Some Recent Trends on Iron and Steel Research and Control Methods

Abstract

Investigations on raw-materials and sintering charact-eristics : Although in recent years a considerable amount of work has been done towards beneficiation and treatment of blast furnace raw materials leading to increased production in a given furnace, there is considerable scope for further investigation in this field with reference to indigenous materials and particularly sintering of ore blended with other Materials. Scientific definition and standardisation of so-called ''Sintering characteris-tics" "Reducibility of Sinter", need further studies and the effects of different constituents and sizes on the rate of sinter production and allied activities may very well lead to fruitful results. Some of the. recent trends in this connection are : (i) quick analysis of constituents in the sintered material by X-ray fluoroxopy--particularly the FeO, Fe_03 and Fe30a contents by diffraction before and after a given treatment. (i i) effects of injection of oxygen on the one hand and reducing gases ova the other during sintering. It has been found for example that injection of 02 instead of raising the maximum temperature T Max and narrowing the zone of combustion, lowers the Tinax value and widens the zone of combustion. This is because the surface activity of coke increases with oxygen pressure and hence the ignition temperature is low- ered with the result that combustion starts before the charge is preheated to a higher temperature.This results in a, widening of the combustion zone and lowering of Tmax. (iii) Investigations on "Reducibility of Sinter" either by varying the CO concentration at definite time intervals and measuring the amount of oxygen removal or preferably by the SCICE method -developed rece- ntly by the British Iron and Steel Research Assoc- iation. (1v) Blending of CaO in sinter is helpful in reducing the thermal requirements and hence coke consumption and therefore helpful for reducing S in pig iron.