A system (10), process and apparatus are disclosed for purifying carbon
black (15) containing sulfur and metal oxide impurities by digesting (20)
the impure carbon black in an acid to extract the metal oxide (25).
Sulfur (45) is then removed from the acid treated carbon black (30) by
solvent extraction (35) with an organic aromatic solvent which is then
recovered (50). The purified carbon black (40) is then suitable for use
as a toner (60) by toner black processing (55).