By definition, science has its eye fixed unerringly on the future, on the next revelation, on taking audacious steps to attain a mere inch of ground. But, if nothing else is true, we know that our work rests on lifetimes of achievement, on the shoulders of those who came before.
Lithium, the third element in the periodic table of elements, was discovered in 1817 by a Swedish scientist named Arfwedson. He had analyzed the content of a mineral called spodumene; the results of the analysis left a sizable percentage of the ore's makeup unaccounted for. Further work resulted in the extraction of a compound with chemical properties suggesting an unknown element was present. Since the new element had been found in chunks of spodumene ore, Arfwedson called it "lithium," from the Greek word for stone.
It was not until 1855 that lithium was prepared as a free metal. In those early years, lithium was little more than a laboratory curiosity. Lithium-bearing minerals were sometimes used as exotic additives to ceramic compositions. Not until World War II were the special properties of lithium compounds fully investigated and exploited. A compact, lightweight source of hydrogen was needed for use in emergency signaling balloons. Lithium hydride was found to be ideal for this purpose; one pound of lithium hydride reacts with seawater to generate 45 cubic feet of hydrogen.
Later, greases containing lithium stearate were formulated and found to retain their lubricating properties at both very high and very low temperatures. For the first time, the same grease could be used for multiple purposes over a wide range of operating conditions. With the advent of rocketry came the search for materials that could withstand the extreme temperatures of high-speed travel through the atmosphere. A ceramic composition containing lithium was developed that expanded very little and resisted cracking during rapid extreme temperature change. This lithium-containing material, "pyroceram," was the forerunner of modern glass-ceramic cookware that resists thermal cracking.
In 1953, the Atomic Energy Commission (AEC) required large amounts of lithium hydroxide from which the lithium-6 isotope was separated and reserved for use in the production of thermonuclear weapons. For about five years, the government was the largest consumer of lithium. After the AEC contracts expired in 1960, the lithium industry, faced with vast over capacity, sought desperately to develop its small commercial markets. Though not an overnight success, it soon became a firmly established supplier to basic industries such as ceramics, lubrication, aluminum reduction, and pharmaceuticals.
Today, even though lithium products are widely used in households, factories and laboratories, lithium's presence often goes unrecognized. Lithium may be as close to the average person as a medicine chest, a television, a swimming pool, or a calculator. Lithium is found in minerals, clays, and brines located in various parts of the world. High-grade lithium ores and brines are the present sources for all commercial lithium operations. Economical brine sources of lithium were rare until several salars in the Andes Mountains of South America were discovered to contain significant deposits of lithium salts.
The salars are large, dry lakebeds where the brines are located just under a layer of crusted salt deposits. The areas are remote and inhospitable. To make them productive requires a considerable investment in research, exploration, and transportation of personnel and materials. However, the concentrations of lithium in these brine deposits range from 200 to 2000 ppm and can be further concentrated using solar evaporation. Contributing to efficient solar evaporation and concentration of the brines are the low rainfall and humidity, high winds and elevations, and relatively warm days in the area of the salars. When such conditions are present, highly concentrated brines can be produced at reasonable cost and used as feed stock for a plant making lithium carbonate.
In 1995, two important breakthroughs took place in the development of a brine-based resource for lithium. While still mining spodumene from its North Carolina mine, FMC Lithium purchased the Salar del Hombre Muerto, an Argentine salar containing high uniform concentrations of lithium with low levels of other contaminants. Concurrently, FMC perfected and commercialized a selective purification process which extracts lithium chloride from the salar brine in a nearly pure form with minimal processing.
The Salar del Hombre Muerto is located in the high Andes at about 13,200 feet above sea level, about 850 miles northwest of Buenos Aires. The location is convenient to major rail lines and seaports. Covering a smaller area than most salars of the region, it contains lithium brines at depths much greater than its neighbors. Lithium reserves are sufficient for well over 75 years. The Salar del Hombre Muerto area also contains plentiful fresh water needed by the selective purification process.
Selective purification uses low-cost raw materials housed in modular units. FMC has installed production facilities for both lithium chloride and lithium carbonate from the Salar del Hombre Muerto.