A method for dephosphorization outside the intermediate frequency furnace smelting furnace

Abstract

The invention relates to the field of dephosphorization of molten metal in a smelting process and particularly relates to an extra furnace dephosphorization method for smelting by an intermediate frequency furnace. The extra furnace dephosphorization method for smelting by the intermediate frequency furnace mainly comprises the following steps: melting by the intermediate frequency furnace, forming an oxidizing atmosphere in the furnace after melting, and discharging molten metal to steel ladles by virtue of high temperatures; in the process of discharging the molten metal, adding a dephosphorizer along with a flow; and heating and melting the dephosphorizer in the steel ladles by virtue of hot melting and oxygen lance heating equipment or an LF finery, and after full treatment, removing steel slags in the ladles to dephosphorize, wherein the dephosphorization rate of the molten steel can reach over 50%, finally. The method is beneficial to lowering the requirements of smelting by the intermediate frequency furnace on steel scraps and is used for improving the application range of the types of steel melted by the intermediate frequency furnace and enhancing the interior quality of the molten metal melted by the intermediate frequency furnace. According to the method, an electric-arc furnace can be further replaced by a medium-frequency induction furnace to coarsely smelt molten steel, so that the smelting cost is lowered and waste residues and exhaust gases are reduced. The method is a simple and efficient dephosphorization operational method.

Description

technical field [0001] The invention relates to the field of dephosphorization of molten metal in the smelting process, in particular to a method for dephosphorization outside the smelting furnace of an intermediate frequency furnace. Background technique [0002] Phosphorus is a harmful element in steel. High phosphorus content will lead to material embrittlement and intergranular cracks. Therefore, castings and forgings have clear requirements for phosphorus content. The phosphorus content is generally required to be below 0.04wt%, and high-end products require phosphorus to be less than 0.015wt. %. For induction furnace smelting, high-quality products can only be produced by selecting high-quality steel scrap and low-phosphorus alloys with low phosphorus content, which will increase production costs and reduce product market competitiveness. However, the induction furnace smelting method is more environmentally friendly than the electric arc furnace smelting method, whic...

AI Technical Summary

Problems solved by technology

But the fact is that the induction furnace is still only a simple molten steel smelting tool, and cannot remove the harmful element phosphorus.

Therefore, the smelting of some high-quality steel types is restricted, and the expansion of the production scale of the enterprise is also hindered. So far, the equipment capacity of the induction furnace has not been brought into full play to a real level.

This is mainly attributed to the following problems in the dephosphorization of the induction furnace: 1) the dephosphorization effect is not obvious; The addition of phosphorus agent makes it difficult to feed the furnace and the smelting time is too long; 4) The operation is too complicated, which brings high additional costs; 5) The lining is severely eroded, reducing the number of times of use and increasing production costs