The invention discloses a 
steelmaking residual heat step recycling method. The invention belongs to the technical field of steel industry iron-making residual heat and 
residual energy utilization. The method is adopted under a condition for further utilizing iron-making low-grade residual heat, and comprises step recycling and high-efficiency utilizations of 
blast furnace gas residual heat, dust removal air residual heat, water 
slag residual heat, hot air furnace low-temperature 
flue gas 
waste heat, and dust cover and 
slag ditch residual heat. According to the technical scheme, 
blast furnace gas residual heat and dust removal air residual heat obtained after furnace top 
residual pressure power generation are connected in parallel, and are supplied for domestic water, cooling, or heating. Recycled water 
slag residual heat and 
flue gas residual heat obtained after hot air furnace gas 
heat exchanger are connected in parallel, and are used for supplying a heat source for low-temperature 
seawater desalination. Recycled dust cover residual heat and slag 
ditch surface 
radiation heat are connected in parallel, and are supplied for 
blast furnace gas supplementary firing residual heat 
boiler power generation. After 
powder generation, high-temperature 
seawater desalination is realized by a steam method. Cooling water and domestic water are treated and are adopted as inlet water replenishment. Through step recycling and graded utilization of the low-grade residual heat and 
residual energy, steel 
system comprehensive 
energy consumption can be reduced to a maximal extent, and energy resource reasonable utilization and comprehensive optimized utilization can be realized.