| Abstract Scope |
REE-bearing minerals (REMs) can be oxides, carbonates, phosphates, and silicates. However, their flotation is problematic if an ore contains various types, leading to poor recoveries and grades but also to wrong conclusions that flotation does not work. For the past decade, MT Tech has investigated REM flotation using salicyl hydroxamic acid (SHA) collector, illustrating that flotation response depends on REE content and ultimately on lanthanide contraction (LC), coordination number (CN), and, for silicates, silicate polymerization (SP). These phenomena can be overcome using collector blends. A systematic study with blended collectors involving SHA as well as Benzoic Acid (BA) and Phthalic Acid (PA) was undertaken. Results illustrate that collector blends are needed. Furthermore, results explain why industry unknowingly uses collector blends. |