Operational experiences of chemical-looping combustion with 18 manganese ores in a 300W unit

•Chemical-looping combustion with 18 manganese ores has been done in a 300 W pilot.•Chemical-looping operation involves 329 h with mainly gaseous fuels.•Correlations between performance and oxygen carrier characteristics were evaluated.•Attrition in operation was not correlated to crushing strength or jet-cup attrition.•Several materials with high reactivity and moderate attrition were identified.