| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for producing high-purity colloidal silica at a low cost in a high efficiency of removal of metallic impurities such as Cu, Mn, Ni, Fe, Zn, and Cr contained in an aqueous alkali silicate solution as a raw material for colloidal silica. <P>SOLUTION: The method for producing the high-purity colloidal silica comprises a step of adding a nitrogen atom-containing or phosphorus atom-containing chelating agent to an aqueous colloidal silica solution to obtain an aqueous colloidal silica solution containing the chelating agent and an anion exchanger contact step of bringing the aqueous colloidal solution containing the chelating agent into contact with an anion exchanger. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
