| 摘要 |
PURPOSE:To reactivate comparatively easily the dephosphorizing agent by bringing seed crystals with reduced dephosphorizing performance into contact with a liquid contg. Ca ions then with a liquid contg. phosphate, and further bringing the crystals into contact with an alkaline agent. CONSTITUTION:The seed crystals contg. calcium phosphate is brought into contact with water contg. phosphate at >=6pH in the presence of calcium ions to remove the phosphate. In said dephosphorization stage, the seed crystals with reduced phosphorizing performance are brought into contact with a liquid contg. calcium ions, and then brought into contact with a liquid contg. phosphate. The seed crystals are subsequently brought into contact with an alkaline agent, and the seed crystals having reduced dephosphorizing performance is reactivated. Phosphate rocks, bone char, etc. which inherently contain calcium phosphate are used as said seed crystals contg. calcium phosphate, and either of said materials can be optionally used as the dephosphorizing agent.
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