Application of μ-XRF in Uranium Mineralogy of the Huanglongpu Carbonate-type Molybdenum Deposit, Shaanxi Province, China

Abstract

BACKGROUND The carbonatite-type molybdenum metallogenic belt in East Qinling is the largest molybdenum metallogenic belt in the world. The Huanglongpu deposit is one of the earliest discovered carbonatite-type molybdenum deposits in China. Our field survey found that the uranium grade of ores in this deposit was higher than the industrial uranium grade, being similar to the Huayangchuan U-Nb-Pb-REE deposit in the Qinling Orogenic Belt. However, the occurrences and mineralogical characteristics of radioactive elements are still unclear. OBJECTIVES To explore the main mineral assemblages, U occurrences and other characteristics of uranium ores in the Huanglongpu deposit. METHODS The detailed geological survey, μ-XRF, SEM and EDS analyses were carried out on the high-radioactivity ore from the Huanglongpu deposit. RESULTS The results showed that major uranium minerals in the Huanglongpu deposit were brannerite, betafite and uraninite, which were associated with calcite, feldspar, pyrite, molybdenite and chalcopyrite. Significant alteration and replacement of uranium minerals were observed in the studied ore sample. The betafite was transformed into Nb-rich Ti-Fe oxides after alteration. After alteration of brannerite and uraninite, a large number of cavities were formed within those minerals. The post-ore fluids were possible from meteoric water. The textural differences of altered brannerite and uraninite on BSE images suggested the variable chemical composition. CONCLUSIONS μ-XRF technology has a great application prospect in the future research of uranium deposit genesis and prospecting prediction.

Keywords

• μ-xrf technology
• sem
• eds
• uranium mineral
• carbonatite
• huanglongpu deposit