Question

Which one of the following elements constitutes a major impurity in pig iron?
a.) Silicon
b.) Oxygen
c.) Sulphur
d.) Graphite

Answer 1

Hint: We should be having an idea about pig iron for answering this question. The composition, as well as the impurities that can be present, should also be known.

Complete step-by-step answer:
Pig Iron is an intermediate product of the iron industry which is also known as the crude iron ,which is obtained by smelting iron ore in a blast furnace.
The major impurity that is present in pig iron is graphite which is an allotrope of carbon. Therefore, the correct answer to the question is Option D.
The name pig iron originated in the early days of iron ore production when the total output of the blast furnace was and cast into pigs, that is a mass of iron roughly resembling the shape of a reclining pig. The oldest method of pig casting in sand beds has been largely suspended by pig casting machines.

Note: We should also be knowing about the proper composition of pig iron. It is an alloy of iron, which consists of carbon, silicon and manganese. It also contains some percentage of phosphorus and sulphur, along with titanium and some traces of other elements as well.
Pig iron can also be used to produce gray iron. This is achieved by remelting pig iron, often along with substantial quantities of steel and scrap iron, removing undesirable contaminants, adding alloys, and adjusting the carbon content. Some pig iron grades are suitable for producing ductile iron.