Purification of phosphate beneficiation wastewater: Separation of phosphate from Eshydia Mine (Jordan) by column-DAF flotation process

About (400–450) m3/h of wastewater is discarded by Eshydia Phosphate Mine/south of Jordan. These effluents consist of 14% solids assaying 18% P2O5; which means that 9600 m3 of fresh water and 200 tons of valuable P2O5 are discarded daily. Therefore, recycling of these effluents will have a significant economical and environmental impact on Jordanian phosphate industry.In this contribution we used a combined column and Dissolved Air Flotation (DAF) to recover phosphate particles. Flotation experiments were conducted in bench scale column and DAF flotation cells. Commercial fatty acid (DSR) was used as phosphate collector while Methyl Isobutyl Carbinol (MIBC) and sodium silicate were used as frother, and depressor, respectively.Maximum phosphate recovery obtained by column flotation was (20%) with 20% P2O5 at the following flotation parameters: 1 kg/t collector dosage, 8 L/min air flow rate, and 40 ppm frother dosage. while, 83% recovery with 20.75% P2O5 was achieved by DAF at the following operating parameters: 100 rpm mixing speed, 1000 ppm collector dosage, 5 ppm frother dosage 500 ppm depressor dosage, pulp pH 9, and 12% recycle ratio. Therefore the overall recovery by combined column-DAF flotation was 86.4% with 20.6%, P2O5.

► Large amounts of wastewater (400–450) m3/h) are generated by phosphate industry in Jordan.
► Waste effluents contain high amounts of valuable phosphate in form of slime during phosphate beneficiation.
► In this work, we used combination of column flotation and Dissolved Air Flotation (DAF) to recover the fine phosphate.
► Hybrid column-DAF flotation of phosphate slime has not been reported in the literature.
► Maximum overall recovery and concentrate grade obtained were 86.4% and 20.6% P2O5, respectively