The attrition of binary mixtures of iron powder, as a representative oxygen carrier, and limestone, as a CO2 sorbent, was investigated to examine the interactions of two different solid species. An air jet apparatus based on ASTM D5757, with several improvements, was used to test particle attrition for various times (3, 6 and 12 h), temperatures (20, 250 and 500 degrees C), gas flow rates (6, 8 and 10 LPM) and particle mixture compositions (Iron: Limestone mass ratios 1:0, 0.75:025, 0.5:0.5, 0.25:0.75 and 0:1). Attrition was affected by the fluidization velocity in relation to the minimum fluidization velocities of the two species, and the mixture mass ratio. High temperature increased the generation of iron fines, while reducing the production of limestone fines. As expected, increasing the air flow rate led to the generation of more fines of both iron and limestone. (C) 2019 Elsevier B.V. All rights reserved.