A new family of rare-earth silicate compositions and the synthetic methods used to prepare them. The materials have open-framework structures and are characterized by their ion-exchange properties. They are represented by the following empirical formula:

A.sup.r+.sub.pM.sup.s+.sub.1-xM′.sup.t+.sub.xSi.sub.nO.sub.m

where A is an exchangeable cation such as sodium, M is at least one element selected from the group of rare-earth elements, and M′ is a framework metal having a valence of +2, +3, +4, or +5. The rare-earth silicate materials have utility in various cation-exchange applications such as dialysis and removal of toxic metals from the gastrointestinal tract.

A new family of rare-earth silicate compositions and the synthetic methods used to prepare them. The materials have open-framework structures and are characterized by their ion-exchange properties. They are represented by the following empirical formula:

A.sup.r+.sub.pM.sup.s+.sub.1-xM′.sup.t+.sub.xSi.sub.nO.sub.m

where A is an exchangeable cation such as sodium, M is at least one element selected from the group of rare-earth elements, and M′ is a framework metal having a valence of +2, +3, +4, or +5. The rare-earth silicate materials have utility in various cation-exchange applications such as dialysis and removal of toxic metals from the gastrointestinal tract.

Proposed is an inorganic ion-exchanger, which is selective to lithium and constituted a non-stoichiometric compound in the form of solid particles of a polymeric aqua-oxo-hydroxo complex represented by the following general formula: H.sub.aNbO.sub.(2.5+0.5.Math.a).cZrO.sub.2.dH.sub.2O, wherein: “a” is a number ranging from 0.5 to 1.5, “c” is a number ranging from 0.01 to 1.0, and “d” is a number ranging from 0.1 to 2.0. The complex has a total ion exchange capacity of at least 3.5 meq/g and an ion-exchange capacity specifically to lithium of at least 2.5 meq/g. This ion-exchanger is intended for selective extraction of lithium from lithium-containing natural and industrial brines.

Proposed is an inorganic ion-exchanger, which is selective to lithium and constituted a non-stoichiometric compound in the form of solid particles of a polymeric aqua-oxo-hydroxo complex represented by the following general formula: H.sub.aNbO.sub.(2.5+0.5.Math.a).cZrO.sub.2.dH.sub.2O, wherein: “a” is a number ranging from 0.5 to 1.5, “c” is a number ranging from 0.01 to 1.0, and “d” is a number ranging from 0.1 to 2.0. The complex has a total ion exchange capacity of at least 3.5 meq/g and an ion-exchange capacity specifically to lithium of at least 2.5 meq/g. This ion-exchanger is intended for selective extraction of lithium from lithium-containing natural and industrial brines.

A montmorillonite slurry, containing a lithium-immobilized montmorillonite having a cation exchange capacity of 50 meq/100 g or less, ammonia, water, and an organic solvent, in which the organic solvent includes at least one kind of organic solvent selected from the group consisting of acetonitrile and methyl ethyl ketone, the proportion occupied by the organic solvent in the total amount of the water and the organic solvent in the slurry is 10% by mass or more and 90% by mass or less, and the content of ammonia in the slurry is 0.1 mmol or more per gram of the lithium-immobilized montmorillonite in the slurry; a method of producing the same; and a clay film.

A process for removing Co.sup.2+, Pb.sup.2+, Cd.sup.2+ and Cr.sup.3+ toxins from bodily fluids is disclosed. The process involves contacting the bodily fluid with an ion exchange composition to remove the metal toxins in the bodily fluid, including blood and gastrointestinal fluid. Alternatively, blood can be contacted with a dialysis solution which is then contacted with the ion exchange composition. The ion exchange compositions are represented by the following empirical formula:

A.sub.mZr.sub.aTi.sub.bSn.sub.cM.sub.dSi.sub.xO.sub.y.

A composition comprising the above ion exchange compositions in combination with bodily fluids or dialysis solution is also disclosed. The ion exchange compositions may be supported by porous networks of biocompatible polymers such as carbohydrates or proteins.

A process for removing Co.sup.2+, Pb.sup.2+, Cd.sup.2+ and Cr.sup.3+ toxins from bodily fluids is disclosed. The process involves contacting the bodily fluid with an ion exchange composition to remove the metal toxins in the bodily fluid, including blood and gastrointestinal fluid. Alternatively, blood can be contacted with a dialysis solution which is then contacted with the ion exchange composition. The ion exchange compositions are represented by the following empirical formula:

A.sub.mZr.sub.aTi.sub.bSn.sub.cM.sub.dSi.sub.xO.sub.y.

A composition comprising the above ion exchange compositions in combination with bodily fluids or dialysis solution is also disclosed. The ion exchange compositions may be supported by porous networks of biocompatible polymers such as carbohydrates or proteins.

A process for removing Sr.sup.2+ toxins from bodily fluids is disclosed. The process involves contacting the bodily fluid with an ion exchanger to remove the metal toxins in the bodily fluid, including blood and gastrointestinal fluid. Alternatively, blood can be contacted with a dialysis solution which is then contacted with the ion exchanger. The ion exchangers are represented by the following empirical formula:

A.sub.mZr.sub.aTi.sub.bSn.sub.cM.sub.dSi.sub.xO.sub.y.

A composition comprising the above ion exchange compositions in combination with bodily fluids or dialysis solution is also disclosed. The ion exchange compositions may be supported by porous networks of biocompatible polymers such as carbohydrates or proteins.

A process for removing Sr.sup.2+ toxins from bodily fluids is disclosed. The process involves contacting the bodily fluid with an ion exchanger to remove the metal toxins in the bodily fluid, including blood and gastrointestinal fluid. Alternatively, blood can be contacted with a dialysis solution which is then contacted with the ion exchanger. The ion exchangers are represented by the following empirical formula:

A.sub.mZr.sub.aTi.sub.bSn.sub.cM.sub.dSi.sub.xO.sub.y.

A composition comprising the above ion exchange compositions in combination with bodily fluids or dialysis solution is also disclosed. The ion exchange compositions may be supported by porous networks of biocompatible polymers such as carbohydrates or proteins.

The present invention concerns the use, for gas separation and/or gas drying, of at least one zeolite adsorbent material comprising at least one type A zeolite, said adsorbent having an external surface area greater than 20 m.sup.2.Math.g.sup.1, a non-zeolite phase (PNZ) content such that 0<PNZ30%, and an Si/Al atomic ratio of between 1.0 and 2.0. The invention also concerns a zeolite adsorbent material having an Si/Al ratio of between 1.0 and 2.0, a mesoporous volume of between 0.07 cm.sup.3.Math.g.sup.1 and 0.18 cm.sup.3.Math.g.sup.1, a (VmicroVmeso)/Vmicro ratio of between 3 and 1.0, non-inclusive, and a non-zeolite phase (PNZ) content such that 0<PNZ30%.