阅读说明：本技术 一种全锰粉矿冶炼装置和方法 (Full manganese powder ore smelting device and method ) 是由 于洪翔 陈圣鹏 吕韬 袁俊红 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种全锰粉矿冶炼装置,包括依据物料加工顺序依次设置的润磨机、圆盘造球机、竖炉、保温料罐和直流矿热炉。本发明还公开了一种全锰粉矿冶炼方法,包括：锰粉矿和膨润土组成的第一混合料进入润磨机进行润磨,然后进入圆盘造球机进行造球,得到生球团；将生球团送入竖炉进行焙烧,得到的高温球团被送入保温料罐与硅石、焦炭和白云石混合制备第二混合料；第二混合料由保温料罐送至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 full manganese powder ore smelting device which comprises a moistening and grinding machine, a disc pelletizer, a shaft furnace, a heat insulation material tank and a direct-current ore smelting furnace which are sequentially arranged according to a material processing sequence. The invention also discloses a method for smelting the full manganese powder ore, which comprises the following steps: feeding a first mixture consisting of manganese powder ore and bentonite into a wet grinding machine for wet grinding, and then feeding the mixture into a disc pelletizer for pelletizing to obtain green pellets; the green pellets are sent into a shaft furnace for roasting, and the obtained high-temperature pellets are sent into a heat-insulating material tank to be mixed with silica, coke and dolomite to prepare a second mixture; and the second mixture is sent to the direct-current submerged arc furnace from the heat-insulating material tank 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 full manganese powder ore smelting device is characterized by comprising a moistening and grinding machine, a disc pelletizer, a shaft furnace, a heat insulation material tank and a direct-current ore smelting furnace which are sequentially arranged according to a material processing sequence; wherein:

the moistening and grinding machine is used for moistening and grinding a first mixture consisting of manganese powder ore and bentonite;

the disc pelletizer is used for pelletizing the grinding material output by the moistening and grinding machine to prepare green pellets;

the shaft furnace is used for roasting the green pellets to prepare high-temperature pellets;

the heat-preservation charging bucket is used for mixing the high-temperature pellets with silica, coke and dolomite to prepare a second mixture and conveying the second mixture to the direct-current submerged arc furnace;

the direct-current ore furnace is used for smelting the second mixture.

2. The full-manganese ore smelting device according to claim 1, wherein said direct current ore 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 full manganese ore smelting plant of claim 1, wherein said electrode column system includes 6 electrodes.

4. A method for smelting full manganese powder ore is characterized by comprising the following steps:

(1) feeding a first mixture consisting of manganese powder ore and bentonite into a wet grinding machine for wet grinding, and then feeding the mixture into a disc pelletizer for pelletizing to obtain green pellets;

(2) the green pellets are sent into a shaft furnace for roasting, the obtained high-temperature pellets, silica, coke and dolomite are sent into a heat-insulating material tank, and a second mixture is prepared by mixing;

(3) and the second mixture is sent to the direct-current submerged arc furnace from the heat-insulating material tank for smelting.

5. The method of smelting full manganese ore of claim 1, wherein the bentonite accounts for 0.8 to 3.0% of the total mix mass.

6. The method of smelting whole manganese ore according to claim 1, wherein the mass of manganese in manganese ore divided by the mass of silicon in manganese ore plus the mass of silicon in silica is 1.5 to 2.4.

7. The process of smelting whole manganese ore according to claim 1, wherein the coke mass is 17 to 23% of the sum of the manganese ore and the silica mass.

8. The method of claim 1, wherein the sum of the weight of calcium oxide and magnesium oxide in the total mix is 0.3-0.35/the weight of silicon oxide in the total mix.

9. The method for smelting full manganese ore according to claim 1, wherein in step (1), the particle size of the green pellets obtained is 8mm to 22 mm.

10. The smelting method of whole manganese ore according to claim 1, characterized in that, in step (2), the temperature in the shaft furnace is 1050 ℃ -1200 ℃;

in the step (3), 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 full manganese ore smelting, and particularly relates to a full manganese ore smelting device and a full manganese ore 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 GB21341-2017 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 whole manganese ore smelting process, there is a need in the industry for a whole manganese ore smelting device and method to overcome the problems of high power consumption and low raw material utilization rate in the whole manganese ore smelting process.

Disclosure of Invention

In view of the above problems, the present invention has been made to provide an apparatus and a method for smelting a full manganese ore that overcome the above problems or at least partially solve the above problems.

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

a full manganese powder ore smelting device comprises a wet grinding machine, a disc pelletizer, a shaft furnace, a heat insulation material tank and a direct-current ore smelting furnace which are sequentially arranged according to a material processing sequence; wherein:

the moistening and grinding machine is used for moistening and grinding a first mixture consisting of manganese powder ore and bentonite;

the disc pelletizer is used for pelletizing the grinding material output by the moistening and grinding machine to prepare green pellets;

the shaft furnace is used for roasting the green pellets to prepare high-temperature pellets;

the heat-preservation charging bucket is used for mixing the high-temperature pellets with silica, coke and dolomite to prepare a second mixture and conveying the second mixture to the direct-current submerged arc furnace;

the direct-current ore furnace is used for smelting the second mixture.

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.

A method for smelting full manganese powder ore comprises the following steps:

(1) feeding a first mixture consisting of manganese powder ore and bentonite into a wet grinding machine for wet grinding, and then feeding the mixture into a disc pelletizer for pelletizing to obtain green pellets;

(2) the green pellets are sent into a shaft furnace for roasting, the obtained high-temperature pellets, silica, coke and dolomite are sent into a heat-insulating material tank, and a second mixture is prepared by mixing;

(3) and the second mixture is sent to the direct-current submerged arc furnace from the heat-insulating material tank for smelting.

Optionally, the bentonite comprises 0.8% to 3.0% by mass of the total mix.

Optionally, the mass of manganese in the manganese ore/mass of silicon in the silica (mass of manganese ore/mass of silicon in silica) is 1.5-2.4.

Optionally, the coke mass is 17% to 23% of the sum of the manganese ore fines and the silica mass.

Optionally, the sum of the mass of calcium oxide and magnesium oxide in the total mixture is divided by the mass of silicon oxide in the total mixture, wherein the mass of silicon oxide is 0.3-0.35.

Optionally, in the step (1), the particle size of the green pellets obtained is 8mm to 22 mm.

Optionally, in step (2), the temperature in the shaft furnace is 1050 ℃ to 1200 ℃.

Optionally, in the step (3), 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 'full manganese powder ore pelletizing + shaft furnace roasting + hot charging into direct current ore furnace smelting' in the manganese-silicon alloy smelting field, and firstly introduces the process of treating hot charging materials by the direct current ore furnace into the manganese-silicon alloy smelting field. 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 shaft furnace roasting material. Therefore, the power consumption for smelting the manganese-silicon alloy is reduced to be not more than 3100 kWh/t.

The invention adopts the hot charging and charging process, recovers energy and reduces smelting energy consumption; and the hot charging process is adopted, a coke drying device is not required to be additionally arranged, the moisture in the coke is dried by utilizing the high temperature of the pellets, the working procedure is simplified, and the production cost is reduced.

The process can utilize the manganese fine ore 100 percent, and reduces the material cost relative to lump ore. During the production process, smelting gas is further recovered and conveyed back to the shaft furnace after being purified. 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 of the smelting of full manganese fine ore according to the present invention.

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 'full manganese powder ore pelletizing, shaft furnace roasting and hot charging into a direct-current ore 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 smelting device and the smelting method for the full manganese powder ore.

In a first aspect, the invention provides a full manganese powder ore smelting device.

The full manganese powder ore smelting device comprises a moistening and grinding machine, a disc pelletizer, a shaft furnace, a heat insulation charging bucket and a direct-current ore smelting furnace which are sequentially arranged according to a material processing sequence; wherein:

the moistening and grinding machine is used for moistening and grinding a first mixture consisting of manganese powder ore and bentonite;

the disc pelletizer is used for pelletizing the grinding material output by the moistening and grinding machine to prepare green pellets;

the shaft furnace is used for roasting the green pellets to prepare high-temperature pellets;

the heat-preservation charging bucket is used for mixing the high-temperature pellets with silica, coke and dolomite to prepare a second mixture and conveying the second mixture to the direct-current submerged arc furnace;

the direct-current ore furnace is used for smelting the second mixture.

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.

In the invention, the moistening and grinding machine, the disc pelletizer, the shaft furnace and the heat insulation material tank can adopt conventional equipment, and the details are not repeated herein.

In a second aspect, the invention provides a method for smelting full manganese powder ore. The method comprises the following steps:

(1) feeding a first mixture consisting of manganese powder ore and bentonite into a wet grinding machine for wet grinding, and then feeding the mixture into a disc pelletizer for pelletizing to obtain green pellets;

(2) the green pellets are sent into a shaft furnace for roasting, the obtained high-temperature pellets, silica, coke and dolomite are sent into a heat-insulating material tank, and a second mixture is prepared by mixing;

(3) and the second mixture is sent to the direct-current submerged arc furnace from the heat-insulating material tank for smelting.

As a preferred embodiment, the method for smelting a whole manganese ore according to the present invention will be described in conjunction with the smelting apparatus according to the present invention with reference to FIG. 1, as follows.

(1) Pelletizing

The manganese ore powder and the bentonite are proportioned, the obtained first mixture is humidified until the water content is 6-10% (by weight), and the mixture is sent to a moistening and grinding machine for moistening and grinding, so that the materials 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 green pellets is preferably 8 mm-22 mm, for example, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm or 22mm, the particle size of the pellets is suitable, and the air permeability of the submerged arc furnace and the material reaction speed are compatible.

(2) Shaft furnace roasting and batching

The green pellets are sent to a shaft furnace for roasting. The firing temperature in the shaft furnace is 1050 to 1200 ℃, for example 1050 ℃, 1060 ℃, 1070 ℃, 1080 ℃, 1090 ℃, 1100 ℃, 1110 ℃, 1120 ℃, 1130 ℃, 1140 ℃, 1150 ℃, 1160 ℃, 1170 ℃, 1180 ℃, 1190 ℃ or 1200 ℃, and the firing atmosphere in the shaft furnace is an oxidizing atmosphere, for example, an air atmosphere.

After the baking, the high-temperature pellets are discharged from the shaft furnace, and the discharge temperature of the pellets is 400 to 600 ℃, for example, 400 ℃, 420 ℃, 440 ℃, 460 ℃, 480 ℃, 500 ℃, 520 ℃, 540 ℃, 560 ℃, 580 ℃, or 600 ℃.

The mixture of the silica, the dolomite and the coke and the high-temperature pellets enter a heat-preserving material tank to obtain a second mixture, and the temperature of the mixture is about 200 ℃. When charging, the mixture of silica, dolomite and coke and the high-temperature pellets can be alternately fed into the heat-insulating material tank, for example, a layer of high-temperature pellets is laid first, then a layer of mixture of silica, dolomite and coke is laid, and then the above steps are repeated, or a layer of mixture of silica, dolomite and coke is laid first, then a layer of high-temperature pellets is laid, and then the above steps are repeated. In addition, the mixed materials of the silica, the dolomite and the coke and the high-temperature pellets can also enter the heat-preservation tank at the same time, for example, the high-temperature pellets are fed into the heat-preservation tank through a vibrating feeder, and the mixed materials of the silica, the dolomite and the coke are simultaneously fed into the heat-preservation tank through vibration of the vibrating feeder.

The heat preservation charging bucket moves to the smelting workshop electric furnace bay through the trolley, the heat preservation charging bucket is lifted to the upper portion of the direct-current submerged arc furnace top bin through the crown block, and then the heat preservation charging bucket unloads the second mixture into the bin.

The pellets are roasted by the shaft furnace, so that the pellets with higher strength can be formed after being roasted by the shaft furnace, and the direct-current submerged arc furnace smelting is facilitated; on the other hand, in the shaft furnace, the roasting hot material and other materials are mixed at a higher temperature, so that the temperature of the raw materials entering the furnace is kept to be increased, and the smelting power consumption of the direct-current submerged arc furnace is reduced.

In the above steps (1) and (2), the ingredients follow the following rules:

the mass of the bentonite accounts for 0.8 to 3.0 percent of the mass of the total mixture, such as 0.8 percent, 1.0 percent, 1.2 percent, 1.4 percent, 1.6 percent, 1.8 percent, 2.0 percent, 2.2 percent, 2.4 percent, 2.6 percent, 2.8 percent or 3.0 percent and the like;

② 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 or 2.4;

③ 0.17 to 0.23 (mass of manganese ore powder + mass of silica) x, i.e., 17 to 23% of the coke mass, for example, 17%, 18%, 19%, 20%, 21%, 22% or 23% of the sum of the mass of manganese ore powder and the mass of silica;

the dolomite quality satisfies: the sum of the mass of calcium oxide and magnesium oxide in the total mixed material is 0.3-0.35, for example, 0.30, 0.31, 0.32, 0.33, 0.34 or 0.35.

The total mixture is the sum of manganese ore powder, bentonite, silica, dolomite and coke.

In the present invention, bentonite is an essential binder for pelletizing. The bentonite with the proportion can realize effective bonding and the high strength of the pellets.

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.

(3) Smelting

The heat preservation material tank is lifted to the upper side of a storage bin at the top of the direct-current submerged arc furnace by a crown block, the heat preservation material tank unloads a second mixture into the storage bin, and the second mixture in the storage bin continuously enters a hearth of the direct-current submerged arc furnace through a material pipe to be smelted to obtain manganese-silicon alloy and further generate furnace slag and coal gas.

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, the coal gas generated in the smelting process of the direct current submerged arc furnace is purified and recovered and returned to the shaft furnace for roasting.

The step adopts a hot charging process, and the high-temperature pellets and other materials are conveyed to the direct-current submerged arc furnace together by the heat-insulating material tank, so that the energy is recovered, and the smelting energy consumption is reduced. In addition, by adopting the hot charging process, a coke drying device is not required to be additionally arranged, and the moisture in the coke is dried by utilizing the high temperature of the pellets, so that the process is simplified, and the production cost is reduced.

The step also adopts the direct-current submerged arc furnace to replace the alternating-current submerged arc furnace, so that the energy can be saved, the yield can be improved, the smelting power consumption can be reduced, and the power consumption can be reduced to 3100 kWh/t.

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) Feeding the manganese ore powder and bentonite into a wet grinding machine for wet grinding, feeding the wet ground material into a disc pelletizer for pelletizing, feeding the obtained pellets into a screening device, and selecting the pellets with the granularity of 8-22 mm to enter the next step.

(2) The green pellets are sent into a shaft furnace for roasting, and then discharged to obtain high-temperature pellets; the roasting temperature of the shaft furnace is 1050 ℃; the inside of the shaft furnace is in an oxidizing atmosphere; the roasting gas is derived from the gas of the ore-smelting furnace. The high-temperature pellets, silica, coke and dolomite are mixed and fed into a heat-insulating material tank.

Wherein, in the step (1) and the step (2), the materials are prepared according to the following proportion:

the mass of the bentonite accounts for 0.8 percent of the mass of the total mixture;

② the mass of manganese in the manganese powder ore/mass of silicon in the manganese powder ore + mass of silicon in the silica is 1.5;

(iii) coke mass ═ mass of manganese ore powder + mass of silica) × 0.17;

the dolomite quality satisfies: the sum of the mass of calcium oxide and magnesium oxide in the total mixed material is divided by the mass of silicon oxide in the total mixed material, which is 0.3.

(3) The heat-preservation material tank is lifted to the upper part of a storage bin at the top of the direct-current submerged arc furnace by a crown block, and then the heat-preservation material tank unloads the 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 the manganese-silicon alloy, the furnace slag and the coal gas. Returning the coal gas to the shaft furnace in the step (2) for being used as roasting gas.

The manganese content of the manganese-silicon alloy obtained by the smelting in this example was 65.2 wt%, and the silicon content was 17.5 wt%. The smelting power consumption of the embodiment is 3080 kWh/t.

Example 2

(1) Feeding the manganese ore powder and bentonite into a wet grinding machine for wet grinding, feeding the wet ground material into a disc pelletizer for pelletizing, feeding the obtained pellets into a screening device, and selecting the pellets with the granularity of 8-22 mm to enter the next step.

(2) The green pellets are sent into a shaft furnace for roasting, and then discharged to obtain high-temperature pellets; the roasting temperature of the shaft furnace is 1200 ℃; the inside of the shaft furnace is in an oxidizing atmosphere; the roasting gas is derived from the gas of the ore-smelting furnace. The high-temperature pellets, silica, coke and dolomite are mixed and fed into a heat-insulating material tank.

Wherein, in the step (1) and the step (2), the materials are prepared according to the following proportion:

the mass of the bentonite accounts for 3.0 percent of the mass of the total mixture;

② 2.4 percent of manganese mass in manganese powder ore/silicon mass in manganese powder ore + silicon mass in silica;

(iii) carbon mass ═ (mass of manganese ore powder + mass of silica) x 0.23;

the dolomite quality satisfies: the sum of the mass of calcium oxide and magnesium oxide in the total mixed material is divided by the mass of silicon oxide in the total mixed material, which is 0.35.

(3) The heat-preservation material tank is lifted to the upper part of a storage bin at the top of the direct-current submerged arc furnace by a crown block, and then the heat-preservation material tank unloads the 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 the manganese-silicon alloy, the furnace slag and the coal gas. Returning the coal gas to the shaft furnace in the step (2) for being used as roasting gas.

The manganese content of the manganese-silicon alloy obtained by the smelting in this example was 67 wt%, and the silicon content was 18.6 wt%. The power consumption for smelting in the embodiment is 2950 kWh/t.

Example 3

(1) Feeding the manganese ore powder and bentonite into a wet grinding machine for wet grinding, feeding the wet ground material into a disc pelletizer for pelletizing, feeding the obtained pellets into a screening device, and selecting the pellets with the granularity of 8-22 mm to enter the next step.

(2) The green pellets are sent into a shaft furnace for roasting, and then discharged to obtain high-temperature pellets; the roasting temperature of the shaft furnace is 1150 ℃; the inside of the shaft furnace is in an oxidizing atmosphere; the roasting gas is derived from the gas of the ore-smelting furnace. The high-temperature pellets, silica, coke and dolomite are mixed and fed into a heat-insulating material tank.

Wherein, in the step (1) and the step (2), the materials are prepared according to the following proportion:

the mass of the bentonite accounts for 2.0 percent of the mass of the total mixture;

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

(iii) coke mass ═ mass of manganese ore powder + mass of silica) × 0.2;

the dolomite quality satisfies: the sum of the mass of calcium oxide and magnesium oxide in the total mixed material is divided by the mass of silicon oxide in the total mixed material, which is 0.32.

(3) The heat-preservation material tank is lifted to the upper part of a storage bin at the top of the direct-current submerged arc furnace by a crown block, and then the heat-preservation material tank unloads the 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 the manganese-silicon alloy, the furnace slag and the coal gas. Returning the coal gas to the shaft furnace in the step (2) for being used as roasting gas.

The manganese content of the manganese-silicon alloy obtained by the smelting in the embodiment is 68.3 wt%, and the silicon content is 19.3 wt%. The power consumption for smelting in the embodiment is 3050 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.