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1336866 Complex hydroxy compounds KYOWA CHEMICAL INDUSTRY CO Ltd 11 Dec 1970 [12 Dec 1969] 59120/70 Heading C1A [Also in Divisions B1 H1 and G6] Compounds of formula where M<SP>2+</SP> is one or more of Cu, Be, Ca, Sr, Ba, Zn, Cd, Sn, Pb, Mn or a Group VIII metal, M<SP>3+</SP> is one or more of Ti, Cr, Mn, Group III, Group V, Group VIII, rare earth, or actinide metal, A is inorganic, and having a given X-ray pattern, may be prepared by reacting x moles M(OH) 2 and y moles M(OH) 3 or precursors thereof (e.g. NO 3 , SO 4 , Cl, Br, CO 3 , HCO 3 , acetate, isopropoxide) with at least z moles A (e.g. as a salt of an alkali metal, NH 4 , M<SP>2+</SP> or M<SP>3+</SP>) in water, at a pH above 7 and a temperature of 0-350‹ C. The reactants may be fed continuously into a reaction zone maintained at the required temperature and pH, and the suspension continuously withdrawn. Various batch methods are also described. An initial salt solution may be adjusted to a pH of less than 1 with HCl, HNO 3 or H 2 SO 4 . The reaction may be effected in an inert or reducing gas, e.g. N 2 or N 3 +H 2 , and a lower alcohol, e.g. EtOH, or a polyhydric alcohol, e.g. mannitol, glycerine or sorbitol, may be present. The pH may be adjusted with alkali metal or ammonium hydroxide or carbonate or NH 3 gas. The crystallinity of the product may be improved by heating at 100-350‹ C. under a pressure of up to 300 atm. or at atmospheric pressure in water. The anion A may be exchanged for another A by treatment with an aqueous solution of Q<SP>1</SP>Q<SP>2</SP>A where Q<SP>1</SP> and Q<SP>2</SP> are alkali metal or ammonium and Q<SP>2</SP> may be H, preferably at a pH above 8 and a temperature of 40-90‹ C. Examples 1-41 and 58-106 describe the preparation of compounds of formula where M<SP>2+</SP>, M<SP>3+</SP> and A are as follows: Examples 42-48 describe Ni-Fe-CO 3 compounds and Examples 50-55 describe Zn-Al-SO 3 compounds, of a range of compositions. Examples 73, 78-81, 84, 86, and 99-104 describe ion-exchange processes. Other anions A mentioned are S 2 O 6 , TeO 4 , TeO 3 , SiO 3 , Mo 2 O 7 , SnO 3 , MnO 4 , UO 4 , UO 6 , GeF 6 , ZnF 6 , SnF 6 , TiF 6 , PtBr 6 , SbF 3 , S, CS 3 , Pt(CN) 4 . When M<SP>3+</SP> is Fe, calcination of the hydroxy compound yields a ferrite, e.g. NiFe 2 O 4 , CoFe 2 O 4 or MnFe 2 O 4 . |