GAMMA-RAY (GR) SPECTROSCOPIC STUDY OF THE PHASE COMPOSITIONS OF FERRITIZED ACTIVATED CHARCOALS

The phase compositions of ferritized activated charcoals for medicinal purposes, which were obtained under various reductive-annealing condi tions, were studied by means of Fe-57 gamma-ray (GR) spectroscopy. It is shown that the compositions and dimensions of the iron-containing p articles formed on the activated charcoals depend on the temperature a nd time of exposure to annealing in hydrogen, as well as on the proper ties of the starting carbon matrix - the porous structure and the surf ace chemistry. Interaction of the iron-containing particles with the c arbon matrix (at high annealing temperatures) and oxidation of the red uced disperse particles on contact with air have a substantial effect on the phase compositions of the ferritized sorbents. An investigation of samples of the activated charcoals with various distributions of t he Fe-57 isotope in the system of pores made it possible to study the dependence of the process involved in the reduction of the iron-contai ning particles on their orientation within pores of various dimensions . It was established that the starting distribution of the modifier in the pores of the activated charcoals is an important factor that affe cts the phase compositions of the ferritized sorbents.