The article presents the results of oxidative leaching of lead sludge from copper production in order to extract rhenium into solution. The optimum regimes for product leaching man-made product in the presence of sodium peroxocarbonate Na₂CO₃1.5H₂O₂ has been established: Experimental work was carried out under the following conditions: oxidant consumption 5 by weight of the raw material, leaching temperature 70C, duration 3060minutes, stirring speed 200rpm, and the ratio of liquid to solid S:L=1:3. The degree of extraction of rhenium into the solution is 9597, and the content reaches 500520mg/L Re.

The Karatau black shale petroleum-like strata (Southern Kazakhstan) belong to rocks with high organic matter content and are compositionally close to the classical Domanik formations of the Volga–Ural petroleum province. They were formed in marine basins with limited hydrodynamics, high concentrations of organic matter, and low oxygen levels. These conditions ensured the accumulation of hydrogen-rich sapropelic organic matter and created favorable conditions for metal enrichment (V, Mo, Ni, U). In the Karatau black shale ores, vanadium occurs at concentrations of 0.05–0.2% V2O5, predominantly in the form of vanadyl porphyrins (V–organic complexes) associated with oil and bitumen. From black shale petroleum-like formations, vanadium is obtained in the form of ammonium metavanadate. Ammonium metavanadate is a key intermediate product for the production of high-purity vanadium, which is widely used in metallurgy, the chemical industry, and increasingly in energy storage systems such as vanadium redox flow batteries. The quality of the electrolyte in these systems critically depends on the purity of NH4VO3, the precursor of compounds such as V2O5 and VO2. This study considers chemical and physicochemical methods for purifying NH4VO3, with a focus on the efficiency of removing impurities such as Na, Mg, P, Al, K, Ca, Cr, Mn, Fe, Ni, As, Mo, Cd, Ba, Pb, and Si. Aluminum sulfate (Al2(SO4)3) was used in the first two purification stages and showed high efficiency in removing phosphorus (65.3% in the first stage, 99.03% in the second), silicon (63.16% and 94.74%), as well as manganese and arsenic (>90%). The total impurity removal reached 26.44% after the first stage and 36.95% after the second. Subsequent three-step recrystallization further increased the purity: 69.31% after the first stage, 87.65% after the second, and 91.97% after the third. After all five stages, an NH4VO3 solution with a purity of 99.94% was obtained.