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Nanban-buki is a method of using lead to remove impurities from blister copper. Blister copper and lead are melted together at high temperatures and then cooled, separating the argentiferous lead from the copper. Next that lead are melted over ash, which absorbs the lead, allowing it to be separated from the silver and the silver to be extracted. Tomomochi Sumitomo (1607–1662), Riemon’s son and the son-in-law of Sumitomo founder Masatomo Sumitomo (1585–1652), moved operations to Osaka and freely taught the new method to others there. As a result, copper from all over Japan flowed to Osaka’s numerous advanced nanban-buki refining operations.
And freely taught their new method to others there. As a result, copper from all over Japan flowed to Osaka’s numerous advanced namban-buki refining operations.
Tomomochi invested heavily in growing his business. In 1636, he built Japan’s largest copper refinery in Nagahori, Osaka. The site had an abundant water supply, essential for the refining process, and abutted a canal, facilitating the transport of intermediate copper products and other materials. Before long, one third of Japan’s copper was being processed at this Sumitomo works. The site included 100 refining furnaces which produced 99.9%-pure copper over a period spanning three centuries. Even when Japan was largely closed to the outside world, this copper was permitted to be exported to Holland, China, the Ryukyu Islands (now Okinawa, then an independent kingdom), and Korea, and via those channels, on to Southeast Asia, India and Europe. Overseas, Japanese copper was used in coins, military products, and ship riggings, and Japan was recognized as a global copper exporter. |
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KS copper
KS copper was produced from 1889 to 1925. The inclusion of small amounts of gold and silver made KS copper highly corrosion-resistant and gave it a leading place in the export market over a long period. The name is taken from the initials of Kichizaemon Sumitomo. This 34.5 x 7.5cm piece is 6.5cm thick. |
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