Chalcopyrite is a copper-iron sulfide mineral that is the main source of metalli
ID: 555646 • Letter: C
Question
Chalcopyrite is a copper-iron sulfide mineral that is the main source of metallic copper Pure copper is produced by a process summarized by the following reactions a) Chalcopyrite (CuFeS:) is roasted in the presence of silicon dioxide and oxygen to yield copper (I) sulfide, Iron (II) silicate and sulfur dioxide b) The copper sulfide resulting from the first process is then roasted again to yield metallic copper and sulfur dioxide 1. Write down and balance both reactions, labeling the phases for reagents and reactants. 2. Determine what type of reaction(s) occurred. oxida tion Combustion 3. In a batch process, an initial load comprised of 500 kg of chalcopyrite and 200 kg of silicon dioxide reacts at high temperature. How much metallic copper (in kilograms) will be obtained? 172g Cu 4. What is the limiting reagent in the first reaction? 5. How much excess reactant will be left over from the first reaction? IqkaS, O left over 6. How much sulfur dioxide (in kilograms) will be produced by the whole process?Explanation / Answer
Balanced equation 1:
2 CuFeS2 + SiO2 + 3 O2 ====> Cu2S + Fe2SiO2 + 3 SO2
Balanced equation 2:
Cu2S + O2 ===> 2 Cu + SO2
Reaction type: single replacement
It is a redox reaction. Oxidation as well as reduxtion occurs
500 Kg of Chalcopyrite = 500 x 1000 / 183.52 = 2724.48 Moles
200 Kg of SiO2 = 200 / 60.08 = 3328.65 Moles
Limiting reagent is Chalcopyrite
Moles of Cu2S produced = 1362.24 Moles
Moles of Cu produced = 2724.482 Moles
Mass of copper = 2724.482 x 63.546 = 173.129 Kg
Excess SiO2 after reaction = 200 - 81.849 = 118.151
Ttoal SO2 produced = 261.811 kg + 87.270 Kg = 349.081 Kg