Life cycle analysis of recycling phosphate mining by-products in compressed earth blocks: a solution towards...

The mining industry plays a critical role in the economic growth worldwide. However, mining activities are linked to significant environmental impacts, including land-use alteration via land degradation, ecotoxicity and ecosystem damage via water/soil contamination and biodiversity loss, and climate change via waste generation and greenhouse gas emissions. A thorough understanding of the environmental impact of mining operations is provided by evaluating these effects using life cycle assessment (LCA), which highlights trade-offs and directions to lower emissions, minimize waste, and protect the ecosystem. Through a life cycle assessment analysis, this work evaluates the environmental impacts of recycling phosphate mining waste to produce interlocking compressed earth blocks (CEB), intending to promote circular economy strategies in both the mining and construction sectors. The study findings demonstrate that the global warming associated with the cradle-to-gate production of 1 ton of CEBs is approximately 50% of that for fired bricks. A Sensitivity analysis revealed that cement content is a key parameter with a coefficient exceeding 0.3 for all studied impact categories. Thus, varying the cement content showed that the CEBs approach the global warming of fired bricks at 23.7% cement. Moreover, the analysis further confirms that other impact indicators, such as terrestrial acidification, also rise with higher cement content. Overall, this study confirms that compressed blocks offer a sustainable alternative in building applications, while enhancing the recycling of mining waste within a circular construction framework.