IRON-BASED HYDROTALCITE TYPE FINE PARTICLE POWDER AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain an iron-based hydrotalcite type fine particle powder as an absorbent, a deodorant an ion exchanging agent or a cosmetic material or useful for producing plate-like iron oxide fine particle powder and provide a method for producing the fine particle powder. ;SOLUTION: This iron-based hydrotalcite type fine particle powder has 0. 050-50μm average particle diameter and has a structure represented by the formula [Fe³⁺(OH^-)₂]⁺ [a(OH^-).b(CO₃^2-).c(H₂O)]^- [0a1; 0b0.5; 0c1; (a+2)×(b=1)]. The fine particle powder is obtained by mixing a ferrous salt with an aqueous alkaline solution containing an aqueous solution of carbonate so that a molar ratio CO₃^2-/Fe of carbonate ion to iron becomes 0.05 to 10 and carrying out oxidation reaction of ferrous in the resultant water suspension containing ferrous-containing precipitate while keeping the temperature of the water suspension to the range of 10-45°C and the pH of water suspension to the range of 7.5 to 11.0 so that decreasing ratio of Fe²⁺ of the ferrous in the water suspension per unit time becomes 0.2-2.0mol%/min.;COPYRIGHT: (C)1997,JPO