Direct-reduction ironmaking device and method based on blast furnace slag waste heat utilization

Abstract

The invention provides a direct-reduction ironmaking device and method based on blast furnace slag waste heat utilization. The device comprises a granulating device and a moving bed reduction device. By means of the device, liquid blast furnace slag is made into high-temperature furnace slag granules, the granules are loaded with a reducing agent and used as a heat carrier to be in direct contact with iron ore powder, and the iron ore powder generates a direct reduction reaction for production and direct-reduction ironmaking. According to the technical scheme, waste heat of the blast furnace slag is adopted as an iron ore powder direct-reduction heat source, the furnace slag heat carrier loaded with the reducing agent is in direct contact with the iron ore powder granules, and therefore efficient heat exchange and mass transfer of the reduction reaction are achieved, the waste heat of the blast furnace slag is efficiently recycled, and low-cost and efficient production of direct-reduced iron is achieved.

Description

technical field [0001] The invention relates to the field of energy recovery and utilization, in particular to a direct reduction ironmaking device and method based on utilization of blast furnace slag waste heat. Background technique [0002] In order to get rid of the constraints of the shortage of coking coal resources on development, adapt to the increasing environmental protection requirements, and reduce the energy consumption of iron and steel production, the modern iron and steel industry has developed a non-blast furnace ironmaking technology using non-coking coal as the basic energy source. The direct reduction method is iron The oxides are not melted, slag-forming, and reduced to produce metallic iron products in a solid state, which is a clean production method. However, due to the lack of a reasonable heat source, it has become a bottleneck restricting its industrial mass production. [0003] Blast furnace slag is the main by-product of the iron and steel produ...

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Problems solved by technology

[0005] (1) Due to the high temperature required for coal gasification, this method requires a secondary cooling system to further cool the granulated slag. In the secondary cooling system, the granulated slag exchanges heat with air, but the slag surface is attached The residual ash content of pulverized coal gasification affects its heat transfer effect;

[0006] (2) The reduction shaft furnace has strict requirements on the components of the reducing gas, and the components of the coal gasification gas products usually cannot meet the requirements, and an additional hydrogenation device is required, which increases equipment investment and operating costs;

[0007] (3) The system requires many reaction devices, and the equipment is complex, difficult to control, and the process is long. The slag needs to be cooled twice, which will lead to a lot of waste of sensible heat, low heat recovery efficiency, and high power consumption.

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