The ores from the Zoujiashan uranium deposit contain a large amount of apatite, and the content of apatite is positively correlated with that of uranium. A systematic study of the mineralogical characteristics of apatite and its relationship with uranium mineralization will shed lights on uranium metallogeney and guide future uranium deposit prospecting. Chemical analysis, electron microprobe analysis and automatic mineral analysis of the uranium ores and surrounding rocks from the Zoujiashan uranium deposit showed that: (1) The P2O5 contents of the ores are positively correlated with those of U, ∑REE, HREE, CaO, TiO2 and LOI, negatively correlated with those of SiO2, Al2O3, MgO, Na2O, K2O and LREE/HREE, and irrelevant with that of Fe2O3, MnO and LREE. (2) The uranium ores consist of 2.18% apatite which commonly occurs as euhedral or subhedral crystals with grain-size larger than that of the uranium-bearing minerals. Two types of apatite can be recognized, i.e., one type apatite is closely associated with uranium-bearing minerals, commonly heavily fractured and showing adsorption structure with sizes larger than 10 μm; whereas the other type is unrelated to uranium-bearing minerals, and characterized by euhedral and relatively integrated crystals larger than 50 μm in size, with flat surfaces and edges. (3) The intergrowth apatite-uranium minerals account for 7.58% of the ores, and the apatite consists mainly of fluorapatite and fluorocarbon apatite. We argue that Ca and P in apatite mainly come from decomposition of plagioclase and biotite, whereas the formation of apatite may consume anions such as F- and CO32-, and disturb the balance of uranyl complex which lead to the precipitation of uranium minerals. © 2020, Science Press. All right reserved.
