Magnetic Separation of Metal Ions

Article abstract of DOI:10.1021/jp030688c

The magnetic separation was investigated for Co²⁺ (9500 ?? 10^-6 cm³ mol^-1) and Fe^3- (14600 ?? 10^-6 cm³ mol^-1) ions and for Cr ³⁺ (6200 ?? 10^-6 cm³ mol^-1) and Al³⁺ (-2 ?? 10^-6 cm³ mol ^-1) ions. The metal ion solutions were spotted on a silica gel support, and exposed to a magnetic field of 410 kOe² cm^-1 intensity ?? gradient. The Co²⁺ ions move farther toward the maximum field than the Fe³⁺ ions. The result is explained by the fact that the Fe³⁺ ions are adsorbed more strongly on the silica gel surface than the Co²⁺ ions. The Cr³⁺ ions move farther toward the field center than the Al³⁺ ions. This occurs because the Cr³⁺ ions are attracted more strongly by the magnetic force than the Al³⁺ ions. It is demonstrated that the separation makes effective use of the adsorption activities as well as the magnetic susceptibilities.