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Method for determination of small amounts of rare earths and thorium in phosphate rocks

January 1, 1953

In laboratory investigations, interest developed in the possible rare-earth content of phosphate samples from Florida and the northwestern United States. Because of the difficulty of making chemical determinations of traces of individual rare earths, a combined chemical-spectrographic method was investigated. After removal of iron by the extraction of the chloride with ether, the rare earths and thorium are concentrated by double oxalate precipitation, using calcium as a carrier. The rare earths are freed from calcium by an ammonium hydroxide precipitation with a fixed amount of aluminum as a carrier. The aluminum also serves as an internal standard in the final spectrographic analysis. The method will determine from 0.02 to 2 mg. of each rare earth with an error no greater than 10%. The investigation has resulted in a fairly rapid and precise procedure, involving no special spectrographic setup. The method could be applied to other types of geologic materials with the same expected accuracy.

Citation Information

Publication Year 1953
Title Method for determination of small amounts of rare earths and thorium in phosphate rocks
DOI
Authors C. L. Waring, H. Mela
Publication Type Article
Publication Subtype Journal Article
Series Title Analytical Chemistry
Series Number
Index ID 70011089
Record Source USGS Publications Warehouse
USGS Organization