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ABSTRACT
Sodium nitrate is a major source of nitrogen, an important component of fertilizers, and is a raw material for the manufacture of saltpeter, an essential ingredient of gunpowder. Until the invention of the Haber-Bosch process in 1909 to produce ammonia from air and water, Chile was the world's leading supplier of sodium nitrate. This paper briefly addresses these uses throughout history and reviews the exploitation of nitrates in South America from the early 19th century through to the present. The increase in the demand for nitrates after the introduction of gunpowder to Europe is touched upon as is the search for higher grade, assured sources which lead to the exploitation of the deposits of Bolivia and southern Peru. Events leading to the Pacific War, fought basically for control of the nitrate fields, after which Chile controlled W0% of the nitrate production are briefly addressed. Included is a description of the early industry, its magnitude and its effects on the Chilean economy.
Introduction
The growth of the Chilean nitrates industry parallels that of the worldwide demand for usable nitrogen to manufacture fertilizers and gunpowder. Prior to the discovery of the Haber-Bosch process to produce ammonia from air and hydrogen gas in Germany in 1909, the main source of nitrogen was sodium nitrate, better known as Chile saltpeter, to distinguish it from true saltpeter or potassium nitrate, which is rarely found in large quantities naturally.
Potassium nitrate is readily made by adding potassium chloride to a hot concentrated solution of sodium nitrate, inducing the following reaction:
NaNO^sub 3^ + KCl [arrow right] KNO^sub 3^ + NaCl
The sodium chloride precipitates out and the solution is decanted to another vat where it is cooled, leading to the formation of saltpeter crystals which are then dried. The product is sold both bagged and in bulk. Some producers melt and prill the potassium nitrate to provide a more easily handled product.
Bird and bat guano have been used since ancient times as fertilizers, and Peruvian guano, mined from islands just off the coast near El Callao, was considered the best in the world. The Moche civilization in the coastal region of Peru fertilized crops with guano long before the advent of the Incan empire. From the late...