The Re-Mo-S system: new data on phase relations between 400 and 1200 degrees C

Abstract

Phase relations in the Re-Mo-S system were studied by the technique of evacuated silica tubes in the temperature range of 400-1200 °C. At 1000 °C, the following assemblages are stable: MoS2 + ReS2 + S2(v); MoS2 + ReS2 + (Re,Mo)ss + v; MoS2 + Mo2S3 + (Re,Mo)ss + v; Mo2S3 + χ + (Re,Mo)ss + v, Mo2S3 + χ + (Mo,Re)ss + v. Experiments aimed at the determination of the MoS2-ReS2 solid state solubility reveal an asymmetrical behaviour: molybdenite dissolves 2.7(9) wt% Re at 1000 °C, 2.6(4) wt% Re at 800 °C, and 2.2(6) wt% Re at 400 °C, whereas ReS2 shows negligible Mo contents at all temperatures. The experimental solubility of ReS2 in MoS2 far exceeds Re contents in natural molybdenite, for which literature reports hundreds to thousands ppm.