JPS6348941B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing a high manganese iron alloy from manganese ore at low cost and with a high manganese yield, without relying on electric power.

(Prior Art) Conventionally, high manganese iron alloys, such as ferromanganese containing 60% or more of Mn, are produced by processing manganese ore and/or its pre-reduced product together with a carbonaceous reducing agent such as coke and a slag forming agent in an electric furnace. It has been manufactured by heating, melting, and reducing.

(Problem to be Solved by the Invention) However, the power used in such a method is
It is approximately 2,200kWH per 1 ton, which is a major factor in rising costs in Japan, where the unit price of electricity is high, and it goes without saying that energy efficiency from the perspective of primary energy is extremely low. It would be extremely advantageous economically if this energy source could be replaced with primary energy (particularly the combustion energy of coal-based solid carbonaceous materials such as coal and coke).

Furthermore, in the production of high-carbon ferromanganese using an electric furnace, the manganese content in the slag discharged from the electric furnace is usually as high as 20 to 30%, and the yield of manganese is low.

On the other hand, the method of using a blast furnace has recently been reconsidered as a method of producing high-carbon ferromanganese without using electricity, but it is difficult to adjust the rate of descent of the melt and the rate of reduction of manganese oxide, and Since it is impossible to utilize the combustion heat from the combustion of CO gas generated by the reaction into CO ₂ , a large amount of carbon material is required as a heat source, and of course a large amount of CO gas is generated. Large energy loss.

In view of these circumstances, the present invention utilizes cheap primary energy (especially the combustion energy of coal-based solid carbonaceous materials such as coal and coke) as a heating heat source, has high energy efficiency, has a high yield of manganese, and has an extremely high yield of manganese. The object of the present invention is to provide a method for producing a high manganese iron alloy using a simple operation method.

(Means for Solving the Problems) The object of the present invention is to provide a converter type reaction vessel in which oxygen or a gas containing oxygen can be blown from the top to the bottom. A carbonaceous material and a slag-forming agent are charged, and oxygen or a gas containing oxygen is supplied into the converter-type reaction vessel to burn the solid carbonaceous material and melt-reduce the charged raw material, thereby producing a slag-forming material. This is achieved by a method for producing a high manganese iron alloy, which is characterized by removing the high manganese iron alloy and slag.

That is, the present invention strongly stirs the molten high manganese iron alloy and molten slag remaining in the reaction vessel by gas blown into the furnace of the reaction vessel from a bottom blowing nozzle provided at the bottom of the reaction vessel. At the same time, manganese ore and/or its pre-reduced product, solid carbonaceous material (functioning as a heat source and reducing agent), and slag-forming agent are introduced, and oxygen or oxygen-containing gas is introduced into the furnace of the reaction vessel using a lance pipe. The method consists of heating, melting and reducing the raw material by blowing into the raw material.

(Action of the Invention) As the top-bottom blown converter type reaction vessel used in the present invention, it is desirable to use a top-bottom blown converter for steelmaking. At the bottom of the reaction vessel one or more nozzles are arranged centrally or concentrically in the bottom. The number of nozzles is determined by the capacity of the reaction vessel and the amount of blown gas, but one nozzle is sufficient if the capacity is about 10 tons or less. The nozzle is a double tube, with a structure that allows oxygen or oxygen-containing gas to be blown into the inner tube and cooling gas from the outer tube. Propane is suitable as the cooling gas, but N ₂ , CO ₂ ,
Ar can also be used.

Next, the raw material, manganese ore, can be dried raw ore, or a pre-reduced product or sintered ore of manganese ore that has been pretreated using pretreatment equipment such as a rotary kiln, fluidized ring furnace, or sintering machine. can be used alone or in combination.

As the solid carbonaceous material, coal-based solid carbonaceous materials such as coal and coke are used, and as the slag forming agent, lime, limestone, etc. are mainly used, and all are kept in a dry state.

When charging each of these raw materials into the top-bottom blown converter reactor, if the raw materials have been pretreated, they can be directly charged into the reactor without being cooled after the pretreatment. Since sensible heat can be used, it is advantageous in terms of saving total energy. For example, when pre-reducing manganese ore in a rotary kiln, manganese ore and carbonaceous material are charged into the kiln and heated and reduced at about 1000°C.
The kiln is directly connected to the top-bottom blowing converter type reaction vessel, and raw materials at a temperature of about 1000°C can be directly charged.

Next, the mode of operation and its effect according to the present invention will be explained.

A certain amount of high manganese iron alloy molten metal and slag are always left in the top-bottom blowing converter type reaction vessel, and oxygen or oxygen-containing gas is supplied from the inner pipe of the bottom-blowing nozzle, and propane, _N2 is supplied from the outer pipe. , CO ₂ , or Ar are blown into the furnace. First, a solid carbonaceous material is charged into the furnace, and oxygen or a gas containing oxygen is started to be blown in from the top blowing lance. In this case, the ratio of top-blown and bottom-blown oxygen is preferably 97:3 to 80:20, for example.

Next, manganese ore and/or its prereduced product, solid carbonaceous material, and slag-forming agent are charged into the reaction vessel. In this case, these raw materials may be charged as a mixed raw material or separately.

The height of the top blowing lance pipe and the amount of blown gas are adjusted so that the temperature of the high manganese iron alloy molten metal in the reaction vessel does not exceed 1600°C.

In this way, after a certain amount of blown acid and the charging of raw materials have been completed, manganese oxides in the molten raw materials are reduced by excess carbon. For this purpose, after charging the raw materials, acid is blown for a certain period of time, and the produced high manganese iron alloy molten metal and molten slag are taken out.

(Effect of the invention) In the above-described operation, CO gas generated by the combustion of solid carbonaceous materials and the reduction of manganese oxides and iron oxides by solid carbonaceous materials is converted into 2CO+O ₂ →2CO ₂ by oxygen by top blowing. A reaction occurs and the heat generated is used as a heating source.
Compared to a method using a coke packed bed reactor, such as a blast furnace, which utilizes only the reaction of 2C + O ₂ → 2CO, this method has the effect of significantly increasing the amount of heat generated per unit amount of solid carbonaceous material.

A further advantage of top-bottom blowing is that heating, melting, and reduction reactions can be easily adjusted by adjusting the amounts of both blown gases. In addition, the reduction reaction rate is significantly increased by strong stirring using bottom-blown gas, and the operation itself can be performed at a relatively low temperature, which is extremely advantageous in terms of the life of the lining of the reaction vessel and equipment.

Furthermore, the effect of bottom blowing is to promote the escape of the reaction product gas from the molten metal, resulting in slag forming and
Fluttering is suppressed, and there is no local heating of the raw material or molten metal, making the temperature uniform.
This makes it possible to significantly reduce the evaporation loss of manganese due to local heating, which was thought to be a drawback when producing manganese alloys by the conventional oxygen blowing method, and also allows for corrosion of the lining of the reaction vessel. is significantly reduced.

In the method of the present invention, since a large amount of molten slag is generated at the top of the high manganese iron alloy molten metal, the final In this method, the manganese content in the slag can be reduced to 10% or less, which is significantly lower than in the case of electric furnaces (20-30%).This, together with the reduction in evaporation loss mentioned above, can reduce the manganese yield. can be significantly improved.

Example 1 When pre-reduced manganese ore was used: As a reaction vessel, a 5-ton small converter was used with a double tube nozzle attached as a bottom blowing nozzle at the center at the bottom.

The manganese ore used is made by heating and reducing two brands of lumpy manganese ore of different grades at 1000℃ with coke as a reducing agent in a separate rotary kiln. At this time, the oxidation degree of manganese (ratio of manganese to total manganese converted to tetravalent manganese) was 5%. This pre-reduced manganese ore was transported and stored in a sealed container in order to be charged into the reaction container as a hot ore.

One ton of high carbon ferromanganese melted in a separate melting furnace was injected into the reaction vessel in advance, and a 2 m/m thick molten silico-manganese slag was prepared on the surface thereof.

At this time, oxygen was blown through the inner tube at a pressure of 3 kg/cm ² from the bottom blowing nozzle, and argon was blown as a cooling gas through the outer tube at a rate of 200/min.

First, 30 kg of dried coke was placed in the reaction vessel.
5N with a pressure of 5Kg/cm ² from the top blowing lance.
Oxygen was blown at m ³ /min.

After ignition was confirmed, 420 kg of the pre-reduced manganese ore was continuously charged, and 200 kg of coke and 30 kg of raw coal were intermittently charged for 40 minutes. During this time, the height of the top blowing lance and the amount of blown acid were adjusted as needed so that the molten metal temperature did not exceed 1600°C.

After charging the raw materials, in order to recover the manganese in the slag, 10 kg of coke was added, the lance position was raised, and the blowing acid conditions were changed to 4 kg/cm ² and 4 Nm ³ /min.
Acid blowing was carried out for a minute.

After the acid blowing was stopped, the metal and slag were poured onto the product floor, and after aging, the metal and slag were separated, weighed, and analyzed.

The weight of the metal obtained is 1240Kg, and the slag is 190Kg.
It was Kg. Considering the influence of the metal and slag charged in advance, the analysis values show that the metal components obtained are Mn 74.2%, Si 1.0%, C 7.1%, P 0.15%, and the yield of manganese is was 92%, and manganese in the slag was 7.8%.

Incidentally, the loss of manganese due to evaporation was surprisingly small, at about 3%.

Example 2 Using manganese ore without pre-reduction: As in Example 1, manganese ore was used instead of pre-reduced manganese ore.

In particular, the operating conditions were the same as in Example 1, only the acid blowing time was slightly longer at 37 minutes. The amount of manganese ore used was the same as in Example 1, but 40 kg more coke was added than in Example 1.

There were no significant differences in the weight and quality of the obtained metal compared to those in Example 1.

Claims (1)

[Claims] 1. A converter-type reaction vessel capable of blowing oxygen or oxygen-containing gas from the top to the bottom is charged with either or both of manganese ore and its pre-reduced product, a solid carbonaceous material, and a slag-forming agent, and the converter is heated. The high manganese iron alloy and slag produced in this manner are characterized by supplying oxygen or a gas containing oxygen into a type reaction vessel to burn the solid carbonaceous material to melt and reduce the charged raw material, and to take out the high manganese iron alloy and slag produced in this way. Method for manufacturing manganese iron alloy.