Pusat Pengajian Kejuruteraan Bahan dan Sumber Mineral - Tesis

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Browsing Pusat Pengajian Kejuruteraan Bahan dan Sumber Mineral - Tesis by Author "Amiliana, Amidi"

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    Recovery of rare earth elements (rees) from processed monazite waste by hydrochloric acid leaching
    (2024-09-01)
    Amiliana, Amidi
    Due to their unique properties, rare earth elements (REEs) are essential in creating sophisticated materials for various sectors, including electronics, clean energy, healthcare, and transportation. This study aims to characterise the processed monazite waste sample, roasted product of processed monazite waste sample, water leach residues, and acid-leach filtrate, to investigate the roasting parameters on the effective phosphate removal and REEs extraction from the complex matrix of monazite waste sample and to investigate the significant parameter of acid leaching parameters of water-leach residues for REEs extraction using statistical approach. Analytical techniques such as XRF, XRD, SEM-EDX, PSD, ICP-OES, and LOI were used to analyze the monazite waste sample. SEM-EDX identifies iron phosphate (FePO4) as the iron-bearing mineral with a 12.82% REE concentration in the monazite waste sample, where rinkite-(Y) (Na2Ca4YTi(Si2O7)2OF3) was the dominant mineral phase. Optimized roasting conditions (sample-to-KOH ratio: 1:1, KOH concentration: 85%, temperature: 300 °C, and roasting time: 120 min) were applied to water-leaching, yielding REE-bearing minerals under specific conditions (sample-to-water ratio: 1:12, temperature: 25 C, leaching time: 60 minutes, three washings, percentage recovery of TREO = 92.67%). These optimized conditions were then used for acid-leaching, with parameters determined by the Design of the Experiment (DOE). This study offers valuable insights into the efficient extraction of REEs from monazite waste samples, emphasizing the importance of optimized process parameters.