Canadian researchers have recently conducted pioneering work that has brought a new method for the recovery and separation of metals from spent alkaline batteries, thus constituting a new step forward for battery recycling. This new method offers an opportunity to increase the efficiency of extraction of these materials and reduce the impact on the environment.
While global energy needs are constantly growing, batteries are playing a more significant role. However, if discarded in the wrong manner, such batteries are environmentally sensitive because of the metals they contain. Recycling can not only reduce these adverse effects but also provide an effective way of obtaining important and scarce materials.
The study published in the Journal of Chemical Technology and Biotechnology illustrates a method that is cheaper and more energy efficient compared to the existing ones. Lead researcher Noelia Muñoz García of the Université de Sherbrooke stressed that the main focus should be made on the main minerals of alkaline batteries, which account for more than 70% of spent batteries in North America.
This research is relevant to the circular economy since it aims to reuse and recycle materials to form a loop. As a result of resource optimization, this approach fosters sustainable economic development and complies with international conventions such as the Paris Climate Accord.
The new process is called hydrometallurgy, where the metal extraction is done using aqueous solutions at room temperature and not at high temperatures, making it more efficient. The improvement is that the extraction of metals follows three steps of leaching, where different leaching agents are used in an attempt to produce better-quality leachates with fewer costs incurred in purification.
The study was able to realize an overall efficiency of extraction of 99.6% for zinc and 86.1% for manganese. Another researcher, Antonio Avalos Ramirez, also stressed the need to use appropriate leaching and reducing agents like sulfuric acid and hydrogen peroxide to boost extraction.
In the future, the researchers plan to advance the technique and create separation and purification units to obtain zinc and manganese of commercial quality for new products. Subsequent research will be devoted to the development of the process for large-scale production and application.
