Flotation experimental research of calcareous–siliceous phosphorite

• Influence factors of flotation process of calcareous–siliceous phosphate were investigated
• The GZ1 mixed collector considered apatite and dolomite surface properties were developed
• The integrated optimal single factor experiment of flotation was carried out.
• REO content in concentration is 0.175 wt.%, and the recovery is 86.08 wt.%.
• P2O5 content in concentration is 26.82 wt.%, and the recovery is 72.09 wt.%.

Based on the analysis of occurrence states and properties of a calcareous–siliceous phosphorite, the effects of GZ1 collector dosage, regulator dosage, pulp density and particles size distribution of sample on concentrate indexes were investigated by reverse flotation technology. The rare earth oxidize (REO) grade and recovery of concentrate were also analyzed in the work. Two-stage reverse flotation technology was applied for the beneficiation of a calcareous–siliceous phosphorite. Under the integrated optimal single factor conditions of GZ1 collector 0.9 kg/t, phosphate regulator 14 kg/t and pulp density 35 wt.%, mass fraction of particles size of − 74 μm of 85 wt.%, flotation time of 11 min and flotation pH of 5.5, the P2O5 grade increases from 14.64 wt.% in raw ore to 26.82 wt.% in the concentrate, and the recovery is 72.09 wt.%, while REO grade increases from 0.08 wt.% in the raw ore to 0.175 wt.% in the concentrate, and the recovery is 86.08 wt.%.