A process is provided for the production of liquid ferric sulfate from finely-divided ferric oxide, sulfuric acid and water in a reaction system comprising at least one closed reaction vessel at temperatures ranging from about 120.degree. C. to about 150.degree. C. and pressures from about 25 psi to about 70 psi. Iron oxide streams are fed countercurrent to the ferric sulfate reaction product stream and to the sulfuric acid and water feeds. The continuity of the reaction is effected by re-circulating fractions while withdrawing a fraction of the liquid ferric sulfate having a trivalent iron concentration of at least 10% from the reaction vessel. Yield and efficiency are provided by controlling the rate of iron ore, sulfuric acid and specific gravity and by counter current cycling the waste stream from the reaction through the dilution water and use of a polymeric settling agent to remove unreacted iron content from the digester output.