Manganese leaching during high concentration flue gas desulfurization process with semi-oxidized manganese ore was studied in this paper. It was found that there were different reaction pathways among which MnO

2

Mn

2

O

3

and MnCO

3

in semi-oxidized manganese ore during flue gas desulphurization and manganese leaching. High SO

2

concentration facilitated redox reaction between MnO

2

and SO

2

and high concentration of H

2

SO

4

accelerated MnCO

3

/Mn

2

O

3

leaching from semi-oxidized ore. Kinetics study showed that manganese leaching in flue gas desulfurization process with semi-oxidized ore was controlled by a mixed-control model

that is the surface chemical reaction and mass diffusion dominated both the oxidation of SO

2

and manganese leaching process. The apparent activation energy was 13.05 kJ·mol

-1

and the reaction orders with respect to SO

2

and H

2

SO

4

concentration were 1.38 and 0.10

respectively. Finally

a semi-empirical rate equation based on shrinking core model was derived to desc

ribe the process.