Effects of ore types and blending strategy on the flotation performance, using igneous phosphate ore from Esfordi deposit

The Esfordi deposit, Iran's largest igneous phosphate resource, exhibits significant mineralogical heterogeneity that causes feed quality fluctuations and compromised flotation performance. This study presents the first systematic comparison of two mineralogically distinct ore types from this deposit: an iron-rich apatite ore (P۱) and a clay-bearing green phosphate ore (P۲). Feed blending was then evaluated as a practical strategy for managing this ore variability. Mineralogical characterization revealed that P۱ contained ۱۳.۸۶% P₂O₅ and ۴۷.۱۷% Fe₂O₃, whereas P۲ assayed ۱۰.۷۲% P₂O₅ and ۱۶.۵۵% Fe₂O₃ and contained ۱۰.۶% clay minerals. Flotation conditions were optimized through systematic studies of collector dosage, pH, starch dosage, and cleaning stages following desliming. Under optimized conditions (pH ۹.۵ and ۴۰۰ g/t starch), P۱ achieved a concentrate grade of ۴۰.۸۱% P₂O₅ and ۸۰.۵۳% recovery, using only ۲۸۰ g/t collector—down from the current plant practice of ۶۸۰ g/t, a ۵۹% reduction. In contrast, P۲ required ۶۸۰ g/t collector and yielded ۳۱.۰۵% P₂O₅ with ۷۱.۳۸% recovery, due to increased reagent consumption associated with clay minerals. Among the tested blending ratios, the ۷۰:۳۰ (P۱:P۲) blend provided the most favorable balance, producing a concentrate containing ۳۵.۲۶% P₂O₅ and ۲.۰۸% Fe₂O₃ with ۶۳.۸۲% recovery while reducing collector consumption by ۳۲% relative to P۲ alone. These findings demonstrated that feed blending can effectively mitigate the adverse effects of ore type, maintain concentrate quality, and reduce reagent requirements. Adjusting blending ratios and reagent dosage according to feed characteristics can improve flotation performance and provide practical guidance for plant operation.

کلیدواژه ها:

Igneous phosphate ore ، Apatite flotation ، Ore variability ، Blending ، Flotation optimization