Copper

foreign [Music] ingenuity technology thousands of years ago in neolithic valleys of the Middle East a new material began to replace flint and bone in the weapons tools and ornaments of an earlier age more durable more workable it changed the course of human history [Music] thank you [Music] foreign [Music] [Music] [Laughter] [Music] minerals like Malachi Azurite and turquoise are still sought and traded for their natural beauty as they were long before ancient Smiths discovered the metal could be won from Rock by fire [Music] by the time of the Pharaohs The Mining and smelting of copper had become a thriving industry a new age had dawned a new science was emerging metallurgy by adding tin bronze was produced harder and more castable than copper alone and so Central to the rise of the first great civilizations it gives that age its name [Music] here began a partnership between metal and the imagination between copper and the inventive mind that yielded new technologies new tools and implements that forever transformed civilization industry and trade science agriculture architecture and art curiosity Ingenuity technology little more than a century ago copper again played a profound and Central role in the birth of a new age an age of electrical energy flowing through a vast and complex web of copper conductors copper its value in every Age based on unique combinations of properties properties that derive from its fundamental form copper is an element number 29 in the atomic table an atom of copper has a nucleus of 29 protons surrounded by 29 electrons arranged in four shells or orbiting pathways 14 atoms bound together by sharing electrons form a unit cell which has all the properties of the metal unit cells joined by sharing atoms form crystals and crystals packed tightly together become the metal whose special properties have given rise to the countless ways it can be shaped and used [Music] are you copper is ductal capable of being drawn or stretched without breaking so ductal a single pound can be drawn down to a wire 100 miles long [Music] [Applause] [Music] [Applause] copper is an excellent conductor of electricity its conductivity its ductility and its availability have made possible our extensive use of electrical energy in this age foreign [Music] [Applause] [Music] [Music] [Music] talk to you later [Music] in many ways we have come to depend on the durability and reliability of copper on its Alloys of brass and bronze and on the ability of these metals to resist corrosion [Music] foreign copper is malleable capable of being hammered rolled or stamped cold as well as hot cold working copper in fact hardens the metal as its atoms are compressed increasing its strength [Music] when heated it can be easily formed by pressure the combination of malleability and corrosion resistance and its workability have made copper a hidden part of our daily routine in a network of copper tubes and pipes unnoticed but essential to our way of life copper is also an excellent conductor of heat a property of increasing importance in the development of Energy Technologies like solar collectors most of which are a combination of heat transfer and Plumbing Systems copper combines easily with other metals with zinc to make brass with tin to make bronze with nickels silver and steel to make alloys more durable more castable more corrosion resistant than copper alone Alloys formed into shapes both useful and beautiful [Music] um from native copper nuggets picked up in some forgotten time the search for copper led to minerals like Malachite and Azurite more than 30 percent copper [Music] by the turn of the century the American West had become the major copper producing region in the world but high grade ore bodies near the surface were soon gone and to meet increasing demands miners turned to leaner and leaner oars twenty percent ten percent five percent copper cut from deep within the Earth [Music] today geologists search for clues of hidden mineral deposits with Technologies made possible in part by the metal they seat Technologies like spectrometry and electromagnetic surveys if the clues are promising exploratory drilling begins and the search goes Underground thank you thousands of feet of core samples are taken [Music] analyzed evaluated [Music] the mineralization of the deposit determined its boundaries delineate the investment required to reach the deposit and its earnings potential are weighed against dozens of other factors Environmental Studies availability of water and power and the social implications of Mining and ore processing [Music] the decision to mine is a calculated risk taken to meet increasing needs at reasonable cost from ores that may now contain less than one percent copper thank you in this Century the primary source of new copper in the United States has been and will continue to be low-grade poor free deposits in the American southwest hard rock copper sulfide ore containing very little metal as little as four tenths of one percent today rarely more than one percent what makes these poor free deposits economical to mine is their enormous size and uniformity the potential for valuable byproducts such as gold and silver and when they're near the surface massive efficient open pit operations [Applause] bench by bench the pit expands slowly consuming The Ore body in a process that may take 50 years or more [Music] to recover 100 pounds of copper from a typical deposit 30 tons of waste rock and overburden must be blasted loose and moved another 10 tons of ore mine eight thousand pounds of Rock gain 100 pounds of metal [Music] open pit mining methods are economical when the ore body is relatively near the surface but when the ore body is far below the surface or copper occurs in a narrow vein running deep into the Earth mining goes Underground [Music] [Music] things [Music] all right far below the surface our Subterranean City evolves by careful design a sophisticated support system for minors and machines to reach the copper bearing ore a maze of drifts or access ways must be cut through hard rock [Music] thank you [Music] foreign [Music] [Music] [Music] [Music] [Music] mining mids are used Underground in some cases ore is recovered by blasting and machine loading in others large blocks of ore are undercut causing them to Cave into collection shoots which convey the broken ore by gravity to haulage levels below where it is transferred to skips and hoisted to the surface by whatever method mined underground or open pit copper is recovered from sulfide ores in a three-step process concentration smelting and refining concentration Begins by crushing the Oar to reduce it to a workable size foreign [Music] mixed with water the crushed ore is ground to a powder in ball Mills huge drums loaded with steel balls releasing tiny copper sulfide and iron sulfide particles in a series of flotation cells injected with air special additives coat these tiny particles causing them to cling to the rising bubbles forming a froth which is skimmed off the mineral-bearing froth filtered and dried is a concentrate of 20 to 30 percent copper Rich enough to be economically smelted the waste rock or tailings remaining after flotation is pumped to thickeners here the solids settle out to be moved finally to tailings dams often large remote areas set aside for permanent disposal the water is recycled if necessary a chemical seal can be applied over the dams to prevent erosion and wind-blown dust or they can be treated to encourage plant growth stabilizing the surface when copper occurs in oxide ores or copper sulfide ores are too low in grade to be economically concentrated the metal can be recovered in a hydrometallurgical process known as leaching under controlled conditions water is percolated through the sulfide ore a chemical reaction causes an acid ferric sulfate solution to form this in turn converts the Copper sulfides to Copper Sulfate which leeches out and flows in solution to collecting ponds when oxide ores are leached a dilute sulfuric acid is usually added to the solution to dissolve the copper minerals by washing the solution over scrap iron an ionic exchange occurs causing the iron to go into solution and the copper to precipitate out the leech solution is recycled and the copper more than 70 percent pure is sent to the smelter along with copper concentrate from the mill [Music] the purpose of smelting is to break the chemical bonds between copper and the sulfur iron and other impurities in the concentrate charged into the furnace into 2 300 degrees Fahrenheit the concentrate melts and some of the sulfur Burns off as sulfur dioxide gas unlike traditional reverberatory furnace systems newer smelters capture this gas as well as particulate matter the captured sulfur dioxide is then transferred to an acid plant to be processed into commercial grade sulfuric acid in the smelter some of the iron and other impurities in the concentrate separate after adding a flux of silica Rock and rise to the surface in a slag which is tapped off and discarded [Music] once again the furnace is tapped releasing a molten sulfide of copper and iron known as matte now 30 to 60 copper the mat is transferred to a converter furnace [Music] in the converter air is forced through the matter oxygen and more of the sulfur burn off as sulfur dioxide gas also collected and sent to the acid plant silica rock is again added and combines with the remaining iron to form converter slag this slag contains some copper and is skimmed off and reprocessed air is once more blown through the converter this time oxidizing all but a small percentage of the remaining sulfur from or to concentrate from concentrate to matte now copper blister copper 97 pure [Music] um one last furnace the anode vessel ear air is again blown through the copper oxidizing the rest of the sulfur reformed natural gas containing carbon monoxide and hydrogen is blown through chemically reducing the oxidized copper leaving it nearly oxygen free copper now more than 99 pure is prepared for the Final Phase refining cast into shapes called anodes [Music] thank you [Music] [Applause] [Music] in an electrolytic Refinery the copper is purified and small amounts of Gold Silver and other precious metals are recovered the anodes are submerged in a solution of dilute sulfuric acid and copper sulfate foreign starter sheets or cathodes of refined copper are interleaved with the anodes carefully spaced to avoid short circuits [Music] an electric current is applied and the anode copper dissolves migrating as copper ions through the solution to the cathodes depositing as Elemental copper valuable impurities including gold and silver sink to the bottom to be recovered later in about 14 days the cathodes are removed 99 and 99 100 percent pure copper the product of complex physical and chemical processes ready to be drawn hammered rolled extruded alloyed cast to do the hundreds of jobs we take for granted every day and in an age of New Perspectives on the finite resources of the Earth the enduring quality of copper may be its greatest value nearly one-third of the two to three million tons of copper we use each year comes from recycled scrap from Mills craft generated during fabrication from obsolete or discarded Copper products a renewable resource recycled at a fraction of the cost and energy needed to produce new Copper from today's low-grade [ __ ] curiosity Ingenuity technology the future is being explored today new secrets of the red metal learned New Uses discovered and the partnership that began thousands of years ago between metal and the imagination between copper and the inventive mind continues [Music] thank you