Gold Production: From textbook Total amount of Au mined to 2000 is estimated to be 130,000 metric Ton
Total World production post 1900 128,833 ton (data from USGS historical tables)
Gold Production: A thought What is the volume of a metric ton of gold? 1000 kg of water=10 3 liters of water=10 6 cm 3 1000 kg of gold=1000/19.3=51,813 cm 3 Or a cube 37.28 cm on each side Or a cube 14.67 in on each side!
Gold: Geological Occurrence Hydrothermal Veins (many of these) E.g. Gold rush of 1849 in California Invisible gold (Carlin type) Placers Paleoplacer Witwatersrand in South Africa Discovered in 1886 20 times larger than any other Au district in the world
Grasberg: Cu and Ag porphyry http://faculty.kutztown.edu/friehauf/indonesia/grasberg.html
Gold uses: Electronic Products Aerospace Industry Special Alloys Dentistry Jewelry Carat24k is pure gold
Gold extraction: Mercury Amalgam (the old way) Panned for gold Used Hg, Au grains wetted by Hg Separated by squeezing out the Hg, or vaporizing it Cyanide (CN) Au is soluble in CN solutions Heap leaching with 0.05% NaCN, pH > 10
Silver: The not so precious Occurs as a native element and as Ag bearing sulfides Athensmines at Laurium Romans brought Ag into coinage What year did we stop using Ag in coins in the U.S.? 1965 In Canada? 1967
Major Silver Producers in 2006 Mexico Peru Australia China For a total of 19,500 metric Tons on reserves of 270,000 tons (570000 reserve base)
Uses of silver Photography (AgI) Jewelry and silverware (check your grandmas) Industrial
Ag: Geological Occurrence By product of Cu mining By product of Pb mining About 25% silver veins where Ag is the main metal
Ag: Substitutes Al and Rh in mirrors Ta in surgical plates, pins, sutures Stainless steel in flatware
Platinum Group Elements The really precious metals Pt, Pd, Os, Rh, Ir, Ru Named after Platinum
Platinum Pre-Incan Adornments 100 BC - Ancient South American civilizations, the most famous being the Incas - gifted metal workers and craftsmen, use platinum and gold to create nose rings and other items of ceremonial jewelry. Platinum is then lost to mankind for two millennia, forgotten for thousands of years, only to briefly re-appear when European explorers discover the new world.
Platina Confused Conquistadores 1590 - Platinum is next encountered by the Spanish conquistadores, who give it the derogatory name 'platina', meaning 'little silver'. Spanish naval officer don Antonio de Ulloa y Garcia de la torre was one of the conquistadores to misunderstand the value of platinum. Thirsty for gold, and unimpressed by platinum's appearance, the Spanish mistakenly dismiss it as an inferior metal and throw it back into the rivers of Ecuador to 'ripen'. Once again, platinum mysteriously disappears from history.
Uses: Platinum (Web Elements) jewellry wire and vessels for laboratory use thermocouple elements electrical contacts corrosion-resistant apparatus in dentistry platinum-cobalt alloys have magnetic properties coating missile nose cones, jet engine fuel nozzles the metal, like palladium, absorbs large volumes of hydrogen, giving it up at red heat in the finely divided state platinum is an excellent catalyst (such as the contact process for producing sulphuric acid). Also as a catalyst for cracking oil and as a catalyst in fuel cells and in catalytic converters for cars platinum anodes are extensively used in cathodic protection systems for large ships and ocean-going vessels, pipelines, steel piers platinum wire glows red hot when placed in the vapor of methanol - acting as a catalyst to convert the alcohol into formaldehyde. This phenomenon has been used commercially to produce cigarette lighters and hand warmers sealed electrodes in glass systems laboratory vessels, corrosion-resistant equipment dentistry currently fashionable use in antipollution devices in cars cis-platin, [PtCl2(NH3)2], is an effective drug for certain types of cancer such as leukaemia or testicular cancer platinum/osmium 90/10 alloy is used in implants such as pacemakers and replacement valves