How is copper extracted from low grade copper ores?

Copper is extracted by hydrometallurgy from low grade copper ores. It is leached out using acid or bacteria. The solution containing $C{u}^{2+}$ is treated with scrap iron, Zn or $H_2$.

$2C{u}^{2+}\left(aq\right)+H_2\left(g\right)\to 2Cu\left(s\right)+2H^{+}\left(aq\right)$

$C{u}^{2+}+Fe\left(s\right)\to F{e}^{2+}\left(aq\right)+Cu\left(s\right)$