EARTHポスター発表（Poster：EARTH）

[PE1-043] Solvent extraction of thorium from monazite leach liquors by use of primary amine-extractant

○Chul Joo Kim¹, Ho Sung Yoon¹, Kyeong Woo Chung¹ (1. Korea Institute of Geoscience and Mineral Resources)

キーワード：Thorium, Solvent extraction, Rare earth elements, Primary amine

Thorium has been considered unwelcome material which is inevitably encountered upon the development of bastnasite and monazite ores due to its radioactivity, while monazite contains large amounts of thorium of up to 20 wt% and bastnasite commonly hosts small amount of thorium. Several methods to separate thorium from rare earth ores or products have been developed to avoid the environmental pollution and the contamination of rare earth products. However, the demand of thorium is lately increasing due to its diversity of industrial applications. Especially, interest in the commercialization of a thorium fuel cycle for generating nuclear power has been lately much increased. Therefore, it is being very important to recover thorium from rare earth ores with high yield and purity in the view point of securing resources as well as protecting environment.
Hydrometallurgy has been applied for process of monazite and bastnasite ores and solvent extraction is a commonly used for separation and purification of target material with high recovery in the field of hydrometallurgy. In this work, tthorium extraction from monazite leach liquor by solvent extraction has been studied and high recovery yield and purity of more than 99% were achieved using primary amine as extractant.