Investigation of the potentials of Nigerian salt deposit as fluxing materials in secondary aluminium production

Abstract

Secondary aluminium has been a major contributor to the total supply of aluminium to the national economy. To obtain high-grade secondary aluminum from scraps, melted scraps are subjected to such treatment as fluxing. Fluxing improves the quality of secondary aluminium products by eliminating the impurities and protecting the surface of the melt from contamination. In this work, fluxing of aluminium scrap was carried out using salt obtained from Keana in Nassarawa State. The preliminary investigation carried out on the salt indicate a high level composition of various cations and anions such as Na+, K+, Cl-, C03-, that are characteristic of aluminium fluxes. Various percentages by mass of Keana salt was used in fluxing melt obtained from aluminium scraps. The results of tests carried out on the specimen using cast samples indicate that the optimum fluxing proportion of this salt is 1.5wt.%. The corresponding values of mechanical properties are UTS = 141N/mm2, Percentage Elongation = 1.11; Brinnel Hardness = 50HRB; Impact strength = 51.54J. These values compares well with those obtained using standard Coverall fluxing materials and in some instances, samples fluxed with Keana salt gave better parameters.



Keywords: Secondary Aluminium, Scraps, Fluxing, Salt, Mechanical Properties.


[Global Jnl Engineering Res. Vol.2(1&2) 2003: 11-15]