During ash decomposition and corrosion tests in a 75t/h circulating fluidized bed(CFB)boiler burning coal and biomass

the corrosion probe equipped with three kinds of metal samples was placed in front of the superheater

and the superheater tube wall temperature was simulated with a system of air cooling.Three kinds of metal deposition samples were obtained in operating mode(duration time of 24hours)with three mixing ratios of coal and biomass.The physicochemical property of the samples was analyzed by SEM-EDX.The results show that

under the testing conditions

no deposition was found at the wind side

and the deposition formed at the lee side was different for different metallic materials.No material loss or significant corrosion was detected.It is proved in this study that depositions at the lee side of the superheater were probably more serious than that at the wind side

and the co-combustion of coal and biomass containing low levels of alkali metal will not cause serious deposition or corrosion and can be applied in industrial production.