Smelting ash treatment method

Abstract

The invention provides a smelting ash treatment method which comprises the following steps: a trapping process: trapping ash generated in a smelting process; a conveying process, wherein the collected soot is conveyed to a blowing device; and a blowing step in which the soot is blown into the molten pool of the melting device by means of the blowing device. According to the smelting ash treatment method, the smelting ash can be recycled, so that the environmental governance pressure caused by flying dust and fly ash can be effectively relieved, and the environmental pollution is reduced. In addition, according to the method, the intermediate links of traditional soot treatment are reduced, the treatment time is shortened, the technological process is simplified, and the technological complexity is reduced. Meanwhile, according to the method, the soot is directly sprayed into the molten pool through the spraying and blowing procedure, the smelting time is shortened, the soot effective charging rate and the smelting efficiency in the smelting process are improved, the technological process is simplified, the device is simplified, and the production cost is reduced.

Description

Technical Field

[0001] This application belongs to the field of pyrometallurgy. Specifically, it relates to a method for treating smelting soot. Background Art

[0002] In traditional smelting processes, a large amount of soot is usually generated during the smelting of materials such as matte. The traditional smelting soot recovery and treatment process mostly adopts the process of smelting soot - dust collection and transfer - pre - wetting and pelletizing - re - entering the smelting. This recovery and treatment process has problems such as a long process flow, low efficiency, the inability to effectively utilize the heat contained in the soot, and serious environmental pollution.

[0003] In the prior art, the method of humidification adhesion is usually used for soot re - aggregation. However, its structural strength is limited by the specific morphology and humidification efficiency, and there are also disadvantages such as low recovery efficiency and high energy consumption. Summary of the Invention

[0004] In view of this, this application provides a method for treating smelting soot to improve smelting efficiency, reduce energy consumption, and reduce environmental pollution.

[0005] Specifically, according to the first aspect of this application, a method for treating smelting soot is provided, which is characterized by including: a trapping process for trapping the soot generated during smelting; a conveying process for conveying the trapped soot to a blowing device; and a blowing process for blowing the soot into the molten bath of a smelting device through the blowing device.

[0006] In this application, the above - mentioned method for treating smelting soot can effectively relieve the environmental governance pressure caused by fugitive dust by trapping the soot and re - using it as a production raw material, reducing environmental pollution. In addition, this method directly conveys the soot generated during smelting to the blowing device, reducing the intermediate links of traditional soot treatment. Therefore, the treatment time is reduced, the process flow is simplified, and the process complexity is reduced. At the same time, this method directly sprays the soot into the molten bath through the blowing process. On the one hand, the metal elements in the soot can quickly participate in the smelting reaction, shortening the smelting time, increasing the effective furnace charging rate of the soot and the smelting efficiency during the smelting process. On the other hand, it avoids the links such as soot - granulation - drying - furnace charging smelting in the prior art, further simplifies the process flow and the device, and reduces energy consumption and production costs.

[0007] In some embodiments, it further includes: before the trapping process, passing the soot generated during smelting into a rotary kiln for temperature reduction treatment.

[0008] In some embodiments, the method further satisfies at least one of the following conditions:

[0009] A. The soot contains nickel and iron elements;

[0010] B. The soot composition contains 1.5 - 1.8% Ni, 32 - 35% Fe,

[0011] 21 - 25% SiO2, 1 - 2.1% CaO, 5 - 9% MgO, 5 - 8.5% Al2O3, 1 - 2% Cr2O3, 0.05 - 0.08% Co by mass percentage;

[0012] C. In the trapping process, ionization enrichment is used for trapping;

[0013] D. In the trapping process, the temperature of the trapped soot is 300 - 400 °C.

[0014] In some embodiments, the method further satisfies at least one of the following conditions:

[0015] A. In the conveying process, the soot is conveyed to the soot storage device and then to the injection device;

[0016] B. In the conveying process, pneumatic pressurization is used for conveying;

[0017] C. In the conveying process, the conveying pressure is 100 - 300 KPa and the conveying gas volume is 300 - 600 Nm

[0018] 3 / h;

[0019] D. In the conveying process, compressed air is used as the conveying medium;

[0020] E. The temperature of the soot entering the injection device is 200 - 300 °C.

[0021] In some embodiments, the soot storage device is provided with a metering feeder for evenly conveying the soot to the injection device.

[0022] In some embodiments, the method further satisfies at least one of the following conditions:

[0023] A. In the injection process, the injection device includes a lance;

[0024] B. In the injection process, multi-point injection technology is used for injection;

[0025] C. In the injection process, compressed air is used as the injection medium.

[0026] In some embodiments, the smelting device is an oxygen-enriched side-blown furnace, an electric arc furnace or a blast furnace.

[0027] In some embodiments, in the injection process, the soot is injected into the molten bath through the top of the smelting device.

[0028] Optionally, the injection position is -200 mm to 1500 mm;

[0029] Optionally, the injection position is 100 mm to 1000 mm;

[0030] Optionally, the injection position is 100 mm to 700 mm;

[0031] Optionally, the caliber of the spray gun for injection is 40 - 70 mm;

[0032] Optionally, the injection pressure is 0.1 - 0.5 MPa;

[0033] Optionally, the injection air - material ratio is 40 - 45 Nm 3 / t.

[0034] In some embodiments, in the injection process, the soot is injected into the molten bath through the side of the smelting device;

[0035] Optionally, the caliber of the spray gun for injection is 3 - 5 mm;

[0036] Optionally, the injection pressure is 0.1 - 0.5 MPa;

[0037] Optionally, the injection air - material ratio is 30 - 35 Nm 3 / t.

[0038] In some embodiments, in the injection process, the soot is simultaneously injected into the molten bath through the top and side of the smelting device;

[0039] Optionally, the injection position through the top is 400 mm to 1500 mm;

[0040] Optionally, the caliber of the spray gun for injection through the top is 40 - 70 mm, the injection pressure is 0.2 - 0.5 MPa, and the injection air - material ratio is 40 - 45 Nm 3 / t;

[0041] Optionally, the caliber of the spray gun for injection through the side is 3 - 5 mm, and the injection pressure is

[0042] 0.1 - 0.5 MPa, and the injection air - material ratio is 30 - 35 Nm 3 / t.

[0043] Additional aspects and advantages of the present application will be given in part in the following description, will become apparent in part from the following description, or will be learned through the practice of the present application. Detailed embodiments

[0044] The present application will be clearly and completely described below in conjunction with the implementation embodiments of the present application. Obviously, the described implementation embodiments are only a part of the implementation embodiments of the present application, rather than all the implementation embodiments. Based on the implementation embodiments in the present application, all other implementation embodiments that can be obtained by those of ordinary skill in the art belong to the scope protected by the present application.

[0045] The "scope" disclosed in the present application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a specific range. The ranges defined in this way can include the end values or not include the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 - 120 and 80 - 110 are listed for a specific parameter, ranges of 60 - 110 and 80 - 120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, then the following ranges are all contemplated: 1 - 3, 1 - 4, 1 - 5, 2 - 3, 2 - 4, and 2 - 5. In the present application, unless otherwise stated, the numerical range "a - b" represents an abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0 - 5" represents that all real numbers between "0 - 5" have been fully listed herein, and "0 - 5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0046] If there is no special instruction, all implementation manners and optional implementation manners of the present application can be combined with each other to form a new technical solution.

[0047] If there is no special instruction, all technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

[0048] If there is no special instruction, all steps of the present application can be carried out in sequence or randomly, preferably in sequence. For example, the method includes steps (a) and (b), which means that the method can include steps (a) and (b) carried out in sequence, or can also include steps (b) and (a) carried out in sequence. For example, it is mentioned that the method may further include step (c), which means that step (c) can be added to the method in any order. For example, the method can include steps (a), (b), and (c), or can also include steps (a), (c), and (b), or can also include steps (c), (a), and (b), etc.

[0049] Unless otherwise specified, the terms "comprising" and "including" mentioned in this application are open-ended and can also be closed-ended. For example, the said "comprising" and "including" can also include or contain other components not listed, or can only include or contain the listed components.

[0050] Unless otherwise specified, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) while B is true (or exists); or both A and B are true (or exist).

[0051] The smelting soot in this application originates from the smelting process, such as the soot generated during the smelting of laterite nickel ore.

[0052] In the field of pyrometallurgy, the main components of the soot generated during the smelting process include valuable metals, metal oxides, etc. Reusing these soots in the smelting process can improve the utilization rate of mineral raw materials, reduce costs, and can also reduce the emission of soot and the harm to the environment. However, as mentioned above, the conventional humidification adhesion soot treatment method usually has problems such as limited structural strength, low recovery efficiency, and high energy consumption.

[0053] Therefore, this application provides a method for treating smelting soot to overcome the above problems existing in the prior art. Specifically, the method for treating smelting soot provided in this application includes: a trapping process for trapping the soot generated during the smelting process; a conveying process for conveying the trapped soot to a spraying device; and a spraying process for spraying the soot into the molten bath of the smelting device through the spraying device.

[0054] In this application, the above method for treating smelting soot can effectively relieve the environmental governance pressure caused by flying dust by trapping the soot and reusing it as a production raw material, and reduce environmental pollution. In addition, this method directly conveys the soot generated during the smelting process to the spraying device, reducing the intermediate links of traditional soot treatment, so the treatment time is reduced, the process flow is simplified, and the process complexity is reduced. At the same time, this method directly sprays the soot into the molten bath through the spraying process. On the one hand, the metal elements in the soot can quickly participate in the smelting reaction, shortening the smelting time, improving the effective furnace charging rate and smelting efficiency of the soot during the smelting process. On the other hand, it avoids the links such as soot - granulation - drying - furnace charging smelting in the prior art, further simplifies the process flow and the device, and reduces the energy consumption and production cost.

[0055] In some embodiments, the above method for treating smelting soot further includes: before the trapping process, passing the soot generated during the smelting process into a rotary kiln for temperature reduction treatment.

[0056] In this implementation, soot mainly exists in the flue gas generated by smelting devices such as oxygen-enriched side-blown furnaces and rotary kilns. Passing the soot generated during the smelting process into the rotary kiln for temperature reduction treatment is actually passing the high-temperature flue gas containing soot into the rotary kiln for temperature reduction treatment.

[0057] In some implementations, the temperature of the high-temperature flue gas is 900 - 1200 °C, and the temperature of the flue gas after temperature reduction treatment is 350 - 450 °C. Before collecting the soot, passing the high-temperature flue gas containing soot into the rotary kiln, on the one hand, can utilize the heat of the high-temperature flue gas to heat the minerals in the rotary kiln, saving energy. On the other hand, it can reduce the temperature of the high-temperature flue gas, making the soot in it easier to be collected and improving the collection efficiency of the subsequent collection process.

[0058] Collection process

[0059] As described above, the collection process is used to collect the soot generated during the smelting process.

[0060] In some implementations, the soot contains nickel (Ni) and iron (Fe) elements. In addition, the soot can also contain one or more of silicon dioxide (SiO2), calcium oxide (CaO), magnesium oxide (MgO), aluminum oxide (Al2O3), chromium oxide (Cr2O3), cobalt (Co), etc.

[0061] In some implementations, the soot composition contains 1.5 - 1.8% Ni, 32 - 35% Fe, 21 - 25% SiO2, 1 - 2.1% CaO, 5 - 9% MgO, 5 - 8.5% Al2O3, 1 - 2% Cr2O3, 0.05 - 0.08% Co by mass percentage. Among them, Ni, Fe, and Co exist in the soot in the form of oxides or elemental substances. When the soot contains elements such as Ni and Fe, the selection of the injection position can further improve the smelting efficiency.

[0062] In some implementations, the collection is carried out by means of ionization enrichment. Ionization enrichment can make the soot particles charged by using an electric field and drive the soot to deposit on the dust collection part under the action of the electric field, realizing the separation of the soot particles from the gas. This soot collection method can not only fully collect the soot, make the soot generated during the smelting process re-enter the smelting process, reduce the impact on the environment, and improve the effective furnace charging rate of the soot, but also improve the separation effect of the flue gas and the cleanliness of the flue gas entering the desulfurization system, thereby improving the desulfurization efficiency and extending the equipment life. When the ionization enrichment soot collection method is combined with the use of a rotary kiln for temperature reduction treatment of the soot, the ionization enrichment equipment can directly process the relatively high-temperature flue gas discharged from the rotary kiln, avoiding the problems of insufficient heat resistance of the equipment, poor filtration effect, and incomplete recovery of the soot existing in the related technologies.

[0063] In some embodiments, an electrostatic precipitator is used for ionization enrichment. Of course, other devices can also be used for ionization enrichment, and the present application does not limit this.

[0064] In some embodiments, in the trapping process, the temperature of the trapped soot is 300 - 400 °C, such as 300 °C, 310 °C, 320 °C, 330 °C, 340 °C, 350 °C, 360 °C, 370 °C, 380 °C, 390 °C, 400 °C.

[0065] Transportation process

[0066] As described above, after the soot is trapped, the trapped soot is transported to the injection device through the transportation process. In some embodiments of the present application, the temperature of the soot entering the injection device is 200 - 300 °C, such as 200 °C, 210 °C, 220 °C, 230 °C, 240 °C, 250 °C, 260 °C, 270 °C, 280 °C, 290 °C, 300 °C. Injecting at this temperature can balance multiple requirements such as heat recovery and equipment heat resistance.

[0067] In some embodiments, in the transportation process, the soot is first transported to the soot storage device and then to the injection device. This can store the trapped soot at any time during the smelting process and apply it to the smelting process when needed, increasing the flexibility and applicability of the smelting soot treatment method.

[0068] In some embodiments, the soot storage device is provided with a metering feeder for ensuring that the soot can be evenly and quantitatively transported to the injection device, so as to be more evenly injected into the molten bath of the smelting device, improving the effective utilization rate of the soot. And it can also transport the soot to the top and / or side of the smelting device according to needs, improving the flexibility of the smelting soot treatment method.

[0069] In some embodiments, in the transportation process, pneumatic pressurization is used for transportation. The soot can be transported through a pneumatic conveying pump, a high-temperature resistant pipeline, etc. In some embodiments, the transportation pressure is 100 - 300 KPa, and the transportation gas volume is 300 - 600 Nm 3 / h.

[0070] In some embodiments, compressed air is used as the transportation medium to transport the soot. Using pneumatic pressurization to transport the soot reduces the additional energy consumption caused by re-drying treatment in the traditional humidification and adhesion method, and overall improves the energy utilization rate.

[0071] Blowing process

[0072] In this application, after the captured soot is transported to the injection device, the soot is directly injected into the molten bath of the smelting device through the injection device. Among them, the injection device includes a lance, and the smelting device can be a side-blown furnace such as an oxygen-enriched side-blown furnace, an electric arc furnace, or a blast furnace. Of course, it can also be other injection devices and smelting devices commonly used in the art that can match the process, and this application does not limit this.

[0073] In some embodiments, the smelting device is an oxygen-enriched side-blown furnace, which is beneficial to ensuring the utilization efficiency of soot while reducing energy consumption, and at the same time improving the smelting efficiency.

[0074] In some embodiments, the multi-point injection technology is used for injection. In this application, multi-point injection refers to injecting at multiple positions of the smelting device, and the positions here can refer to one or more positions at the top, side, top and side of the smelting device. The multi-point injection method can make the soot enter the smelting reaction zone in the molten bath more evenly. In this way, after the soot enters the melt, it can quickly diffuse, increasing the contact area and reaction efficiency with the melt, and avoiding the low efficiency caused by limited structural strength in the traditional method.

[0075] In some embodiments, the injection is carried out in a pneumatic pressurization manner. In some embodiments, compressed air is used as the injection medium.

[0076] Top blowing method

[0077] In some embodiments, the soot is injected into the molten bath through the top of the smelting device. In this top injection method, the injection position is from -200 mm to 1500 mm, for example, -200, -100, 0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500 mm. In the embodiment of the top injection method, the injection position is the distance from the position where the soot is ejected to the slag surface in the molten bath, and can be calculated by the following formula: injection position = distance from the furnace top to the slag surface - lance insertion depth.

[0078] When the injection position is from -200 to 0 mm, that is, the soot directly enters the slag in the molten bath. On the one hand, the heat in the gas phase region can be used to heat the injection device, thereby indirectly heating the soot, increasing the temperature of the soot entering the molten bath. In this way, the soot can quickly complete the smelting, reduction, and sulfidation processes after entering the molten bath, and realize the enrichment of valuable metals such as nickel and iron, saving energy and improving the smelting efficiency. On the other hand, at this injection position, the soot directly enters the slag, which can avoid the waste of soot and improve the effective furnace charging rate of the soot.

[0079] When the injection position is greater than 0 mm and less than or equal to 1500 mm, the soot is injected by the injection device and then passes through the gas phase area above the molten bath and enters the molten bath. During this process, the soot can fully absorb and utilize the heat in the gas phase area, complete its own energy aggregation, increase its own temperature, so that it can quickly complete smelting, reduction, sulfidation, and sedimentation into the metal phase after entering the molten bath, realizing the enrichment of valuable metals such as nickel and iron and saving energy. Further, the soot may also be fully melted when passing through the gas phase area and fully blend with the melt in the molten bath after entering, which can avoid the waste of soot and can improve the recovery rate of valuable metals and the smelting efficiency. Even further, when the injection position is 0 - 1200 mm, the soot injected from the top can not only absorb the heat in the gas phase area to increase its own temperature, but also rely on the pneumatic pressure of the injection to participate in the agitation of the molten bath, promote the occurrence of smelting reactions, and increase the yield of valuable metals.

[0080] In some preferred embodiments, in this top injection method, the injection position is 100 mm to 1200 mm. At this injection position, a relatively high effective furnace charging rate of soot can be achieved, which can be maintained above 87%, up to 96.5% at most, and the energy saving rate is as high as 14.3%. More preferably, the injection position is 100 mm to 1000 mm, and even more preferably, the injection position is 100 mm to 700 mm. Within the above preferred ranges, the effective furnace charging rate of soot and the energy saving rate are further continuously improved.

[0081] In some embodiments, in this top injection method, the diameter of the lance used for injection is 40 - 70 mm, such as 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm.

[0082] In some embodiments, in this top injection method, the injection pressure is 0.1 - 0.5 MPa, such as 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.1 - 0.2 MPa, 0.2 - 0.3 MPa, 0.3 - 0.4 MPa, 0.4 - 0.5 MPa, 0.2 - 0.5 MPa, 0.2 - 0.4 MPa, 0.3 - 0.5 MPa. At this pressure, it can be ensured that the soot can be completely injected into the molten bath relying on the pneumatic pressure and can participate in the agitation of the molten bath in some cases, promoting the occurrence of smelting reactions and increasing the effective furnace charging rate of soot and the smelting efficiency. A large number of examples show that the greater the injection pressure, the more soot enters the molten bath and the higher the furnace charging rate of soot.

[0083] In some embodiments, in this top injection method, the injection gas-to-material ratio is 40 - 45 Nm 3 / t, such as 40, 41, 42, 43, 44, 45 Nm3 / t. In the present application, the "gas-to-material ratio" of injection refers to the ratio of the volume of gas required for injection to the mass of the injected material, with the unit of Nm 3 / t. Specifically, the gas-to-material ratio of injection is 40 - 45 Nm 3 / t means that 40 - 45 standard cubic meters (Nm 3 ) of gas is consumed for injecting per ton (t) of material.

[0084] By controlling the injection position of top injection, the caliber of the lance, the injection pressure, and / or the gas-to-material ratio of injection, the effective furnace charging rate of the soot can be improved, and energy can be saved. In some embodiments, the effective furnace charging rate of the smelting soot treatment method using the top injection method can reach 96.5%, and the energy saving rate can reach 14.3%.

[0085] Side blowing method

[0086] In some embodiments, in the injection process, the soot is injected into the molten bath from the side of the smelting device. Specifically, by injecting from the side of the smelting device, the soot can be injected into the molten bath at a position close to the diaphragm.

[0087] In this injection method, the soot can be directly injected into the melt, fully mixed with the melt, achieving nearly 100% recycling of the soot and effectively reducing environmental pollution. At the same time, under the action of the injection pressure, the soot injected directly into the melt will quickly spread, and at the high temperature of the molten bath, it will quickly melt into the melt, thus quickly participating in the smelting reaction and improving the reaction efficiency. In addition, after the soot is injected into the agitation zone of the molten bath under the injection pressure, it will promote the agitation of the melt. This agitation has a layering effect, separating the metal phase and the liquid phase, and at the same time promoting the valuable metal to pass through the diaphragm and enter the melt, thereby promoting the enrichment of the valuable metal. It can be understood that by injecting the soot containing elements such as nickel and iron into the molten bath, the momentum of the soot can also be used to increase the agitation ability of the gas, and at the same time, nickel and iron can participate in the relevant smelting reactions near the diaphragm, further reducing the hindrance of the diaphragm to the entry of valuable metals into the melt and improving the smelting efficiency and metal recovery rate.

[0088] In some embodiments, the caliber of the lance is 3 - 5 mm, such as 3, 3.5, 4, 4.4, 5 mm.

[0089] In some embodiments, the injection pressure is 0.1 - 0.5 MPa, such as 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.1 - 0.2 MPa, 0.2 - 0.3 MPa, 0.3 - 0.4 MPa, 0.4 - 0.5 MPa, 0.2 - 0.5 MPa, 0.2 - 0.4 MPa, 0.3 - 0.5 MPa. At this pressure, it can be ensured that the soot can be completely injected into the molten bath by pneumatic pressure and quickly spread, and can participate in the agitation of the molten bath, promoting the occurrence of smelting reactions and improving the smelting efficiency.

[0090] In some embodiments, in this side injection method, the injection gas-to-material ratio is 30 - 35 Nm 3 / t, such as 30, 31, 32, 33, 34, 35 Nm 3 / t.

[0091] By controlling the nozzle diameter of the lance, the injection pressure, and / or the injection gas-to-material ratio, the hourly yield of valuable metals can be improved. In some embodiments, the smelting soot treatment method using the side injection method can increase the hourly nickel yield by 12.47%.

[0092] Dual blowing method

[0093] In this application, the dual injection method refers to an injection method that combines top injection and side injection. The injection position of the top injection is the distance from the position where the soot is ejected to the slag surface in the molten bath, which can be calculated by the following formula: injection position = distance from the furnace top to the slag surface - lance insertion depth. The position of the side injection is the position on the side of the smelting device close to the diaphragm.

[0094] Specifically, in the injection process, the soot is injected simultaneously through the top and side of the smelting device. This dual injection technology has the technical effects of the above-mentioned top injection and side injection at the same time, which will not be elaborated here. In addition, using side and top injection simultaneously can also make the soot enter the molten bath from multiple directions, achieve multi-point fusion, increase the contact area between the metal particles in the soot and the melt in the molten bath, and further improve the effective furnace charging rate and smelting efficiency of the soot. The dual injection method can maximize the utilization of the heat and valuable metals of the soot, significantly improve the smelting efficiency, and reduce energy consumption and pollution emissions.

[0095] In some embodiments, in the double injection mode, the injection position for top injection is 400 mm to 1500 mm, such as 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500 mm. This enables the soot injected from the top to make full use of the heat in the gas phase region to increase its own temperature, so that it can quickly participate in the smelting reaction after entering the molten bath, thereby increasing the effective furnace charging rate of the soot and the energy saving rate.

[0096] In some embodiments, in the injection mode of double injection, the diameter of the lance for top injection is 40 - 70 mm, such as 40, 45, 50, 55, 60, 65, 70 mm; the injection pressure is 0.2 - 0.5 MPa, such as 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.2 - 0.3 MPa, 0.3 - 0.4 MPa, 0.4 - 0.5 MPa, 0.2 - 0.5 MPa, 0.2 - 0.4 MPa, 0.3 - 0.5 MPa; the injection gas-to-material ratio is 40 - 45 Nm 3 / t, such as 40, 41, 42, 43, 44, 45 Nm 3 / t. The same parameters in a similar range as described above can also achieve similar technical effects and will not be elaborated here.

[0097] In some embodiments, in the injection mode of double injection, the diameter of the lance for side injection is 3 - 5 mm, such as 3, 3.5, 4, 4.4, 5 mm, the injection pressure is 0.1 - 0.5 Mpa, such as 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.1 - 0.2 MPa, 0.2 - 0.3 MPa, 0.3 - 0.4 MPa, 0.4 - 0.5 MPa, 0.2 - 0.5 MPa, 0.2 - 0.4 MPa, 0.3 - 0.5 MPa; the injection gas-to-material ratio is 30 - 35 Nm 3 / t, such as 30, 31, 32, 33, 34, 35 Nm 3 / t. The same parameters in a similar range as described above can also achieve similar technical effects and will not be elaborated here.

[0098] By controlling the diameter, injection pressure, and / or injection gas-to-material ratio of the top and side lances, the hourly yield of valuable metals in smelting can be improved. In some embodiments, the smelting soot treatment method using the double injection mode can increase the hourly nickel yield by 12.8%.

[0099] The present application will be described more specifically and in detail below in conjunction with embodiments. The embodiments are only preferred implementation schemes of the present application and are not used to limit the present application. Unless otherwise specified, all raw materials and reagents of the present application are raw materials and reagents on the conventional market.

[0100] The following embodiments take the smelting process of producing nickel matte by smelting laterite nickel ore in an oxygen-enriched side-blown furnace as an example to describe in detail the method for treating smelting soot of the present application. Of course, the present application is also applicable to other smelting equipment and the smelting processes of other minerals. In the smelting process of producing nickel matte by smelting laterite nickel ore in an oxygen-enriched side-blown furnace, the soot generated by the oxygen-enriched side-blown furnace and / or rotary kiln is captured and recovered as fine powder of production raw materials.

[0101] The specific operation of the method for treating smelting soot using the top injection method is as follows:

[0102] Ionize and enrich the soot generated by the oxygen-enriched side-blown furnace and / or rotary kiln through an electrostatic precipitator, and collect the soot at a temperature of 300°C - 400°C. Use compressed air to transport it through a pneumatic conveying pipeline to the soot bin (i.e., the soot storage device) of the oxygen-enriched side-blown furnace. The soot bin is provided with a metering and feeding distributor to ensure that the soot can be evenly and quantitatively transported to the oxygen-enriched side-blown furnace, where the conveying pressure is 150 KPa and the conveying gas volume is 400 Nm 3 / h. The soot is distributed through the metering and feeding distributor and sprayed into the gas phase area of the oxygen-enriched side-blown furnace through a spray gun arranged at the top of the oxygen-enriched side-blown furnace. The soot passes through the spray gun and through the gas phase area and is immersed in the molten bath, and quickly fuses with the melt under agitation.

[0103] The specific operation of the method for treating smelting soot using the side injection method is as follows:

[0104] Ionize and enrich the soot generated by the oxygen-enriched side-blown furnace and / or rotary kiln through an electrostatic precipitator, and collect the soot at a temperature of 300°C - 400°C. Use compressed air to transport it through a pneumatic conveying pipeline to the soot bin (i.e., the soot storage device) of the oxygen-enriched side-blown furnace. The soot bin is provided with a metering and feeding distributor to ensure that the soot can be evenly and quantitatively transported to the oxygen-enriched side-blown furnace, where the conveying pressure is 180 KPa and the conveying gas volume is 500 Nm 3 / h. The soot is distributed through the metering and feeding distributor and sprayed into the molten bath area of the oxygen-enriched side-blown furnace through a spray gun arranged on the side of the oxygen-enriched side-blown furnace.

[0105] The specific operation of the method for treating smelting soot using the double injection method is as follows:

[0106] The double injection method refers to the combination of top injection and side injection to perform double injection treatment on the soot, which can improve the smelting efficiency. The soot collected by the oxygen-enriched side-blown furnace and / or rotary kiln is treated by an electrostatic precipitator to collect the soot at a temperature of 300°C - 400°C. The compressed air is used to transport it through a pneumatic conveying pipeline to the soot bin (i.e., the soot storage device) of the oxygen-enriched side-blown furnace. Optionally, the soot bin is provided with a metering feeder to ensure that the soot can be evenly and quantitatively transported to the oxygen-enriched side-blown furnace. Two independent conveying lines are respectively connected to the spray guns arranged at the top and side of the oxygen-enriched side-blown furnace. A part of the soot is injected into the oxygen-enriched side-blown furnace through the top spray gun, and another part of the soot is injected into the molten bath through the side spray gun.

[0107] The following examples are used to study the effects of injection methods, injection pressures, injection gas-to-material ratios, spray gun diameters, etc. on the method for treating smelting soot, and it is evaluated through indicators such as the effective furnace charging rate of soot, energy saving rate, and hourly nickel production increase rate, where:

[0108] Effective furnace charging rate of soot = (Actual amount of soot charged into the furnace / Amount of soot injected) × 100%;

[0109] Actual amount of soot charged into the furnace = (Increase in nickel metal) / (Recovery rate × Nickel content in soot), where the increase in nickel metal is the weight of the increased nickel metal during soot injection, the nickel content in soot refers to the weight percentage of nickel metal contained in the soot, and the recovery rate = Amount of nickel produced / Amount of nickel input;

[0110] Energy saving rate = (Heat carried by the actually charged soot into the furnace / Total heat consumption for soot smelting) × 100%;

[0111] Hourly nickel production increase rate = (Nickel production weight after injection - Nickel production weight before injection) / (Nickel production weight before injection) × 100%, where the nickel production weight after injection is the weight of the nickel metal produced after adopting the injection method of this application, and the nickel production weight before injection is the weight of the nickel metal produced without injection.

[0112] Example 1

[0113] Through the above method for treating smelting soot using the top injection method, the soot is injected into the furnace from the top melting material area of the oxygen-enriched side-blown furnace, where the injection pressure is 0.3 MPa, the diameter of the spray gun is 50 mm, and the injection gas-to-material ratio is 45 Nm 3 / t. The following examples are used to study the effects of the injection position on the effective furnace charging rate (effective utilization rate) and energy saving rate of the soot, and the results are shown in Table 1 below:

[0114] Table 1

[0115]

[0116]

[0117] It can be seen that when the injection position is 100 mm - 1500 mm, the effective furnace charging rate is 87.3% - 96.5%. That is to say, within this range, good immersion of soot can be maintained. When the injection position is 100 mm - 1000 mm, the effective furnace charging rate is 90.1% - 96.5%, which is the preferred range. In addition, it can also be seen that within the range of 100 - 1500 mm, energy savings are achieved. This indicates that after the soot particles are heated in the gas phase environment and immersed in the liquid phase in the molten bath, they can quickly complete smelting, reduction, and sulfidation, thereby using the heat in the gas phase region to achieve energy savings, and the lower the injection position, the higher the energy savings rate.

[0118] Example 2

[0119] Through the above - mentioned method for treating smelting soot by top - injection, the soot is injected into the furnace from the top melting material area of the oxygen - enriched side - blown furnace, where the injection pressure is 0.2 MPa, the nozzle diameter r of the lance is 50 mm, and the injection gas - to - material ratio is 42 Nm 3 / t. The following examples are used to study the influence of the injection position on the effective furnace charging rate (effective utilization rate) and energy savings rate of the soot, and the results are shown in Table 2 below.

[0120] Table 2

[0121]

[0122] It can be seen that when the injection position is 100 mm - 1500 mm, the effective furnace charging rate is 85.8% - 96.3%. That is to say, within this range, good immersion of soot can be maintained. When the injection position is 100 mm - 900 mm, the effective furnace charging rate is 90.0% - 96.3%, which is the preferred range. In addition, it can also be seen that within the range of 100 - 1500 mm, energy savings are achieved. This indicates that after the soot particles are heated in the gas phase environment and immersed in the liquid phase in the molten bath, they can quickly complete smelting, reduction, and sulfidation, thereby using the heat in the gas phase region to achieve energy savings, and the lower the injection position, the higher the energy savings rate.

[0123] Example 3

[0124] Through the above - mentioned method for treating smelting soot by top - injection, the soot is injected into the furnace from the top melting material area of the oxygen - enriched side - blown furnace, where the injection pressure is 0.1 MPa, the nozzle diameter r of the lance is 50 mm, and the injection gas - to - material ratio is 40 Nm 3 / t. The following examples are used to study the influence of the injection position on the effective furnace charging rate (effective utilization rate) and energy savings rate of the soot, and the results are shown in Table 3 below.

[0125] Table 3

[0126]

[0127] It can be seen that when the injection position is 100 mm - 1500 mm, the effective furnace charging rate is 82.8% - 95.2%. That is to say, within this range, good soot immersion can be maintained. When the injection position is 100 mm - 700 mm, the effective furnace charging rate is 92.3% - 95.2%, which is the preferred range. In addition, it can also be seen that within the range of 100 - 1500 mm, energy savings are achieved. This indicates that after the soot particles are heated in the gas phase environment and immersed in the liquid phase in the molten pool, smelting, reduction, and sulfidation can be quickly completed, thereby achieving energy savings by utilizing the heat in the gas phase region. Moreover, the lower the injection position, the higher the energy savings rate.

[0128] Example 4

[0129] Through the above-mentioned method for treating smelting soot by side injection, the soot is injected into the furnace from the side water jacket nozzle of the oxygen-enriched side-blown furnace. The diameter of the spray gun is 3.5 mm. The following examples are used to study the effects of injection pressure and injection gas-solid ratio on the hourly nickel production increase rate. The results are shown in Table 4 below.

[0130] Table 4

[0131]

[0132] It can be seen from the above examples that the method for treating smelting soot by side injection can improve the hourly nickel production increase rate. Specifically, it can be increased by at least 12.67%.

[0133] Example 5

[0134] Through the above-mentioned method for treating smelting soot by side injection, the soot is injected into the furnace from the side water jacket nozzle of the oxygen-enriched side-blown furnace. The diameter of the spray gun is 3 mm. The following examples are used to study the effects of injection pressure and injection gas-solid ratio on the hourly nickel production increase rate. The results are shown in Table 5 below.

[0135] Table 5

[0136]

[0137]

[0138] It can be seen from the above examples that the method for treating smelting soot by side injection can improve the hourly nickel production increase rate. Specifically, it can be increased by at least 12.47%.

[0139] Example 6

[0140] Through the above smelting soot treatment method using double injection technology, among which, the injection position of the top injection is 700 mm, the gun nozzle diameter is 60 mm, the injection pressure is 0.3 MPa, the gun nozzle diameter of the side injection is 3.5 mm. The following examples are used to study the effects of the injection gas-solid ratio of the top injection, the injection pressure and the injection gas-solid ratio of the side injection on the hourly nickel production increase rate. The results are shown in Table 6 below.

[0141] Table 6

[0142]

[0143] It can be seen from the above examples that the smelting soot treatment methods using the side injection method can improve the hourly nickel production increase rate. Specifically, it can be increased by at least 12.8%.

[0144] Example 7

[0145] Through the above smelting soot treatment method using double injection technology, among which, the injection position of the top injection is 600 mm, the gun nozzle diameter is 70 mm, the injection pressure is 0.4 MPa, the gun nozzle diameter of the side injection is 4 mm. The following examples are used to study the effects of the injection gas-solid ratio of the top injection, the injection pressure and the injection gas-solid ratio of the side injection on the hourly nickel production increase rate. The results are shown in Table 7 below.

[0146] Table 7

[0147]

[0148] It can be seen that the smelting soot treatment methods using the double injection method can improve the hourly nickel production increase rate. Specifically, it can be increased by at least 12.87%.

[0149] In the following comparative examples:

[0150] Effective furnace charge rate of granulated soot = (actual furnace charge amount of soot / furnace charge amount of granulated soot) × 100%;

[0151] Energy consumption increase rate = (heat consumed in preheating and roasting of soot / total heat consumed in soot smelting) × 100%;

[0152] Hourly nickel production increase rate = (nickel production weight after adding granulated soot - nickel production weight before adding) / (nickel production weight before adding) × 100%.

[0153] Comparative Example 1

[0154] Using the traditional method for treating smelting soot, the specific operation is as follows: The soot overflowing during the production of nickel matte from laterite nickel ore in an oxygen-enriched side-blown furnace is used as fine powder of production raw materials, and is collected and recovered by an electrostatic precipitator. The recovered soot is pre-wetted and stirred with 19% water, pelletized by a disk pelletizer, conveyed by a belt into a rotary kiln for preheating and roasting, passes through the gas phase region from the top of the oxygen-enriched side-blown furnace, and enters the liquid phase of the molten bath to participate in smelting, reduction, and sulfidation. The effective furnace charging rate of the pelletized soot is 74.35%, the energy consumption increase rate is 26.58%, and the hourly nickel increase rate is 10.87%.

[0155] Comparative Example 2

[0156] Using the traditional method for treating smelting soot, the specific operation is as follows: The soot overflowing during the production of nickel matte from laterite nickel ore in an oxygen-enriched side-blown furnace is used as fine powder of production raw materials, and is collected and recovered by an electrostatic precipitator. The recovered soot is pre-wetted and stirred with 24% water, pelletized by a disk pelletizer, conveyed by a belt into a rotary kiln for preheating and roasting, passes through the gas phase region from the top of the oxygen-enriched side-blown furnace, and enters the liquid phase of the molten bath to participate in smelting, reduction, and sulfidation. The effective furnace charging rate of the pelletized soot is 79.76%, the energy consumption increase rate is 33.57%, and the hourly nickel increase rate is 11.66%.

[0157] Comparative Example 3

[0158] Using the traditional method for treating smelting soot, the specific operation is as follows: The soot overflowing during the production of nickel matte from laterite nickel ore in an oxygen-enriched side-blown furnace is used as fine powder of production raw materials, and is collected and recovered by an electrostatic precipitator. The recovered soot is pre-wetted and stirred with 30% water, pelletized by a disk pelletizer, conveyed by a belt into a rotary kiln for preheating and roasting, passes through the gas phase region from the top of the oxygen-enriched side-blown furnace, and enters the liquid phase of the molten bath to participate in smelting, reduction, and sulfidation. The effective furnace charging rate of the pelletized soot is 81.43%, the energy consumption increase rate is 41.96%, and the hourly nickel increase rate is 11.91%.

[0159] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: They can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for treating smelting soot, characterized in that, Including: A trapping process for trapping the soot generated during the smelting process; A conveying process for conveying the trapped soot to a blowing device; And A blowing process for blowing the soot into the molten bath of the smelting device through the blowing device.

2. The smelting soot treatment method according to claim 1, wherein It further includes: Before the trapping process, the soot generated during the smelting process is introduced into a rotary kiln for temperature reduction treatment.

3. The smelting soot treatment method according to claim 1 or 2, characterized in that, The method further satisfies at least one of the following conditions: A. The soot contains nickel and iron elements; B. The composition of the soot includes 1.5 - 1.8% Ni, 32 - 35% Fe, 21 - 25% SiO2, 1 - 2.1% CaO, 5 - 9% MgO, 5 - 8.5% Al2O3, 1 - 2% Cr2O3, 0.05 - 0.08% Co by mass percentage; C. In the trapping process, the trapping is carried out by means of ionization enrichment; D. In the trapping process, the temperature of the trapped soot is 300 - 400°C.

4. The smelting soot treatment method according to claim 1, characterized in that, The method further satisfies at least one of the following conditions: A. In the conveying process, the soot is conveyed to a soot storage device and then to the blowing device; B. In the conveying process, the conveying is carried out by means of pneumatic pressurization; C. In the conveying process, the conveying pressure is 100 - 300 KPa, and the conveying gas volume is 300 - 600 Nm 3 / h; D. In the conveying process, compressed air is used as the conveying medium; E. The temperature of the soot entering the blowing device is 200 - 300°C.

5. The smelting soot treatment method according to claim 4, characterized in that The soot storage device is provided with a metering and feeding distributor for evenly conveying the soot to the blowing device.

6. The smelting soot treatment method according to claim 1, characterized in that, The method further satisfies at least one of the following conditions: A. In the blowing process, the blowing device includes a spray gun; B. In the blowing process, the blowing is carried out by means of multi-point blowing technology; C. In the blowing process, compressed air is used as the blowing medium.

7. The smelting soot treatment method according to claim 1, characterized in that, The smelting device is an oxygen-enriched side-blown furnace, an electric arc furnace or a blast furnace.

8. The smelting soot treatment method according to claim 1, characterized in that, In the blowing process, the soot is blown into the molten bath through the top of the smelting device; Optionally, the blowing position is -200mm to 1500mm; Optionally, the blowing position is 100mm to 1000mm; Optionally, the blowing position is 100mm to 700mm; Optionally, the caliber of the spray gun for blowing is 40 - 70mm; Optionally, the blowing pressure is 0.1 - 0.5MPa; Optionally, the blowing gas-to-material ratio is 40 - 45 Nm 3 / t.

9. The smelting soot treatment method according to claim 1, wherein, In the blowing process, the soot is blown into the molten bath through the side of the smelting device; Optionally, the caliber of the spray gun for blowing is 3 - 5mm; Optionally, the blowing pressure is 0.1 - 0.5MPa; Optionally, the blowing gas-solid ratio is 30 - 35 Nm 3 / t.

10. The smelting soot treatment method according to claim 1, characterized in that, In the blowing process, the soot is blown into the molten bath through the top and side of the smelting device simultaneously; Optionally, the blowing position for blowing through the top is 400mm to 1500mm; Optionally, the nozzle diameter of the lance for top blowing is 40 - 70 mm, the blowing pressure is 0.2 - 0.5 MPa, and the blowing gas-solid ratio is 40 - 45 Nm 3 / t; Optionally, the nozzle diameter of the lance for side injection is 3-5 mm, the injection pressure is 0.1-0.5 MPa, and the injection air-to-material ratio is 30-35 Nm 3 / t.

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