blister copper

American  

noun

Metallurgy.

1. a matte of from 96 to 99 percent copper, having a blistered surface after smelting because of gases generated during solidification.

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blister copper British  

noun

1. an impure form of copper having a blister-like surface due to the release of gas during cooling

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Etymology

Origin of blister copper

First recorded in 1860–65

Example Sentences

The plant produces blister copper, which contains almost entirely copper with 3% of other precious metals.

From The Wall Street Journal • Oct. 6, 2025

The Katanga district in the Congo produces blister copper that contains as much as 4 per cent of cobalt, though usually less than 2 per cent.

From The Economic Aspect of Geology by Leith, C. K. (Charles Kenneth)