界面化学的分散制御高せん断解砕洗浄による放射能汚染土壌の微細・分散化

Structural refinement and dispersion of high level radioactive contaminated soil processing by chemical interface controlled and high-speed shearing washing technique

石山 新太郎

Ishiyama, Shintaro

570,000Bq/kgを越える村道脇土壌や原野土壌並びに校庭土壌の界面化学的分散制御高速せん断解砕洗浄法による解砕洗浄フィールド試験を福島県下で実施し、各土壌の解砕微細化のための最適化条件の検討を行い、その結果下記結論を得た。(1)解砕洗浄時のpH調整を等塩基点近傍の10-11で調整することにより各種土壌において高い微細分散化効果が得られる。(2)洗浄装置表面への汚染土壌粒子衝突並びに粒子/粒子間衝突による解砕微細化促進には、固形物濃度50%程度まで高濃度化する必要があるとともに、洗浄液の高粘性化に対応する高トルク型の解砕洗浄装置が必要とされる。(3)上記条件の下で村道脇土壌や原野土壌並びに校庭土壌の解砕洗浄を行った結果、土壌粒度10m以下に微細化された高濃度スラリー化を2時間内で生産することができた。

Chemical interface controlled dispersion and high-speed shearing water washing tests were implemented for the purpose of optimization of processing conditions with highly radioactive contaminated soils of over 570,000 Bq/kg in Fukushima and the following results were obtained. (1) Dispersion of the radioactive contaminated soil over 570,000 Bq/kg was enhanced in alkalized washing solution at babe equilibrium point of pH=10-11. (2) Refinement of contaminated soils was also promoted by collision of contaminated soil particles toward washing machine walls and inter-particle collision during soil washing process and remarkable washing performance was achieved under the combination of dispersion and high-speed shearing washing condition with 50% solid density in wash solution.