Chemically bonded ceramic radiation shielding material and method of preparation

Abstract

A composition of matter and method of forming a radiation shielding member at ambient temperatures in which the composition of matter includes a ‘cold-fired’ chemically bonded oxide-phosphate ceramic cement matrix; with one or more suitably prepared and distributed radiation shielding materials dispersed in the ‘cold-fired’ chemically bonded oxide-phosphate ceramic cement matrix.

What is claimed is: 
     
         1 . A composition of matter, comprising: a chemically bonded oxide-phosphate based ceramic matrix; and a radiation shielding material, wherein the radiation shielding material is dispersed in the chemically bonded oxide-phosphate based ceramic cement matrix and the radiation shielding material is selected from the group consisting of barite, barium oxide, barium sulfate, cerium oxide, tungsten oxide, gadolinium oxide, depleted uranium oxide, annealed leaded glass 40% to 75% both powdered and fibers, zeolites, clinoptilotites, and celestites 
     
     
         2 . The composition of matter of  claim 1  wherein the zeolite comprises the following by percentages by weight: 52.4% SiO2, 13.13% Al2O3, 8.94% Fe2O3, 6.81% CaO, 2.64% Na2O, 4.26% MgO, and MnO 0.10%. 
     
     
         3 . The composition of matter of  claim 1  wherein barite by weight is approximately in the range of 89% to 99% BaSO 4  and in the range of 1% to 5.8% silicates, and wherein the range of percentages by weight of zeolite that will be present in the composition of matter of  claim 2  is 0.2% to 50%. 
     
     
         4 . The composition of matter of  claim 1  wherein the phosphate based ceramic matrix is selected from the group consisting of KH 2 PO 4  (potassium dihydrogen phosphate), MgHPO 4  (hydrogen phosphate), Fe 3 (HPO 4 ) 2  (iron(II) phosphate), Fe 3 (HPO 4 ) 2 .8H 2 O (iron(II) phosphate octahydrate), FeHPO 4  (iron(III) phosphate), FeHPO 4 .2H 2 O (iron(III) phosphate dihydrate) AlPO 4  aluminum phosphate, AlPO 4 .1.5 H 2 O (aluminum phosphate hydrate), CaHPO 4  (calcium hydrogen phosphate), CaHPO 4 .2H 2 O (calcium hydrogen phosphate dihydrate), BiPO 4  (bismuth phosphate), CePO 4  (cerium(III) phosphate), CePO 4 .2H 2 O (cerium(III) phosphate dihydrate), GdPO 4 1H 2 0 (gadolinium phosphate), BaHPO 4  (barium hydrogen phosphate), and UPO 4  (depleted uranium (U-238) phosphate). 
     
     
         5 . The composition of matter of  claim 1  wherein the oxide-phosphate based ceramic matrix is MgHPO 4 .3H 2 O (magnesium hydrogen phosphate trihydrate). 
     
     
         6 . The composition of matter of  claim 1  wherein the radiation shielding material is formed as at least one or more of the aggregates or powders dispersed in the oxide-phosphate ceramic. 
     
     
         7 . The composition of matter of  claim 1  wherein the oxide-phosphate ceramic matrix includes at least two different metal phosphates. 
     
     
         8 . The composition of matter of  claim 7  wherein the at least two different metal phosphates are selected from the group consisting of magnesium hydrogen phosphate, iron(III) phosphate, aluminum phosphate, calcium hydrogen phosphate, bismuth phosphate, cerium(III) phosphate, gadolinium phosphate, and barium hydrogen phosphate. 
     
     
         9 . The composition of matter of  claim 1  wherein the oxide-phosphate based ceramic matrix is of the formula:
   MHPO 4 .xH 2 O 
 
       wherein M is a divalent cation selected from the group consisting of:
 Mg (magnesium), Ca (calcium), Fe (iron(II)), and Ba (barium); and 
 wherein x is at least one of 0 (zero), 2 (two), 3 (three), or 8 (eight). 
 
     
     
         10 . The composition of matter of  claim 1  wherein the oxide-phosphate based ceramic matrix is of the formula:
   MPO 4 .xH 2 O 
 
       wherein M is a trivalent cation selected from the group consisting of:
 Al (aluminum), Ce (cerium (III)), U 238  (depleted uranium); and Fe (iron(III)); 
 and wherein x is at least one of 0 (zero), 1.5 (one point five), or 2 (two). 
 
     
     
         11 . The composition of matter of  claim 1  wherein the oxide-phosphate based ceramic matrix is of the formula:
   MM′PO 4 .xH2O
 
 
       wherein M is a divalent cation selected from the group consisting of: Ba (barium), and Mg (magnesium); wherein M′ is a monovalent cation selected from the group consisting of: Li (lithium), Na (sodium), and K (potassium); and wherein x is at least one of 0 (zero), 2 (two), 3 (three), or 6 (six). 
     
     
         12 . The composition of  claim 1 , comprising at least two radiation-shielding materials to form a multiple layer structure. 
     
     
         13 . A radiation shielding composition of matter, comprising: a chemically bonded oxide-phosphate based ceramic matrix having, a cation constituent, exhibiting radiation shielding capability; and a radiation shielding material selected from the group consisting of a powder, an aggregate, and a fiber, wherein the radiation shielding material is dispersed in the chemically bonded oxide-phosphate based ceramic matrix. 
     
     
         14 . The radiation shielding composition of matter of  claim 13  wherein the chemically bonded oxide-phosphate based ceramic cures to hardness at less than 100° C. (one hundred degrees Celsius). 
     
     
         15 . The radiation shielding composition of matter of  claim 13  wherein the cation is selected from the group consisting of aluminum, barium, bismuth, cerium, tungsten, gadolinium, and depleted uranium. 
     
     
         16 . The radiation shielding composition of matter of  claim 13  wherein the radiation shielding material is selected from the group consisting of barite, barium sulfate, bismuth metal, cerium oxide, gadolinium oxide, tungsten oxide, and zeolites. 
     
     
         17 . A method of constructing a radiation shielding member at ambient temperature, comprising: mixing a metal oxide having a radiation shielding capability with a phosphate containing material; incorporating a radiation shielding material into the metal oxide and phosphate containing material mix; curing the incorporated radiation shielding material and metal oxide and phosphate containing material mix at ambient temperature. 
     
     
         18 . The method of constructing a radiation shielding member at temperature conditions of  claim 17  wherein curing occurs at less than 100° C. (one hundred degrees Celsius). 
     
     
         19 . The method of constructing a radiation-shielding member at ambient temperature of  claim 17  wherein the phosphate containing material is phosphoric acid.