this invention is concerned with a process for dissolving oxidic trivalent cobalt compounds in hydrochloric acid while avoiding the generation of chlorine . it includes the following steps slurrying in water the trivalent cobalt compound to be dissolved and treating the resulting slurry with a reduction agent from the group consisting of methanol , formaldehyde and formic acid and with hydrochloric acid . the contact of the hydrochloric acid with the slurry should occur in the presence of the reducing agent . the rate of acid addition should be controlled to maintain the slurry at a ph above 1 .