The dissolved copper then binds to one of the sulfate ions to make copper (II) sulfate, which lends the persulfate etchant solution a familiar blue-green tinge as etching proceeds. Another etchant ...

The mixture is heated and then a piece of copper scouring pad is placed in. The scouring pad is partially dissolved, providing copper ions, and turning the solution blue. The next step is to clean ...

Rather than dig ore out of the ground through open-pit or underground mining, dissolved copper is essentially sucked out of the ground. The in-situ mining operation involves drilling more than 100 ...