Abstract

ALUJAS DIAZ, Adrián; QUINTANA PUCHOL, Rafael; GONZALEZ RUIZ, Jesús Eduardo  and  YEE MADEIRA, Hernani. Concentrado Cromífero Del Yacimiento Merceditas , Una Fuente Alternativa Para Recubrimientos Cromo-Difusivos En Aceros. Rev. LatinAm. Met. Mat. [online]. 2003, vol.23, n.2, pp.62-71. ISSN 0255-6952.

In this paper a quantitative phasical characterization of a chromite concentrate with refractory characteristic belonging to the deposit Merceditas is presented, using for it technicals of infrared and Mössbauer spectroscopies, X-ray difractometry, chemical and grain size analysis. It settles down that the concentrate is constituted by the phases mineralogical well-known as chromopicotite, antigorite and chlorite, being determined its respective cristalochemical formulae. From the knowledge of the cell parameter a , finded using Cohen´s method, it´s value as a potential source of chrome is estimated and four mixtures with different composition are made for the controled aluminothermic reduction. By means of the techniques of thermal analysis (DTA, TG and DTG) the thermal behavior of a mixture of chromite concentrated and aluminum is studied and the range of temperature for thermal reduction is determinated. The reduced product is evaluated for its like a suitable carrier of chrome in the thermodifusive treatment saturating mixtures for the thermodifusives surfaces of chromium and silicon in steels of steel surfaces in the powder mixture method. The best results are obtained for a variant which involves particles of grain size 55 m m, and reduction time 4 hours at 960ºC.

Keywords : refractory chromite; aluminothermic reduction; cristalochemical formulae.