Method for increasing molten steel finishing point manganese content by adding manganese ore outside furnace

Abstract

The invention provides a method for increasing the molten steel finishing point manganese content by adding manganese ore outside a furnace, which comprises the steps of: setting the tapping temperature of the revolving furnace to be medium or upper limit according to the type of the made steel, adding the manganese ore and a little reducing agent, and controlling the finishing point carbon content and the slag thickness; adopting strong argon for stirring in a ladle furnace (LF), and replenishing aluminum particles and calcium carbide for making reducing slag according to the top slag condition; and reducing manganese oxide in the slag into metal manganese to realize manganese alloying. Compared with the prior art, the method has the advantages of being simple in technology, convenient to operate and control, short in smelting time, low in energy consumption and high in yield of manganese alloy, reducing pollution, prolonging the service life of a furnace liner and the like; and the yield of manganese in the manganese ore reaches more than 96.5%, so that the consumption of the manganese alloy is greatly reduced, and the steel-making cost is remarkably reduced. Meanwhile, the original equipment does not need to be reformed, and other production processes are not influenced, so that the investment is low, and the effect is rapid.

Description

technical field [0001] The invention belongs to the technical field of steelmaking technology, and in particular relates to a steelmaking method in which manganese ore is added outside a furnace to increase the end-point manganese content in steel. Background technique [0002] Manganese is the main alloying element in steel materials and plays an important role in improving the properties of steel. Usually, when manganese is alloyed in steelmaking, manganese-containing ferroalloys such as ferromanganese and silicomanganese are used for manganese alloying in the process of tapping or refining. This process of manganese alloying with manganese-containing ferroalloy is very mature, and the recovery rate of manganese is high and stable, but manganese ore needs to be smelted into manganese-containing ferroalloy. Since the process of manufacturing manganese-containing ferroalloys is a process of high energy consumption and high pollution, it will eventually lead to an increase i...

AI Technical Summary

Problems solved by technology

This method solves the problems of high cost, high energy consumption and large pollution in the production process of the alloying route using manganese alloys as raw materials in the existing steelmaking process

However, due to the large amount of converter slag and the high oxidizability of the final slag, this process requires a large amount of reducing agent to reduce part of the manganese oxide in manganese ore to manganese, and the general yield is low, so it has not been used in industrial production.

And because the nitrogen is blown from the top, it is not suitable for steel types that require nitrogen content

[0006] According to the principle of thermodynamics, under the conventional smelting conditions of the converter, it is possible to realize the direct reduction alloying of manganese ore, but the traditional converter has too many smelting slag, too strong oxidation of slag, too low carbon content at the end point, etc., which will reduce the The yield of manganese, so the yield of manganese in general converter smelting is lower than 30%

Correspondingly, if the double-slag or double-link process is adopted, although the final rolling capacity of the converter can be reduced, it also increases the difficulty of smelting operations, and at the same time prolongs the smelting time accordingly, which increases the cost of steelmaking and has a certain impact on the process connection

In addition, due to the addition of manganese ore in the steelmaking furnace, it will inevitably bring about the problem of aggravating the corrosion of the furnace lining