Abstract:

Due to the slump of steel scrap price in domestic，using steel scrap as the raw material for converter smelting can greatly reduce the production costs. Combined with its own process features，Tianjin Tiangang United Special Steel Co.，Ltd. fully used the arc heat source of LF furnace and the residual temperature of molten steel to melt steel scrap. According to the thorough research on the melting mechanism，melting and mixing time and inclusion analysis of steel scrap adding to LF refining furnace，the reasonable process of LF refining furnace with steel scrap as the addition was determined，thus the steel scrap ratio in steelmaking was improved，and the iron loss was reduced. Through production practice，when LF refining furnaces were fed with steel scraps reaching 1.54t per furnace in June，2019，iron loss could be reduced to 10.56kg/t. By means of benefit accounting，when a gap between the price of steep scraps used in LF refining and the sales price of actual steel billets reached more than 280yuan/t，distinct economic benefits could be produced. Furthermore，adding steel scraps during LF refining didn’t cause adverse effects to the quality of molten steel，The endpoint oxygen level met steel grade requirements，and showed remarkable effects.

Key words: LF refining, steel scrap, process, iron consumption