For example, some scrap steel can be added to iron from a blast furnace to…

The idea

Iron is extracted from iron ore in a blast furnace by reduction with carbon. Steel is made from that iron by removing some carbon and adding controlled amounts of other elements. Scrap steel is steel that has already been used and collected, for example from old cars, buildings or machinery. Instead of sending all the scrap to landfill, some of it can be added to the molten iron coming from the blast furnace when new steel is made. The scrap provides part of the iron needed, so less iron ore must be mined and less iron must be extracted from it. This conserves a limited resource, saves the energy and carbon emissions of extraction, and reduces waste. The scrap must be sorted and cleaned so that unwanted materials do not spoil the steel.

What earns the marks

• Iron is extracted from iron ore in a blast furnace, and this uses a limited, non-renewable resource.
• Scrap steel is recycled steel that can be added to iron from the blast furnace during steelmaking.
• Adding scrap steel means less iron ore needs to be mined and less iron needs to be extracted from the ore.
• Using scrap conserves iron ore, saves energy and reduces waste sent to landfill.
• The scrap must be separated from other materials first, otherwise impurities could affect the properties of the new steel.
• A good answer names the blast furnace, states that scrap is added to the iron, and explains that this reduces the amount of ore extracted.

Common mistakes and how to put them right

• Saying scrap steel is added to iron ore in the blast furnace.

  Put it right: Scrap steel is added to the iron produced from the blast furnace during steelmaking.

• Confusing iron with steel.

  Put it right: Iron is extracted from the ore, and steel is made from iron by controlling the carbon content and adding other elements.

• Claiming recycling removes the need for extraction completely.

  Put it right: Scrap only reduces the amount of iron that must be extracted from ore; some new iron is still needed.

Exam tips

• Use the chain: iron ore → blast furnace → iron → add scrap steel → new steel.
• Link the example to the benefit by writing 'so less iron ore needs to be extracted'.
• If asked to evaluate, mention that scrap must be collected, sorted and transported, which also has costs and energy use.