Fly-ash or Pozzolanic Material Test - Loss on Ignition


Staff member
Loss on Ignition (Refer IS 1727: 1967, Clause5.3, Page No.8 - attached)

  1. Ignite I.00 g of the air-dried, finely ground sample in a platinum crucible of 20 to 25 ml capacity by placing it in a muffle furnace at 1000 f 25°C to constant weight ( for about 20 to 30 minutes ). Air should have free access to the sample to maintain oxidizing conditions.
  2. Cool and weigh the crucible to 0.1 mg and check the loss in weight by second heating for 5 minutes and reweighing after cooling.
  3. The percentage loss on ignition nearest to 0.1 shall be calculated as follows:
    Loss on ignition, percent = A/B x 100

    where, A = loss in weight, and
    B = weight of moisture-free sample used.
Note -The significance of the determination of loss on ignition will vary according to the nature of the sample. The figure obtained may include loss due to the oxidation of any carbonaceous matter and gain due to the oxidation of any ferrous iron present.