The use of recycled raw materials in the refining of battery chemicals

Abstract

The increasing demand for lithium-ion batteries has led to a heightened demand for the raw materials required for their production. To expand the supply capacity alongside the primary raw material stream, secondary streams, such as the recycling of battery materials, can be utilized. Recycling is driven by multiple factors, including legislation, continuously evolving recycling technologies, sustainability, and the increasing volume of material available for recycling. Despite the growing availability of recycled materials, primary production remains essential to meet the demand for battery metals. As recycled materials are not yet available in substantial quantities, exploring methods to integrate recycling streams into existing primary stream processing could enhance the efficiency and sustainability of battery metal production.

This thesis investigates the integration of recycling streams into the refining process of primary raw materials within the battery value chain. The objective was to identify points within the process where the integration of black mass, an intermediate product from battery recycling, could be incorporated into the battery metal refining process, with a focus on impurities. Given the numerous options for both primary and secondary processes, it is challenging to provide a singular solution for the integration point and therefore a process-specific approach is required.

As there is more than one option for integrating the recycling stream into the primary stream, a few considerations must be taken into account, such as the relative size of the secondary stream and the specific impurities present in the black mass. If the amount of black mass is relatively small compared to the primary stream, there are more options for the integration point and fewer considerations compared to scenarios where the black mass constitutes a larger part compared to the primary stream. Also, impurities are less critical if the secondary stream is minor relative to the primary stream. However, the quality of recycled materials can vary significantly, complicating the alignment of primary and secondary streams.

One of the most significant impurities in the black mass, as examined in this thesis, is fluorine, due to its potential corrosive effect. From the perspective of fluorine management, the safest option for integrating the black mass into the hydrometallurgical process route is post-leaching, after the removal of some fluorine before incorporating the black mass into the primary stream. Recycling streams from batteries can also be integrated into the pyrometallurgical process; however, some pretreatment of the batteries would be desirable to control the fluorine levels.