Recovery of uranium from Malaysian non-conventional sources

Abstract

ABSTRACT

The recovery of uranium from non-conventional sources has its importance in the security of nuclear fuel supply as well as producing a more value-added product to the contaminated source. In this paper, uranium is recovered both by developing a hydrothermal process as well as using the removal method. Developing hydrothermal process involves using high uranium concentrated starting material such as xenotime and thorium hydroxide waste produced from the monazite cracking process. Oxalate separation enable to produce a better uranium and thorium separation from the yttrium in xenotime as compared to the hydroxide precipitation. Also, a solvent extraction stage was included to separate the uranium from the thorium in the process using thorium hydroxide waste. The removal method involves using selective leaching for minerals with lower uranium content such as zircon.  A better removal for uranium and thorium in zircon is achieved when a heat treatment process was done prior to the leaching stage. White zircon mineral was produced after this treatment and its quality meets the requirement for white ceramic opacifier and glaze. 

ABSTRAK

Perolehan semula uranium dari sumber bukan lazim adalah mustahak  bagi keselamatan didalam pembekalan bahan api nuklear serta menghasilkan produk sampingan yang bernilai tinggi dari sumber yang berkontaminasi. Kertas kerja ini menunjukkan bagaimana uranium telah diperolehi menggunakan kaedah-kaedah hydrothermal dan pelucutan. Bagi proses hydrothermal bahan permulaan yang mempunyai kandungan uranium yang tinggi seperti xenotime dan sisa thorium hidroksida yang dihasilkan dari kilang pemprosesan monazite. Teknik pemisahan oksalat boleh memisahkan uranium dan thorium dengan lebih baik berbanding dengan menggunakan teknik pemisahan hidroksida. Kaedah pelucutan pula melibatkan teknik nyahlarut pilihan bagi mineral-mineral yang mengandungi kandungan uranium dan thorium yang rendah seperti zircon. Pelucutan uranium dan thorium yang lebih baik bagi zirkon diperolehi apabila kaedah pemanasan dilakukan sebelum nyahlarut. Zirkon yang berwarna putih boleh dihasilkan dari rawatan ini dan kualitinya memenuhi criteria bagi opacifier dan licau.