Gold and iron are two of many minerals mined in South Africa. Iron is mined in
open-cast mines, while gold is usually found in deep-shaft (underground) mines.
During the process of refining, the following chemical reactions take place to extract
the metal from the ore:
Gold is dissolved in a solution containing cyanide ions (CN–) to extract it from the ore. The balanced chemical equation for the reaction is:
Iron(Vl) oxide and carbon are heated in a furnace to extract iron from the ore. The
balanced chemical equation for the reaction is:
10.1 State TWO advantages of open-cast mining when compared to deep-shaft
(underground) mining. (2)
Consider the iron extraction reaction.
10.2 Is iron oxidised or reduced during the reaction? Give a reason for the answer.(2)
10.3 State TWO disadvantages of using carbon in this reaction.(2)
Consider the gold extraction reaction.
10.4 Give ONE reason why gold is present as an element in the ore.(2)
10.4 What role does oxygen gas (O2) play in the reaction?(2)