Possible explanation of primordial 7Li deficit

Abstract A reduction mechanism of the theoretically predicted excessive abundance of 7 Li via baryons evaporated by primordial black holes is suggested. It is shown that the fraction of 7 Li with respect to the number density of baryons can be diminished down to the observed value via the process of 7 Li transformation by neutron or proton capture. The created in this process 8 Li or 8 Be quickly decay into a pair of 4 He nuclei.