Method for preparing low-phosphorous medium-carbon ferromanganese by decarbonizing and dephosphorizing high-carbon ferromanganese through molten salt

Abstract

The invention discloses a method for preparing low-phosphorous medium-carbon ferromanganese by decarbonizing and dephosphorizing high-carbon ferromanganese through molten salt and belongs to the technical field of ferroalloy refining. According to the method, the high-carbon ferromanganese is used as a raw material and added into a high-temperature resistance furnace to be dephosphorized and decarbonized after being crushed, and then the low-phosphorous medium-carbon ferromanganese is obtained. The molten salt in a crucible of the resistance furnace is mixed molten salt of chlorate and carbonate of alkali metal and alkaline-earth metal. After decarbonizing and dephosphorizing, the crucible is taken out and cooled to the normal temperature, the molten salt is separated from the low-phosphorous medium-carbon ferromanganese under the action of gravity, the motel salt on the upper layer in the crucible is recycled and continues to be used, and the low-phosphorous medium-carbon ferromanganese on the lower layer in the crucible is directly remelted through the resistance furnace so as to obtain the final product. The molten salt is used for decarbonizing the solid-state high-carbon ferromanganese, the temperature is low, the efficiency is high, and dephosphorizing and decarbonizing of the non-national-standard high-carbon ferromanganese obtained by smelting high-phosphorous manganese ore can be achieved.

Description

technical field [0001] The invention belongs to the technical field of ferroalloy refining, and in particular relates to a method for producing low-phosphorus medium-carbon ferromanganese by using molten salt to dephosphorize and decarburize high-carbon ferromanganese. Background technique [0002] There are three methods for producing medium and low carbon ferromanganese: electrothermal silicon reduction method, shaking bag method and oxygen blowing decarburization method. Due to the low recovery rate of manganese in the process of oxygen blowing decarburization, at present, electrothermal silicon reduction method and shaking bag method are often used. Both the electrothermal silicon reduction method and the shaking bag method use silicon-manganese alloy desiliconization to obtain medium and low carbon ferromanganese, resulting in high production costs of medium and low carbon ferromanganese. How to use cheap high-carbon ferromanganese as raw material to prepare medium and...

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Problems solved by technology

[0003] Chinese patent CN 201210289348.8 uses a kind of air to blow into molten high-carbon ferromanganese three times to produce medium and low carbon ferromanganese. Due to the high nitrogen content in the air, the heat release of carbon-oxygen reaction is insufficient, and the nitrogen content in medium and low carbon ferromanganese is too high. This makes the promotion of this technology insufficient

[0004] Chinese patent CN201010294120.9 uses microwave heating to decarburize high-carbon ferromanganese with calcium carbonate. Due to slow solid phase diffusion, long decarburization time, and serious segregation of carbon content in the product, this technology has not yet been popularized and applied.

[0005] In addition, my country's manganese ore contains relatively high phosphorus. During the smelting process, almost all phosphorus enters the high-carbon ferromanganese alloy. Require

Since liquid manganese metal is easy to oxidize and volatilize, oxidative dephosphorization of high-temperature liquid manganese ferroalloys will lead to volatilization and oxidation of manganese, reducing the recovery rate of manganese

So far, the dephosphorization problem of non-national standard high-phosphorus and high-carbon ferromanganese produced by high-phosphorus manganese ore has not been completely solved

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