@article{Gómez-Pinilla_Larrea_Valle_1998, title={Problematic of the Imini pyrolusites in the production of ferromanganese for metallurgical applications}, volume={34}, url={https://revistademetalurgia.revistas.csic.es/index.php/revistademetalurgia/article/view/778}, DOI={10.3989/revmetalm.1998.v34.iExtra.778}, abstractNote={The possibility of eliminating lead impurities from the pyrolusite of Ímini (Morocco) has been studied. The material undergoes a minerallurgical process which allows the separation of six fractions based on their differences in density and electromagnetic behaviour. Among the fifteen mineralogical species found, none of them contains lead in its theorical formulation. In order to detect the presence of this element the microanalysis by dispersive energies was used and a "mapping" of lead was made in each of the fractions. This element is concentrated in the psylomelane crystals. The chemical composition of the psylomelane was compared with that of the hollandite, taken from the references. The presence of lead inside the psylomelane crystalline structure avoids its separation by a classical minerallurgic of process and therefore the use of this material is not feasible for the production of ferromanganese.}, number={Extra}, journal={Revista de Metalurgia}, author={Gómez-Pinilla, I. and Larrea, M. T. and Valle, F. J.}, year={1998}, month={May}, pages={390–394} }