Question

How is $FeO$ removed during the Extraction of Copper?

Answer 1

For answering this we have to understand the process of Extraction of Copper. Copper is extracted form. The method used for extraction depends upon the type of ore used. Sulphide ores like Chalcopyrite $CuFe{S_2}$ are converted to copper by different methods using silicate, sulphate or carbonate ores. Chalcopyrite is also known as copper pyrites and it is one of the common ores of copper. The ores contain low amounts of copper and are concentrated before refining. This process is also known as Froth flotation.

Complete answer:
The concentrated ore is treated with Silicon dioxide (or Silica) and air (or Oxygen) under strong heating conditions in a series of furnaces. The copper ions in the Chalcopyrite are reduced to form Copper sulphide which is then converted into pure Copper. The sulphur in the Chalcopyrite is converted into Sulphur dioxide gas, this sulphur dioxide gas is used for making Sulphuric acid using Contact process.
Iron oxide is found as an impurity in the extraction of copper. iron oxide is removed by converting it into a slag. Iron oxide reacts with silica to form an Iron Silicate slag. The reaction is given as:
$FeO + Si{O_2} \to FeO.Si{O_2}$
Iron oxide is removed as slag during the Extraction of copper.

Note:
Slag is the by-product formed in various processes such as smelting, welding other metallurgical and combustion processes by various impurities in the ores or metal that is being heated. It is a waste product, which is left after the metal is being extracted through a particular process.