A Thermodynamic and Environmental Assessment of Lanthanide Chloride Production from Bastnaesite

Mining and processing of bastnaesite ore, (Ln)CO3F, for lanthanides extraction is investigated in this paper. This series of elements proved to be applicable for a wide range of high-tech uses. In spite of the strategic importance of lanthanides, no LCA and energy analyses of their extraction have ever been published. We perform in this paper a Life Cycle Assessment of the Lanthanide production cycle, based on available database and literature data from Mountain Pass mine (USA) and other worldwide mining and processing sites, most of which in China. We investigated three main steps: mining, milling (including transport, grinding and drying), and flotation (for lanthanide chloride extraction). We do not investigate here the separation of pure oxides from lanthanide chloride, a compound which is also marketed as such. The conventional LCA was integrated by means of energy and emergy evaluations, aimed at investigating respectively the global energy cost and the environmental sustainability of the process. Indicators of material intensity, thermodynamic efficiency, and environmental impact (including LCA and ecological footprint impact categories) are calculated and discussed.