Pyroprocessing

About Pyroprocessing:

• It is a way to change a solid material physically or chemically using high temperature.
• It is a dry process and very energy-intensive. Three sectors that use it most are cement-making, metallurgy, and nuclear power.
• Applications of Pyroprocessing:
• Cement Making:
  • This sector uses pyroprocessing the most and it involves
  • First, finely ground limestone, clay and iron — the raw materials — are fed into a rotary kiln.
  • As the temperature increases to 900° C, the limestone loses its carbon dioxide, and at around 1,450° C, the mix partly melts to form marble-sized nodules called clinker.
  • The clinker is then ground to produce cement.
• Metallurgy Sector:
  • Pyroprocessing is used to extract metals from their ores in multiple stages.
  • For example, sulphide ores are heated in air, or roasted, to convert them into metal oxides, like zinc sulphide.
  • Smelting melts an ore to separate the metal from waste impurities called slag.
• Nuclear industry:
  • It uses pyroprocessing to reprocess spent nuclear fuel.
  • First, used nuclear fuel is broken up into pieces and placed in a salt bath — usually a mixture of lithium and potassium chlorides at 500° C or more.
  • Then, an electric current is passed through the salt bath, causing different elements to become separated depending on their electrochemical properties.
  • Operators then recover the elements of interest in separate streams.