Mandur (Bhasma)

English Name

Iron Slag

Definition

Mandur is a metallic oxide-cum-silicate of iron, generally having the composition Fe2SiO4 and commonly called Slag.

Synonyms

Samskrta : Kitta, Lohamala, Loha Kitta

Regional Name

English - Slag, Gujarati - Mandūra, Hindi - Mandūra, Loha kīta, Singhanaka, Kannada - Loha kitta, Malayalam - Ierumbin Kittam, Marathi - Mandūra, Tamil - Manturam, Irumbukittam (S.F.I.), Telugu - Loha kittam, Urdu - Khabus-ul-Hadeed, Zang-e-Aahan (N.F.U.M.)

Broad Classification

Metallic oxide-cum-silicate

Origin and occurrence:

Mandur is the by-product of the metallurgical process during extraction of Iron (Fe) and Copper (Cu) from their respective ores. It occurs as lumps, boulders or aggregates at the areas where smelting activity is carried out for the extraction of copper and iron. Iron is the main constituent of Mandur followed by Silica with minor amounts of Cu, S, Pb, Zn, Ag, Cd and Au. Mandur is known since ancient times in India and occurs in over 500 years old slag dumps near village Singhana (Khetri), distt. Jhunjhunu (Rajasthan). Mandur of similar quality may occur at other places also in the country where smelting of copper ore was carried out in the past.

Physical Properties

Nature : Rough lumpy masses, exhibiting voids, Colour : Black, Streak : Black, Cleavage : None, Fracture : Conchoidal, Lustre : Dull, Tenacity : Brittle but hard, Transparency : Opaque, Magnetism : Non-magnetic, Hardness : 6 to 6.5, Sp. Gr. : 3 to 3.8

Chemical Properties:

Assay: 
  • Mandur should contain not less than 30% Iron (Fe) when analysed by gravimetric method (Appendix-3.1.4).
  • Mandur should contain not less than 30% Silica when analysed by gravimetric method (Appendix-3.1.3).
  • Mandur should show not less than 80% fayalite (Fe2SiO4) when studied through XRD method (Appendix- 1.13).
  Heavy metals and Arsenic: Mandur should not contain more than the stated limits for the following: - Arsenic = 6 ppm and Cadmium = 8 ppm (Appendix-3.2). Other elements: May contain the following within ± 20% of the stated limits:- Copper = 0.45%, Zinc = 50 ppm and Silver = 7 ppm (Appendix-3.2).

Śodhana

Man² ūra shall not be used in formulations without subjecting it to śodhana. Mandur is used in the form of bhasma, the details of which are given in the monograph of bhasma.  
Formulations