Spent Ni–Cd batteries are now considered an important source for many valuable metals. The recovery of cadmium, cobalt, and nickel from spent Ni–Cd Batteries has been performed in this study. The optimum leaching process was achieved using 20% H2SO4, solid/liquid (S/L) 1/5 at 80 °C for 6 h. The leaching efficiency of Fe, Cd, and Co was nearly 100%, whereas the leaching efficiency of Ni was 95%. The recovery of the concerned elements was attained using successive different separation techniques. Cd(II) ions were extracted by a solvent, namely, Adogen® 464, and precipitated as CdS with 0.5% Na2S solution at pH of 1.25 and room temperature. The extraction process corresponded to pseudo-2nd-order. The prepared PTU-MS silica was applied for adsorption of Co(II) ions from aqueous solution, while the desorption process was performed using 0.3 M H2SO4. Cobalt was precipitated at pH 9.0 as Co(OH)2 using NH4OH. The kinetic and thermodynamic parameters were also investigated. Nickel was directly precipitated at pH 8.25 using a 10% NaOH solution at ambient temperature. FTIR, SEM, and EDX confirm the structure of the products.
Considering how important rare earth elements (REEs) are for many different industries, it is important to separate them from other elements. An extractant that binds to REEs inexpensively and selectively even in the presence of interfering ions can be used to develop a useful separation method. This work was designed to recover REEs from spent nickel–metal hydride batteries using ammonium sulfate. The chemical composition of the Ni–MH batteries was examined. The operating leaching conditions of REE extraction from black powder were experimentally optimized. The optimal conditions for the dissolution of approximately 99.98% of REEs and almost all zinc were attained through use of a 300 g/L (NH4)2SO4 concentration after 180 min of leaching time and a 1:3 solid/liquid phase ratio at 120 °C. The kinetic data fit the chemical control model. The separation of total REEs and zinc was conducted under traditional conditions to produce both metal values in marketable forms. The work then shifted to separate cerium as an individual REE through acid baking with HCl, thus leaving pure cerium behind.
The ferruginous shale iron content (27.5 %) is a serious problem that prevents the separation of uranium. Chemical dissolution of the ferruginous shale from Um Bogma Formation, Egypt, has been studied for the recovery of uranium using the acidic leaching method. Um Bogma representative sample assays 700 ppm of uranium as the element of interest. The effective dissolution parameters such as acid concentrations, solid/liquid addition ratio, leaching time, and leaching temperature were planned to investigate. It was found that The dissolution rate was greatly influenced by the studied dissolution factors. Analysis of the kinetic data showed that the dissolution mechanism is fitted well to shrinking core model within chemical reaction as a rate determining step. It was found that the recorded activation energy (Ea) of uranium dissolution is 205 kJ/mol. The uranium dissolution efficiency of 95.2 % has been achieved with optimized conditions of 250 g/L H2SO4; 1 : 7 (S/L) phase ratio; 250 °C for 7 hours. Finally, the best‐controlling factors were applied for uranium separation from Um Bogma leach liquor to produce a uranium concentrate with 69.985 % uranium purity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.