Under the double influence of global resources shortage and strict environment protection policies,the traditional blast furnace ironmaking process has entered the deceleration period and met more and more fierce competition and challenges.COREX,as an alternative route to the blast furnace,is the first and only commercially established smelting-reduction process in the world.As an international advanced iron and steel production enterprise,Baosteel has built two sets of large-scale smelting-reduction COREX C3000 units ( named 1# COREX and 2# COREX in this article).Up to now,there is a paucity of publications relating to the heat dissipation testing of COREX process as it is extremely helpful to understand the energy utilization of COREX system to explore a way of increasing production and reducing fuel consumption.In this paper,based on the processes and characteristics of two sets of Baosteel COREX C3000 units,a comprehensive furnace shell heat dissipation testing scheme was established in aspect of pre-reduction shaft furnace ( shaft furnace for short) and melting-gasifier.The testing scheme contains point distribution,testing method and testing tools.Then the furnace shell temperature and surrounding environmental conditions in the practical smelting process of the two COREX C3000 units were tested with the cooperation of the field operators.After that,the heat dissipation amount was calculated based on the tested data and the corresponding furnace area calculated through the design drawings.Eventually,the two COREX C3000 systems were compared in furnace shell temperature and heat dissipation amount.It is proved that the heat dissipation amount of the earlier-built l# COREX is much higher than the newly-built 2# COREX and much refractory must be repatched on l# COREX system.