METHOD FOR SINTERING CONCENTRATE OF RARE-EARTH ELEMENTS Russian patent published in 1999 - IPC

FIELD: recovery and disposal of radioactive wastes of nuclear fuel cycle and their immobilization in ceramic matrix materials. SUBSTANCE: method involves settling of orthophosphates of rare-earth elements out of their concentrate, calcination of slurry obtained, mixing of sediment obtained with magma rock containing quartz and minerals whose crystal-chemical textures allow for isomorphic enclosure of rare-earth elements in them, mixture grinding to homogeneous state, its compression at room temperature, and firing at 960-1050 C until ceramic material is obtained. In the process, multiple-barrier safety compositions are produced while obeying principle of phase and chemical agreement in matrix-enclosing rock system. EFFECT: facilitated procedure, reduced cost of source material and its availability, improved environmental friendliness. 3 cl