Which process is used for the extraction of copper from low-grade copper ores?

Which of the following chemical equations represents the hydrometallurgical process for the extraction of copper from its ore?

Explain the extraction/purification of copper.

The type of iron obtained from a blast furnace in the extraction of iron is:

Which of the following furnaces can achieve the highest temperature?

Formation of metallic copper from the sulphide ore in the commercial thermo-metallurgical process essentially involves which one of the following reactions as the major reaction?