↑   Estimates fluctuate worldwide, but most resources provide a figure of two–4kg of bauxite for every 1kg of alumina. The one lighter metals would be the metals of groups 1 and a pair of, which apart from beryllium and magnesium are way too reactive for structural use (and beryllium is quite https://spencerwmbpd.theblogfairy.com/36448074/new-step-by-step-map-for-sheds-and-garages