鉱物処理

[P-7] 特性評価およびスラウェシ島（インドネシア）からのサプロライトラテライトの大気クエン酸浸出：ミネラル溶出挙動への洞察

^○アストゥティウィディ^1,2, 平島剛¹, 笹木圭子¹, 沖部奈緒子¹ (1.Kyushu University, 2.Indonesian Institute of Sciences, Indonesia)

Keywords:atmospheric leaching, citric acid, saprolitic ore, mineral dissolution, mineralogy characterization

The characterization and atmospheric leaching using citric acid of a saprolitic laterite from Sulawesi Island (Indonesia) have been investigated. The mineral and chemical compositions of the laterite were studied by X-ray diffraction (XRD) analysis, X-ray fluorescence (XRF), inductively coupled plasma-optical emitting spectrometer (ICP-OES) and scanning electron microscopy/X-ray energy dispersive spectroscopy (SEM/EDS). The saprolitic laterite mainly contained goethite, talc, serpentine and chromite; Ni was incorporated in all major minerals. Atmospheric leaching experiments were carried out to study the effect of acid concentration, ore particle size and leaching temperature on the leach recovery of Ni. The maximum nickel recovery (95.6%) can be achieved at 1 M citric acid concentration, 20% (w/v) of pulp density, ore particle size of -212+355 μm and leaching temperature of 40oC. The minerals dissolution order was studied by XRD and SEM/EDS according to determination of the leaching residues, and the result order was serpentine>goethite>talc.