阅读说明：本技术 一种锰硅合金冶炼装置和方法 (Manganese-silicon alloy smelting device and method ) 是由 于洪翔 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种锰硅合金冶炼装置,包括干式球磨机、润磨机、圆盘造球机、链篦机、回转窑、和直流矿热炉。本发明还提供了一种锰硅合金冶炼方法,包括：将锰粉矿、硅石、焦炭、白云石与膨润土按预定比例进行配料,得到混合料；混合料依次经过干式球磨机和润磨机研磨之后送入圆盘造球机进行造球,得到球团；球团经过链篦机干燥、预热之后进入回转窑进行预还原；预还原物料送入直流矿热炉进行冶炼。本发明能够将冶炼电耗降低至3100kWh/t,并实现锰粉矿的完全利用,从而降低了生产成本。(The invention discloses a manganese-silicon alloy smelting device which comprises a dry ball mill, a wet mill, a disc pelletizer, a chain grate machine, a rotary kiln and a direct-current submerged arc furnace. The invention also provides a manganese-silicon alloy smelting method, which comprises the following steps: mixing manganese powder ore, silica, coke, dolomite and bentonite according to a predetermined proportion to obtain a mixture; the mixture is ground by a dry ball mill and a wet mill in sequence and then sent to a disc pelletizer for pelletizing to obtain pellets; the pellets are dried and preheated by a chain grate and then enter a rotary kiln for pre-reduction; and (4) feeding the pre-reduced material into a direct-current submerged arc furnace for smelting. The invention can reduce the smelting power consumption to 3100kWh/t and realize the complete utilization of the manganese fine ore, thereby reducing the production cost.)

1. A manganese-silicon alloy smelting device comprises a dry ball mill, a wet mill, a disk pelletizer, a grate, a rotary kiln and a submerged arc furnace, and is characterized in that the submerged arc furnace is a direct-current submerged arc furnace; the mixture is sequentially processed by a dry ball mill, a wet mill, a disc pelletizer, a chain grate machine, a rotary kiln and a direct-current submerged arc furnace to obtain the manganese-silicon alloy.

2. The mn-si alloy smelting apparatus according to claim 1, wherein the dc submerged arc furnace includes: the device comprises a furnace body, a furnace cover, an electrode column system, a feeding system, a flue gas leading-out system, a power supply system, a cooling water system and a hydraulic system; the furnace body consists of a furnace bottom, a furnace shell and a furnace lining which are arranged from outside to inside in sequence and is used for accommodating furnace burden; the furnace cover is arranged above the furnace body and used for ensuring the sealing of the furnace body; the electrode column system penetrates through the furnace cover and extends into the hearth; the feeding system is used for feeding materials into the hearth and comprises a bin arranged outside the furnace body and a discharging pipe, one end of the discharging pipe is connected with an outlet of the bin, and the other end of the discharging pipe extends into the hearth; the power supply system is arranged outside the furnace body and used for supplying power to the electrode system; the cooling water system is arranged outside the furnace body and used for cooling the part of the direct-current submerged arc furnace to be cooled; the hydraulic system is arranged outside the furnace body and used for providing power for the electrode column system.

3. The Mn-Si alloy smelting unit according to claim 2, wherein the electrode column system includes 6 electrodes.

4. The manganese-silicon alloy smelting device according to claim 1, wherein the rotary kiln is arranged in an elevated manner, and a heat-insulating material tank is arranged below the rotary kiln; and the materials output by the rotary kiln are conveyed to the direct-current submerged arc furnace through the heat-insulating material tank.

5. The Mn-Si alloy smelting device according to claim 1, wherein a gas return path is provided between the DC submerged arc furnace and the rotary kiln; optionally, a gas purification unit is disposed on the gas return path.

6. The manganese-silicon alloy smelting method is characterized by comprising the following steps of:

(1) mixing manganese powder ore, silica, coke, dolomite and bentonite according to a predetermined proportion to obtain a mixture;

(2) the mixture is ground by a dry ball mill and a wet grinding mill in sequence and then sent to a disc pelletizer for pelletizing to obtain pellets;

(3) the pellets are dried and preheated by a chain grate and then enter a rotary kiln for pre-reduction;

(4) and (4) feeding the pre-reduced material obtained in the step (3) into a direct-current submerged arc furnace for smelting.

7. The manganese-silicon alloy smelting method according to claim 6, wherein in step (1), the ingredients are mixed according to the following proportions:

dividing the mass of manganese in the manganese powder ore by the mass of silicon in the manganese powder ore and the mass of silicon in silica into 1.5-2.4;

② coke mass (manganese ore powder mass + silica mass) multiplied by 0.17-0.23;

and the quality of dolomite meets the following requirements: the sum of the mass of calcium oxide and magnesium oxide in all the raw materials is divided into the mass of silicon oxide in all the raw materials, which is 0.3-0.35;

the mass of the bentonite is equal to the total mass of all the raw materials multiplied by 0.8 to 3.0 percent.

8. The manganese-silicon alloy smelting process according to claim 6, wherein in step (2), the pellet size is 12mm to 22 mm.

9. The Mn-Si alloy smelting method according to claim 6, wherein in step (3), the temperature in the rotary kiln is 1100-1350 ℃, and the atmosphere in the rotary kiln is a nitrogen atmosphere.

10. The Mn-Si alloy smelting method according to claim 6, characterized in that in the step (4), the conditions in the direct current submerged arc furnace are that the secondary side voltage is 140-165V, the electrode current is 5.5-6.5 ten thousand amperes, and the smelting temperature is not lower than 1500 ℃.

Technical Field

The invention belongs to the technical field of manganese-silicon alloy smelting, and particularly relates to a manganese-silicon alloy smelting device and a manganese-silicon alloy smelting method.

Background

The raw materials for smelting the manganese-silicon alloy comprise various manganese ores, cokes, silica, dolomite and the like. A conventional smelting unit is an ac submerged arc furnace (otherwise known as an ac submerged arc furnace). The raw materials of the ores with various qualified granularities are evenly mixed according to a certain proportion and then directly input into an alternating-current submerged arc furnace for smelting to obtain the manganese-silicon alloy.

The alternating-current submerged arc furnace has reactance loss, skin effect and eddy current loss, and the electric energy waste is large. The power consumption for smelting the manganese-silicon alloy by adopting the conventional method is high, the smelting power consumption allowed value is 4000kWh/t, and the smelting advanced index can reach 3800 kWh/t. The reference standard is the energy consumption limit GB 21341-2017 of the unit product of the ferroalloy), and the reference standard is as follows:

TABLE 1 iron alloy submerged arc furnace production enterprise unit product energy consumption grade

At present, raw material treatment for manganese-silicon alloy smelting is to add a step of sintering fine ores into blocks at most, and then the sintered ores are matched with manganese ores, cokes, silica, dolomite and the like and fed into a furnace. However, the whole fine ore cannot be used, and the smelting power consumption is high.

In view of the above problems in the manganese-silicon alloy smelting process, a manganese-silicon alloy smelting device and method are needed in the industry at present, so as to overcome the problems of high power consumption and low raw material utilization rate in the manganese-silicon alloy smelting process.

Disclosure of Invention

In view of the above, the present invention has been made to provide a manganese-silicon alloy smelting apparatus and method that overcomes or at least partially solves the above problems.

Specifically, the invention is realized by the following technical scheme:

a manganese-silicon alloy smelting device comprises a dry ball mill, a wet mill, a disc pelletizer, a chain grate machine, a rotary kiln and a submerged arc furnace, wherein the submerged arc furnace is a direct-current submerged arc furnace; the mixture is sequentially processed by a dry ball mill, a wet mill, a disc pelletizer, a chain grate machine, a rotary kiln and a direct-current submerged arc furnace to obtain the manganese-silicon alloy.

Optionally, the dc submerged arc furnace includes: the device comprises a furnace body, a furnace cover, an electrode column system, a feeding system, a flue gas leading-out system, a power supply system, a cooling water system and a hydraulic system; the furnace body consists of a furnace bottom, a furnace shell and a furnace lining which are arranged from outside to inside in sequence and is used for accommodating furnace burden; the furnace cover is arranged above the furnace body and used for ensuring the sealing of the furnace body; the electrode column system penetrates through the furnace cover and extends into the hearth; the feeding system is used for feeding materials into the hearth and comprises a bin arranged outside the furnace body and a discharging pipe, one end of the discharging pipe is connected with an outlet of the bin, and the other end of the discharging pipe extends into the hearth; the power supply system is arranged outside the furnace body and used for supplying power to the electrode system; the cooling water system is arranged outside the furnace body and used for cooling the part of the direct-current submerged arc furnace to be cooled; the hydraulic system is arranged outside the furnace body and used for providing power for the electrode column system.

Optionally, the electrode column system comprises 6 electrodes.

Optionally, the rotary kiln is arranged in an elevated form, and a heat-insulating material tank is arranged below the rotary kiln; and the materials output by the rotary kiln are conveyed to the direct-current submerged arc furnace through the heat-insulating material tank.

Optionally, a gas backflow path is arranged between the direct-current submerged arc furnace and the rotary kiln; optionally, a gas purification unit is disposed on the gas return path.

A manganese-silicon alloy smelting method comprises the following steps:

(1) mixing manganese powder ore, silica, coke, dolomite and bentonite according to a predetermined proportion to obtain a mixture;

(2) the mixture is ground by a dry ball mill and a wet grinding mill in sequence and then sent to a disc pelletizer for pelletizing to obtain pellets;

(3) the pellets are dried and preheated by a chain grate and then enter a rotary kiln for pre-reduction;

(4) and (4) feeding the pre-reduced material obtained in the step (3) into a direct-current submerged arc furnace for smelting.

Optionally, in the step (1), the ingredients are prepared according to the following proportion:

dividing the mass of manganese in the manganese powder ore by the mass of silicon in the manganese powder ore and the mass of silicon in silica into 1.5-2.4;

② coke mass (manganese ore powder mass + silica mass) multiplied by 0.17-0.23;

and the quality of dolomite meets the following requirements: the sum of the mass of calcium oxide and magnesium oxide in all the raw materials is divided into the mass of silicon oxide in all the raw materials, which is 0.3-0.35;

the mass of the bentonite is equal to the total mass of all the raw materials multiplied by 0.8 to 3.0 percent.

Optionally, in step (2), the pellet has a particle size of 12mm to 22 mm.

Optionally, in the step (3), the temperature in the rotary kiln is 1100-1350 ℃, and the atmosphere in the rotary kiln is a nitrogen atmosphere.

Optionally, in the step (4), the conditions in the direct current submerged arc furnace are that the secondary side voltage is 140-165V, the electrode current is 5.5-6.5 ten thousand amperes, and the smelting temperature is not lower than 1500 ℃. Compared with the prior art, the manganese-silicon alloy smelting device and the method have the following beneficial effects that:

the invention firstly provides a production process of 'material prereduction + high-temperature melting and separating reduction of a direct-current submerged arc furnace' in the manganese-silicon alloy smelting field, introduces the process of carrying out high-temperature melting and separating treatment on a prereduced material by the direct-current submerged arc furnace into the manganese-silicon alloy smelting field for the first time, carries out prereduction treatment on the material, and then thermally loads the prereduced material into the direct-current submerged arc furnace for smelting. Because the direct-current submerged arc furnace has no reactance loss, skin effect and eddy current loss, the electric energy utilization efficiency is high, and the electric arc is stable and stronger, so that the direct-current submerged arc furnace is suitable for treating the pre-reduced materials. Therefore, the power consumption for smelting the manganese-silicon alloy is reduced to be not more than 3100 kWh/t.

In addition, the process can utilize the manganese fine ore 100%, and reduces the material cost relative to lump ore. And smelting gas is further recovered in the production process and is used for pre-reducing the rotary kiln material. Therefore, the adverse effect on the environment is reduced, and meanwhile, the production cost is greatly reduced.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a process flow diagram for smelting manganese-silicon alloy.

FIG. 2 is a schematic structural diagram of a DC submerged arc furnace used in the present invention.

FIG. 3 is a top view of a DC submerged arc furnace used in the present invention.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Aiming at the problems of high energy consumption and high cost in the manganese-silicon alloy smelting process at present, the inventor of the invention carries out deep analysis and research on a smelting device and a smelting method, thereby creatively providing the invention concept of adopting 'material pre-reduction + high-temperature melting reduction of a direct-current submerged arc furnace' in the manganese-silicon alloy smelting process.

Based on the conception of the invention, the inventor of the invention creatively improves the smelting device and the smelting method, thereby providing the manganese-silicon alloy smelting device and the smelting method.

In a first aspect, the invention provides a manganese-silicon alloy smelting device.

The manganese-silicon alloy smelting device comprises a dry ball mill, a wet mill, a disc pelletizer, a chain grate machine, a rotary kiln and a direct-current ore furnace which are arranged in sequence. When in use, the mixture is sequentially treated by a dry ball mill, a wet mill, a disk pelletizer, a chain grate machine, a rotary kiln and a direct-current ore furnace.

Preferably, as shown in fig. 2 and 3, the direct current ore furnace in the present invention includes: the device comprises a furnace body, a furnace cover, an electrode column system, a feeding system, a flue gas leading-out system, a power supply system, a cooling water system and a hydraulic system.

The furnace body 1 includes a furnace shell 2, a furnace lining 3, and a furnace bottom (not shown). Wherein, the furnace shell 2 and the furnace lining 3 are arranged in sequence from outside to inside; the furnace bottom is positioned at the bottom and surrounds the furnace shell 2 and the furnace lining 3 to form a hearth 4 for containing furnace charge. One or more discharge holes 13 are arranged on the side wall of the furnace body 1.

The furnace cover 6 is arranged above the furnace body 1, and the furnace cover 6 and the furnace shell 2 are arranged in a sealing way and used for ensuring the sealing performance of the furnace body 1.

The electrode column system 5 comprises a number of electrode columns, each electrode column comprising a cathode and an anode. The electrode column penetrates through the furnace cover 6 to reach the hearth 4, the end of the electrode can be directly inserted into the furnace charge, and the furnace charge in the hearth 4 is heated and melted by using direct current electric arc. The electrodes of the cathode and the anode are arranged in a staggered way in the direct current ore smelting furnace. The electrodes may take a variety of forms, such as graphite electrodes and the like.

The charging system 7 comprises a silo 8 and a blanking pipe 9. The feed bin 8 is arranged above the outside of the furnace body 1, a discharge hole of the feed bin 8 is connected with one end of the discharging pipe 9, and the other end of the discharging pipe 9 penetrates through the furnace cover 6 to enter the hearth 4. The storage bin and the blanking pipe can be arranged into one group or a plurality of groups, and can be determined according to the requirement.

The power supply system 10 is arranged outside the furnace body 1 and is used for supplying power to the electrodes of the electrode column system 5. The power supply system 10 includes a rectifier and a transformer (not shown in the figures). The transformer inputs alternating current at the primary side, the alternating current is adjusted to be voltage required by smelting of the direct-current submerged arc furnace through the transformer, the transformer secondary side is connected with the rectifier, the rectifier outputs two groups of interfaces of a cathode and an anode which are respectively connected to bottom mechanisms of the cathode and the anode (namely, the cathode interface is connected with the cathode electrode, and the anode interface is connected with the anode electrode), and the transformer is matched with a set of rectifier corresponding to the cathode and the anode to form a set of power supply system. Each set of power supply system can independently supply power. The power supply system 10 is connected to a hydraulic system (not shown in the figures) for powering the electrode column system 5.

And the cooling water system 11 is arranged outside the furnace body 1 and is connected with the mechanisms to be cooled of the direct-current submerged arc furnace through pipelines so as to provide cooling water for the mechanisms to be cooled. The mechanism to be cooled comprises a furnace body 1, a furnace shell 2, a furnace bottom, a power supply system 10 and a flue gas leading-out system 12.

The flue gas guiding system 12 comprises a flue gas flue, and one end of the flue gas flue penetrates through the furnace cover 6 and extends into the hearth 4.

The specific locations of the power supply system, the cooling water system and the hydraulic system can be set reasonably by those skilled in the art according to actual production needs.

More preferably, the electrode column system 5 comprises 6 electrodes, of which 3 are positive electrodes and the other 3 are negative electrodes. Meanwhile, 3 rectifiers are arranged in a matched mode, two adjacent electrodes are connected with the output end of each rectifier, and one rectifier is a positive electrode and the other rectifier is a negative electrode. The 6-electrode direct-current submerged arc furnace can utilize a power grid in a balanced manner compared with other forms of direct-current submerged arc furnaces, and the fact that the power grid is unstable is avoided.

When the direct-current submerged arc furnace is used, materials are loaded into the bin 8, and then the materials enter the hearth 4 through the discharge pipe 9. The continuous feeding mode can be adopted, and the blanking pipe 9 is always in a full state. When the material level in the hearth 4 descends along with the output of the products from the discharge port 13, the materials in the bin 8 are automatically supplemented into the hearth 4 through the blanking pipe 9 under the action of gravity. The electrode column system 5 heats, melts and smelts the materials in the hearth 4 by using direct current electric arc. The gas generated in the smelting process is led out by a flue gas leading-out system 12. After smelting, the cooling water system 11 provides cooling water for the furnace body 1, the furnace shell 2, the furnace bottom, the power supply system 10 and the flue gas leading-out system 12.

Preferably, in the invention, the rotary kiln is arranged in an overhead form and directly extends into a main workshop where the submerged arc furnace is located. A heat-insulating material tank is arranged below the rotary kiln, is provided with a guide wheel and can run to the upper part of a furnace top bin of the submerged arc furnace along a track. By means of the design, the high-temperature materials pre-reduced by the rotary kiln can be conveyed to the direct-current submerged arc furnace through the heat-insulating material tank for smelting, the charging temperature of furnace materials is increased, and the smelting power consumption is fully reduced.

In the invention, the dry ball mill, the wet mill, the disk pelletizer, the chain grate machine, the rotary kiln and the heat preservation material tank can adopt conventional equipment, and the details are not repeated herein.

In a second aspect, the invention provides a manganese-silicon alloy smelting method. The method comprises the following steps:

(1) mixing manganese powder ore, silica, coke, dolomite and bentonite according to a predetermined proportion to obtain a mixture;

(2) the mixture is ground by a dry ball mill and a wet mill in sequence and then sent to a disc pelletizer for pelletizing to obtain pellets;

(3) the pellets are dried and preheated by a chain grate and then enter a rotary kiln for pre-reduction;

(4) and (4) feeding the pre-reduced material obtained in the step (3) into a direct-current submerged arc furnace for smelting.

As a preferred embodiment, the manganese-silicon alloy smelting method of the present invention will be described in conjunction with the smelting apparatus of the present invention with reference to FIG. 1, as follows.

(1) Ingredients

The smelting method takes manganese ore powder, silica, coke, dolomite and bentonite as raw materials. Optionally, the manganese ore fines, silica, coke and dolomite are dried prior to batching.

Comprehensively considering the carbon amount, products and alkalinity required by selective reduction, mixing the dried manganese ore powder, silica, coke, dolomite and bentonite according to the following rules to obtain a mixture:

the mass of manganese in the manganese ore powder (mass of silicon in the manganese ore powder + mass of silicon in silica) is 1.5 to 2.4, and the obtained value is in the range of 1.5 to 2.4, for example, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, and the like;

② coke mass (manganese powder ore mass + silica mass) × 0.17-0.23, that is, coke mass is 17-23% of the sum of manganese powder ore and silica mass, for example, 17%, 18%, 19%, 20%, 21%, 22% or 23% etc.;

and the quality of dolomite meets the following requirements: the sum of the mass of calcium oxide and magnesium oxide in all raw materials ÷ the mass of silicon oxide in all raw materials ═ 0.3 to 0.35, for example, 0.30, 0.31, 0.32, 0.33, 0.34, or 0.35;

(iv) 0.8 to 3.0% by mass of the total mass of all raw materials, that is, 0.8 to 3.0% by mass of the total mass of all raw materials, for example, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 2.2%, 2.4%, 2.6%, 2.8%, or 3.0% by mass of bentonite.

The invention has no special requirements on the raw materials of manganese powder ore, silica, coke, dolomite, bentonite and the like, and the conventionally used manganese powder ore, silica, coke, dolomite and bentonite can be applied to the invention, and the dosage of each substance only needs to meet the blending rule.

(2) Grinding and pelletizing

And (3) feeding the mixture into a dry ball mill for dry grinding to obtain a material with the particle size of less than 0.074 mm. Then, the material is humidified to the water content of 6-10% (weight), and is sent to a moistening and grinding machine for moistening and grinding, and the material can be mixed more uniformly by virtue of moistening and grinding. Subsequently, the material obtained by the wet grinding is sent to a disc pelletizer for pelletizing, the particle size of the obtained pellets is preferably 12mm to 22mm, such as 12mm, 14mm, 16mm, 18mm, 20mm, 22mm and the like, the pellet size is suitable, and the air permeability of the submerged arc furnace and the material reaction speed are both considered.

(3) Pre-reduction of

First, the pellets are sent to a grate for drying and preheating. The pellets are then fed to a rotary kiln for pre-reduction.

In the rotary kiln, the pre-reduction temperature is set to 1100 ℃ to 1350 ℃, for example, 1100 ℃, 1150 ℃, 1200 ℃, 1250 ℃, 1300 ℃, 1350 ℃, or the like. By adopting the temperature, the pellet granularity is suitable, and the air permeability and the material reaction speed of the submerged arc furnace are both considered.

In the rotary kiln, it is necessary to ensure a reducing atmosphere in order to avoid secondary oxidation of the prereduced material. The reducing atmosphere is, for example, a nitrogen atmosphere, i.e., nitrogen is blown into the rotary kiln so that the oxygen content in the rotary kiln system is less than 2%. Therefore, the oxidation of the pre-reduced pellets caused by high oxygen content in the air is avoided.

(4) Smelting

And discharging the pellets pre-reduced by the rotary kiln into a heat-insulating material tank from the kiln head of the rotary kiln. The heat preservation material tank moves to the upper part of the storage bin at the top of the direct-current submerged arc furnace along a track through a guide wheel of the heat preservation material tank, and discharges materials into the storage bin. The pellets pre-reduced by the rotary kiln are transported by the heat-insulating material tank, so that the charging temperature of furnace charge can be increased, and the power consumption of smelting is fully reduced.

And then, continuously feeding the materials in the bin into a hearth of the direct-current submerged arc furnace through a material pipe for smelting to obtain manganese-silicon alloy, and generating furnace slag and coal gas. The invention utilizes the obvious advantages of the direct-current submerged arc furnace compared with the alternating-current submerged arc furnace, can save energy, improve the yield and reduce the smelting power consumption, and can reduce the power consumption to 3100 kWh/t.

For example, the conditions in the direct current submerged arc furnace are that the secondary side voltage is 140-165V (for example, 140V, 146V, 150V, 156V, 160V or 165V and the like), the electrode current is 5.5-6.5 kiloamperes (for example, 5.5-6-kiloamperes, 5.7-kiloamperes, 5.8-kiloamperes, 5.9-kiloamperes, 6.0-kiloamperes, 6.1-kiloamperes, 6.2-kiloamperes, 6.3-kiloamperes, 6.4-kiloamperes or 6.5-kiloamperes and the like), the smelting temperature is not lower than 1500 ℃, and the material is discharged once in about 2.5 hours.

Preferably, coal gas generated in the smelting process of the direct-current submerged arc furnace is purified and recovered and is returned to the rotary kiln for pre-reduction.

Examples

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

Example 1

(1) Respectively drying the manganese ore powder, the silica, the coke and the dolomite, and then mixing the dried manganese ore powder, the silica, the coke and the dolomite with bentonite according to the following proportion:

dividing the mass of manganese in the manganese powder ore (the mass of silicon in the manganese powder ore + the mass of silicon in silica) into 1.5;

② coke mass (manganese ore powder mass + silica mass) x 0.17;

and the quality of dolomite meets the following requirements: the sum of the mass of calcium oxide and magnesium oxide in all raw materials is divided into the mass of silicon oxide in all raw materials, which is 0.3;

and fourthly, the mass of the bentonite is equal to the total mass of all the raw materials multiplied by 0.8 percent.

(2) And (3) feeding the mixture into a dry ball mill for dry grinding to obtain a material with the particle size of less than 0.074 mm. Then, the material is humidified and sent to a moistening and grinding machine for moistening and grinding. And then, sending the material obtained by the wet grinding to a disc pelletizer for pelletizing, feeding the obtained pellets into a screening device, and selecting the pellets with the particle size of 12-22 mm to enter the next step.

(3) And conveying the pellets to a chain grate for drying and preheating. The pellets are then fed to a rotary kiln for pre-reduction. The pre-reduction temperature of the rotary kiln is 1100 ℃; the reducing atmosphere is ensured in the rotary kiln, and the material is prevented from being oxidized for the second time.

(4) And discharging the pellets pre-reduced by the rotary kiln into a heat-insulating material tank from the kiln head of the rotary kiln. The heat preservation material tank moves to the upper part of the storage bin at the top of the direct-current submerged arc furnace along a track through a guide wheel of the heat preservation material tank, and discharges materials into the storage bin. The materials in the bin continuously enter a hearth of a direct-current submerged arc furnace for smelting through a material pipe, the direct-current submerged arc furnace is a 30MVA six-electrode rectangular hearth direct-current submerged arc furnace, and the smelting temperature is more than 1500 ℃. The electrode current was 59000A. Finally obtaining manganese-silicon alloy and furnace slag; and (3) purifying and recycling coal gas generated by smelting in the submerged arc furnace for prereduction in the rotary kiln.

The manganese content of the manganese-silicon alloy obtained by the smelting in this example was 65.5 wt%, and the silicon content was 17.3 wt%. The power consumption for smelting in the embodiment is 3000 kWh/t.

Example 2

(1) Respectively drying the manganese ore powder, the silica, the coke and the dolomite, and then mixing the dried manganese ore powder, the silica, the coke and the dolomite with bentonite according to the following proportion:

dividing the mass of manganese in the manganese powder ore (the mass of silicon in the manganese powder ore + the mass of silicon in silica) into 2.4;

② coke mass (manganese ore powder mass + silica mass) x 0.23;

and the quality of dolomite meets the following requirements: the sum of the mass of calcium oxide and magnesium oxide in all raw materials is divided into the mass of silicon oxide in all raw materials, which is 0.35;

and fourthly, the mass of the bentonite is equal to the total mass of all the raw materials multiplied by 3.0 percent.

(2) And (3) feeding the mixture into a dry ball mill for dry grinding to obtain a material with the particle size of less than 0.074 mm. Then, the material is humidified and sent to a moistening and grinding machine for moistening and grinding. And then, sending the material obtained by the wet grinding to a disc pelletizer for pelletizing, sending the obtained pellets into a screening device, and selecting the pellets with the particle size of 16mm to enter the next step.

(3) And conveying the pellets to a chain grate for drying and preheating. The pellets are then fed to a rotary kiln for pre-reduction. The pre-reduction temperature of the rotary kiln is 1350 ℃; the reducing atmosphere is ensured in the rotary kiln, and the material is prevented from being oxidized for the second time.

(4) And discharging the pellets pre-reduced by the rotary kiln into a heat-insulating material tank from the kiln head of the rotary kiln. The heat preservation material tank moves to the upper part of the storage bin at the top of the direct-current submerged arc furnace along a track through a guide wheel of the heat preservation material tank, and discharges materials into the storage bin. The materials in the bin continuously enter a hearth of a direct-current submerged arc furnace for smelting through a material pipe, the direct-current submerged arc furnace is a 30MVA six-electrode rectangular hearth direct-current submerged arc furnace, and the smelting temperature is more than 1500 ℃. The electrode current was 65000A. Finally obtaining manganese-silicon alloy and furnace slag; and (3) purifying and recycling coal gas generated by smelting in the submerged arc furnace for prereduction in the rotary kiln.

The manganese content of the manganese-silicon alloy obtained by the smelting in the example was 66.3 wt%, and the silicon content was 18 wt%. The power consumption for smelting in the embodiment is 2980 kWh/t.

Example 3

(1) Respectively drying the manganese ore powder, the silica, the coke and the dolomite, and then mixing the dried manganese ore powder, the silica, the coke and the dolomite with bentonite according to the following proportion:

dividing the mass of manganese in the manganese powder ore (the mass of silicon in the manganese powder ore + the mass of silicon in silica) into 2;

② coke mass (manganese ore powder mass + silica mass) x 0.2;

and the quality of dolomite meets the following requirements: the sum of the mass of calcium oxide and magnesium oxide in all raw materials is divided into the mass of silicon oxide in all raw materials, which is 0.32;

and fourthly, the mass of the bentonite is equal to the total mass of all the raw materials multiplied by 2.5 percent.

(2) And (3) feeding the mixture into a dry ball mill for dry grinding to obtain a material with the particle size of less than 0.074 mm. Then, the material is humidified and sent to a moistening and grinding machine for moistening and grinding. And then, sending the material obtained by the wet grinding to a disc pelletizer for pelletizing, feeding the obtained pellets into a screening device, and selecting the pellets with the particle size of 12-22 mm to enter the next step.

(3) And conveying the pellets to a chain grate for drying and preheating. The pellets are then fed to a rotary kiln for pre-reduction. The pre-reduction temperature of the rotary kiln is 1200 ℃; the reducing atmosphere is ensured in the rotary kiln, and the material is prevented from being oxidized for the second time.

(4) And discharging the pellets pre-reduced by the rotary kiln into a heat-insulating material tank from the kiln head of the rotary kiln. The heat preservation material tank moves to the upper part of the storage bin at the top of the direct-current submerged arc furnace along a track through a guide wheel of the heat preservation material tank, and discharges materials into the storage bin. The materials in the bin continuously enter a hearth of a direct-current submerged arc furnace for smelting through a material pipe, the direct-current submerged arc furnace is a 30MVA six-electrode rectangular hearth direct-current submerged arc furnace, and the smelting temperature is more than 1500 ℃. The electrode current was 61000A. Finally obtaining manganese-silicon alloy and furnace slag; and (3) purifying and recycling coal gas generated by smelting in the submerged arc furnace for prereduction in the rotary kiln.

The manganese content of the manganese-silicon alloy obtained by the smelting in this example was 67.2 wt%, and the silicon content was 17.6 wt%. The smelting power consumption of the embodiment is 3100 kWh/t.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.