User:Twilson r/sandbox

Shirome is a term in Japanese metallurgy. It primarily refers to an historically Japanese metal, a natural by-product of copper mining and processing, used in the production of irogane metals such as shakudo.

The secondary meaning of the word is as a synonym for antimony; this meaning dates back over a thousand years.

Composition
When copper ore was processed in historical liquation methods, a by-product was a run-off compound of copper, arsenic, lead and antimony, as well as, sometimes, other elements. The percentage composition probably varied considerably. It was removed in a manual process and set aside for further use rather than simply being disposed of.

Production
Copper has been produced in Japan for over a thousand years but the process that produces shirome was brought by the Portuguese in the 16th century (one account mentions a certain Soga Ri’eimon Jusai in 1591 as receiving the details of the process). It was based on a German liquation method, but was heavily modified in Japan, so that it could be used effectively even for small batches. The resulting processes, such as nanban'buki as used by the Sumitomo clan, for example, separated copper from silver, lead and other materials, and one by-product was the variable-content material shirome. For a period from the late 1670s to the 1740s, Japan took over from Sweden as the world's largest exporter of copper, and even when China took the lead, Japan remained a major producer, so it is also likely that a substantial volume of shirome was produced over more than a century.

The process began with the extraction and breaking up of copper-bearing ore, followed by smelting, and re-smelting and refining. Then, as Japanese copper-bearing ore was usually notably contaminated with silver, lead was introduced, and then the silver and most of the lead processed out again. Shirome was extracted as a surface layer during this process, and like the copper itself, cast into bars.

Study
Practical uses of shirome were discussed in a few written works in Japan. The first western analysis of the material was a paper by William Gowland in 1891. (or 1894?)

Shibuichi and kuromido.

Etymology
The term shirome refers to ___ and ___.

History
Shirome is mentioned