Model for the approximate assessment of nitrogen content in swollen reduced iron ore from single measurements

Resumen

A method of calculation has been derived to assess the nitrogen estimated content in iron reduced samples. The method is based on the review of observations and laboratory measurements of relationships between the rate of reduction and the corresponding metallic iron formation during the reduction process. The metallic iron formation has been calculated from relationships that apply to a wide variety of types of ores undergoing reduction under a nitrogen-containing gas mixture in proportions above 50% by volume. The empirical correlations found between the rates of metallization, the sample swelling index, and the equilibrium nitrogen solubility in iron can be used for determining the approximate final content of nitrogen in the reduced samples from the estimated and measured final volume of the reduced specimens. It is necessary to have an accurate analysis of the starting sample as well as the reducibility information.

Keywords: Iron ore, nitriding, catastrophic swelling, rate of metallization, reduction degree.