In the prior art, the temperature in the smelting process is generally compensated by adding quasi-graphite or silicon carbide as a carburizer for steelmaking during the converter smelting process. The heating efficiency of the carburizing agent used in steelmaking is related to the quality of the heating agent itself and the converter smelting process conditions. Theoretical calculations show that under the conditions of 30-ton converter semi-steelmaking, 1 ton of quasi-graphite or silicon carbide can increase the temperature of molten steel by 100-120°C/furnace, and make the temperature of molten steel exceeds 1700°C, usually requiring more than 500 kg of quasi-graphite or silicon carbide. But generally, 1 ton of converter semi-steel needs to use no more than 10 kg of quasi-graphite or silicon carbide. If the amount added is too large, it will lead to: (1) For quasi-graphite, not only the utilization rate is low, but also some unreacted quasi-graphite will be wasted along with the dust entering the dust removal pipeline, and the slagging in the initial stage of converter steelmaking is difficult, and the steelmaking process (2) For silicon carbide, the relative price is high, and the addition amount is too much, which not only leads to slow slagging in the early stage, but also has too high sio2 content in steelmaking slag, and the binary alkalinity ( cao/sio2) is low, the dephosphorization effect is poor, and the steelmaking process is easy to splash. That is to say, in the semi-steel steelmaking process, it is difficult to achieve the temperature required for the smelting process by adding a steelmaking carburizer to compensate for the temperature. Furthermore, the slag discharge time is generally 3-4 minutes, because the addition of the heating agent will delay the slag discharge time to 4-5 minutes. The slow slag discharge speed directly leads to the delay in the steelmaking process, and at the same time, it is easy to cause deep blowing, affecting Steel quality. During the converter smelting process, the heating agent is added to the molten steel through the scrap tank at the converter mouth or top hopper. This method is time-consuming and laborious, making it difficult to operate in the steelmaking production process. Therefore, the semi-steel converter smelting process under this condition is difficult to proceed smoothly.
Carburizer for steelmaking
On the other hand, due to the high price of domestic raw iron and the low price of scrap steel, in order to reduce costs, foundries use a large amount of scrap steel to synthesize cast iron and directly add carburizers in steelmaking to make steel. Electric furnace, but because of its different melting characteristics. Ordinary steel-making carburizers need to be placed in an electric furnace to lower or raise the melting temperature of the electric furnace to melt the steel-making carburizer. For example: currently, commercially available carburizers include pig iron, pitch coke carburizers, graphite electrode carburizers, petroleum coke carburizers, coal-based carburizers, and artificial graphite. The adjustment of temperature reduces the optimal smelting time of cast iron, which leads to problems such as high temperature. The defective rate of cast iron is high and the production efficiency is low.