Method and device for improving energy efficiency of iron-making technology

The invention relates to a method for improving energy efficiency of an iron-making technology. Liquid blast furnace slag is introduced into a waste heat recovery tank body, and at the same time, a solid coolant is added into the waste heat recovery tank body; the solid coolant comprises at least iron-containing solid particles; slag flows and coolant material flows converge, so that a hot solid mixture material flow is formed; during the falling process, the hot solid mixture material flow is impacted and broken; scattered hot solid mixtures exchange heat with upstream cooling gas; high-temperature gas after heat exchange is exhausted out of the waste heat recovery tank body for recovery; and low-temperature solid mixtures after heat exchange are discharged out of the waste heat recovery tank body, and then crushing and magnetic separating are carried out, so that iron-containing solid particles and glassy-state blast furnace slag is obtained. The invention further relates to a device which can implement the method. According to the simple method for processing blast furnace slag, heat of the blast furnace slag can be effectively recovered; the provided device is simple in structure, easy to maintain and small in occupied area; local materials can be used as the coolant and the cooling gas and the like; and the investment cost and the operation cost are extremely low.