Magnesium aluminate anion exchangers
AssigneeThe Dow Chemical Company
InventorsJohn M. Lee, William C. Bauman
Life of this patent
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Abstract
Preparations and uses are shown for novel crystalline aluminates which conform generally to the empirical formula MgA.sub.a.sup.v Z.sub.b.sup.v.nAl(OH).sub.3.mH.sub.2 O where A and Z represent negative-valence ions or radicals selected from the group comprising hydroxyl, halide, inorganic acid, and organic acid, n is a value of from about 1 to about 2, v is a negative valence of 1, 2, or 3, a and b each have values of from zero to 2, with (va)+(vb) equal to 2, and with m being a value of zero or more.
Claims27
Crystalline magnesium aluminates conforming generally to the empirical formula
- MgA.sub.a.sup.v Z.sub.b.sup.v. nAl(OH).sub.3.mH.sub.2 O
- where
- A and Z represent negative-valence ions or radicals selected from the group comprising hydroxyl, halide, inorganic acid, and organic acid,
- n is a value of from about 1 to about 2,
- v is a negative valence of 1, 2, or 3,
- a is a value of from zero to 2,
- b is a value of from zero to 2,
- with (va)+(vb) equal to 2, and with m being a value of zero or more.
A method for preparing crystalline Mg(OH).sub.2.nAl(OH).sub.3.mH.sub.2 O, where n is a value of from about 1 to about 2 and m is a value of zero or more, said method comprising reacting crystalline MgX.sub.2.2Al(OH).sub.3, where X is halide, with NaOH in aqueous medium, thereby replacing at least part of the halide groups with hydroxyl groups.
A composition of matter comprising crystalline Mg(OH).sub.2.nAl(OH).sub.3.mH.sub.2 O, where n is a value of about 1 to about 2 and where m is a value of zero or more.
A process for preparing crystalline Mg(OH).sub.2.nAl(OH).sub.3.mH.sub.2 O where n is a value of from about 1 to about 2 and m is a value of zero or more, said processing comprising
- reacting amorphous Al(OH).sub.3 with Mg(OH).sub.2 at elevated temperature in an alkaline aqueous medium.
Dependencies are inferred from the claim text.