Unsteady Process of Maintenance for Cast Blast Furnace Hearth with Titanium Ore

Titanium ore furnace protection is an important means to ensure the safe production of blast furnace. Based on the industrial test of titanium ore furnace protection in the hearth of a cast vertical blast furnace in China, this paper analyzes the influence of titanium ore furnace protection on the fuel consumption of blast furnace, explores the reasonable titanium load suitable for smelting, and analyzes the unsteady process of titanium deposition. The relationship between Ti content and C, Si, and S content in molten iron is clarified, and the reasonable titanium content range for controlling Ti (C, N) precipitation is established. It is found that the fuel ratio is reduced by about 5 kg/t during the industrial test, and the titanium load should be maintained at 6–8 kg/t. Since the titanium ore is put into the furnace, the titanium deposition process has a delay of 6–7 days, and the unsteady period of the whole furnace protection process is 10 days. The Ti content in molten iron will increase with the increase of C content and Si content, and decrease with the increase of S content. Under the condition of Ti (C, N) precipitation, when the Ti content in molten iron is greater than 0.074%, the Si content is greater than 0.42%, and the S content is less than 0.061%, a better furnace protection effect can be obtained.