Rough copper

…In 1754 (4th year of the Horeki era), the fixed amount of copper to be exported was 3.1 million kin, but this was to be met by copper produced in the three copper mines of Akita, Morioka (Osarizawa), and Besshi and Tachikawa. During the Edo period, rough copper from various copper mines was sent to Osaka, where it was blown into copper shibori and kanbuki at the Osaka blowing houses, which then smelted it into various types of copper, such as copper shafts for export, copper rounds, copper long shafts for sale, and other types of copper. As rough copper often contains silver, the cupellated silver is extracted using the Nanban blowing method, and the copper from which the silver has been extracted is called kanbuki. …

*Some of the terminology that refers to "rough copper" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…1754年(宝暦4)当時の輸出銅定高は310万斤であったが，秋田，盛岡(尾去沢)，別子立川の3銅山の産銅をもって充当することになった。江戸時代は諸国銅山の荒銅は大坂に回送され，大坂の吹屋で鉸銅（しぼりどう），間吹銅に吹き，これを輸出用の棹銅や地売用の丁銅，丸銅，長棹銅その他，種々の型銅に小吹した。荒銅には銀を含むものが多いので南蛮吹によって灰吹銀を抜きとるが，抜銀された銅を鉸銅という。…

※「荒銅」について言及している用語解説の一部を掲載しています。

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