A study has been conducted on the flotation concentration of sedimentary phosphorite from Sierra Espu (n) over tildea, in the province of Murcia (Spain), using a Denver D-12 mechanical subaeration cell. First, the mineral was pretreated through grinding, sorting and discarding slimes. The effect on flotation of pH, collector concentration, particle size and flotation time was then analyzed. The results achieved show that a neutral or slightly alkaline pH and short flotation times promote the concentration of sedimentary phosphorite.