Gasification is an attractive technology for converting biomass to syngas. This study is focused on investigating the dependence of the concentration and transformation of inorganics on ash particle sizes during gasification of corncobs. Under the investigated gasification conditions, the contents of volatile elements increased obviously upon decreasing ash particle size, while the size dependence of nonvolatile elements showed the opposite trend. The fine particles containing potassiumspecies with low melting points tended to adhere to relatively large particles. With the decreasing particle size, the agglomeration degree was increased. The mass balance linking fuel composition with resultant ash compositions implied that the closure of the mass balances for K, Cl, and S resulted in the deviations with 35.21%, 27.95% and 23.57%, respectively. The mass concentrations of K in the bottom and fly ashes were as high as 7832.40 mg/kg and 22,135.94 mg/kg, respectively, reflecting their potential for utilizing as an ideal alkali source. (C) 2020 Elsevier B.V. All rights reserved.