Separation of gold and silver

After many essential improvements, this technique, the Miller process, has been introduced in all big gold refineries [5.4], 

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Thus you have again quicksilver. The following descriptions of the separation of gold and silver, and silver from copper, closely resemble similar processes in the Probier-buchlein, but the descriptions are less complete. 

QUARTATIO — is a separation of Gold and Silver it is the alloying of one part of Gold, with three of Silver. 

Figure 8.1 Separation of gold and silver in a sixteenth-century metallurgical laboratory. From bookX of Agricola [1556].

The separations of metals from each other in the wet way were described in very similar terms. In his book on ores and assaying of 1574, the German assay master Lazarus Ercker (1530-1594) described the separation of gold and silver from each other by means of aqua fortis or parting acid (nitric acid) as follows ... 

Coordination compounds have a wide variety of applications. Complexes of monodentate ligands are used in qualitative analysis, identification of copper(II) and iron(II), dyes [Prussian (TurnbuU s) blue], the cyanotype printing process, the separation of gold and silver from their ores, the purification of nickel, and as fixers in black-and-white photography. 

Nitric acid reacts energetically at ordinary temperatures, with formation of the nitrate and of the oxides of nitrogen. The behaviour of the metal with hydrochloric acid is similar to that of lead. The action of concentrated sulphuric acid and of nitric acid finds application in the separation of alloys of gold and silver. The corrosive effect of acids is accelerated by the presence of an oxidizer.5... 

Figure 3. Processes depicting the separation and return of the spiritual part of the dissolved body of gold and silver, from the Rosarium Philosophorum (Frankfurt, 1550). The captions read (left to right) Here the four elements divide [while] the soul nimbly separates from the body and Here the soul springs downward and revives the purified corpse. ... 

Preliminary studies have shown that ionic liquids have potential as solvents and electrolytes for metal recovery, and the feasibility of these solvents has been demonstrated for the extraction of gold and silver from a mineral matrix [7], the recovery of uranium and plutonium from spent nuclear fuel [8], and the electrodeposition and electrowinning of metals (especially, for active metals such as Li, Na, Al, Mg, and Ti) from ionic liquids [9-11], Ionic liquids as green solvents and electrolytes have shown important and potential application in extraction and separation of metals. In this chapter, the new applications and the important fundamental and appUed studies on the extraction and separation of metal in ionic liquids including metal oxides and minerals or ores processing, electrodeposition of metals (mainly for active metals), and extraction and separation of metal ions are described. 

In the separation of gold from silver, nitric acid was at one time universally employed, but in 1802 D Arcet utilised the fact, discovered in 1753 by Scheele, that concentrated sulphuric acid was equally suitable for the purpose. This constituted an improvement of considerable value, effecting a saving both of cost and time, and it must be remembered that in this connection time is money, for gold brings interest. 

Since a crama is not per se one but rather a collection of particles with their own forms united per accidem, it should be possible, ScaHger sa), to separate the ingredients from one another. At this point, then, he introduces the alloy of gold and silver that Sennert would later employ to much wider effect. 

The Separation of Gold from Silver The proper method and procedure in parting gold perfectly from silver in quantity, by means of acid. The method of parting gold from silver by means of sulfur or antimony... 

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