Dataset for "Red mud (bauxite residue) as a resource for carbon dioxide removal?"

Large-scale deployment of carbon dioxide removal (CDR, or negative emission technology) is increasingly relied on in model projections to achieve future carbon neutrality. These geoengineering techniques propose to remove CO2 from the atmosphere and store it for decades to millennia in other carbon reservoirs. Yet the techno-environmental viability of CDR schemes is largely unproven, and careful consideration is required concerning the long-term environmental and socioeconomic implications of increasing CDR reliance. One key viability challenge concerns the vast scale of material and energy resources required to support the CDR industry operating at gigaton CO2 year-1 removal capacity. Concepts such as ocean alkalinity enhancement (OAE) and enhanced weathering require alkaline minerals, which, if mined to support the CDR industry, will incur increasing environmental footprints. There are, however, perhaps some opportunities to better use existing waste resources to support these CDR concepts. Notably, red mud (bauxite waste) is an alkaline waste material from the aluminium industry with low (~5%) utilization. Around 4.6 billion tons of red mud are accumulated worldwide, thus red mud disposal is an increasing environmental and financial burden. Here, we critically evaluate whether red mud could make a suitable mineral for OAE. Whilst the impurity of red mud is a key challenge for its utilization, its cost-effectiveness is very favorable compared to other minerals. Thus, even if only a fraction of red mud can be utilized for OAE or other CDR purposes, doing so may be more cost-effective, more socially acceptable, and less environmentally damaging than mining new resources.