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Advanced process to dephosphorize monazite for effective leaching of rare earth metals (REMs)

IR@NML: CSIR-National Metallurgical Laboratory, Jamshedpur


Field	Value

Title	Advanced process to dephosphorize monazite for effective leaching of rare earth metals (REMs)

Creator	Kumari, Archana Jha, Manis K Yoo, Kyoungkeun Panda, Rekha Lee, J Y Kumar, J Rajesh Pathak, D D

Subject	Materials Charcterization

Description	The present paper reports an improved process using cheaper reagent at atmospheric conditions compared to the expensive pressure leaching technique (Temperature = 140 °C) as well as other processes available at higher temperature. An effective baking reagent, potassium hydroxide (KOH) was used to dephosphorize monazite. Roasting studies were carried out to optimize various process parameters such as temperature, time and doses of baking reagents. The dephosphorization of monazite was completed in 30 min at temperature 250 °C and monazite:KOH ratio of 1:1 (wt/wt). The experimental data was validated scientifically using TG-DTA. Further, leaching studies with selected lixiviant was carried out to optimize various process parameters viz. leachant concentration, time, pulp density, temperature and dosage of hydrogen peroxide (H2O2). More than 90% rare earth metals (REMs) were found to be leached from dephosphorized and washed residue using hydrochloric acid (HCl) at optimized condition i.e. 1 M HCl with 10% H2O2 (v/v), temperature 80 °C, time 120 min and pulp density 50 g/L. The novel process flow-sheet after scale-up studies can be used for monazite processing in industries.

Publisher	Elsevier

Date	2019-08

Type	Article PeerReviewed

Relation	https://doi.org/10.1016/j.hydromet.2019.05.013 http://eprints.nmlindia.org/7932/

Identifier	Kumari, Archana and Jha, Manis K and Yoo, Kyoungkeun and Panda, Rekha and Lee, J Y and Kumar, J Rajesh and Pathak, D D (2019) Advanced process to dephosphorize monazite for effective leaching of rare earth metals (REMs). Hydrometallurgy, 187 . pp. 203-211.