Recovery of phosphorite from coarse particle magnetic ore by flotation

• A large-scale flotation cell is developed for coarse particle separation.
• Overweight particles are just suspended off the bottom instead of being circulated.
• The optimized large-scale flotation cell improves the settlement of coarse particles.
• The optimized large-scale flotation cell consumes less power consumption.

Chengde area in China is rich in magnetite resources containing phosphorus. It is meaningful to comprehensively recover phosphorus from the tailings of magnetic separation by flotation. However, the phosphorite particles are severely coarse with only 25% particles in size of − 0.074 mm approximately and over 50% particles in size of + 0.25 mm. The coarse particle settlement in conventional flotation cell usually appeared when the minerals are processed by flotation. In order to solve particle settling problem, JJF flotation cell is specially optimized to strengthen suspension capacity and circulation capacity for coarse particles, and the industrial experiment was carried out to recover phosphorite from the tailings of magnetite separation with 160 m3 optimized JJF flotation cell. The industrial experiment results prove good adaptability of the optimized 160 m3 flotation cell for coarse particles. When the feed grade of P2O5 is 2.12%, the concentrate grade is up to 30.68%, tailing grade is 1.14%, recovery is 47.97% and the yield of concentrate is 3.35%. Good metallurgical performances are achieved. The comprehensive utilization of phosphorus resources could be significantly improved in this area in the future.