Zeolite compositions and their use
A method of using a zeolite composition comprises forming a mixture of (a) a crystalline aluminosilicate and (b) a salt of a second metal selected from the group consisting of Group III metals, metallic elements of Group IV, magnesium, titanium, chromium, iron, nickel, copper, zinc, zirconium and silver, said salt of a second metal being present in an amount which is sufficient to replace from about 2.0 to about 40 percent of a first metal moiety, and using said mixture in an aqueous composition at a pH in the range 4 to 10. A further aspect of the invention is a powder comprising a mixture of (a) a crystalline aluminosilicate and (b) a salt of a second metal selected from the group consisting of Group III metals, metallic elements of Group IV, magnesium, titanium, chromium, iron, nickel, copper, zinc, zirconium and silver, said salt of a second metal being present in an amount which is sufficient to replace from about 2.0 to about 40 per cent of a first metal moiety. Methods according to the invention include paper making, paint preparation, dental applications, use of detergents and adsorption and catalytic applications.
1 . A method of preparing a composition, comprising:
a) forming an aqueous zeolite composition by:
i) preparing a dry mix comprising a crystalline aluminosilicate, a salt of a second metal and mixing said dry mix and water; or
ii) mixing said crystalline aluminosilicate and an aqueous solution of said second metal; or
iii) simultaneously mixing water, said crystalline aluminosilicate and said salt of the second metal,
b) adding said aqueous zeolite composition to a pre-composition to form a second composition; and
c) forming said composition from said second composition;
wherein:
d) said crystalline aluminosilicate is represented by the empirical formula
M 2/n O.Al 2 O 3 .xSiO 2 .yH 2 O
wherein M represents a first metal moiety with a valency of n;
x indicates the ratio of atoms of silicon to atoms of aluminium; and
y indicates the ratio of molecules of water to atoms of aluminium; and
e) said salt of a second metal selected from the group consisting of Group III metals, metallic elements of Group IV, magnesium, titanium, chromium, iron, nickel, copper, zinc, zirconium and silver, said salt of a second metal being present in an amount which is sufficient to replace from about 2.0 to about 40 percent of said first metal moiety; and
f) said composition is selected from a detergent composition, paper composition, dental composition, or paint composition; and
g) said aqueous zeolite composition has pH in the range of 4 to 10.
2 . The method according to claim 1 wherein said M is an alkali metal.
3 . The method according to claim 1 wherein the aluminosilicate is zeolite P, zeolite X or zeolite A.
4 . The method according to claim 1 wherein the second metal is aluminium or tin.
5 . The method according to claim 1 wherein the aluminosilicate is a zeolite having a particle size in the range 0.1 μm to 20 μm.
6 . The method according to claim 1 wherein the aqueous zeolite composition is formed by mixing the crystalline aluminosilicate with said aqueous solution of the second metal or by simultaneously mixing the water, the aluminosilicate and the salt of a second metal.
7 . The method according to claim 1 wherein the aqueous zeolite composition has a pH in the range 4 to 9.
8 . The method according to claim 1 wherein said composition is a detergent composition.
9 . The method according to claim 1 wherein said composition is a paper composition.
10 . The method according to claim 1 wherein said composition is a dental composition or a paint composition.
11 . A powder comprising a mixture of
a) a crystalline aluminosilicate represented by the empirical formula
M 2/n O.Al 2 O 3 .xSiO 2 .yH 2 O
wherein M represents a first metal moiety said first metal having a valency of n, x indicates the ratio of atoms of silicon to atoms of aluminium and y indicates the ratio of molecules of water to atoms of aluminium; and
b) a salt of a second metal selected from the group consisting of Group III metals, metallic elements of Group IV, magnesium, titanium, chromium, iron, nickel, copper, zinc, zirconium and silver, said salt of a second metal being present in an amount which is sufficient to replace from about 2.0 to about 40 percent of the first metal moiety.
12 . A powder according to claim 11 characterised in that up to 25 per cent by weight water is present.
13 . A method of preparing an aqueous zeolite composition, comprising:
a) preparing a dry mix comprising a crystalline aluminosilicate, a salt of a second metal and mixing said dry mix and water; or
b) mixing said crystalline aluminosilicate and an aqueous solution of said second metal; or
c) simultaneously mixing water, said crystalline aluminosilicate and said salt of the second metal,
wherein:
i) said crystalline aluminosilicate is represented by the empirical formula
M 2/n O.Al 2 O 3 .xSiO 2 .yH 2 O
wherein M represents a first metal moiety with a valency of n;
x indicates the ratio of atoms of silicon to atoms of aluminium; and
y indicates the ratio of molecules of water to atoms of aluminium; and
ii) said salt of a second metal selected from the group consisting of Group III metals, metallic elements of Group IV, magnesium, titanium, chromium, iron, nickel, copper, zinc, zirconium and silver, said salt of a second metal being present in an amount which is sufficient to replace from about 2.0 to about 40 percent of said first metal moiety; and
iii) said aqueous zeolite composition may be used directly in a detergent composition, paper, a dental composition, or a paint; and
iv) said aqueous zeolite composition has pH in the range of 4 to 10.
14 . The method according to claim 13 wherein said M is an alkali metal.
15 . The method according to claim 13 wherein the aluminosilicate is zeolite P, zeolite X or zeolite A.
16 . The method according to claim 13 wherein the second metal is aluminium or tin.
17 . The method according to claim 13 wherein the aluminosilicate is a zeolite having a particle size in the range 0.1 μm to 20 μm.
18 . The method according to claim 13 wherein the aqueous zeolite composition is formed by mixing the crystalline aluminosilicate with said aqueous solution of the second metal or by simultaneously mixing the water, the aluminosilicate and the salt of a second metal.
19 . The method according to claim 13 wherein the aqueous zeolite composition has a pH in the range 4 to 9.
20 . The method of claim 7 , wherein said aqueous zeolite composition is slurry and no acid is added.