doré bar
{{Short description|Alloy of gold and silver}}
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{{More citations needed|date=December 2018}}
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A doré bar is a semi-pure alloy of gold and silver. It is usually created at the site of a mine and then transported to a refinery for further purification.
The proportions of silver and gold can vary widely. Doré bars weigh as much as 25 kg.
During the 19th century gold rushes, gold nuggets and dust were melted into crude gold bars mistakenly called "bullion" by miners. They were, more accurately, doré bars with higher contents of silver and other adulterants than the mints would accept. Mint and private assayers would subsequently refine the doré bars to an acceptable purity, 999 fine, gold bullion, with the silver and base metals removed. By the time of the California gold rush, mints were moving away from the age-old process of cupellation to "part" bullion and moving toward the acid refining process developed by chemist Joseph Louis Gay-Lussac for the French mint.{{Clarify|date=September 2024}} By the time of the Klondike gold rush, mints were replacing Gay-Lussac's acid process and introducing electrolysis to refine doré bars into 999.9 purity gold bullion.{{cite book |title=Metallurgy of Gold, Silver, Lead and Zinc |date=1902 |publisher=International Correspondence Schools |location=Scranton, Pennsylvania |pages=87–91 |url=https://babel.hathitrust.org/cgi/pt?id=chi.73098814&view=1up&seq=339 |accessdate=3 April 2020}}
Associated industry codes
According to the United States Census Bureau,{{cite web|url=https://www.census.gov/en.html|title=US Census Bureau|website=Census.gov|accessdate=5 December 2018}} the creation of doré bars is conducted at establishments engaged either in "Gold Ore Mining" (NAICS Code 212221),{{Cite web |url=http://www.census.gov/epcd/naics02/def/ND212221.HTM |title = 2002 NAICS Definitions: 212221 Gold Ore Mining |archive-url=https://archive.today/20030421023251/http://www.census.gov/epcd/naics02/def/ND212221.HTM |archive-date=21 April 2003 |url-status=dead}} or "Primary Smelting and Refining of Nonferrous Metal (except Copper and Aluminum)" (NAICS Code 331419).{{Cite web |url=http://www.census.gov/epcd/naics02/def/ND331419.HTM |title = 2002 NAICS Definitions: 331419 Primary Smelting and Refining of Nonfe… |archive-url=https://archive.today/20021221184658/http://www.census.gov/epcd/naics02/def/ND331419.HTM |archive-date=21 December 2002 |url-status=dead}}
Derivation of the term
The word {{wikt-lang|fr|doré}} is French for "gilded" or "golden".{{Cite web |url=http://www.wordreference.com/fren/dor%C3%A9 |title=Doré - Dictionnaire Français-Anglais WordReference.com |access-date=2007-01-02 |archive-url=https://web.archive.org/web/20071007103740/http://www.wordreference.com/fren/dor%C3%A9 |archive-date=2007-10-07 |url-status=dead }}
See also
References
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External links
- [https://web.archive.org/web/20100402232416/http://info.goldavenue.com/info_site/in_glos/in_glos_dorebullion.html Doré Bullion]
- [http://www.waihigold.co.nz/mining/the-mining-process/ore-processing/ Ore Processing from mine to Doré production, from Newmont Waihi]
- [https://web.archive.org/web/20121017014151/http://www.odt.co.nz/files/story/2009/12/an_oceana_gold_employee_stamps_a_raw_unrefined_dor_1456015798.JPG Photograph of a doré bar weighing 17.42 kg]
- [http://www.gold.org/pr_archive/html/bars/Categ.htm#Dore Categories of gold bar: 'Dore' Bars]
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