How is copper extracted industrially from its ore? Compare this proces with the extraction of aluminum from bauxite. Explain the method of extraction in terms of "activity" of the metal and/or "stability of the compounds of the metal".
Copper ore mostly consists of copper sulfides including chalcopyrite (CuFeS2) and chalcocite (Cu2S). The ore is crushed and inititally heated with silica (SiO2) to remove most of the iron present as slag. The copper is then in a form called copper matte which consists of Cu2S. This matte is heated in the presence of oxygen to convert the copper sulfide into copper oxide. The oxide is then heated in furnaces to remove the oxygen and produce crude copper metal. The metal can be electrochemically refined to produce highly pure copper metal.
Aluminum is produced from the ore bauxite, which is a mixture of various aluminum oxides. The aluminum metal is ultimately produced via the electrochemical reduction of molten bauxite, but the temperatures required to melt bauxite are higher than required to melt copper ores because aluminum oxides are extremely stable. Also, bauxite does not have iron mixed in with it that has to be first removed like with copper.