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Increasing fluosilicic acid evolution from phosphate rock by digestion with phosphoric acid.
Blake-HE Jr.; Nash-BD
NTIS: PB 240 099 :1-16
The Bureau of Mines has been engaged in a continuing research effort to develop processes for increasing the recovery and utilization of fluorine from low-grade resources. This current research has shown that over 98 percent of the fluorine in phosphate rock is extracted when the ore is treated with excess phosphoric acid in the presence of water vapor at 150 deg to 180 deg c. More than 80 percent of the fluorine can be recovered as fluosilicic acid, which can then be converted to commercially useful hydrogen fluoride or fluorspar by previously developed Bureau processes. Extraction of p2o5 from the ore was about 98 percent in batch tests and 90 percent in semicyclic tests.
IH; Report of Investigations
NTIS Accession No.
NTIS: PB 240 099
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division