Partitioning of Nb, Ta, Ti, Ce, and La between Granitoid Magmatic Melts and Minerals

Abstract

Experimental data on the Nb, Ta, Ti, Ce, and La concentrations in felsic magmatic melts of various alkalinity and alumina content upon dissolving ilmenorutile, ferrotapiolite, and loparite in them and the partitioning of these metals between the melt and the mineral at 650–850°C and 100 MPa, which allow one to obtain quantitative characteristics for creating physicochemical models of the genesis of rare metal and rare earth deposits, are presented. It is shown that ilmenorutile and ferrotapiolite are stable in the peraluminous melt. Ilmenorutile is also stable in the subaluminous melt and at 650°C in the alkalized melt, and loparite is unstable in all melts participating in the experiments. The dependences of the content and partitioning of Nb on dissolving ilmenorutile and loparite are similar to each other and to those on dissolving columbite and tantalite. At the same time, the dependence obtained by dissolving ferrotapiolite is similar to that obtained by dissolving microlite and pyrochlore.