b) Zinc concentrates of a location are compdsed of 60% zinc, present as ZnS, iron present as Fe5z and 7%SiO2. On roasting Zn oxidises to ZnO, Fe to Fe2O3 and S to SO2,3% of Zn however. remains unchanged. Coal equal to 20% of raw ore is used: the ash from the coal does not mix with the roasted ore. but the gaseous products of combustion pass through the furnace and into the flue mixed with gases from roasting. The coal composition is 72%C,6%H,8%0,2%5 and 12% ash. The flue gas contains 12% oxygen. Using a basis of 1000kg of concentrate calculate: (v) The quantity of roasted ore and the $5 in the roasted ore (ii) The theoretical air used in roasting and coal combustion (Wi) The % composition of the flue gases and the % of excess air used. You oversee a cellhouse for electrowinning of zinc; at which increased current density would you have to operate in ordant. : production by 20%, given the following conditions: Question 4 b) Zinc concentrates of a location are compdsed of 60% zinc, present as ZnS, iron present as Fe5z and 7%SiO2. On roasting Zn oxidises to ZnO, Fe to Fe2O3 and S to SO2,3% of Zn however. remains unchanged. Coal equal to 20% of raw ore is used: the ash from the coal does not mix with the roasted ore. but the gaseous products of combustion pass through the furnace and into the flue mixed with gases from roasting. The coal composition is 72%C,6%H,8%0,2%5 and 12% ash. The flue gas contains 12% oxygen. Using a basis of 1000kg of concentrate calculate: (v) The quantity of roasted ore and the $5 in the roasted ore (ii) The theoretical air used in roasting and coal combustion (Wi) The % composition of the flue gases and the % of excess air used. You oversee a cellhouse for electrowinning of zinc; at which increased current density would you have to operate in ordant. : production by 20%, given the following conditions: Question 4