| 摘要 |
PURPOSE:To obtain the title soil conditioner which is excellent in water permeability, retention of fertilizer component and prevention of occurrence of problems related to repeated cultivation, by calcining a granule of a pulverized green tuff and again calcining the granule at a higher temp. and, if necessary, further repeating the calcination treatment. CONSTITUTION:A tuff having a color such as green is pulverized into an about 150-meth granule. The granule is fed into a heating rotary oven and calcined therein at a temp. of 215-250 deg.C for about 10min. The calcined granule is again fed into the heating rotary oven and calcined therein at a temp. of 460-540 deg.C for about 15min and, if necessary, the calcination treatment is repeated for removal of water and water of crystallization as well as sterilization to obtain the title soil conditioner which is a porous hardened solid granule. |
