ZINC 



699 



EXPLOITATION 



The zinc industry of modern times began with the 

 smelting of the metal at Liege, Belgium, in 1806. 

 Historically, however, zinc was an alloy constituent 

 long before it was used in its purer metallic form. 

 Brass was known to the Greeks and Romans, prob- 

 ably from about the 2d century before the Christian 

 era, and was produced by melting copper with zinc 

 minerals. The identity of zinc as a distinct metal 

 was not known in the western world until the Middle 

 Ages when it began to be imported from China and 

 India. Ensuing centuries saw increasing amounts 

 imported by Europeans until finally the technology 

 itself was brought from China to England in about 

 1730. 



Belgium and Germany were the chief zinc- 

 producing countries during the 19th century and 

 produced about 70 percent of the century's smelter 

 output. The first zinc produced in the United States 



was smelted at the Government Arsenal in Wash- 

 ington, D.C., using ore from Franklin Furnace, N. J. 

 The main U.S. zinc industry, however, did not start 

 until about 1860, when successful smelters were 

 erected in Illinois and Pennsylvania. From this time 

 the industry boomed rapidly. Probably the most sig- 

 nificant technological advance contributing to this 

 surge was the successful commercial concentration 

 of sulfide ores by froth-flotation processes shortly 

 after the beginning of the 20th century. 



Production of zinc for the world and for the United 

 States from 1830 through 1970 is summarized in 

 figure 77. Consumption of zinc (including secondary 

 material) in the United States after 1937 also is 

 shown. Before that time the United States had been 

 virtually self-sufiicient in zinc, and total domestic 

 annual production generally exceeded consumption. 



The record of world production is one of exponen- 

 tial growth since the end of the 19th century, inter- 



2 2- 



"1 \ \ ^ I I I \ I \ r 



1830 1840 18S0 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 



Figure 77. — Primary production of zinc in the world and in the United States, 1830-1970, and consumption of zinc, in- 

 cluding scrap, in the United States, 1938-70. 



