Process optimization on leaching of a lean weathered crust elution-deposited rare earth ores

The process on leaching of rare earth from the lean weathered crust elution-deposited rare earth ores with ammonium sulfate solution was elucidated and optimized with the chromatographic plate theory. The effects of the flowrate, the packed ore height, the concentration of leach reagents and leach reagent consumption on leaching performance were examined with column elution. It was found that the relationship between the height equivalent to a theoretical plate (HETP) and leaching flowrate can be described by the van Deemter equation. There is an optimum flowrate in the leaching process. It provides a scientific approach to leaching the lean weathered crust elution-deposited rare earth ores with high efficiency and low reagent consumption, and is applied to optimize the leach process and extraction conditions, to improve the rare earth received rate and to reduce the NH4 +–N pollution.

There is an optimum flowrate (Uopt = 0.38mL/min) in the leaching process.Figure optionsDownload as PowerPoint slideHighlights
► Process optimized on leaching of rare earth
► The lean weathered crust elution-deposited rare earth ores
► Chromatographic plate theory
► The height equivalent to a theoretical plate(HETP  )
► van Deemter equation: HETP=A+BU+CU.