An Innovative Method for Complex Processing of Black Shale Ores to Produce Uranium, Vanadium, Molybdenum, and Rare Earth Concentrates

The current study provides a new leaching method for extracting valuable metals, such as uranium, vanadium, molybdenum, and rare earth metals (REMs), from black shale ores. Initial characterization indicated that these metals are encapsulated in hard “carbon-silica shells,” presenting severe extraction challenges. A novel low-temperature sintering process is considered in this work with ammonium hydrosulfate at ۳۵۰ °C for ۶۰ minutes, much lower than the conventional process of over ۸۰۰ °C. The devised treatment effectively ruptures the protective shell, converting metal constituents into soluble forms. Subsequent leaching yielded good recovery rates: uranium (۹۳.۳%), vanadium (۸۱.۷%), molybdenum (۸۲.۲%), and REMs (۷۸.۳%). Thermogravimetric analysis revealed the stepwise decomposition mechanism and emission profiles upon sintering. The leaching parameters (solid-liquid ratio, temperature, time, and solution concentration) were optimized for maximum metal recovery, along with selective sorption conditions (pH, redox potential, and duration) and desorption variables. Additionally, the cost-effective production routes for vanadium concentrate were specified as ammonium metavanadate, molybdenum concentrate as calcium molybdate and REM concentrate as carbonates, instead of depending on high-pressure or high-temperature processes. Solid residue carbon flotation enrichment was accompanied by a recovery yield of ۸۹.۰% by weight of carbon, enabling enhanced utilization of the entire resource. Altogether, the adopted approaches offer a closed-loop, energy-saving pathway to the efficient recovery of the rare and essential metals from the black shale ore.

کلیدواژه ها:

Black shale ore ، Sintering ، Leaching ، REM ، Sorption ، Concentrate