Abstract
Pelletizing and sintering have historically been developed out of the necessity of treating different types of raw materials, of which screen analyses define the respective fields of application; thus they act as supplementary rather than competitive methods.
Diminishing supply of high-grade iron ores will call for the utilization of ores with wider variety, and the fines from beneficiation plants are expected to increase.In order to meet this situation more attention should be paid to the study of extending the fine limit of sintering, particularly on such processes as the semi-pellet sintering, the use of drum mixers and sintering with limestone addition.At the same time recognition of pellets as a superior blast furnace charge would call for consideration about the possibility of better utilizing even relatively coarse fines as ground to make pellets than as they are to make sinters.
This article purports to make further consideration on raw material problems in the future such as the fine limit of sintering, the method of estimating the power consumption to grind three types of fines represented by magnetite, hematite and limonite to their respective optimum sizes for pelletizing, technical problems involved in pelletizing, and comparison of some physical and chemical properties of pellets and sinters.On the basis of the present study it may be concluded that, if they are fired at optimum temperatures, pellets will aquire better quality than sinters with respect to bulk density, strength, reducibility, strength under reduction, etc., and particularly self-flux pellets will show much promise as blast furnace charge.
