\(\%Cu_{\left(CuFeS_2\right)}=\dfrac{64}{64+56+32.2}.100=34,78\%\Rightarrow m_{Cu}=\dfrac{34,78}{100}.\dfrac{80.1000}{100}=278,24\left(kg\right)\)
\(\%Cu_{\left(Cu_2S\right)}=\dfrac{64.2}{64.2+32}.100=80\%\Rightarrow m_{Cu}=\dfrac{80}{100}.\dfrac{80.1000}{100}=640\left(kg\right)\)
\(\%Cu_{\left(Cu_3FeS_3\right)}=\dfrac{64.3}{64.3+56+32.3}.100=55,81\%\Rightarrow m_{Cu}=\dfrac{55,81}{100}.\dfrac{80.1000}{100}=446,48\left(kg\right)\)
\(m_{Cu\left(max\right)}=m_{Cu\left(Cu_2S\right)}=640kg\)