What is Loss On Ignition

Description on the LOI

Loss on ignition (LOI) refers to the percentage of the mass of the original sample that is lost after drying the raw material in the temperature range of 105-110 ℃ and burning it for a long enough time in a muffle furnace at a certain high temperature (950℃-1100℃). The high temperature environment here, with the characteristics of different industries, has been specified in detail in the technical standards of each industry. The analysis of the firing loss of raw materials has its special significance. It represents the amount of gaseous products (such as internal water, SO2, CO2, etc.) released by physical evaporation or chemical decomposition of raw materials. For example, when heated to 1000℃, the internal water contained in raw materials will be dried within the temperature range of 105-110 ℃ without evaporation, and will be evaporated. The material contained in the sublimation point below 1000℃, will evaporate at 1000℃ heating conditions; Some substances whose decomposition temperature is lower than 1000℃ will decompose, releasing substances whose boiling point is lower than 1000℃; Under aerobic conditions, the combustible material contained in the raw material will be oxidized to form gas and released. Through the measurement of LOI, it can be determined whether the raw material needs to be calcined in advance when used to make the composition of the raw material more stable. According to the composition obtained by chemical analysis, the purity of the raw material can be judged, the fire resistance can be roughly calculated, and the mineral composition can be roughly calculated with the help of the relevant phase diagram.

Procedures for LOI

  1. Take about 1g of sample and placed in a crucible which had been burned at constant temperature to a precision of 0.0001g.
  2. Then placed in a high temperature muffle furnace which has been set programs already, rise temperature up to 1000C and hold temperature 30min.
  3. Take the sample out and place in the drying oven to cool down to room temperature and weigh.
  4. Repeated burning, until the constant.
Scroll to Top