Influence on the sintering process of lime distribution between the blending storage and the mix department of SP-5 PJSC “MMK”

Abstract

A research methodology is presented to determine the rational distribution of lime for the agglomeration process between the blending storage (fraction 0‒10 mm) and the mix department of the sinter plant (0‒3 mm). Together with the technological staff of the sinter plant four variants of lime distribution were tested and, accordingly, four piles with different lime content fraction 0‒10 mm were formed. The results of determining the granulometric composition and temperature of the mix under the conditions of lime dissociation along the process line for preparing the mix for sintering are presented. It has been established that when lime fraction of 0‒3 mm is supplied to the mix department, which ensures its content in the mix of 3%, it is heated to a temperature of 62 °C, i.e. to the “dew point”, which practi-cally prevents moisture condensation in the bed of the sintered mix. The analysis of the chemical composition of raw iron ore materials, mix and sinter, and its fluctuations has been carried out. It has been established that both for iron ore raw materials and mix, and as a result for sinter, the fluctuations of the chemical composition, estimated from the homogeneity coefficient, does not exceed 10%. The influence of the basicity of the sinter on the sulfur content in it has been established. It was found that when the content of lime fraction 0‒3 mm in the mix reaches 3%, the productivity of the sinter machine increases by at least 5.2% compared with the supply of all lime fraction 0‒10 mm to the blending storage. In this case, there are no problems for the blending storage in the cold season, when the remaining 1.5% of lime fraction 0‒10 mm is introduced into the concentrate consumption. Thus, it is recommended in winter conditions to sup-ply lime fraction of 0‒3 mm to the mix department in an amount that ensures its content in the mix equal to 3%, and the rest of the lime with a fraction of 0‒10 mm is fed to the blending storage.