Between 2020 and 2050, global tailing generation is projected to reach 300 Gt. When poorly managed, mine tailings pose significant environmental and safety risks, contributing to more than 2,650 recorded deaths since 1915. Despite this, the mining industry continues to rely heavily on reactive waste strategies—repurposing and reuse—rather than preventing tailings at the source. Ore-sand, a by-product derived from mineral processing, offers a preventative pathway. This opportunity stems from the realisation that most mineral waste originates from discarding dominant minerals—particularly silicates—that could instead be mined as fit-for-purpose by-products. Ore-sand has demonstrated strong technical feasibility as a substitute for natural sand, the world’s second-most consumed resource. An estimated 50 billion tonnes of natural sand are extracted annually from rivers and coasts, with environmental and social consequences particularly severe for communities in coastal regions. Successful implementations already exist. Vale’s Brucutu iron ore mine produces around 2 Mt of ore-sand per year, while Newmont’s Cadia copper–gold mine has demonstrated the viability of coarser ore-sand production using HydroFloat technology. However, despite these promising examples, no comprehensive method currently exists to estimate ore-sand resources, reserves, and recoverable quantities as a by-product, nor to align these estimates with application-specific and market-driven requirements such as particle size distribution, shape, elemental and mineralogical composition. In this study, we present the first framework for estimating ore-sand resources, reserves, and recoveries across different sand applications. We evaluate key factors influencing ore-sand generation, including primary commodity production, mineral processing circuits and technologies, market-based performance criteria, and market absorption. This framework provides a crucial foundation for understanding the true valorisation potential of ore-sand, including the volume of tailings that can be avoided, the degree to which natural sand extraction can be offset, and the extent to which ore-sand can meet the technical requirements of various sand applications.