Example $3\mathrm{.}5$ A blast furnace produces hot metal containing $3\mathrm{.}5\%C,1\mathrm{.}5\%Si$ and $95\%Fe.$ Iron ore contains $80\%F{e}_2{O}_3$ and $20\%$ gangue $(Si{O}_2+A{l}_2{O}_3).$ The coke rate is $850k\frac{g}{t}hm,$ and coke contains $80\%$ fixed carbon and $20\%$ ash. Flux rate is $450k\frac{g}{?}$ thm and contains $90\%CaC{O}_3,$ and rest is $Si{O}_2.$ BF gas contains $(\frac{CO}{C{O}_2})$ ratio $=(\frac{24}{16}).$

Calculate $($i$)$ weight of iron ore used, $($ii$)$ weight of slag produced and $($iii$)$ volume of BF gas.