The precipitation of cobalt carbonate nanocrystals was achieved through the reaction of a pure and rich solution of cobalt sulphate (Co 2+ : 16.80 g/l) with a solution of carbonate solution (200 g/l). A surfactant was added to the reacting mixture in order to control the shape and size of generated crystallites. Two parameters were then varied i.e., the weight of surfactant agent and the precipitation time in accordance with Taguchi's L4 full experimental procedure (2 2 ). Chemical and structural characterizations tests of the obtained precipitates were done through X-Rays Fluorescence (XRF), Scanning Electron Microscopy (SEM) and X-Rays Diffractometer (XRD); whereas the size of crystallites was assessed according to the Laue-Scherrer formula. The results obtained from the variance analysis (ANOVA) indicated an optimal size of cobalt carbonate's crystallites of 13 nm with a cobalt content of 44.35% (equivalent to 89.45% of CoCO 3 ) at ambient temperature under the following conditions: pH = 7; Mixing speed: 800 tr/min; Surfactant weight: 8 g; and a mixing time: 10 minutes. SEM images revealed an agglomeration of the obtained nanocrystals due to suspected drying conditions i.e., drying temperature and drying atmosphere. It is suggested that the experiment should be conducted under neutral conditions at a temperature below that of cobalt carbonate's decomposition (181.41˚C).
A sulphate solution of cobalt (18.93 g/L Co 2+ ) containing major impurities such as copper (1.35 g/L Cu 2+ ), iron (0.28 g/L Fe tot ), zinc (0.70 g/L Zn 2+ ) and manganese (4.83 g/L Mn 2+ ) was purified through the solvent extraction method using two extractants; MEXTRAL and D2EHPA for the removal of copper and for the removal in two stages of a zinc-iron-manganese complex respectively. The effects of the solution's pH, O/A ratio, extraction time and stirring intensity were investigated. The purification extent was enhanced by optimizing these four parameters through Taguchi's L16 (4^4) experimental. The final solution obtained through sequential extractions showed a reduction in Cu, Fe, Zn and Mn content of 98.7, 97.5, 98.2, and 80.5% respectively. This study showcased the possibility of obtaining high purity cobalt as a precursor for Lithium ion battery applications, representing 49% of its current global use. The coextraction value of cobalt was estimated at 6.2%.
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.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.