Lithium minerals, essential for energy storage technologies, are considered critical raw materials (CRM). They play a crucial role in enabling a carbon-free future through their utilisation in batteries and electric vehicles (EV). However, extracting lithium minerals (eg spodumene) from hard rock pegmatite ores requires overcoming significant challenges. Conventional flow sheets, which combine processes such as dense media, magnetic and flotation, enable effective metallurgical performance but do not target a waste production strategy. Consequently, this study addresses flow sheet development which combines explicitly metallurgical performance and waste management. In order to do so, a common thread has been identified through density among all the separation stages. In other words, a density-driven strategy, forming a zero-waste triangle based on mineralogy, flow sheet design, and waste management (that is to say, aiming at zero-waste). Dense Media Separation (DMS) and flotation rely on density as the common separation driver. DMS exploits particle density to concentrate out valuable mineral (from reject gangue). In contrast, flotation operates at lower bulk density scales, where the formation and stability of bubble-particle aggregates govern separation. Understanding the phenomenological behaviour of DMS and flotation aggregates provides the foundation for a robust resource recovery strategy. This approach frames waste not merely as a by-product, but as an integral element of the flow sheet, one that must be managed strategically over time and considered within technical and economic constraints. The current stage of the study focuses on flotation, beginning with mica removal to enhance selectivity and using bubble-particle aggregate density to guide spodumene recovery within a staged, zero-waste process. This research supports the development of an alternative and sustainable flow sheet for spodumene beneficiation at the Savannah mine (Portugal), as part of the EXCEED project funded by the European Union. Results from flotation testing will guide process scale-up and the refinement of density-based control strategies in hard rock lithium processing.