Composite ammonium diuranate gel particles with a phenolic resin phase, and methods of making the same

A composite gel particle comprising an ammonium diuranate matrix phase and a phenolic resin phase incorporated within the ammonium diuranate matrix phase, produced by:

• preparing a uranyl nitrate solution comprising uranyl nitrate, a phenol, and a C1-C4 aldehyde in a first portion of a first liquid carrier, wherein the uranyl nitrate and the phenol are present in a mole ratio ranging from 2:1 to 25:1;
• preparing a second solution comprising hexamethylenetetramine and urea in a second portion of the first liquid carrier;
• reacting the phenol and the C1-C4 aldehyde in the uranyl nitrate solution to produce the phenolic resin particles suspended in the uranyl nitrate solution;
• mixing the uranyl nitrate solution with the phenolic resin particles therein and the second solution to form a mixture;
• adding individual drops of the mixture into a heated second liquid, wherein:
• the first liquid carrier is immiscible in the second liquid;
• heat from the second liquid causes the hexamethylenetetramine to decompose to form ammonia;
• and
• the ammonia reacts with the uranyl nitrate to cause each of the individual drops to form an ammonium diuranate gel particle;
• and
• collecting the ammonium diuranate gel particles formed from the individual drops of the mixture;
• wherein the ammonium diuranate gel particles comprise the phenolic resin particles within the ammonium diuranate matrix phase.