海洋鉱物資源とエアリフトポンプ方式における移送評価技術

抄録

Subsea minerals, such as seafloor massive sulfides, rare earth elements in deep-sea mud, are found in deep sea within the exclusive economic zone of Japan. However, the development of subsea resources has not reached the commercialization stage because many technical issues still need to be addressed. Then, efforts for solving these issues are conducted in Japan and other countries. Air-lift pumping systems are one of the promising methods for subsea mineral resource productions. In developing air-lift pumping systems, one of the technical issues is flow assurance for gas-liquid-solid three-phase flow. We reviewed the correlations of volume fractions and frictional pressure drops in gas-liquid and liquid-solid two-phase flows and proposed correlations for three-phase flows. We carried out some experiments of air-lift pumping systems and obtained data of volume fractions of each phase and frictional pressure drops. To validate the proposed correlation, we compared calculated results by the proposed correlations with experimental data. The comparison suggested that the volume fraction of gas-phase and the frictional pressure drops could be calculated by the proposed correlations. Meanwhile, deviations between experimental data of solid-phase and calculated results of that was large and new methods were needed for calculated them.