Copper And Molybdenum Deposits In The United States :: essays research papers

Copper and minute Deposits in the United StatesCopper and second options were not recognized as valuablecommodities until economic needs enquireed the collection and processing of theseminerals in colossal amounts. The most expansive deposits of tomentum and molybdenumoccur in big low grade ores and argon found in intrusive porphyritic rock formations,although many smaller sized only higher grade ores atomic number 18 located in non-porphyry theaters. The nation has abundant home(prenominal) copper ore reserves but because of manydetrimental economic factors much of the copper use by the U.S. industry isimported. Molybdenum ore is profuse and exports of it are high to occupy theneeds of foreign demand.Copper was first used by tribe around 4000 B.C. in the manufacture oftools because of its malleability and later became an important bilinear inharder, more useful metals such as bronze (copper+ tush 2500 B.C.) and brass(copper+zinc 0 A.D.). The growth of copper merchandis e in the United States hasbeen a relatively recent occurrence. North American French explorers knew ofsources of native copper in the region of Lake Superior and the area natives hadcopper jewelry and ornamentation. Earnest copper mining began in Simsbury,Connecticut close to 1709 and copper was actually exported to England after asource was discovered in New Jersey around 1719. In later times domestic copperresources did not satisfy national needs until the discovery of aureate inCalifornia shifted the focus of mineral exploration westward and strikes of teemingcopper ores occurred in Tennessee and the Cordilleran base regions. The Civilwarfare caused copper demand to increase greatly in order to manufacture cartridgesand canned goods, this resulted in the openings of numerous copper mines ofwhich more than 90% were in the Lake Superior area giving an important advantageto the Union armies. Major copper production districts then shifted to Montanaand Arizona in the early 1890s. Production change magnitude to reach peak levels of900,000 tons a year during World War I and in 1970 1,600,000 tons of copper wereproduced but recent levels are lower, fluctuating between 1-1.5 million tons ayear. Technology has assist in increasing production efficiency wich resulted inspectacular resource development in the U.S. and around the world.Molybdenum has been a major mineral since 1898 when it was discovered toharden steel as an additive and useful in compounding chemicals and dyes.Substantial mining began in 1900 in the southwest but the demand was so low thatactivity ceased in 1900. In 1906 the molybdenum industry boomed and with thedawn of WWI the need for quality steel further increase the necessity for this