Hematite Ore Decomposition at Particle Scale

EasyChair Preprint 9288

Abstract

It is well established that pure hematite (Fe₂O₃) decomposes to magnetite (Fe₃O₄) in the air at a temperature of 1390°C. TGA experiments were conducted in the air using NETZSCH 449 F1 simultaneous analyzer to find the decomposition temperature of laboratory-grade Fe₂O₃ powder which was found to be 1356°C. The mass change for the decomposition was 3.3% which is in line with the stoichiometric calculations. Subsequently, experiments were also conducted using hematite ore concentrate obtained from Hospet, Karnataka. Interestingly the decomposition temperature was found to be 1150°C, more than 200°C lower than that for the pure Fe₂O₃. The decomposed samples were also analyzed using XRD and peaks corresponding to Fe₃O₄, and SiO2 were found. The decomposed sample was again oxidized at 750°C in the air to obtain the Fe₂O₃ phase back. Interestingly when this oxidized sample was thermally treated again at a high temperature in presence of air, no decomposition was observed till 1350°C. This is an interesting result that can have large implications for the induration of magnetite and hematite pellets. Further investigations are in progress to understand this interesting phenomenon.

Keyphrases: Hematite, TGA, thermal stability

@booklet{EasyChair:9288,
  author    = {Raja Ankit Anand and Nurni Neelakantan Viswanathan and Manish M Pande},
  title     = {Hematite Ore Decomposition at Particle Scale},
  howpublished = {EasyChair Preprint 9288},
  year      = {EasyChair, 2022}}