03-16U

The results of investigation of aggregation processes, which take place in multicomponent silica glass and different crystalline matrices activated by Pb$^{2+}$ ions, are reported. Aggregation of lead ions in different crystalline matrices can be regarded as a model for formation of microcrystalline inclusions in lava-like fuel-containing materials, which determine their physical-chemical properties, including magnetic ones. We also study the influence of a certain type nanoparticles on the magnetic characteristics of amorphous materials, relevant to possible magnetic separation of lava-like fuel-containing materials.