Question

9. (1.5 marks) There are typically two smelting operations and an electrolytic reduction operation in the production of copper (Cu) from chalcopyrite (CuFeS2) a) Describe the chemical reaction that occurs during the first smelting operation b) Name the two resultant liquid phases. c) Into which of these liquid phases do each of the elements involved in the reaction primarily reside?

Answer 1

Background:

The term smelting is the metal extraction process like Tin or copper from its native ores. Most of the ores are chemical compounds of metals with other elements such as oxygen, sulphur etc. Smelting extraction process utilizes heat and reducing agents like coals to remove unwanted elements or impurities from the required metal.

9a) Answers:

The oxygen in the air selectively reacts with the iron ore (chalcopyrite) to form the iron oxide, FeO and leaves copper in the form of the sulfide, CuS

In the second step, the excess sulfur in the ore reduces copper(II) sulfide (CuS) to copper (I) sulfide, Cu₂S which melts and flows out of the bottom of the furnace.

Finally, Copper (I) sulfide reacts with oxygen produces metallic copper and sulfur dioxide.

9b) Answer:

Liquid phases are : Copper (I) sulfide Cu₂S, and Slag CaSiO₃ + FeSiO₃

9c) Answer

The elements involved in the reaction primarily reside on Cu₂S sulfide liquid phase.