遠心分離法による土壌粘土の定量

概要

論文の詳細を見る
In order to separate clay part (0.002mm. diam.) from soils there are three kinds of method ; namely, elutriation, subsidence, and centrifugation. Among three the last one is most characteristic in its shortening the time of manipulation. Depending upon the follwing equation, deduced from the STOKE'S formula, we separated clay part from soils, especially regulating the required revolution begins within 30 seconds after the beginning of manipulation. [numerical formula] t・・・required time (sec). n・・・viscosity constant of water (0.01009). dp・・・specific gravity of soil particle (2.60). d・・・specific gravity of water (1.00). r・・・radius of particle (0.0001 cm). R_1・・・distance from the axis to the surface of suspension at the beginning・・・12 cm. R_2・・・distance from the axis to the surfaces of suspension at the final period・・・16 cm. N・・・number of revolution, per sec. Remarks : When N is 1000. (per min.), t is 28.8 sec When N is 500 (per min.), t is 261 sec. Of two kinds of soil, the amount of clay part, got by authors, was compared to that by pipette method. The comparison (see Table 1) induced us to conclude that the centrifugation, here arranged, may be used as one of the means of separating clay part from soils.
社団法人日本土壌肥料学会の論文
1952-11-10