Distribution, occurrence and exploration prospect of associated rare earth elements in Yichang phosphate deposit, Hubei Province

This paper is the result of mineral exploration engineering.

Objective The Yichang phosphate ore in Hubei Province contains associated rare earth elements. Studying their distribution patterns and occurrence states is of significant importance for the recycling and utilization of rare earth elements. Additionally, the comprehensive utilization of associated minerals is expected to become a crucial source for future rare earth ores.

Methods This study primarily focuses on rare earth−containing phosphate rocks. Based on systematic sampling, analyses including rock and mineral identification, whole−rock geochemical analysis, XRD diffraction analysis, SEM observation, and LA−ICP−MS testing are carried out.

Results The total rare earth element content (ΣREE+Y) in phosphate rock ranges from 63.5×10⁻⁶ to 271.8×10⁻⁶. There are variations in rare earth element contents among different layers or rock types of phosphate rock.

Conclusions The content of rare earth elements is notably controlled by rock types, with an increase from dolomite → dolomitic phosphorite → dense massive phosphorite → argillaceous banded phosphorite to mudstone. Trace elements compositions reflect the ancient climate of the Yichang phosphate deposits, characterized mainly by a dry and hot climate, with a slightly warm and humid characteristic in the northwest. Ce anomaly, V/Ni and Y/Ho ratio reflect the oxidation of seawater conditions from the bottom to the top, corresponding to the the Ph₂² to the Ph₁³ phosphogenesis periods. The total rare earth elements content in the Yichang phosphate deposit are relatively low, and mudstone has higher content compared to phosphate rocks, indicating a higher concentration of adsorbed rare earth elements than the isomorphic rare earth elements. The rare earth resources associated with the Yichang phosphate deposit can be comprehensively recovered using appropriate technologies, holding significant importance for the rational utilization of the Yichang phosphate ore resources and economic development.