Question

The production of nickel and copper metals from their ores involves sulfur dioxide emissions because

A: the ores of these elements are composed primarily of NiSO2 and CuSO2.
B: the ores of these elements are composed primarily of NiS and CuS.
C: to release the metals from their ores, the ores are heated with sulfur-containing coal.
D: the release of metals from their ores involves the reaction of SO3 with the ore.

Answer 1

Sulfur dioxide emissions during the production of nickel and copper metals occur because their ores are primarily composed of sulfides, such as NiS and CuS. Roasting of these sulfides in the presence of oxygen is a key step in their processing, which yields SO2 as a byproduct.

Step-by-step explanation:

The production of nickel and copper metals from their ores involves sulfur dioxide emissions primarily because the ores of these elements are composed primarily of their sulfides (NiS and CuS). During the extraction process, these sulfides are subjected to roasting, which involves heating them in the presence of oxygen. This step not only helps to remove sulfur as sulfur dioxide (SO2), but also converts the sulfides into their respective oxides. Following this, further reduction processes are carried out to obtain the pure metal.

For copper, for example, an important source is from the ore chalcocite (Cu2S). Upon heating, this compound decomposes to form copper and sulfur. The subsequent reaction of sulfur with oxygen produces sulfur dioxide, which is represented by the equation:

2 Cu2S + 3 O2 → 2 Cu2O + 2 SO2

Overall, the roasting process is efficient as it helps in the oxidation of sulfides and assists in the separation and purification of metals like copper.