Rotary hearth furnace thermal control method for directly reducing carbon-containing pellets

Abstract

The invention relates to the field of iron and steel production, in particular to a rotary hearth furnace thermal control method for directly reducing carbon-containing pellets. The rotary hearth furnace thermal control method for directly reducing the carbon-containing pellets, which is disclosed by the invention, comprises the following steps: 1) the furnace temperature is controlled from 1050 to 1250 DEG C on a preheating section; 2) the furnace temperature is controlled from 1200 to 1400 DEG C on a reducing section I and a reducing section II; 3) the furnace temperature from 1180 to 1420 DEG C on a soaking section I and controlled from 1050 to 1250 DEGC on a soaking section II; and in the step 1), the step 2) and the step 3), components of furnace gas at the furnace bottom are controlled, wherein the volumetric component ratio of O2 is controlled to be less than 3 percent and that of CO is controlled to be less than 500ppm. The rotary hearth furnace thermal control method disclosed by the invention not only satisfies national policy requirements of energy conservation, emission reduction and circular economy, but also provides space for the reduction of own production cost of an enterprise.

Description

technical field [0001] The invention relates to the field of iron and steel production, in particular, the invention relates to a rotary hearth furnace thermal control method for direct reduction of carbon-containing pellets. Background technique [0002] The predecessor of the rotary hearth furnace is the ring-shaped heating furnace for steel rolling. It has been used in the direct reduction process of carbon-containing pellets in the past 30 years, and has gradually developed into a new coal-based direct reduction ironmaking process. Because this process does not require the preparation of fuel and the deep processing of raw materials, it has a positive effect on the rational use of natural resources and the protection of the human environment, so it has received widespread attention from the metallurgical industry. At present, the research and development of rotary hearth furnace technology has developed from the United States, Canada, Japan and Germany to many countries ...

AI Technical Summary

Problems solved by technology

Compared with the traditional steel rolling heating process, no matter considering the combustion, flow and gas-solid heat exchange process in the furnace, or analyzing the physical and chemical reaction and heat and mass transfer process inside the material, it can be seen that the process of direct reduction of rotary hearth furnace is more efficient. It is complicated. If the existing thermal control method of the steel rolling annular heating furnace is directly used to control the rotary hearth furnace, there will be many problems in meeting the requirements of the direct reduction process of carbon-containing pellets, energy saving and emission reduction of equipment, etc.

Images