Commercial Introduction of Cyanex~R 600 for Molybdenum Solvent Extraction

摘要

Amine-based extractants have been traditionally used for recovery of molybdenum and rhenium from solvent extraction circuits due to their high affinity for the metals. However, for applications requiring selectivity between the two metals, alternative extractants have been found to offer advantages. Cyanex~R 600, a phosphinic acid-based extractant, was developed for enhanced selectivity of molybdenum. In addition to Mo/Re separation, improved physical performance and reduced base consumption have been observed. Elimination of chemical acid and anion transfer with Cyanex~R 600 results in operational costs savings. Ligand-molybdenum complex solubility is improved, reducing challenges associated with crud generation. The extractant has been piloted for selective extraction of Mo from concentrate leach liquor feeds, molybdenum-bearing copper raffinates, and molybdenum containing effluents from smelting/roasting applications. Cyanex~R 600 was commercialized in 2017 and adopted by Freeport-McMoRan at the Bagdad operation in Arizona. Positive pilot plant results have been previously presented, as well as economics that led to the decision to convert to the new extractant. During the first year of use, Cyanex~R 600 demonstrated tangible operational cost savings. This paper will discuss the economic and operational advantages witnessed during pilot trials and highlight optimization activities during the first year of commercial use.