The use of phosphate glasses based on the system iron sodium for the treatment of inorganic waste has been soon proposed. The coacervation of polyphosphates permits to formulate glass precursor in aqueous media and at room temperature from the mix FeCl2-NaPO3. The rheologic properties permit to coat each particle of the waste before the curing step. In this paper we determine the conditions of coacervate's formation. By Mossbauer spectroscopy, we show that the iron stays always in a ferrous state during the coacervate formation. It confirm also the presence of chlorine ions in the coacervate. By curing the coacervates give glasses and a part of iron is oxidised in a ferric state even in argon atmosphere. Mossbauer hyperfine parameters indicate that both Fe II and Fe III ions are in octahedral or pseudo octahedral coordination.