Reaction Kinetics and Catalysis Letters, Vol.92, No.2, 257-266, 2007
The role of pyrrhotite (Fe7S8) and the sample texture in the hydrothermal transformation of pentlandite ((Fe,Ni)(9)S-8) to violarite ((Ni,Fe)(3)S-4)
The catalytic role of pyrrhotite (Fe7S8) in the reaction kinetics of the hydrothermal transformation of pentlandite ((Fe,Ni)(9)S-8) to violarite ((FeNi2S4) was found to depend on the physical form of pyrrhotite. Pyrrhotite in fine scale intergrown with pentlandite boosts the reaction, whereas in a mechanical mixture of pyrrhotite and pentlandite, it plays the opposite role. This phenomenon was interpreted as result of dissolution of pyrrhotite under reaction conditions.