A PROCESS FOR PRODUCING SPONGE IRON

摘要

The present invention relates to a process for producing sponge iron with in-situ carbon removal. The process for producing the sponge iron includes the steps of preparing a sandwich of at least two layers wherein the at least two layers includes a first layer (10) of iron oxide source which content is carbon free or comprises of only self- contaminant carbon or carbonaceous and second layer (12) is a mixture of iron oxide source and carbon source and subjecting the sandwich of at least two layers to a pyrolysis process in a non-oxidative environment at temperature between 950°C to 1900°C for a period between 10 minutes to 36 hours. The carbon source in the second layer (12) is equal to or more than stoichiometric weight of carbon according to a predominant reaction. The non-oxidative pyrolysis occurs in a reactor. The sandwich of two layers is placed in a moving carrier (16) such as tray to accommodate the sandwich of two layers in the reactor. For maximum level of carbon removal and for lower processing time, at least one layer of organic material (14) or at least one heat conductor can be inserted into the sandwich as a divider. When the at least one layer of organic material (14) is burnt off at processing temperature between 950°C to 1900°C, it increases reaction rate of iron extraction. If there are traces of unreduced iron oxide source in the first layer (10) after the non-oxidative pyrolysis process, the sponge iron produced is then pulverized and heated at same condition as mentioned above for a second cycle. This second cycle produces sponge iron with better removal of carbon and increases extraction rate of sponge iron.