Solar irradiation above various levels for 10-min and 1-hr integrals

In the summer of 1977 several 10 g samples of molybdenite ore containing 5–6 per cent Mo as MoS₂ were heated in one of the 2kW solar furnaces at the Laboratoire des Ultra-Refractaires, Odeillo, Frnace. The end products showed excellent separation with pure yellow acicular crystals of 9⁺ per cent MoO₃ and pure white SiO₂ powder being the two major components. Impurity levels in the MoO₃ did not exceed 6000 ppm while only a small fraction of the molybdenite was entrained along with the SiO₂. All treatment was done in a flowing oxygen atmosphere, and other elements condensed out at specific sites in the gas transport system. Analysis of the products was done by X-ray diffraction and X-ray fluorescence, emission spectroscopy, and wet chemical analysis. The ore was donated by Climax Molybdenum Co., Climax Co. The work is a joint effort of LASL and the Laboratoire des Ultra-Refractaires in Odeillo.