Rare-earth elements in the ore of the Bukukinskoye tungsten deposit (the Eastern Transbaikalia)

Abstract

Research subject. This study investigated the mineral association of quartz-wolframite veins of the Bukukinskoye tungsten deposit, with a particular focus on the content of rare-earth elements and their carrier minerals, their chemical composition and the distribution of light and heavy lanthanides. Materials and methods. The chemical composition of two groups of samples containing different ore minerals, as well as the mineral composition of ores was investigated on 143 samples in thin and polished sections using an AXIO ScopeAI optical polarizing microscope and a LEO 1430 VP scanning electron microscope. Chemical examination of ores was carried out using the ISP MS method. Results. The study of the chemical composition of group samples determined that the content and distribution of REE, the ratio of light and heavy lanthanides in ores depends on the ratio of wolframite and other ore minerals, associated with fluorite and apatite. The main REE concentrator mineral in the wolframite-sulfide-quartz ores of the Bukukinskoye deposit is monazite-(Ce) containing (wt %) Ce (27.09–31.59) La (13.13–17.67), Nd (5.59–10.26), Pr (up to 2.86), Sm (up to 1.14), Th (up to 6.59). Conclusion. The obtained results confirmed our earlier findings for the wolframite of the Sherlova Gora that an increase in the concentration coefficient of heavy lanthanides depends on a decrease in their ionic radius. The contents, mineral forms and ratios of REE of the cerium and yttrium groups in the ore of the Bukukinskоyе deposit can be typochemical signs of greisen tungsten deposits, thus being useful for typification of ore formation in geological forecasting and prospecting.