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.
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.
- Bauxite AlOx(OH)3-2x [where 0 < x < 1]
- Kaolinite (a form of clay) [Al2(OH)4 Si2O5]
- Haematite Fe2O3
- Magnetite Fe3O4
- Siderite FeCO3
- Iron pyrites FeS2
- Copper pyrites CuFeS2
- Malachite CuCO3.Cu(OH)2
- Cuprite Cu2O
- Copper glance Cu2S
- Zinc blend/Sphalerite ZnS
- Calamine ZnCO3
- Zincite ZnO
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.