| 摘要 |
PURPOSE:To effectively utilize geomagnetism and to improve water retentivity and drainage characteristic by specifying porosity and average diameter, respectively. CONSTITUTION:A ferrite powder prepared by crushing after calcination, a wax powder, and an aqueous solution of PVA are mixed, and the resulting mixture is formed into granulated state, dried, and burned, by which a granulated ferrite powder having 5-95% porosity, <=15cm average diameter, and 0.5mum-5mm pore diameter can be obtained. |
