Column Flotation of Multiple Products from a Fluorite Ore

摘要

The U.S. Bureau of Mines investigated column flotation for recovery of a high-grade fluorite (CaF2) concentrate and byproduct concentrates from the Fish Creek fluorite deposit in Eureka County, NV. The recovery scheme consisted of (1) grinding the ore to minus 48 mesh, (2) fluorite rougher and cleaner flotation, (3) desliming the rougher fluorite flotation tailings at 20 micrometers, (4) mica flotation and (5) silicate rougher flotation. Acid-grade fluorspar, mica, free silica (SiO2) sand, and low-grade beryl concentrate were produced in a 100 lb/h continuous column flotation unit (CCFU). The highest results achieved were 96.6-pct CaF2 recovery in a first cleaner concentrate containing 99.7 pct CaF2. Beryl recovery was as high as 92 pct at a grade of 5.3 pct BeO. The silica sand, which assayed 98 pct SiO2, was recovered as the rougher beryl flotation tailings. Collector reagent consumption was reduced 45 pct for fluorite and 58 pct for silicate flotation in comparison with bench-scale conventional flotation. All products were significantly improved in both grade and recovery over conventional flotation results, and the recovery scheme was simplified by removal of several stages of flotation in the fluorite and silicate flotation steps.