Zinc Industry

ZINC INDUSTRY

ZINC INDUSTRY. Zinc was first introduced commercially in the United States during the 1850s, with small-scale smelting plants in New Jersey, Pennsylvania, Illinois, Missouri, and Arkansas, near sources of ore and fuel. The principal early use of zinc was in the production of brass, a zinc-copper alloy. The first known domestic zinc production was at the Washington, D.C., arsenal in 1835, by Belgian workers. A furnace was built primarily to produce zinc for making brass to be used in standard weights and measures.

Early zinc production used oxidized forms of the ore, reduced by externally heating closed clay vessels containing a mixture of ore and coal. The vaporized zinc was condensed and cast into slabs. As ore deposits were worked to greater depths during the 1880s, larger quantities of sulfides and smaller quantities of oxides occurred. This required new technology for preroasting the sulfides to form crude oxides. As a result of this technology, sulfuric acid became a by-product of the zinc industry. Development of zinc-lead ore fields in Missouri, Kansas, and Oklahoma in 1895 gave a great impetus to the building of gas-fired zinc smelters in the region. The discovery of natural gas in and west of this area fueled developments, and the tri-state region became known as the Gas Belt. Westward migration created a great need for galvanized, zinc-coated steel for fencing, corrugated sheet metal, and brass hardware. In 1852, Samuel Wetherill invented a grate furnace to produce zinc oxide from oxidized ores, a so-called American process that was perfected in the last half of the nineteenth century.

During the first quarter of the twentieth century, as new mining districts were opened up in the Rocky Mountain area, in Tennessee, and in Virginia, the froth flotation technique for separating sulfide minerals from associated rock became the major mode of production. Demand for zinc during World War I led to great expansion of the U.S. zinc mining and smelting industry. It also spurred introduction of the electrolytic process in 1916, which used electrical energy as a substitute for coal and gas in freeing zinc from its mineral compounds. In the course of improving the process, it became possible to produce high-purity zinc. The uses for this zinc were vast, enabling mass production of intricate, precision shapes. When alloyed with aluminum, zinc products were instrumental in the burgeoning automobile and appliance industries beginning in the 1930s. New smelting techniques recovered cadmium as a by-product, which is valuable for its attractive and durable finish when plated onto other metals.

The U.S. zinc industry built up during World War I was the largest in the world and remained so through the end of World War II. The smelting segment of the U.S. industry ranked first in tonnage of zinc produced until 1971, when a combination of economic factors, environ-mental pressures, and shifting patterns of foreign-resource allocation resulted in nearly one-half of the domestic smelters ceasing operation in a two-year period. Of the 1.4 million tons of zinc used annually in the United States as of the early 1970s, only about 40 percent was mined domestically. By 2002, the United States was the fifth leading producer of zinc worldwide, with production expected to rise to just over 400,000 metric tons by the year 2004. Between 2000 and 2004, U.S. zinc consumption was expected to rise 1.5 percent to more than 1.45 million metric tons annually. In everyday life, zinc is largely unrecognized, although it has many uses, including as a protectant against rust on galvanized steel containers and highway guardrails, as an alloy component in die-cast cases for transistor radios or automobile carburetors, in brass alloy water faucets, as zinc oxide in white house paint or rubber tires, as a chemical compound additive for animal nutrition, and as a self-contained source of electrical energy in flashlight batteries.

BIBLIOGRAPHY

Faloon, Dalton B. Zinc Oxide: History, Manufacture, and Properties as a Pigment. New York: Van Nostrand, 1925.

Gent, Ernest V. The Zinc Industry: A Mine to Market Outline. New York: The American Zinc Institute, 1940.

Gibson, Arrell M. Wilderness Bonanza: The Tri-State District of Missouri, Kansas, and Oklahoma. Norman: University of Oklahoma Press, 1972.

Smith, Duane A. Mining America: The Industry and the Environment, 1800–1980. Lawrence: University Press of Kansas, 1987.

Carl H. Cotterbill / h. s.

See also Industrial Revolution .