Even a very short duration (30 s) of friction polishing in the laboratory polisher used in the present work was accompanied by substantial loses of minerals such as Fe, Mg, P, K and Mn (Table 1).
Even a very short duration(30 s) of friction polishing in the laboratory polisher used in thepresent work was accompanied by substantial loses of mineralssuch as Fe, Mg, P, K and Mn (Table 1).