English NameIron Ore
DefinitionKānta Lauha is an Iron ore containing magnetite, a ferric oxide (Fe3O4) mineral.
SynonymsSa¼sk¨ta : Kānta, Kāntaka, Kāntāyasa
Regional NameEnglish - Magnetite, Gujarati - Nātīsa, Hindi - Cumbaka, Cumbaka patthar, Tamil - Kantham (S.F.I.), Telugu - Sudantu rāyi, Ayaskāntamu, Urdu - Faulad, Aahan (N.F.U.M.)
Origin and occurrence:Kānta Lauha occurs in igneous as well as metamorphic rocks as accessory mineral. It is a wide-spread oxide mineral found in earth’s crust in ore form. Kānta Lauha is commonly associated with hematite (Fe2O3). In India, Kānta Lauha occurs mainly at Guntur in Andhra Pradesh, Salem and Tirucirappalli in Tamil Nadu, Shimoga and Kudramukh in Karnataka, Mandi in Himachal Pradesh, Mayurbhanj in Orissa and Noamundi, Notoburu, Gore Pahar and Biwabathan in Jharkhand. Other known deposits with hematite aspredominent mineral occur in the states of Bihar, Goa, Madhya Pradesh and Rajasthan.
Physical PropertiesNature : Lump, Colour : Greyish black, Streak : Reddish black, Cleavage : None, Fracture : Uneven, Lustre : Metallic, Tenacity : Brittle, Transparency : Opaque, Magnetism : Magnetic in nature, Hardness : 5.5 to 6, Sp.Gr : 5 to 6
- Assay: Kānta Lauha in ore form should contain not less than 60% Iron (Fe) when analysed by gravimetric method (Appendix-3.1.4).
- Heavy metals and Arsenic: Kānta Lauha in ore form should not contain more than the stated limits for the following: - Arsenic = 2 ppm and Cadmium = 7 ppm (Appendix-3.2).
- Other Elements: Kānta Lauha in ore form may contain the following within ± 20% of the stated limits:- Zinc = 95 ppm, Manganese = 500 ppm and Silver = 5 ppm (Appendix-3.1 & 3.2).
- Acid Insoluble : Take about 1 g of pre-dried finely powdered (150 mesh) sample of Kānta Lauha in 250 ml beaker. Add 50 ml dilute hydrochloric acid. Stir the solution and cover the beaker with a watch glass. Heat on the hot plate at 1500 and digest for two hours. Cool, filter in buchnar funnel, wash with water and ignite at 9000. Weigh the residue. It should not be more than 13 % of the initial weight of the sample.
ŚodhanaShall not be used in formulations without subjecting it to śodhana. Kānta Lauha is used in the form of bhasma, the details of which are given in the monograph of bhasma.