Pattinson's process or pattinsonisation is a method for removing silver from lead, discovered by Hugh Lee Pattinson in 1829[1] and patented in 1833.
The process is dependent on the fact that lead which has least silver in it solidifies first on liquefaction, leaving the remaining liquid richer in silver.
In practice several crystallisations were required, so Pattinson's equipment consisted basically of nothing more complex than a row of up to 13 iron pots, which were heated from below. Some lead, naturally containing a small percentage of silver, was loaded into the central pot and melted. This was then allowed to cool. As the lead solidified it was removed using large perforated iron ladles and moved to the next pot in one direction, and the remaining metal which was now richer in silver was then transferred to the next pot in the opposite direction. The process was repeated from one pot to the next, the lead accumulating in the pot at one end and metal enriched in silver in the pot at the other.[2][3]
Sections of a pot
Arrangement of pots used in a smelting mill
The level of enrichment possible is limited by the lead-silver eutectic and typically the silver content of the silver-rich melt could not be raised above 2% (around 600 to 700 ounces per ton), so further separation is carried out by cupellation.[4]
The process was economic for lead containing at least 250 grams of silver per ton.[5] Being the first process applicable to low-grade lead,[1] it supplemented earlier patio process and pan amalgamation.
It was replaced by the Parkes process in the mid-19th century.
pattinson, process, pattinsonisation, method, removing, silver, from, lead, discovered, hugh, pattinson, 1829, patented, 1833, process, dependent, fact, that, lead, which, least, silver, solidifies, first, liquefaction, leaving, remaining, liquid, richer, silv. Pattinson s process or pattinsonisation is a method for removing silver from lead discovered by Hugh Lee Pattinson in 1829 1 and patented in 1833 The process is dependent on the fact that lead which has least silver in it solidifies first on liquefaction leaving the remaining liquid richer in silver In practice several crystallisations were required so Pattinson s equipment consisted basically of nothing more complex than a row of up to 13 iron pots which were heated from below Some lead naturally containing a small percentage of silver was loaded into the central pot and melted This was then allowed to cool As the lead solidified it was removed using large perforated iron ladles and moved to the next pot in one direction and the remaining metal which was now richer in silver was then transferred to the next pot in the opposite direction The process was repeated from one pot to the next the lead accumulating in the pot at one end and metal enriched in silver in the pot at the other 2 3 Sections of a pot Arrangement of pots used in a smelting millThe level of enrichment possible is limited by the lead silver eutectic and typically the silver content of the silver rich melt could not be raised above 2 around 600 to 700 ounces per ton so further separation is carried out by cupellation 4 The process was economic for lead containing at least 250 grams of silver per ton 5 Being the first process applicable to low grade lead 1 it supplemented earlier patio process and pan amalgamation It was replaced by the Parkes process in the mid 19th century See also editParkes process a method for separation of metals from lead through precipitation References edit a b Desilverization of Lead Process of Silver Removal by Pattinson 25 April 2017 Tylecote R F 1992 A history of metallurgy London Institute of Materials pp 157 158 Rowe 1983 pp 189 190 Metallurgy An Elementary Text Book E L Rhead F I C F C S Longmans 1895 pp193 195 Tylecote 1992 pp 157 158 This article incorporates text from a publication now in the public domain Wood James ed 1907 The Nuttall Encyclopaedia London and New York Frederick Warne a href Template Cite encyclopedia html title Template Cite encyclopedia cite encyclopedia a Missing or empty title help External links editReference to Pattinson s Process in mining 1 Pattinson s process Pattinson s white lead nbsp This industry related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Pattinson 27s process amp oldid 1172556338, wikipedia, wiki, book, books, library,
