Molybdenum chemistry in molten LiCl–KCl eutectic: an electrochemical and absorption spectroscopy study of the concentration dependent stability of solutions of K3MoCl6

Behavior of molybdenum in pyrochemical reprocessing: A spectroscopic study of the chlorination of molybdenum and its oxides in chloride melts

“…It can be seen that the absorbance did not change much in the 500-600 nm range but decreased considerably below 500 nm and a previously masked peak around 420 nm appeared. The resulting profile, B, corresponds closely to the spectrum of MoCl 3À 6 reported by Scheffler et al [10] at 25°C, and by Aleksandrov et al [13] and Gabriel et al [14] in high temperature melts. During the evacuation the absorbance above 500 nm remained essentially unchanged but below 500 nm there was a considerable decrease.…”

“…1 and 2). At high temperatures in chloride melts Mo(III) disproportionates to Mo(V) and Mo metal [13,14]:…”

“…This is identified as molybdenum pentachloride, formed as a result of the disproportionation of MoCl 3À 6 [13,14], Eq. (6).…”

“…Later Carlin and Osteryoung [11] and Barnard et al [12] studied molybdenum(II) and (III) chloride dimers in the same room temperature system but there are reports of such dimers in high temperature studies. Available hightemperature spectroscopy studies are limited to Aleksandrov et al [13] on the spectra of Mo(III) solutions obtained by anodic dissolution of Mo metal in CsCl, NaCl-CsCl and NaCl-KCl melts; and Gabriel et al [14] on the stability of molybdenum(III) solutions in LiClKCl eutectic. In both these studies the authors observed disproportionation of Mo(III) at high temperature, yielding Mo(V) and an insoluble fraction, attributed to molybdenum metal.…”

Stability of complex molybdenum(III) ions in molten alkali metal chlorides

“…ions are formed during anodic dissolution of the metal, as well as when molybdenum interacts with hydrogen chloride or chlorine in a melt or when alkali metal hexachloromolybdates(III) are dissolved [1][2][3][4][5][6][7]. During the chlorination of molybdenum by chlorine, the metal should be in excess; otherwise, Mo(III) is oxidized to the compounds of higher oxidation state.…”