Abstract: A process for separating precious metals from an MnO.sub.2, sulfidic or carbonaceous refractory ore or refractory feed such as tailings is provided. The process includes the step of leaching a feed with a leach liquor that includes an acid selected from the group of HCl and H.sub.2 SO.sub.4 in the presence of MnO.sub.2 and a reductant. A source of chloride ion is added to the leach sufficient to dissolve at least about 50% of the precious metals present in the ore. A portion of the leach is removed and precious metals are recovered from the removed portion. A portion of the chloride carrier is recycled to the leach to carry chloride values to the leach. In one embodiment, HCl is regenerated by pyrohydrolysis, which minimizes harmful waste products. The present process can advantageously avoid the use of noxious reagents.

Abstract: A process for producing a high grade molybdenum disulfide powder suitable for use in the formulation of chemicals and as an intermediate for synthesizing high purity molybdenum compounds by which an impure particulated molybdenite concentrate feed material is pulverized and thereafter is subjected to a plurality of purification treatments to effect a progressive extraction of the contaminating mineral constituents entrapped within the molybdenite particles. The purification treatments comprise a wash treatment of the molybdenite concentrate containing up to 10% by weight of hydrocarbon oil employing an aqueous solution forming a slurry which is subjected to successive steps of high shear agitation and low shear agitation to break up the agglomerated molybdenite particles and to effect a release of the mechanically entrapped very fine mineral particles which remain suspended in the aqueous liquid phase.