The solid-liquid equilibria of the binary system (Mn(NO3)(2) + H2O) and the ternary system (Mn(NO3)(2) + Fe(NO3)(3) + H2O) at 0 degrees C and 20 degrees C were studied under air pressure using a synthetic method based on conductivity measurements. The branch of solubility of manganese nitrate tetrahydrate in the binary system was reviewed and clearly redefined in order to explain the scatter of solubility values in previous studies. The characterization of solid phases formed in the two isotherms of the ternary system was conducted using chemical analysis, atomic absorption spectroscopy (AAS), X-ray diffraction (XRD) and was confirmed by Schreinemaker's method of wet residue and the 'ensembles' method. The stable solid phases in both isotherms are: manganese nitrate hexahydrate (Mn(NO3)(2)center dot 6H(2)O) and iron nitrate nonahydrate (Fe(NO3)(3)center dot 9H(2)O). (C) 2018 Elsevier B.V. All rights reserved.