Bauxite, the ore of aluminium, is purified by which process?

Bauxite is the primary ore of aluminum. Its purification involves removing impurities like silica, iron oxide, and titanium oxide. This is typically achieved through the Bayer process, but in the context of the given options, Hall's process (commonly associated with aluminum extraction) is the most relevant, as Hoope's process refines aluminum, Mond's process purifies nickel, and liquation is used for low-melting-point metals.