Multibillion oil shale resources within the Volga shale basin central part (Privolzhsky Federal District: Samara, Saratov, Ulyanovsk, and Orenburg regions) are low-quality sulfurous mineral raw materials. The commercial rhenium content in oil shale was found in the randomly selected samples from the Kashpirsky, Orlovsky, Perelyubsky, and Kotsebinsky fields. Rhenium concentration varies from 0.013 to 0.22 g/t with the ore marginal commercial concentration (as a concomitant component) of 0.05 g/t.
