Extraction of rhenium from calcines of the oxidation roasting of low-grade molybdenite concentrate in a rotating tubular furnace

Consideration is given to the effect of various oxidizers used in the process of leaching on the extent of extraction of rhenium remained in the calcine as a result of incomplete sublimation upon the oxidation roasting of molybdenite concentrate in a tubular furnace. Its maximum extraction α Re = 88%) is reached when using manganese concentrate. It has been established that for the Almalyk Metallurgical Integrated Works the most suitable oxidizer is a mixture of nitric and sulfuric acids (α Re = 71–73%); in this case, a virtually complete purification of the calcine from copper takes place (≤0.05–0.07% Cu is retained in it). It is shown that molybdenum and rhenium that passed into solution can be separated by precipitation and ion-exchange methods.