Evaluation of the Kinetic of Cu2+ Adsorption in the PVA Membranes Crosslinked with Sulfosuccinic and Citric Acids

Membrane of Poly (vinyl alcohol) (PVA) crosslinked with sulfosuccinic acid (SSA) and citric acid (CA) were characterized for the adsorption of copper ions (Cu2+). Usually the membranes used for this application have inorganic materials in their structure. However, when using only these acids, it was verified that the membrane containing SSA presents less swelling than the PVA and absorbs a higher content of Cu2+ when compared to the membrane containing CA. Therefore, it can be assumed that the membrane containing SSA can be used to cover soils that need protection against this type of ion. leaching. Kinetic models of diffusional and chemical control were used to understand the interaction phenomena of adsorption of ions and membranes. The mixed control kinetic model was also evaluated, in which it was possible to evaluate different parameters regarding the interaction ions and membranes. The obtained results indicated that the developed process has relevant utility. The kinetic modeling results contribute to a better understanding of heating phenomena of adsorption and also to the development of new cleaner technologies.

Roasting Pretreatment Combined with Ultrasonic Enhanced Leaching Lead from Electrolytic Manganese Anode Mud

A method of conventional roasting pretreatment combined with ultrasonic enhanced leaching with ammonium acetate was proposed to solve the difficult problem of lead in electrolytic manganese anode mud. The effects of concentration, liquid–solid ratio, temperature, leaching time and rotating speed on the leaching process under conventional and ultrasonic conditions were studied, and the lead leaching rate can be as high as 93.09% under optimized process parameters. A leaching kinetic model under conventional and ultrasonic conditions was established to explore the restrictive links of the leaching process. The results show that the leaching process under both conventional and ultrasonic conditions is controlled by diffusion, and the activation energies are 29.40 kJ/mol and 26.95 kJ/mol for the conventional and ultrasound enhance leaching processes, respectively.

Sustainable recovery of valuable metals from spent lithium-ion batteries using DL-malic acid: Leaching and kinetics aspect

An eco-friendly and benign process has been investigated for the dissolution of Li, Co, Ni, and Mn from the cathode materials of spent LiNi1/3Co1/3Mn1/3O2 batteries, using DL-malic acid as the leaching agent in this study. The leaching efficiencies of Li, Co, Ni, and Mn can reach about 98.9%, 94.3%, 95.1%, and 96.4%, respectively, under the leaching conditions of DL-malic acid concentration of 1.2 M, hydrogen peroxide content of 1.5 vol.%, solid-to-liquid ratio of 40 g l-1, leaching temperature of 80°C, and leaching time of 30 min. In addition, the leaching kinetic was investigated based on the shrinking model and the results reveal that the leaching reaction is controlled by chemical reactions within 10 min with activation energies (Ea) of 21.3 kJ·mol-1, 30.4 kJ·mol-1, 27.9 kJ·mol-1, and 26.2 kJ·mol-1 for Li, Co, Ni, and Mn, respectively. Diffusion process becomes the controlled step with a prolonged leaching time from 15 to 30 min, and the activation energies (Ea) are 20.2 kJ·mol-1, 28.9 kJ·mol-1, 26.3 kJ·mol-1, and 25.0 kJ·mol-1 for Li, Co, Ni, and Mn, respectively. This hydrometallurgical route was found to be effective and environmentally friendly for leaching metals from spent lithium batteries.