If you are looking for high-quality products, please feel free to contact us and send an inquiry, email: brad@ihpa.net
iron pellets are an essential part of the steel making process. They reduce the requirement of coking coal in blast furnace and allow for more efficient use of low-grade ore. They also allow for the direct utilization of iron ore fines which were previously considered a waste product. The granulation process combines iron ore fines with a binder and a flux to form agglomerates called green pellets that can be fired in a grate or rotary kiln.
The quality of the green pellets depends on input parameters like mineralogy and chemistry of the ore, granulometry of the ore fines and balling conditions. The metallurgical properties of the product pellets are determined during induration, which is the stage when the components of the green pellets react together to form different phases and microstructures. This reaction decides the metallurgical properties of the pellets during reduction in the subsequent iron making process.
A primary determinant of the pellets’ reducibility and strength is the composition of the slag phase. The slag phase in iron pellets contains calcium ferrite and magnesium silicate (forsterite). This phase is determined by the basicity of the pellets, which influences its melting point and decomposition behavior.
The slag phase is formed by the oxidation of silicate minerals in the iron ore concentrate and the reaction with CaO and MgO in the fluxes and the binder. The quantity of slag formation depends on the ratio of hematite and magnetite in the concentrate, as well as the amount of gangue and CaO in the feed.