Abstract: Coal residue with high pyrite contents could be oxidized in the presence of water and oxygen，and produce acid mine drainage （AMD）. Fe3+ is a stronger oxidant in this oxidation reaction. In order to study the oxidation characteristics of coal residue under the effect of Fe3+， the acid conditions with different Fe3+ initial concentrations were set up to simulate the oxidation of coal residue samples KL， DZ， SX from three coal measures with different sulfur contents and pyrite samples， and the ［SO42?］/［Fe2+］ stoichiometry in the acid production simulation test was used to verify the chemical reaction followed by the experimental system. The results showed that the oxidation rate of each sample increases with the increase of Fe3+ initial concentration in the liquid phase under acidic conditions. The experimental period of 1~7 days is the rapid oxidation reaction period of coal gangue and pyrite， and the acid production reaction is mainly controlled by chemical reaction. Under the experimental conditions， the oxidation rate of pyrite could reach 5.23×10-5 mol/(L·h)， the maximum oxidation rates of KL， DZ and SX were 1.91×10-5 mol/（L·h）、1.1×10-7 mol/（L·h） and 1.5×10-6 mol/（L·h）， respectively. It is found out that the oxidation process of coal residue is significantly different from that of pure pyrite. The oxidation rate of pyrite is higher than that of coal residue， but the iron dissolution rate of coal residue is higher than that of pyrite. The oxidation characteristics of different coal residue are quite different. DZ （22.89 kg/t， converted by H2SO4， the same later） with the lowest net acid production potential has lower oxidation rate than other coal residue， but KL （92.21 kg/t） and SX （90.58 kg/t） with the same net acid production potential have great differences in the oxidation process of Fe3+， which is showed in the ［SO42?］/［Fe2+］ stoichiometric ratio. KL has a similar ratio with pyrite， which follows the oxidation mechanism of FeS2 under the corresponding conditions ， but the ratio of SX is much higher than the theoretical value. This may be due to the composition of alkali producing minerals of coal residue. In general， the mineral contents and weathering degree of coal residue lead to the difference of acid production process. The higher the sulfur contents of coal gangue， the acid production pollution potential increases with the degree of weathering.

Key words: weathering degree and sulfur contents, Fe3+ initial concentration, oxidation rate, net acid production quantity, stoichiometric proportion, acid mine drainage（AMD）