Regular Article

Preparation of Al-Sr master alloys by the aluminothermic reduction of SrO using aluminum scrap at pilot plant scale

¹ Universidad Autonoma de Chihuahua, Universidad Avenue and Pascual Orozco, 31110 Chihuahua, Mexico
² Cinvestav-Saltillo, Industria Metalurgica 1062, 25900 Ramos Arizpe, Mexico
³ Instituto Tecnológico de Saltillo, Venustiano Carranza Avenue 2400, Tecnológico, 25280 Saltillo, Mexico

^* Email: rochoa@itsaltillo.edu.mx

Received: 23 February 2017
Received in final form: 10 July 2017
Accepted: 24 July 2017

Abstract

Al-Sr master alloys were prepared by aluminothermic reduction of SrO in molten aluminum processed from scrap. The trials were performed at 500 kg pilot plant scale, using a gas operated furnace with a silicon carbide crucible. The effect of temperature, initial magnesium concentration and agitation speed on the aluminothermic reduction rate of SrO powders was studied. Moreover, the microstructure of Al-Sr master alloys prepared has been analyzed by means of optical microscopy, X-ray diffraction (XRD), and scanning electron microscopy (MEB). In this sense, the morphology of secondary constituents and the structure of Al₄Sr phase were evaluated. The results showed that the aluminothermic reduction technique is useful for producing Al-Sr master alloys, observing the presence of the Al₄Sr intermetallic phase as the main secondary constituent.