A Study on the Thermal Infrared Spectroscopy Characteristics of the Skarn Minerals in Zhuxi Tungsten Deposit, Jiangxi Province

The mineralization of scheelite in the Zhuxi tungsten deposits is closely related to skarnization. Scheelite is mostly produced together with skarn minerals such as garnet and diopside. In this study, for the first time, the typical skarn minerals such as garnet, diopside, vesuvianite, wollastonite and actinolite are measured by micro infrared spectroscopy and electron probe analysis to explore the thermal infrared spectral characteristics of skarn minerals in Zhuxi and their implications for mineralization, and to establish a thermal infrared spectral library of skarn minerals in Zhuxi area. The results show that the garnet in Zhuxi tungsten deposit is mainly grossular-and radite series. There are two absorption peaks (a large and a small) near 800 and 920 cm and there is a characteristic absorption valley near 880 cm (1). When the grossular content in garnet is greater than 50 %a, the characteristic absorption valley of garnet is located at 880 similar to 900 cm (1). When grossular content is less than 50 %a, the absorption valley of garnet is located at 865 similar to 875 cm (1) With the increase of Al2O3 content in garnet, the characteristic absorption valley moves towards the high-wavenumber direction. Grossular tends to high wavenumber while andradite tends to low wavenumber; Diopside is mainly diopside-hedenbergite series. There is a diagnostic step-shaped absorption peak in the wavenumber range of 850 similar to 950 cm (1) anabsorption peak at 1 050 cm (1) and a weak double-valley absorption at 1 000 cm (1) With the decrease of diopside content, MgO content decreases the diopside absorption peak moves to the low-wavenumber direction. The absorption peak of hedenbergite is concentrated in the low-wavenumber range compared with diopside, which is consistent with the changing law of garnet. It is speculated that the reason is that Al and Mg are more active than Fe. Vesuvianite has similar absorption peaks in the range of 850 similar to 950 cm (1) as diopside. The difference is that vesuvianite still has anabsorption peak at 800 cm; Wollastonite has three absorption peaks (a large and two small) near 875, 1 000 and 1 060 cm (1), and two characteristic absorption valleys near 980 and 1 040 cm; Actinolite has two absorption peaks (a small and a large) near 750 and 900 cm and three characteristic absorption valleys near 770, 930 and 1 020 cm (1). The scheelite mineralization in the Zhuxi deposit is most closely related to garnet and diopside, and it mainly grows in veins along the boundary