11. Capacities of Leach Pad, Merril-Crowe Plant & Haul Truck
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11. Capacities of Leach Pad, Merril-Crowe Plant & Haul Truck
by Engineer Golden in the Merrill-Crowe processing plant in the Goldspring mining property near the Hartford Complex, south of Gold Hill, Nevada, southerly west of historic Virginia City, Nevada, high altitude and wealtiest small town in the USA, 1865-1890. Merrill-Crowe Precious Metal Ore Chemical Extraction Process developed in the late 1800s. Cyanide in "Barren" Solution scavenges/leaches gold and silver from low grade ore into the "Preg" Solution (Impregnated with Precious Metals). Solution cleansed of dirt. Powdered Zinc is induced. Cyanide leaves chemical hold of gold and silver. Zinc chemically bonds to the Precious Metals. Zinc-PM is trapped on fine filters, scrapped off. Zinc separated from Precious Metals by a process using heat. Molten Gold is poured into 75 pound billets, "pencils", known as Dore. Dore is sent to a refinery to achieve a higher purity level. Merrill-Crowe (M-C) Circuit -- A process which recovers precious metals from solution by first clarifying the solution, then removing the air contained in the clarified solution, and then precipitating the gold and silver from the solution by injecting zinc dust into the solution. The valuable sludge is collected in a filter press for drying and further treatment. InsideMetals - Milling - Heap Leaching - Mining Glossary http://www.insidemetals.com/index.php?view=mining_glossary A precipitation process to recover precious metals using zinc dust to treat a deoxygenated precious metals-cyanide solution. This is most applicable to ores with higher silver content. from a glossary of common mining terms http://www.trustingold.com/content/view/32/51/ EPA Report (No huff and puff and Don't mess with the U.S. Environmnetal Protection Agency) Summary of Known Gold and Silver Smelter and Refineries, 18 pages, a springboard to study Mining Locations for Precious Metal Investors http://www.epa.gov/epaoswer/other/mining/minedock/id/id4-au.pdf Modern Improvements ------------------- US Patent 5336474 - Process for Leaching of Precious Metals The present invention relates to a process for leaching of precious metals (e.g., gold and/or silver) from particle-shaped, solid materials, particularly ores and ore concentrates. The process includes the use of a cyanide-containing alkaline leach solution in the presence of a peroxo compound releasing oxygen. The present invention also relates to a process for leaching of such precious metals from ores, ore concentrates and waste material from previous incomplete leachings by grinding of the material to be leached in the presence of a cyanide-containing leaching solution which has a pH value of 8 to 13 and which contains a peroxo compound. http://www.patentstorm.us/patents/5336474/description.html University of North Carolina (UNC) at Charlotte Thesis explains the Merrill-Crowe process with a good diagram on the last page http://education.uncc.edu/cmste/summer/2005 Rocks & Minerals/Cyanide in Gold Mining.doc UNC Charlotte, 9201 University City Boulevard, Charlotte NC 28223 Geologist Dennis mentions another process for recovering precious metals from carbonaceous refractory ores and specifically to leaching processes for recovering precious metals from carbonaceous refractory ores. http://www.wipo.int/pctdb/en/wo.jsp?IA=US2001043408&DISPLAY=DESC Two websites have Warning by Google "This site may harm your computer" (Dipsticks lodged in to catch searchers of knowledge? - where there is money there are schrewd leaches, hacker leaching of a person's computer by use of counterfeit sites using good info). There are enough other good sites, move on! http://www.google.com/search?hl=en&q=Merrill+Crowe+Precious+Metal+Ore+Chemical+Extraction+Process Abbreviations -------------- Atomic chart element symbols: "Au" for Gold, and "Ag" for Silver. Silver quantities range from 4 to 20 times that gold in a ton of ore, historic Comstock One overall average is 4:1. 2005 Goldspring Exploratory Mine, Billy the Kidd Open Pit, ratio of silver to gold was similar. Links to that data are futher down in this article. "Barren" Solution: Vast quantities of water with a very low content of cyanide. "Preg" Solution: Barren Solution after it has been sprinkled on ore where it leaches gold and silver from ore Impregnated with Precious Metals. PM: Precious Metals http://comstockgold.blogspot.com SEC Filings, Company Press Releases, Investor Brochures as Powerpoint Presentations and Third Party web sites reporting about GSPG in this library of web links A DD library, Due Diligence - what made America strong - Explorers, Pioneers, Developers, Innovators, Marketers - who thought and did one new thing AND SO DID MANY OTHERS, because of Freedom! http://www.goldspringfacts.blogspot.com Video portion #11 made during the May 9, 2008 Comstock Nevada Mine Tour by Long Ranger Bob Goldspringer of the Yahoo Financial Message Board.
YouTube | July 12, 2008
