Extraction of Metals: Ores and Minerals

Isolation of elements in Chemistry class 12 aims to teach the students about various processes of extraction of metals from ores. The compounds which contain metals along with impurities are called minerals. Ores are the minerals from which metals can be easily and economically extracted. Very few metals such as noble metals, i.e., Gold, Silver, Platinum etc. are present in their original metallic forms in nature. Metallurgy is the field of science that deals with the extraction of metals from ores which are naturally found in the environment.

Most of the elements especially metals are present in combination with other elements or with sand, limestone, and earthy impurities and these are called minerals. An element may combine with a variety of other elements to make myriad minerals but out of them, only a few are viable sources of that metal. Such sources are called ores.

Also read:

• Bauxite

Extraction of metals

The process of extracting metal ores buried deep underground is called mining. The metal ores are found in the earth’s crust in varying abundance. The extraction of metals from ores is what allows us to use the minerals in the ground. The ores are very different from the finished metals that we see in buildings and bridges. Ores consist of the desired metal compound and the impurities and earthly substances called gangue. The extraction of metals and their isolation occurs over a few major steps:

• Concentration of Ore – Here the ore is separated from earthy impurities.
• Isolation of metal from concentrated Ore – Here the ore is converted to its oxide form and then reduced. The steps involved are either calcination or roasting and then heating with a reducing agent.
• Purification of the metal – Here the metal is purified for practical purposes.

Aluminium:

• Bauxite                                          AlO_x(OH)_3-2x [where 0 < x < 1]
• Kaolinite (a form of clay)          [Al₂(OH)₄ Si₂O₅]

Iron:

• Haematite                                     Fe₂O₃
• Magnetite                                      Fe₃O₄
• Siderite                                          FeCO₃
• Iron pyrites                                   FeS₂

Copper:

• Copper pyrites                               CuFeS₂
• Malachite                                        CuCO₃.Cu(OH)₂
• Cuprite                                            Cu₂O
• Copper glance                                Cu₂S

Zinc:

• Zinc blend/Sphalerite                   ZnS
• Calamine                                         ZnCO₃
• Zincite                                              ZnO

Recommended Video

You now know about ores and minerals. Learn more about the extracting metals and metallurgy in the next article titled ‘Concentration of Ore’ only on BYJU’s, The Learning App.