Experimental and theoretical approach of the hydrolysis of pelleted magnesium alloys scraps

Abstract

Industrial Mg alloys scraps containing 3% of Al and 3% of Zn (and about 20% of MgO and Mg(OH)2) were ball milled with the addition of 5 wt% C and 5 wt% of Ni, Cu, Co or SiO2. 3 h of ball milling were needed to obtain optimum hydrolysis performances of the mixtures (e.g. yields of almost 90% obtained within 1 min). Pellets of such obtained powder were prepared as it is easier for an application. The shape of the hydrolysis curves highlights first an incubation period depending on the compactness of the pellets and then a second part with a logarithmic shape. A new model is presented that allows to take into account both parts of the hydrolysis curve. The model is applied successfully to all the pellets having various compactness.