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

Dehghani, Mohammad; Maleki, Hassan; Alishahiha, Yasamanzahra; Noaparast, Mohammad; Jozanikohan, Golnaz

doi:10.22059/ijmge.2026.419137.595411

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

Articles in Press

Document Type : Research Paper

Authors

Mohammad Dehghani ¹

Hassan Maleki ¹

Yasamanzahra Alishahiha ²

Mohammad Noaparast ²

Golnaz Jozanikohan ³

¹ School of Mining Engineering, College of Engineering, University of Tehran, Tehran.

² School of Mining Engineering, College of Engineering, University of Tehran.

³ School of Mining Engineering, College of Engineering, University of Tehran, Tehran, Iran.

10.22059/ijmge.2026.419137.595411

Abstract

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 (P1) and a clay-bearing green phosphate ore (P2). Feed blending was then evaluated as a practical strategy for managing this ore variability. Mineralogical characterization revealed that P1 contained 13.86% P₂O₅ and 47.17% Fe₂O₃, whereas P2 assayed 10.72% P₂O₅ and 16.55% Fe₂O₃ and contained 10.6% clay minerals. Flotation conditions were optimized through systematic studies of collector dosage, pH, starch dosage, and cleaning stages following desliming. Under optimized conditions (pH 9.5 and 400 g/t starch), P1 achieved a concentrate grade of 40.81% P₂O₅ and 80.53% recovery, using only 280 g/t collector—down from the current plant practice of 680 g/t, a 59% reduction. In contrast, P2 required 680 g/t collector and yielded 31.05% P₂O₅ with 71.38% recovery, due to increased reagent consumption associated with clay minerals. Among the tested blending ratios, the 70:30 (P1:P2) blend provided the most favorable balance, producing a concentrate containing 35.26% P₂O₅ and 2.08% Fe₂O₃ with 63.82% recovery while reducing collector consumption by 32% relative to P2 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.

Keywords

Igneous phosphate ore

Apatite flotation

Ore variability

Blending

Flotation optimization

Subjects