Abstract: A method for producing MoO.sub.3 from MoS.sub.2. MoS.sub.2 is combined with water to form a slurry which is then combined with at least one oxygen-containing oxidizing gas in a reaction chamber in order to initiate oxidization and conversion of MoS.sub.2 into MoO.sub.3. The oxidization and conversion of MoS.sub.2 into MoO.sub.3 is terminated before complete conversion of MoS.sub.2 to MoO.sub.3 takes place in order to generate a solid reaction product comprising MoO.sub.3 and unreacted MoS.sub.2 in combination with a residual liquid product comprising dissolved Mo therein. The oxidization and conversion process may be terminated when about 70-95% by weight MoS.sub.2 has been converted to MoO.sub.3. Thereafter, the solid reaction product is separated from the residual liquid product and the residual liquid product combined with at least one extractant in order to generate a liquid fraction containing dissolved Mo.