In the extraction of aluminium, the leaching method chosen depends on the predominant impurity in th — Metallurgy and Isolation of Elements Chemistry Question

💡 Solution & Explanation

Serpeck's process is used for white bauxite (high $SiO_2$). It involves heating with C and $N_2$ to form $AlN$, while $SiO_2$ is reduced to volatile Si. Baeyer's is for red bauxite ($Fe_2O_3$ impurity) using $NaOH$. Hall's process uses $Na_2CO_3$, not $NaOH$.