Using Brazilian Nepheline Syenite Waste as an Alternative Mineral Resource for Various Applications

The high extraction of natural resources and the limited use of mining waste as alternative mineral resources are intensifying the depletion of natural reserves. The linear economic structure used by industrial sectors needs to be replaced with more sustainable models, such as the one proposed in the circular economy. This study aimed to evaluate strategies for the valorization of nepheline syenite waste (NSW) as an alternative mineral resource to natural and conventional ones. To this end, a set of criteria was adopted, consisting of a systematic approach for waste valorization, namely classification, potentiality, quantity/viability, and applicability (CPQvA). This involved investigating the properties of NSW, including its environmental, physical, chemical, morphological, and durability characteristics. The findings provide evidence of several potential applications for NSW, including the civil construction (fine aggregate and supplementary cementitious material), metallurgical (segregation of the iron fraction), and agricultural (segregation of the alkaline fraction) sectors. Methodologies for the beneficiation of NSW are suggested for each of the investigated applications. The valorization of NSW not only reduces the environmental impact of mining but also contributes to sustainable development by creating new products and economic opportunities, thereby promoting industrial symbiosis and advancement in the circular economy.