Romelt Process Production Indices with Partial Replacement of Coal by Natural Gas

Resumo

Results are provided for calculation of the material and heat balances of cast iron smelting in a Romelt furnace using coal with a different fixed carbon content with addition of natural gas to the blast of the lower tuyeres. It is shown that under constant heat flow conditions due to gas combustion in the slag bath an increase in natural gas consumption is accompanied by a reduction in coal consumption. In this case saving coal does not depend on its form and is proportional to natural gas consumption. An increase in natural gas consumption is accompanied by a reduction in oxygen consumption in the lower tuyeres and an increase in the upper tuyeres. Saving oxygen in the Romelt process is at a maximum for coal with a low fixed carbon content. It decreases as there is an increase in fixed carbon content and with ≈ 75% C_fix saving oxygen is replaced by a small over-consumption.