Leaching and weathering of the original carbonatite rock has resulted in more than 200 million metric tons of residual soil in which apatite, pyrochlore, magnetite, zircon, and baddeleyite have been concentrated to levels well above those in the parent carbonatite. The carbonatite is subeconomic, but soil containing 20 to 40 percent apatite can be worked economically to produce a high-grade phosphate concentrate. Stockpiled magnetitic discards from apatite production could provide an iron ore concentrate in the future. The soil contains 0.3 to 1.0 percent pyrochlore, but a pilot plant process for recovering high-grade pyrochlore concentrates is not economic at prevailing prices. Although grades are subeconomic, a zircon concentrate would be a useful by-product if the production of pyrochlore became viable.--Modified journal abstract.

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