Optimization of Recuperative System in Rotary Furnace for Minimization of Elemental Loss during Melting

Abstract

Two rotary furnaces of different construction model were used for the research work. One has no recuperating system and the second one has recuperating system. 60 kg of grey cast iron scrap was charged into each of the furnaces at different time, after preheating the furnaces for 40 minutes. 0.5 kg graphite and 0.2 kg ferrosilicon were charged along with the scrap. The theoretical charge calculations have the composition of the melt as 4.0% carbon and 2.0% silicon. Charges in the furnaces were heated to obtain molten metal suitable for casting at 1350&degC. The content of the furnaces was tapped three times after the attainment of 1350&degC with 15 minutes interval between each tapping. Optical light emission spectrometer was used to analyze the resulting composition of the tapped samples. For type A furnace (without recuperation), sample A has its carbon and silicon contents reduced compared to expected value by 25.5% and 10.8%, sample B reduced by 29% and 13.4% and sample C reduced by 32% and 17.0% respectively. In Type B furnace (with recuperation), sample D has its carbon and silicon contents reduced by 12.2% and 7.3%, Sample E reduced by 13.0% and 8.0% and sample F reduced by 13.9% and 8.9% respectively.