Froth flotation separation of phosphate ore using a novel hammer-like amidoxime surfactant

Comparison diagram of reverse flotation behavior of Phosphorite by a novel hammer-like amidoxime surfactant DPA and traditional collector DA. [Display omitted] •A novel amidoxime surfactant DPA was introduced in phosphate fertilizer production.•DPA exhibited superior selectivity for quartz against phosphorite.•DPA displayed superior flotation performances than conventional surfactant DA.•Amidoxime is a promising collector for sustainable phosphate fertilizer production. Phosphate fertilizer, as a necessary nutrient for crops in agriculture, plays a vital role in addressing global food security concerns. The source of phosphate fertilizer is mainly obtained through the production of phosphate ore, which has caused widespread concern. However, in the traditional process, the low production efficiency and high dosage of common surfactants have severely restricted the development and utilization of phosphate rock resources. In this work, a new designed hammer-like amidoxime surfactant (DPA) was characterized and introduced as an outstanding collector to recover high quality phosphate ore. The micro-flotation tests indicated that DPA had more excellent collecting ability and selectivity(The phosphorite recovery was always lower than 15%) than common monomolecular collector 1-dodecylamine (DA). Bench-scale flotation tests showed that a high quality phosphorite concentrate with higher grade and recovery (33.65% and 79.46%, respectively) could be enriched using lower dosage DPA. Economic estimate for a 5000 t/d phosphorite ore concentrator would result in an annual profit increase of approximately $8675330.65 by DPA collector. Density functional theory(DFT) calculations revealed that DPA reacted with Nucleophilic reagent (Phosphorite) by the reactive site of –CH2NH(CH2)2C(NOH)N+H3 group and more easily absorbed on the surface of Phosphorite than DA. Therefore, the above results prove that amidoxime surfactant DPA is an efficient and economic collector to recover high quality phosphate ore, which provides an important guarantee for the production of phosphate fertilizer.