Production of foundry grade iron from sponge iron fines

Abstract

Presently foundry grade iron is being produced in mini blast furnace (MBF)-an eco-friendly cost effective unit for sophisticated technological applications in the automotive, capital goods and other engineering or foundry industries. The foundry grade iron can also be produced by an alternative route in a submerged arc furnace (SAF).The huge quantity of sponge iron fines generated in sponge iron plants by coal based process , which cannot be easily utilized and are often considered as waste, can be smelted in a submerged arc furnace (SAF) to produce foundry grade iron. In present investigation, an innovative process has been developed to smelt the discharged fines from rotary kiln sponge iron plants in a 50 kVA submerged arc furnace making use of high carbonaceous reductant (petroleum coke), good quality quartzite and limestone as flux in the charge mix and its parameters namely smelting temperature, quartzite addition in the charge mix and slag basicity have been optimized by making 55 tappings in six sets of experiments. The entire smelting study was conducted with sponge iron fines having 86.43% total iron and 18.78 % FeO using petroleum coke as reductant and limestone as flux in the charge mix by varying the slag basicity and smelting temperature. The hot metal temperature varied in four ranges namely (1360-13850C), (1380-14100C), (1400-14200C) and (1430-14450C) in order to produce basic grade and foundry grade iron. An eco-friendly cost effective innovative process has been developed to produce foundry grade iron using sponge iron fines.