Lead production during twentieth century

Aluminum is a metal that came of age in the twentieth century. Its volume of production has grown from about 1/lOOth that of copper, lead, and zinc prior to 1900, to two to four times the volume of these more common nonferrous metals during the last century (Table 12.1). H.C. Oersted, in 1825 (Table 12.1) in Denmark, was the first to isolate aluminum in impure form by the reduction of aluminum chloride with potassium amalgam. Two years later in Germany, F. Wohler obtained higher purity metal and fully described its properties. H.E. St.-Claire Deville put aluminum production into commercial practice in France by 1845 using sodium fusion to reduce aluminum chloride (Eq. 12.1). 

Spectroscopy in the ultraviolet and visible range has been used to follow the evolution of NO2 in order to study the autoxidation kinetics (29), and symmetric NO3 has been characterized by the method already in the early twentieth century (5,48) it can be prepared in easily detectable quantities by the reaction of N2O5 or NO2 with ozone. It is, however, not very fikely an intermediate of NO autoxidation, because its formation would require the splitting of02, and because the electrode potential ofits reduction to NOs" has been estimated to be higher than 2 V, which would lead to side reactions that would have been hardly overlooked. In contrast, the electronic spectrum of ONOO is not known, and it would most likely not be helpfijl in detecting it at steady-state concentrations, since known extinction coefficients of N-O compounds in the visible and near ultraviolet spectrum are all below 1000 cm Thus, the absorption of ONOO during autoxidation would vanish under the contribution of the product, NO2. ... 

The recorded domestic primary lead production peak for the twentieth century in 1926 of 744,000 MT was surrounded by primary production in excess of 700,000 MT for 5 years during the 1920s, a performance not to be repeated during the balance of the century. While primary production declined or remained relatively static after the 1920s, secondary production continued to increase. Secondary production exceeded 500,000 MT in 1974, exceeded 800,000 MT by 1989, and exceeded 1,000,000 MT by 1996. In 1996, the figure for primary production was only 326,000 MT, but the import level was 280,000 MT. 

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