Method for separating and immobilizing radioactive materials

Claim 3

The method of claim 1 wherein said reactive composition is a preformed mass.

Claim 4

The method of claim 1 wherein said reactive composition is a preformed molecular sieve.

Claim 5

The method of claim 1 wherein the mole ratio of said alkali metal to said Group IIIB metal is from about 1.1 to about 1.9.

Claim 6

The method of claim 1 wherein the mole ratio of said phosphorus oxide to said Group IIIB is from about 1.1 to about 1.9.

Claim 7

The method of claim 1 wherein said reactive composition comprises a precursor combination of at least one alkali metal source, at least one Group IIIB metal source and at least one phosphorous oxide source.

Claim 8

The method of claim 6 wherein the mole ratio of said alkali metal source to said Group IIIB metal source is from about 1 to about 12.

Claim 9

The method of claim 6 wherein the mole ratio of said alkali metal source to said Group IIIB metal source is from about 2 to about 8.

Claim 10

The method of claim 6 wherein the mole ratio of said phosphorus oxide source to said Group IIIB metal source is from about 1 to about 10.

Claim 11

The method of claim 1 wherein said radioactive material is selected from the group consisting of Sr, Cs, Th, U, Np, Pu, Am, Cm or a mixture of two or more thereof.

Claim 12

The method of claim 1 wherein said aqueous medium has a pH of up to about 5.

Claim 13

The method of claim 1 wherein said aqueous medium has a pH in the range of about zero to about 5.

Claim 14

The method of claim 1 wherein the temperature of said aqueous medium ranges from about 20° C. up to the boiling point of said aqueous medium.

Claim 15

The method of claim 1 wherein the concentration of said radioactive material in said aqueous medium ranges up to about 1% by weight.

Claim 16

The method of claim 1 wherein the concentration of said radioactive material in said aqueous medium is greater than about 1% by weight.

Claim 17

The method of claim 1 wherein said radioactive material comprises uranium.

Claim 18

The method of claim 1 wherein said reactive composition is a preformed mass represented in terms of mole ratios of oxides by the formula x(M'.sub.2 O):y(M.sub.2 O.sub.3):z(P.sub.2 O.sub.5):nH.sub.2 O wherein M' is an alkali metal, M is a Group IIIB metal, x/y is a number ranging from about 1.1 to about 1.9, z/y is a number ranging from about 1.1 to about 1.9, and n/y is a number ranging from zero to about 8.

Claim 19

The method of claim 17 wherein said preformed mass is a molecular sieve.

Claim 20

The method of claim 17 wherein M' is sodium.

Claim 21

The method of claim 17 wherein M is scandium, yttrium, lanthanum or a mixture of two or more thereof.

Claim 22

The method of claim 17 wherein M is yttrium.

Claim 23

The method of claim 18 wherein said molecular sieve shows the following significant lines in its X-ray diffraction pattern: ______________________________________ Interplanar Relative Spacing d(A) Intensity ______________________________________ 16.0 ± 0.2 s 9.2 ± 0.2 m 7.9 ± 0.2 w 6.8 ± 0.1 m 5.45 ± 0.05 m 5.17 ± 0.05 w 4.49 ± 0.05 w 3.79 ± 0.03 w-m 3.69 ± 0.03 w 3.38 ± 0.03 w 3.17 ± 0.03 w 3.06 ± 0.03 w 2.99 ± 0.03 m 2.94 ± 0.02 m 2.86 ± 0.02 w-m 2.77 ± 0.02 w-m 2.72 ± 0.02 m 2.68 ± 0.02 w-m ______________________________________

Claim 24

The method of claim 17 wherein said preformed mass is a molecular sieve, said molecular sieve being made by the process comprising: (A) forming a mixture comprising at least one alkali metal source, at least one Group IIIB source, and at least one phosphorus oxide source; (B) maintaining said mixture at a temperature of at least about 70° C. under autogenous pressure until crystals are formed; and (C) separating said crystals from their mother liquor.

Claim 25

The method of claim 23 wherein the mole ratio of said alkali metal source to said Group IIIB source is in the range of from about 1 to about 12.

Claim 26

The method of claim 23 wherein the mole ratio of said source for said phosphorus oxide source to said Group IIIB metal source is from about 1 to about 10.

Claim 27

The method of claim 23 wherein said phosphorus oxide source is a phosphoric acid, a phosphate or a phosphite.

Claim 28

The method of claim 23 wherein said Group IIIB metal source is an oxide, hydroxide or salt of said metal.

Claim 29

The method of claim 23 wherein said alkali metal source is an oxide, hydroxide or salt of said metal.

Claim 30

The method of claim 6 wherein said phosphorus oxide source is selected from the group consisting of a phosphoric acid, a phosphate or a phosphite.

Claim 31

The method of claim 6 wherein said Group IIIB metal source is an oxide, hydroxide or salt of said metal.

Claim 32

The method of claim 6 wherein said alkali metal source is an oxide, hydroxide or salt of said metal.

Claim 33

The method of claim 6 wherein said phosphorus oxide source is phosphoric acid.

Claim 34

The method of claim 6 wherein said alkali metal is sodium.

Claim 35

The method of claim 6 wherein said Group IIIB metal is yttrium.

Claim 36

The method of claim 1 wherein said reactive composition is a preformed mass, said alkali metal is sodium, said Group IIIB metal is yttrium and said phosphorus oxide is phosphorus pentoxide.

Claim 37

The method of claim 35 wherein said preformed mass is a molecular sieve.

Claim 38

The method of claim 1 wherein said reactive composition is a preformed mass derived from a mixture comprising sodium hydroxide, yttrium oxide and phosphoric acid.

Claim 39

The method of claim 37 wherein said preformed mass is a molecular sieve.

Claim 40

The method of claim 1 wherein said reactive composition comprises a sodium source, a yttrium source and a phosphorus oxide source.

Claim 41

The method of claim 1 with the step of heat-treating said radioactive-material-containing composition at a temperature in the range of about 1000° C. to about 2000° C. for an effective period of time to reduce the leachability of said radioactive material from said radioactive-material-containing composition and enhance the thermal stability of said radioactive-material-containing composition.

Claim 42

The method of claim 1 with the step of heat-treating said radioactive-material-containing composition at a temperature of about 1500° C. for an effective period of time to reduce the leachability of said radioactive material from said radioactive-material-containing composition and enhance the thermal stability of said radioactive-material-containing composition.

Claim 43

The method of claim 40 wherein said period of time for said heat-treating step is in the range of about one hour to about 7 days.

Claim 44

The method of claim 41 wherein said period of time for said heat-treating step is in the range of about one hour to about 7 days.

Claim 45

The method of claim 40 wherein the product of said heat-treating step is a heat-treated-radioactive-material-containing composition, the X-ray diffraction pattern for said heat-treated-radioactive-material-containing composition showing at least the following significant lines: ______________________________________ Interplanar Relative Spacing d(A) Intensity ______________________________________ 3.15 ± 0.05 s 2.73 ± 0.05 m 1.931 ± 0.05 m ______________________________________

Claim 46

The method of claim 1 wherein said radioactive material comprises at least one radioisotope, the molar ratio of phosphorus in said reactive composition to said radioisotope being at least about 1:1.

Claim 47

The radioactive-material-containing composition produced by the method of claim 1.

Claim 48

The radioactive-material-containing composition produced by the method of claim 6.

Claim 49

The radioactive-material-containing composition produced by the method of claim 7.

Claim 50

The radioactive-material-containing composition produced by the method of claim 18.

Claim 51

The radioactive-material-containing composition produced by the method of claim 23.

Claim 52

The radioactive-material-containing composition produced by the method of claim 35.

Claim 53

The radioactive-material-containing composition produced by the method of claim 37.

Claim 54

The radioactive-material-containing composition produced by the method of claim 31.

Claim 55

The radioactive-material-containing composition produced by the method of claim 40.

Claim 56

The radioactive-material-containing composition produced by the method of claim 41.

Claim 57

The heat-treated-radioactive-material-containing composition produced by the method of claim 44.

Claim 58

A composition comprising at least one radioactive material, at least one Group IIIB metal and at least one phosphorus oxide, said composition being characterized by a leach rate of said radioactive material of 10 -3 or less gram/m 2 -day.

Claim 59

A composition comprising at least one radioactive material, at least one Group IIIB metal and at least one phosphorus oxide, said composition being characterized by a leach rate of said radioactive material of 10 -3 or less gram/m 2 -day.

Claim 60

The composition of claim 57 wherein said leach rate of said radioactive material is 10 -4 or less gram/m 2 -day.

Claim 61

The composition of claim 57 wherein said radioactive material comprises Sr, Cs, Th, U, Np, Pu, Am, Cm or a mixture of two or more thereof.

Claim 62

The composition of claim 57 wherein said radioactive material is uranium.

Claim 63

The composition of claim 57 wherein said Group IIIB metal is yttrium

Claim 64

The composition of claim 57 wherein said composition comprises an amorphous structure.

Claim 65

The composition of claim 57 wherein said composition comprises a crystalline structure.

Claim 66

The composition of claim 57 wherein said composition comprises a crystalline structure, the X-ray diffraction for said crystalline structure showing at least the following significant lines: ______________________________________ Interplanar Relative Spacing d(A) Intensity ______________________________________ 3.15 ± 0.05 s 2.73 ± 0.05 m 1.931 ± 0.05 m ______________________________________

Claim 67

A radioactive-material-containing composition represented in terms of mole ratios by the formula x(M.sub.2 'O):y(M.sub.2 O.sub.3):z(P.sub.2 O.sub.5):g(GO.sub.a):nH.sub.2 O wherein M' is an alkali metal; M is a Group IIIB metal; G is a radioisotope; x/y is a number ranging from about zero to about 1.9, z/y is a number ranging from about 1.1 to about 1.9, g/y is a number ranging from about 0.05 to about 10, and n/y is a number ranging from zero to about 8.

Claim 68

A radioactive-material-containing composition represented in terms of mole ratios by the formula x(M.sub.2 'O):y(M.sub.2 O.sub.3):z(P.sub.2 O.sub.5):g(GO.sub.a):nH.sub.2 O wherein M' is an alkali metal; M is a Group IIIB metal; G is a radioisotope; x/y is a number ranging from about zero to about 1.9, z/y is a number ranging from about 1.1 to about 1.9, g/y is a number ranging from about 0.05 to about 10, and n/y is a number ranging from zero to about 8.