Question

A certain copper ore contains 2 % Cu₂S. The metallurgical process for recovering elemental

Cu from this ore gives 70 % of the theoretical yield. How much Cu is recovered from 2.0 tons of this one?

Answer 1

2.0 tons = 2000 kg

The actual mass of Cu₂S is $2000\times0.02=40kg$

Mass percent of Cu in Cu₂S:

$\%Cu=\frac{2A_r(Cu)}{M_r(Cu_2S)}\times100\%=\frac{63.55\times2}{159.16}\times100\%=79.9\%$

Therefore, the actual mass of Cu in the ore is $40kg\times0.799=32kg$

Considering the 70% recovery yield, the mass of Cu recovered equals $32kg\times0.7=22.4kg\approx22 kg$

Answer: 22 kg