Micro-carbon ferromanganese alloy and preparation method thereof

Abstract

The application discloses a micro-carbon ferromanganese alloy and a preparation method thereof, and belongs to the technical field of ferroalloy preparation, and solves the problems of the micro-carbon ferromanganese alloy produced in the prior art, such as difficult control of carbon content, poor stability, complex production process, poor production environment, and high carbon emission. The micro-carbon ferromanganese alloy is prepared by using manganese-containing minerals as raw materials and adopting an electrothermal metal reduction method, the raw materials are heated and melted in an electric furnace, and then refining and heat preservation are carried out, and then pouring, demolding and slag-iron separation are carried out, so that the micro-carbon ferromanganese alloy with Mn greater than or equal to 75%, Si less than or equal to 1.0% and C less than or equal to 0.15% is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to a ferroalloy preparation technology, in particular to a micro-carbon ferromanganese alloy and a preparation method thereof. BACKGROUND

[0002] The ferromanganese alloy is an iron alloy composed of manganese and iron. The micro-carbon ferromanganese alloy is an alloy additive for smelting high-quality pure steel, which is suitable for low-carbon alloy structural steel and high-quality variety steel. Moreover, in the preparation process, the original steelmaking process does not need to be changed, the alloy can be optimized, the internal quality of the steel can be improved, the alloy cost of steelmaking can be reduced, and obvious economic benefits can be obtained.

[0003] The traditional production method of the micro-carbon ferromanganese alloy is a two-step method. In the first step, a silicon-manganese alloy is produced in a submerged arc furnace by using a carbothermic method. In the second step, a desiliconization method is used, that is, the silicon in the silicon-manganese alloy is oxidized by the oxides in the manganese ore to produce different grades of micro-carbon ferromanganese alloy. The desiliconization production method includes an electric silicon-thermal method and a ladle method. This process method is complex because it uses ore smelting and requires a submerged arc furnace and an electric furnace / ladle dual production. The manganese yield is low. In addition, to produce the micro-carbon ferromanganese alloy, the carbon content of the silicon-manganese alloy needs to be strictly controlled. The traditional two-step method has certain difficulties in controlling the carbon content of the silicon-manganese alloy because the raw materials are manganese ore, silica, coke, iron filings, etc., and the reducing agent is coke. The overall production process has high energy consumption, high carbon emission, and poor production environment. SUMMARY

[0004] In view of the above analysis, the present application aims to provide a micro-carbon ferromanganese alloy and a preparation method thereof, which solves the problems of the micro-carbon ferromanganese alloy produced by the prior art, such as difficult control of carbon content, poor stability, complex production process, poor production environment, and high carbon emission.

[0005] In one aspect, the present application provides a preparation method of a micro-carbon ferromanganese alloy, which uses manganese-containing minerals as raw materials and adopts an electric heating metal reduction method to produce the micro-carbon ferromanganese alloy in one step.

[0006] Further, the electric heating metal reduction method is a silicon-thermal reduction method, and the reducing agent is one or more of industrial silicon and industrial silicon waste residue.

[0007] Further, the manganese-containing minerals are manganese carbonate ore and / or semi-manganese carbonate ore, the mass percentage of Mn in the manganese-containing minerals is ≥25%, and the mass ratio of Mn / Fe is ≥7.

[0008] Further, the preparation method of the micro-carbon ferromanganese alloy includes the following steps:

[0009] Step 1: adding manganese-containing minerals, a reducing agent, and a slag-making agent into an electric furnace, and heating to melt the materials;

[0010] Step 2: the electric furnace is heated to 1350-1450 DEG C and kept for 30-60 minutes;

[0011] Step 3: after the keeping, pouring, cooling, demolding and slag-iron separation, the micro-carbon ferromanganese alloy is obtained.

[0012] Further, in step 1, the manganese-containing mineral, the reducing agent and the slagging agent are mixed and then added into the electric furnace, or the manganese-containing mineral and the slagging agent are mixed and added into the electric furnace first, and then the reducing agent is added after the material is melted.

[0013] Further, in step 3, the slag is poured out of the furnace, and the molten steel and the slag in the furnace are poured into the mold together; after the ingot mold is cooled, it is demolded, the slag-iron is separated, and the micro-carbon ferromanganese alloy is obtained.

[0014] Further, the slag basicity of the slag is 1.2-1.5.

[0015] Further, the composition of the slag is as follows in terms of mass percentage: Mn: 5-25%, SiO2: 20-30%, CaO: 25-40%, MgO: 1-8%; and the slag is partially or wholly replaced by the manganese-containing mineral to return to use.

[0016] On the other hand, the application also provides a micro-carbon ferromanganese alloy prepared by the above method.

[0017] Further, the composition of the micro-carbon ferromanganese alloy is as follows in terms of mass percentage: Mn≥75%, Si≤1.0%, C≤0.15%, S≤0.050%, P≤0.050%, and the balance is Fe.

[0018] Compared with the prior art, the application has the following beneficial effects:

[0019] 1) The method for producing the micro-carbon ferromanganese alloy by the electric heating metal reduction method provided by the application uses (semi-) manganese carbonate containing manganese material, uses one or more of industrial silicon and industrial silicon waste as the reducing agent, and the carbon in the (semi-) manganese carbonate containing manganese material exists in the form of manganese carbonate, which is decomposed in the form of CO2 gas during the heating process. The reducing agent, industrial silicon or industrial silicon waste, is a low-carbon substance, which can stably and effectively control the carbon content in the manganese-iron alloy.

[0020] 2) In the prior art, the traditional production method of micro-carbon ferromanganese alloy is a two-step method, the first step is to produce silicon-manganese alloy by carbon thermal reduction, and the second step is to remove silicon in a ladle (which can also be understood as silicon thermal reduction). First, silicon-manganese alloy is produced by carbon thermal reduction in an electric furnace, and the raw materials are manganese ore, silica, coke, iron filings, etc., and the reducing agent is coke. Using carbon as a reducing agent for carbon thermal reduction leads to uncontrollable carbon content in the produced silicon-manganese alloy. Then the low-carbon silicon-manganese alloy is mixed with manganese ore, and the silicon in the silicon-manganese alloy is oxidized by manganese in the manganese ore, thereby obtaining ferromanganese alloy. This process requires the silicon-manganese alloy as an intermediate alloy to have a low carbon content and a high silicon content, generally not less than 28%, in order to finally produce micro-carbon ferromanganese alloy that meets the requirements. The present application produces micro-carbon ferromanganese alloy by one-step method in an electric furnace, simplifying the process.

[0021] 3) Compared with the prior art of using coke and silicon-manganese alloy as a reducing agent, using carbon thermal reduction and electric furnace / ladle silicon removal to prepare ferromanganese alloy, the present application uses silicon thermal reduction to prepare ferromanganese alloy, which has the following advantages: one or more of industrial silicon and industrial silicon waste are selected as reducing agents, which will not introduce a large amount of carbon elements and other impurity elements, and can effectively control the carbon content in the ferromanganese alloy. The mass percentage of carbon in the micro-carbon ferromanganese alloy product prepared by the present application is ≤0.15%, which can meet the requirements of high-quality alloy steel production on carbon content.

[0022] 4) The method for producing micro-carbon ferromanganese alloy by electric heating metal reduction provided by the present application controls the highest temperature in the electric furnace to be 1350-1450 DEG C. This avoids incomplete reaction due to too low temperature, and avoids loss of a large amount of Mn elements due to too high temperature.

[0023] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and attained by the structure particularly pointed out in the written description. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present application will be specifically described below, and the embodiments are used to illustrate the principles of the present application, but are not used to limit the scope of the present application.

[0025] In the prior art, the conventional preparation method of micro-carbon ferromanganese alloy is a two-step method. First, silicon-manganese alloy is produced by carbon thermal reduction process in an electric arc furnace, and the raw materials are manganese ore, silica, coke, iron filings, etc., and the reducing agent is coke. The content of impurity elements such as silica, coke and iron filings in the raw materials is relatively high, and the carbon content of the prepared silicon-manganese alloy is uncontrollable. The low-carbon high-silicon silicon-manganese alloy is mixed with manganese ore, the silicon in the silicon-manganese alloy is oxidized by manganese in the manganese ore to complete desiliconization, thereby obtaining manganese-iron alloy of different grades. Since the ore smelting is used in this process, and the electric arc furnace and the electric furnace / ladle double production are required, the process is complex. At the same time, in order to obtain the required micro-carbon ferromanganese alloy, the silicon-manganese alloy used as an intermediate alloy has a relatively low carbon content and a relatively high silicon content, and the silicon content is generally not less than 28%, so that the required micro-carbon ferromanganese alloy can be finally prepared. The overall production process has high energy consumption, high carbon emission and poor production environment.

[0026] The present application provides a preparation method of micro-carbon ferromanganese alloy, which uses manganese-containing minerals as raw materials and adopts electric heating metal reduction method to prepare micro-carbon ferromanganese alloy in one step. After the raw materials are heated, melted, refined and heat preserved in an electric furnace, they are poured, demolded and slag-iron separated to obtain micro-carbon ferromanganese alloy with Mn≥75%, Si≤1.0% and C≤0.15%.

[0027] Compared with the prior art, the present application adopts electric heating metal reduction to prepare micro-carbon ferromanganese alloy in one step, simplifies the process, uses (semi-) manganese carbonate ore as raw material, and the carbon in the manganese-containing material of (semi-) manganese carbonate ore exists in the form of manganese carbonate, which is decomposed in the form of CO2 gas during the heating process. The reducing agent used is low-carbon industrial silicon or industrial silicon waste, which does not introduce a large amount of carbon elements and other impurity elements, and can stably and effectively control the carbon content in the manganese-iron alloy. The mass percentage of carbon in the micro-carbon ferromanganese alloy product prepared by the present application is ≤0.15%, which can meet the requirements of high-quality alloy steel production for carbon content, and solves the problems of the micro-carbon ferromanganese alloy produced by the prior art, such as uncontrollable carbon content, poor stability, complex production process, poor production environment and high carbon emission.

[0028] Specifically, the manganese-containing minerals are manganese carbonate ore and / or semi-manganese carbonate ore, the mass percentage of Mn in the manganese-containing minerals is ≥25%, and the mass ratio of Mn / Fe is ≥7, which meets this ratio relationship and can ensure that the Mn content of the finally prepared micro-carbon ferromanganese alloy meets the standard, and the mass percentage of Mn is ≥75%. If the Mn / Fe ratio is too low, the Mn content of the obtained micro-carbon ferromanganese alloy will be low.

[0029] It should be noted that in the prior art, the direct production raw material of micro-carbon ferromanganese alloy is silicon-manganese alloy and manganese-containing mineral, wherein the silicon-manganese alloy belongs to an intermediate alloy, and in order to obtain micro-carbon ferromanganese, it is generally required that the silicon content of the silicon-manganese alloy is not less than 28%, which is difficult to produce and has poor production stability. (Semi-) manganese carbonate is mainly used for producing manganese-based alloy, but is not used as a raw material for directly producing micro-carbon ferromanganese. In the present application, (semi-) manganese carbonate ore is used as a direct raw material, and micro-carbon ferromanganese can be produced by one-step method without producing silicon-manganese alloy and then producing micro-carbon ferromanganese. The carbon element in manganese carbonate ore and / or semi-manganese carbonate ore is decomposed in the form of CO2 at high temperature, so as to ensure that the carbon content of the obtained alloy does not exceed the standard.

[0030] Specifically, the electrothermal metal reduction method of the present application is silicon-thermal reduction method, and the reducing agent is one or more of industrial silicon or industrial silicon waste. Compared with the prior art which uses coke and silicon-manganese alloy as reducing agents to easily introduce impurity elements and cause the carbon content of the prepared silicon-manganese alloy to be uncontrollable, the industrial silicon or industrial silicon waste is a low-carbon substance, which will not introduce a large amount of carbon elements and other impurity elements, can stably and effectively control the carbon content in the manganese-iron alloy, and can fully utilize metallurgical waste to reduce costs and realize comprehensive utilization of resources.

[0031] Specifically, a slag former needs to be added in the present application, and the slag former is lime, which mainly has two functions: one is to remove sulfur and phosphorus, and the other is to promote the forward and full progress of the reduction reaction of manganese ore and improve the recovery rate of manganese.

[0032] Specifically, the above preparation method comprises the following steps:

[0033] Step 1: adding manganese-containing mineral, reducing agent, and slag former into an electric furnace, and heating to melt the materials;

[0034] Step 2: heating the electric furnace to 1350-1450 DEG C for heat preservation, and the heat preservation time is 30-60 min;

[0035] Step 3: after the heat preservation is completed, pouring, cooling, demolding, and slag-iron separation are performed to obtain micro-carbon ferromanganese alloy.

[0036] In the present application, an electric furnace (such as a high-temperature electric heating furnace or a microwave oven) is used, and there is no electrode (such as a carbon material) in the electric furnace (such as a high-temperature electric heating furnace or a microwave oven), which can effectively avoid the carbon thermal reduction reaction of the electrode (carbon material), that is, the reaction of the electrode made of carbon material with manganese oxide in the manganese-containing mineral to generate manganese carbide impurities, which is difficult to remove and pollutes the manganese-iron alloy.

[0037] In step 1, the manganese-containing mineral, reducing agent, and slag former are added into the furnace, and in the specific implementation, the manganese-containing mineral, reducing agent, and slag former can be mixed and then added into the furnace, or the manganese-containing mineral and slag former can be mixed and added into the electric furnace, and then the reducing agent is added after the materials are melted.

[0038] The adding amount of the manganese-containing mineral, the reducing agent and the slagging agent is calculated according to the composition requirement of the target manganese-iron alloy product. If the manganese content in the target manganese-iron alloy is high, the manganese-containing mineral with high manganese content can be added more; if the iron content in the target manganese-iron alloy is high, the manganese-containing mineral with low manganese content can be added more. The manganese content and the iron content in the final manganese-iron alloy product are mainly determined by the manganese-iron ratio in the manganese-containing mineral raw material and the degree of silicon thermal reduction, and the more sufficient the silicon thermal reduction is, the higher the manganese content in the final product is. At present, in the small-scale test, the silicon matching coefficient can be 0.9-1.2, among which the silicon matching coefficient 1.0 has the best effect, one is that the silicon content of the prepared alloy does not exceed the standard, and two is that under the condition that the silicon does not exceed the standard, the element recovery rate is higher.

[0039] In order to promote the forward progress of the silicon thermal reduction reaction and improve the manganese content of the manganese-iron alloy, the slag basicity is controlled to be 1.2-1.5, that is, the mass ratio of CaO to SiO2 in the slag is 1.2-1.5, and the slagging agent lime needs to be added, and the specific adding amount is calculated according to the slag basicity. The specific method is as follows: first, the amount of SiO2 generated by the silicon thermal reduction reaction is calculated theoretically, and the amount of CaO and SiO2 in the manganese-containing mineral is combined to calculate the mass of CaO that needs to be added according to the basicity, and then the adding amount of lime is calculated, that is, the adding amount of the slagging agent is obtained.

[0040] In the above step 2, the highest temperature in the electric furnace is controlled to be 1350℃-1450℃. In the refining and heat preservation process, the temperature control is closely related to the slag basicity. If the slag basicity is high, the melting point of the slag is high, and the function of the slag must be fully played under a certain high temperature. At the same time, the higher the temperature is, the more serious the volatilization of manganese elements is. Considering comprehensively, in the refining and heat preservation process of the present application, the highest temperature in the electric furnace is controlled to be 1350℃-1450℃. If the temperature is too low, the reaction is not complete; if the temperature is too high, a large amount of manganese elements will be lost.

[0041] The reaction principle of the above preparation method is electric heating metal thermal reduction, specifically silicon thermal reduction.

[0042] The reducing agent used is one or more of industrial silicon and industrial silicon waste, and the reaction principle is silicon thermal reduction. The smelting chemical reaction of silicon thermal reduction is as follows:

[0043] MnCO3=MnO+CO2

[0044] 2MnO+Si=2Mn+SiO2

[0045] 2Fe2O3+3Si=4Fe+3SiO2

[0046] The reaction (silicon thermal reduction) is faster at greater than 1000℃, and the amount of each material is adjusted according to the composition requirements of the target ferromanganese product. During smelting, 60-90% of the Mn enters the micro-carbon ferromanganese alloy, 2-8% of the Mn enters the fume, and the rest enters the manganese-containing slag.

[0047] In step 3, the slag is poured out of the furnace and cast, the molten steel and slag in the furnace are poured into the mold together; after the ingot mold is cooled, it is demolded and the slag and iron are separated, to obtain the micro-carbon ferromanganese alloy. The composition of the slag is: Mn: 5-25%, SiO2: 20-30%, CaO: 25-40%, MgO: 1-8% by mass; and part or all of the slag is returned for use to replace the manganese-containing mineral.

[0048] The application also provides a micro-carbon ferromanganese alloy prepared by the above method.

[0049] Specifically, the composition of the micro-carbon ferromanganese alloy is: Mn≥75%, Si≤1.0%, C≤0.15%, S≤0.050%, P≤0.050%, and the balance is Fe by mass.

[0050] Example 1

[0051] The method for producing the micro-carbon ferromanganese alloy by the electrothermal metal reduction method provided in this example is carried out in a high-temperature electric heating furnace.

[0052] The raw materials used are semi-carbonate manganese ore, industrial silicon and lime. The composition of the manganese ore is: Mn: 38.05%, Fe: 4.36%, SiO2: 5.41%, P: 0.025%, CaO: 13.74%, MgO: 1.72%, Al2O3: 0.86%, H2O: 0.53%. The Si content in the industrial silicon is 99.6%. The CaO content in the lime is 85%. The amount of each material is: manganese ore 50 kg, industrial silicon 6.75 kg, and lime 15 kg.

[0053] The smelting includes the following steps:

[0054] Step 1: First, the raw materials manganese ore 50 kg, industrial silicon 6.75 kg, and lime 15 kg are crushed to a powder (> 50 mesh), and the three powders are mixed uniformly and placed in an electric furnace, and the material is melted by sending electricity to heat;

[0055] Step 2: The electric furnace is heated to 1380℃ and kept for 40 minutes.

[0056] Step 3: After the holding is completed, the slag is poured out of the furnace and cast, the molten steel and slag in the furnace are poured into the mold together, the ingot mold is cooled and demolded, the slag and iron are separated, and the micro-carbon ferromanganese alloy is obtained.

[0057] The micro-carbon ferromanganese alloy product obtained after analysis has the following composition: Mn: 76.16%, Si: 0.31%, C: 0.043%, S: 0.006%, and P: 0.01%.

[0058] Example 2

[0059] The method for producing micro-carbon ferromanganese alloy by electrothermal metal reduction provided in this example is performed in a high-temperature electric heating furnace.

[0060] The raw materials used are semi-carbonate manganese ore, industrial silicon powder, and lime. The manganese ore has the following composition: Mn: 38.05%, Fe: 4.36%, SiO2: 5.41%, P: 0.025%, CaO: 13.74%, MgO: 1.72%, Al2O3: 0.86%, and H2O: 0.53%. The industrial silicon powder has Si: 99.7%. The lime has CaO: 85%. The amounts of the materials used are as follows: manganese ore 50 kg, industrial silicon powder 6.8 kg, and lime 15 kg.

[0061] The smelting includes the following steps:

[0062] Step 1: First, the raw materials manganese ore 50 kg, industrial silicon powder 6.8 kg, and lime 15 kg are crushed into powder (> 50 mesh), and the three powders are mixed uniformly and placed in an electric furnace, and the material is melted by heating.

[0063] Step 2: The electric furnace is heated to 1350°C and kept for 60 minutes.

[0064] Step 3: After the holding is completed, the slag is taken out of the furnace and poured, and the molten steel and slag in the furnace are poured into a mold together, the mold is cooled and demolded, the slag and iron are separated, and the micro-carbon ferromanganese alloy is obtained.

[0065] The micro-carbon ferromanganese alloy product obtained after analysis has the following composition: Mn: 78.52%, Si: 0.81%, C: 0.047%, S: 0.008%, and P: 0.01%.

[0066] Example 3

[0067] The method for producing micro-carbon ferromanganese alloy by electrothermal metal reduction provided in this example is performed in a microwave oven.

[0068] The raw materials used are semi-carbonate manganese ore, industrial silicon, and lime. The manganese ore has the following composition: Mn: 38.05%, Fe: 4.36%, SiO2: 5.41%, P: 0.025%, CaO: 13.74%, MgO: 1.72%, Al2O3: 0.86%, and H2O: 0.53%. The industrial silicon has Si: 99.6%. The lime has CaO: 85%. The amounts of the materials used are as follows: manganese ore 50 kg, industrial silicon 6.75 kg, and lime 15 kg.

[0069] Smelting includes the following steps:

[0070] Step 1: First, the raw material manganese ore 50 kg, industrial silicon 6.75 kg, lime 15 kg are crushed to powder (> 50 mesh), the three powders are mixed uniformly, and then placed in an electric furnace, and the material is melted by heating;

[0071] Step 2: The electric furnace is heated to 1350℃ and kept for 30 minutes;

[0072] Step 3: After the holding time is over, the slag is taken out of the furnace for pouring, the molten steel and slag in the furnace are poured into a mold together, the mold is cooled and demolded, and the slag and iron are separated to obtain micro-carbon ferromanganese alloy.

[0073] Analysis shows that the composition of the obtained micro-carbon ferromanganese alloy product is: Mn: 79.20%, Si: 0.41%, C: 0.045%, S: 0.008%, P: 0.01%.

[0074] Example 4

[0075] The method for producing micro-carbon ferromanganese alloy by electric heating metal reduction provided in this example is carried out in a high-temperature electric heating furnace.

[0076] The raw materials used are semi-carbonate manganese ore, industrial silicon and lime. The composition of the manganese ore is: Mn: 38.05%, Fe: 4.36%, SiO2: 5.41%, P: 0.025%, CaO: 13.74%, MgO: 1.72%, Al2O3: 0.86%, H2O: 0.53%. The Si content in industrial silicon is 99.6%. The CaO content in lime is 85%. The amount of each material is: manganese ore 50 kg, industrial silicon 6.75 kg, and lime 20 kg.

[0077] Smelting includes the following steps:

[0078] Step 1: First, the raw material manganese ore 50 kg, industrial silicon 6.75 kg, lime 20 kg are crushed to powder (> 50 mesh), the three powders are mixed uniformly, and then placed in an electric furnace, and the material is melted by heating;

[0079] Step 2: The electric furnace is heated to 1450℃ and kept for 60 minutes;

[0080] Step 3: After the holding time is over, the slag is taken out of the furnace for pouring, the molten steel and slag in the furnace are poured into a mold together, the mold is cooled and demolded, and the slag and iron are separated to obtain micro-carbon ferromanganese alloy.

[0081] Analysis shows that the composition of the obtained micro-carbon ferromanganese alloy product is: Mn: 80.20%, Si: 0.51%, C: 0.035%, S: 0.007%, P: 0.01%.

[0082] Example 5

[0083] The method for producing micro-carbon ferromanganese alloy by electrothermal metal reduction provided in this example is performed in a microwave oven.

[0084] The raw materials used are semi-carbonate manganese ore, industrial silicon and lime. The composition of the manganese ore is: Mn: 38.05%, Fe: 4.36%, SiO2: 5.41%, P: 0.025%, CaO: 13.74%, MgO: 1.72%, Al2O3: 0.86%, H2O: 0.53%. The Si content in the industrial silicon is 99.6%. The CaO content in the lime is 85%. The amounts of the materials used are: manganese ore 50 kg, industrial silicon 6.75 kg, and lime 20 kg.

[0085] The smelting includes the following steps:

[0086] Step 1: First, the raw materials manganese ore 50 kg, industrial silicon 6.75 kg, and lime 20 kg are crushed to a powder (> 50 mesh), and the three powders are mixed uniformly and placed in an electric furnace, and the material is melted by heating.

[0087] Step 2: The electric furnace is heated to 1450°C and held for 40 minutes.

[0088] Step 3: After the holding is completed, the slag is poured out of the furnace and cast, and the molten steel and slag in the furnace are cast together into a mold, the mold is cooled and demolded, the slag and iron are separated, and the micro-carbon ferromanganese alloy is obtained.

[0089] Analysis shows that the composition of the obtained micro-carbon ferromanganese alloy product is: Mn: 81.20%, Si: 0.61%, C: 0.055%, S: 0.006%, P: 0.02%.

[0090] Example 6

[0091] The method for producing micro-carbon ferromanganese alloy by electrothermal metal reduction provided in this example is performed in a high-temperature electric heating furnace.

[0092] The raw materials used are semi-carbonate manganese ore, industrial silicon and lime. The composition of the manganese ore is: Mn: 29.8%, Fe: 3.6%, SiO2: 5.3%, P: 0.04%, CaO: 14.1%, MgO: 2.1%, Al2O3: 1.1%, H2O: 1.5%. The Si content in the industrial silicon is 99.6%. The CaO content in the lime is 85%. The amounts of the materials used are: manganese ore 50 kg, industrial silicon 4.5 kg, and lime 10 kg.

[0093] The smelting includes the following steps:

[0094] Step 1: First, the raw materials manganese ore 50 kg, industrial silicon 4.5 kg, lime 10 kg are crushed to powder (> 50 mesh), the three powders are mixed uniformly, and then placed in an electric furnace, and the material is melted by heating;

[0095] Step 2: The electric furnace is heated to 1390℃ and kept for 40 minutes.

[0096] Step 3: After the end of the holding, the slag is taken out of the furnace and poured, the molten steel and slag in the furnace are poured into the mold together, the ingot mold is cooled and demolded, and the slag and iron are separated to obtain the micro-carbon ferromanganese alloy.

[0097] The obtained micro-carbon ferromanganese alloy product has the following composition: Mn: 76.8%, Si: 0.48%, C: 0.07%, S: 0.005%, P: 0.03%.

[0098] Example 7

[0099] The method for producing the micro-carbon ferromanganese alloy by the electric heating metal reduction method provided in the example is carried out in a high-temperature electric heating furnace.

[0100] The raw materials used are semi-carbonate manganese ore, industrial silicon and lime. The composition of the manganese ore is: Mn: 46.5%, Fe: 3.7%, SiO2: 6.2%, P: 0.03%, CaO: 13.5%, MgO: 2.1%, Al2O3: 0.9%, H2O: 1.5%. The Si in the industrial silicon is 99.6%. The CaO in the lime is 85%. The amount of each material is: manganese ore 50 kg, industrial silicon 6.6 kg, lime 28.5 kg.

[0101] The smelting includes the following steps:

[0102] Step 1: First, the raw materials manganese ore 50 kg, industrial silicon 6.6 kg, lime 28.5 kg are crushed to powder (> 50 mesh), the three powders are mixed uniformly, and then placed in an electric furnace, and the material is melted by heating;

[0103] Step 2: The electric furnace is heated to 1450℃ and kept for 40 minutes.

[0104] Step 3: After the end of the holding, the slag is taken out of the furnace and poured, the molten steel and slag in the furnace are poured into the mold together, the ingot mold is cooled and demolded, and the slag and iron are separated to obtain the micro-carbon ferromanganese alloy.

[0105] The obtained micro-carbon ferromanganese alloy product has the following composition: Mn: 79.2%, Si: 0.49%, C: 0.07%, S: 0.005%, P: 0.04%.

[0106] Example 8

[0107] The method for producing micro-carbon ferromanganese alloy by electric heating metal reduction method provided in the embodiment is performed in a microwave oven.

[0108] The raw materials used are manganese carbonate ore, industrial silicon and lime. The composition of the manganese ore is: Mn: 42%, Fe: 2.9%, SiO2: 7.2%, P: 0.05%, CaO: 17%, MgO: 1.8%, Al2O3: 1.1%, H2O: 1.5%. The Si content in the industrial silicon is 99.6%. The CaO content in the lime is 85%. The amounts of the materials are as follows: 50 kg of manganese ore, 6.5 kg of industrial silicon and 18 kg of lime.

[0109] The smelting includes the following steps:

[0110] Step 1: First, the raw materials, i.e., 50 kg of manganese ore, 6.5 kg of industrial silicon and 18 kg of lime, are crushed into powder (> 50 mesh), and then the three kinds of powders are uniformly mixed and placed in an electric furnace, and power is supplied to heat the materials to melt them;

[0111] Step 2: The electric furnace is heated to 1450°C and kept at this temperature for 40 minutes.

[0112] Step 3: After the heat preservation is completed, the slag is taken out of the furnace and poured, and the molten steel and slag in the furnace are poured into a casting mold together, the ingot mold is cooled and demolded, and the slag and iron are separated, thereby obtaining the micro-carbon ferromanganese alloy.

[0113] Analysis shows that the composition of the obtained micro-carbon ferromanganese alloy product is: Mn: 82.1%, Si: 0.98%, C: 0.06%, S: 0.003%, P: 0.03%.

[0114] Example 9

[0115] The method for producing micro-carbon ferromanganese alloy by electric heating metal reduction method provided in the embodiment is performed in a high-temperature electric heating furnace.

[0116] The raw materials used are manganese carbonate ore, industrial silicon and lime. The composition of the manganese ore is: Mn: 42%, Fe: 2.9%, SiO2: 7.2%, P: 0.05%, CaO: 17%, MgO: 1.8%, Al2O3: 1.1%, H2O: 1.5%. The Si content in the industrial silicon is 99.6%. The CaO content in the lime is 85%. The amounts of the materials are as follows: 50 kg of manganese ore, 6.5 kg of industrial silicon and 18 kg of lime.

[0117] The smelting includes the following steps:

[0118] Step 1: First, the raw materials, i.e., 50 kg of manganese ore, 6.5 kg of industrial silicon and 18 kg of lime, are crushed into powder (> 50 mesh), and then the three kinds of powders are uniformly mixed and placed in an electric furnace, and power is supplied to heat the materials to melt them;

[0119] Step 2: the electric furnace is heated to 1400 DEG C and kept for 60 min;

[0120] Step 3: after the keeping, the furnace is taken out with slag and poured into a mold, the mold is cooled and demolded, the slag and iron are separated, and the micro-carbon ferromanganese alloy is obtained.

[0121] Through analysis, the micro-carbon ferromanganese alloy product obtained has the following components: Mn: 83.4%, Si: 0.49%, C: 0.05%, S: 0.006%, and P: 0.03%.

[0122] The above merely describes the preferred specific embodiments of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements within the technical scope disclosed by the present application can be easily thought of by those skilled in the art, and should be covered within the protection scope of the present application.

Claims

1. A method for producing micro-carbon ferromanganese alloy, characterized by, The micro-carbon ferromanganese alloy is prepared by using manganese-containing minerals as raw materials and adopting an electric metal reduction method; The electric metal reduction method is a silicon-thermal reduction method, and comprises the following steps: Step 1: manganese-containing minerals, a reducing agent, and a slagging agent are added into an electric furnace, and the materials are melted by heating; Step 2: the electric furnace is heated to 1350-1450 DEG C and kept for 30-60 minutes; Step 3: after the keeping, the materials are poured, cooled, demolded, and slag-iron separated to obtain the micro-carbon ferromanganese alloy; The manganese-containing minerals are manganese carbonate minerals and / or semi-manganese carbonate minerals, the mass percentage of Mn in the manganese-containing minerals is greater than or equal to 25%, and the mass ratio of Mn / Fe is greater than or equal to 7; The reducing agent is one or more of industrial silicon and industrial silicon slag; The slagging agent is lime; In step 3, the materials are poured out of the furnace with slag, the molten steel and the slag in the furnace are poured into a mold, the mold is demolded after cooling, the slag-iron is separated, and the micro-carbon ferromanganese alloy is obtained; The slag has a slag basicity of 1.2-1.5; In the micro-carbon ferromanganese alloy, the mass percentage of carbon is less than or equal to 0.15%.

2. The production method according to claim 1, characterized by, In step 1, the manganese-containing minerals, the reducing agent, and the slagging agent are mixed and then added into the electric furnace, or the manganese-containing minerals and the slagging agent are mixed and added into the electric furnace, and then the reducing agent is added after the materials are melted.

3. The preparation method according to claim 2, characterized in that, The composition of the slag is as follows in terms of mass percentage: Mn: 5-25%, SiO2: 20-30%, CaO: 25-40%, and MgO: 1-8%; and the slag is partially or totally replaced by the manganese-containing minerals and returned for use.

4. A micro-carbon ferromanganese alloy, characterized by, The micro-carbon ferromanganese alloy is prepared by using the preparation method of any one of claims 1-3.

5. The micro-carbon ferromanganese alloy according to claim 4, characterized in that, The composition of the micro-carbon ferromanganese alloy is as follows in terms of mass percentage: Mn: greater than or equal to 75%, Si: less than or equal to 1.0%, C: less than or equal to 0.15%, S: less than or equal to 0.050%, P: less than or equal to 0.050%, and the balance being Fe.