A low-grade iron ore from one of the largest Mexican deposits was investigated. Flotation was performed on samples with different particle size distribution to verify the influence of liberation and evaluate iron losses in case of a possible screening prior flotation. The results show that there is a considerable difference in the quality of the final product from flotation between the samples which proves that liberation is a very important factor for the flotation process. CITATION:Veloso, C H, Filippov, L O, Filippova, I V and Araujo, A C, 2019. Flotation applied to iron ores with complex mineralogy, in Proceedings Iron Ore 2019, pp 823827 (The Australasian Institute of Mining and Metallurgy: Melbourne).