日本地球惑星科学連合2016年大会

講演情報

ポスター発表

セッション記号 S (固体地球科学) » S-RD 資源・鉱床・資源探査

[S-RD41] 資源地質学

2016年5月25日(水) 17:15 〜 18:30 ポスター会場 (国際展示場 6ホール)

コンビーナ:*実松 健造(国立研究開発法人 産業技術総合研究所 地圏資源環境研究部門 鉱物資源研究グループ)、大竹 翼(北海道大学大学院工学研究院 環境循環システム部門)、高橋 亮平(秋田大学国際資源学部)、野崎 達生(海洋研究開発機構海底資源研究開発センター)、米津 幸太郎(九州大学大学院工学研究院地球資源システム工学部門)

17:15 〜 18:30

[SRD41-P02] 重希土類資源としてのアパタイトの可能性

*星野 美保子1実松 健造1渡辺 寧2 (1.(国研)産業技術総合研究所、2.秋田大学)

キーワード:アパタイト、重希土類資源

Phosphorous is one of the three major nutrients (N, K, P) required by plants and 80-90% of the phosphate mined in the world is used to produce chemical fertilizers. Securing stable supply of phosphate fertilizers is essential to a sustainable food production considering a continuing rapid growth of world population (Van Kauwenbergh et al., 2013). The world resources of phosphate rocks are more than 300 billion tons (U.S. Geological Survey, 2015). “Phosphate rock” is the term generally used in industry to describe mineral assemblages with a high concentration of phosphate minerals, commonly francolite (Ca5(PO4, CO3)3(OH, F, Cl)) - apatite (Ca5(PO4)3(OH, F, Cl)) series. There are two main types of phosphate deposits: sedimentary and igneous. The former deposits sometimes are called phosphorite and contain varieties of francolite (CO2-rich fluorapatite), the latter mainly consist of fluorapatite (F-rich apatite) (Ihlen et al. 2014).
Apatites contain a variety of REEs in concentrations from several thousands of ppm to several wt.%. They are generally enriched in LREEs (e.g., Roeder et al., 1987), however, some apatites are rich in HREEs: apatites in sedimentary phosphate rocks (Emsbo et al. 2015) and deep sea mud (e.g., Kon et al. 2014), and igneous phosphate rocks (e.g., Hoshino et al., 2015). In addition, both Th and U contents in apatite are very low in contrast to common REE minerals such as monazite and xenotime, and this may be a big advantage over the other types of REE deposits (e.g., alkaline REE deposits).
In view of the future of HREE supply (considering both feasibility and sustainability), one of the most promising sources of HREEs is apatite ores that are mined for fertilizer production, because apatite ores are sufficient in reserves and contain enough amounts of the whole REEs that can cover the world demand.