3] M. Inoue, H. Grijalva, M.B. Inoue, Q. Fernando, “Spectroscopic and magnetic properties of Chevreul’s salt, a mixed valence copper sulfite Cu3(SO3)2.2H2O”, Inorgan. Chim. Acta, vol. 295, 1999, pp. 125-127.
[4] A.J. Parker, D.M. Muir, “Recovery of copper powder from copper concentrates and from solutions of copper (II) sulfates using sulfur dioxide and aqueous acetonitrile”, Hydrometallurgy vol. 6, 1981, pp. 239-260.
[5] L.A. Silva, J.R. Matos, J.B. de Andrade, “Synthesis, identification and thermal decomposition of double sulfites like Cu2SO3.MSO3.2H2O (M = Cu, Fe, Mn or Cd)”, Thermochimica Acta, 360, 17 (2000).
[6] S. Çolak, T. Çalban, M. Yesilyurt, D. Sergili, Z. Ekinci, “Recovery of copper powders from leach solutions containing copper by means of ammonia, sulphur dioxide and acetonitrile”, Powder Technology, vol. 134, 2003, pp. 65-71.
[7] M. Yesilyurt, T. Çalban, “Precipitation of Chevreul’s Salt from CuSO4 Solutions with Na2SO3”, Chemical and Process Engineering, vol. 28, 2007, pp. 85-91.
[8] T. Çalban, S. Kuslu, S. Çolak, “Precipitation Conditions of Chevreul’s Salt from Syntetic Aqueous CuSO4 Solutions”, Chemical Engineering Communications, vol. 196, 2009, pp. 1018-1029.
[9] T. Çalban, B. Kaynarca, F. Sevim, H. Eroğlu, “Precipitation Conditions of Chevreul's Salt Using (NH4)2SO3 from Synthetic Aqueous CuSO4 Solutions”, Asian Journal of Chemistry, vo.. 26 (18), 2014, pp. 6111- 6117.
[10] P. Kierkegaard, B. Nyberg, “The crystal structure of Cu2SO3.CuSO3.2H2O”, Acta Chem. Scand., vol. 19, 1965, p. 2189.