Nuremberg was one of Germany's main centres of metal refining and fabrication, and was a leader in metallurgical techniques.
Five liquation plants soon sprang up around the city, and within 15 years had spread throughout Germany, Poland and the Italian Alps.
[4] However, he was not an expert in metallurgy, so his writings may not be accurate, and though there were similar cauldrons in the 12th century, no compositional analysis has been published that supports this theory.
[1] The copper-lead alloy created can be tapped off and cast into large plano-convex ingots known as ‘liquation cakes’.
If the cakes are too small, the product would not be worth the time and costs spent on the process, if they are too large then the copper would begin to melt before the maximum amount of lead has drained away.
[7] It is important that this takes place in a reducing atmosphere, i.e. one with little oxygen, to avoid the lead oxidising; the cakes are therefore well covered by charcoal and little air is allowed into the furnace.
[1] It is impossible to stop some of the lead oxidising, however, and this drops down and forms spiky projections known as ‘liquation thorns’ in the channel underneath the hearth.
[1] The ‘exhausted liquation cakes’ which still contain some lead and silver are ‘dried’ in a special furnace which is heated to a higher temperature under oxidising conditions.
[1] Waste products can be reused to produce new liquation cakes to try to minimise loss of metals, especially silver.
At the Lautenthal, Altenau, and Sankt Andreasberg smelting-works in the Upper Harz between 1857 and 1860 25% of the silver, 25.1% of the lead and 9.3% of the copper was lost.
John U. Nef, an expert on Renaissance economics, described liquation as ‘even more important than the invention of the printing press’ for the development of industry during this period.
Some of the wealthiest merchants in Europe invested in mining, including the French Royal Banker Jacques Coeur and the powerful Medici family of Florence.
A mine at Jáchymov (Joachimstal) in the Ore Mountains was so successful that a coin called 'tolar' was created, which led to the term, dollar.
[3] Others of note included Schneeberg, and Annaberg (also in the Ore Mountains), Schwaz, in the valley of the Inn, and at Neusohl in Hungary.