The Occurrence of Niobium in Shapinggou Molybdenum Deposits, Jinzhai County, Anhui Province

During the exploration process of Shapinggou oversize molybdenum deposits, it was determined that partial samples contain 100-350 μg/g Nb, but mineralization of Ta is not obvious. Since the exploration work is coming to an end, the focus now is to investigate the occurrence states of Nb and Ta in order to determine if there is a molybdenum associated deposit. In this paper, a study of the samples from the ore district by chemical analysis, thin sections, single mineral analysis and electron microprobe analysis to study the occurrence states of Nb and Ta is described. The contents of Nb and Ta in quartz syenite and alkali feldspar granite porphyry, which is the upper part of molybdenum ore were 172.9 μg/g and 10.6 μg/g, respectively, meanwhile, syenite and granite porphyryare in molybdenum ore were 84.5 μg/g and 5.2 μg/g, respectively by using chemical and spectral analysis. The analysis showed that the mine was a single primary Nb mineralization which mainly happened in the quartz syenite upper molybdenum ore body. No Nb and Ta minerals were observed under the polarizing microscope. The electron microprobe analysis results for single mineral showed Nb mineralization mainly occurred in the rutiles by sphene alteration, and Ta mineralization is not obvious. Rutiles were mainly xenomorphic granular-subhedral plate and grain sizes were less than 0.2 mm. The aggregates showed sphene pseudomorph, and the average content of Nb₂O₅ in Rutile was 9.224%. The allocation calculations of Nb in various minerals showed that 75.13% Nb were hosted in Rutiles. Comprehensive analyses showed that the Nb and Ta in Shapinggou Mo deposit were not associated minerals for Mo and have no industrial value since the mineralization was weak.