CN111363885B - Method for treating stainless steel dedusting ash by using electric arc furnace - Google Patents
Method for treating stainless steel dedusting ash by using electric arc furnace Download PDFInfo
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Abstract
The invention belongs to the technical field of metallurgical solid waste recycling application, and particularly relates to a method for treating stainless steel dedusting ash by using an electric arc furnace. The invention is suitable for an electric arc furnace for smelting stainless steel mother liquor or nickel-chromium-iron alloy, fine stainless steel dedusting ash powder, carbon powder and oxygen are sprayed into a molten pool of the electric arc furnace together by utilizing a three-layer sleeve type spray gun arranged on the wall of the electric arc furnace, a high-temperature high-carbon reaction area is formed near an outlet of the spray gun, the fine stainless steel dedusting ash powder is rapidly melted and reduced in the area, and other impurities float upwards to enter slag of the electric arc furnace. The method can safely and efficiently treat the highly toxic stainless steel dedusting ash, valuable elements such as chromium, nickel, iron and the like in the dedusting ash are reduced to enter the stainless steel mother liquor, and the rest components are converted into the slag of the electric arc furnace; the stirring of the electric arc furnace molten pool is greatly enhanced, and Cr in the slag is greatly enhanced2O3And the FeO content is reduced, which is beneficial to reducing the consumption of reducing agents such as ferrosilicon and the like.
Description
Technical Field
The invention belongs to the technical field of metallurgical solid waste recycling application, and particularly relates to a method for treating stainless steel dedusting ash by using an electric arc furnace.
Background
The stainless steel dedusting ash is a mixture collected by various dedusting equipment in the stainless steel smelting process. The stainless steel dedusting ash has great recovery value due to containing a great amount of nickel, chromium, iron and other elements, and simultaneously has great harm to the environment due to containing a great amount of heavy metal ions, particularly Cr contained in the stainless steel dedusting ash6+The stainless steel dedusting ash is defined as toxic waste due to extremely high toxicity, and the treatment difficulty is high. With the continuous expansion of stainless steel production energy in China, the accumulated amount of stainless steel dedusting ash increases sharply, and how to safely and efficiently digest the stainless steel dedusting ash becomes a great problem for stainless steel production enterprises.
At present, stainless steel fly ash is generally pressed into balls, then the balls are put into an ore-smelting furnace or an electric furnace through a high-level bunker, the fly ash balls are firstly dissolved in furnace slag, valuable elements such as nickel, chromium, iron and the like in the fly ash are reduced through slag-gold reaction, and virulent Cr is reduced6+Processed into nontoxic Cr3+. Although the method solves the utilization problem of the fly ash, the process is complex, the process cost is increased, the reaction kinetic condition of adding the spherical fly ash into the ore-smelting furnace or the electric furnace is poor, the slag-gold is difficult to reach a balanced state, the yield of the fly ash is low, and Cr in the slag is low2O3The content is high, and the consumption of reducing agents such as ferrosilicon and the like is large; in addition, the pelletizing process and the transportation process have the problem of secondary pollution.
Disclosure of Invention
In order to solve the problem of safe and efficient utilization of stainless steel dedusting ash, the invention provides a novel method for treating stainless steel dedusting ash by using an electric arc furnace, wherein a three-layer sleeve type spray gun is arranged on the wall of the electric arc furnace for smelting stainless steel mother liquor or nickel-chromium-iron alloy, the outlet of the spray gun is positioned between the steel liquid level and the smelting liquid level, fine-powder stainless steel dedusting ash and carbon powder are sprayed into a molten pool of the electric arc furnace by using the spray gun, the quick reduction of the dedusting ash is completed in the molten steel, the yield of the dedusting ash is greatly improved, the stirring is strengthened, and the Cr of final slag is reduced2O3And FeO content.
The technical scheme of the invention is as follows:
a method for treating stainless steel dedusting ash by using an electric arc furnace comprises the following steps:
(1) installing a three-layer sleeve type spray gun on the furnace wall of the electric arc furnace, wherein the outlet of the spray gun is positioned between the retained steel liquid level and the smelting liquid level; the spray gun comprises a central passage, a first annular seam passage and a second annular seam passage;
(2) in the process of smelting stainless steel mother liquor or nickel-chromium-iron alloy by using an electric arc furnace, the central channel stage-by-stage injects mixed powder of carbon powder, carbon powder and stainless steel dedusting ash fine powder, the first annular gap channel injects oxygen, and the second annular gap channel injects protective gas; realizing the melting and reduction of the stainless steel dedusting ash and finishing the treatment of the stainless steel dedusting ash.
According to the invention, a high-temperature and high-carbon reaction zone is formed near the outlet of the spray gun, the method is suitable for 30-300 tons of electric arc furnaces for smelting stainless steel mother liquor or nickel-chromium-iron alloy, and preferably, the number of the three-layer sleeve type spray guns is 1-5; the granularity of the fine powder of the stainless steel dedusting ash is 50-200 meshes.
In the invention, the step of jetting the mixed powder of carbon powder, carbon powder and stainless steel dedusting ash fine powder by stages comprises the following steps:
(1) in the scrap steel melting stage of the electric arc furnace, a first carrier gas and carbon powder are injected into a central channel, oxygen is injected into a first annular seam channel, and a first protective gas is injected into a second annular seam channel; supplementing carbon and heat to the furnace to accelerate the melting of the scrap steel;
(2) in the melting reduction stage, the central channel injects a mixed powder of a second carrier gas, carbon powder and stainless steel dedusting ash fine powder, the first annular gap channel injects oxygen, and the second annular gap channel injects a second protective gas; the rapid reduction of the fly ash is realized by utilizing the high-temperature high-carbon atmosphere near the outlet of the spray gun;
(3) in the final reduction stage, a third carrier gas and carbon powder are injected into the central channel, oxygen is injected into the first annular gap channel, and a third protective gas is injected into the second annular gap channel; strengthening the stirring of the molten pool and further reducing the Cr in the slag2O3And FeO;
(4) in the non-converting stage, nitrogen is blown through the central passage, the first annular gap passage and the second annular gap passage.
Preferably, the conditions at the start of the smelting reduction stage are: the scrap steel in the electric arc furnace is completely melted down, the temperature of a molten pool is higher than 1550 ℃, and the carbon content of the molten pool is higher than 0.5%; in the melting reduction stage, the solid-gas ratio of the central channel is 3-10; the mass flow ratio of the central channel carbon powder to the central channel stainless steel dedusting ash fine powder to the first annular seam oxygen is (30-50) to 100 to (20-40); the first carrier gas is any one or a mixture of any two or more of carbon monoxide, hydrogen, nitrogen, methane and propane; the second carrier gas is any one or a mixture of any two or more of carbon monoxide, hydrogen, nitrogen, methane and propane; the third carrier gas is any one or a mixture of any two or more of carbon monoxide, hydrogen, nitrogen, methane and propane; the first protective gas is any one or a mixed gas of gaseous hydrocarbon and nitrogen, the second protective gas is gaseous hydrocarbon, and the third protective gas is any one or a mixed gas of gaseous hydrocarbon and nitrogen; after the electric arc furnace taps steel, the spray gun outlet is exposed out of the liquid level, and the slag intermittently covers the spray gun outlet by tilting the electric arc furnace back and forth. Slag is adhered around the spray gun by utilizing the condensation effect of nitrogen injected by the spray gun, so that the spray gun and the refractory material around the spray gun are protected.
The principle of the invention is as follows: (1) the temperature of an electric arc furnace molten pool for smelting the stainless steel mother liquor is 1500-1650 ℃, the carbon content of the molten pool is less than 1%, the melting point of the stainless steel dedusting ash is high, the stainless steel dedusting ash is dissolved slowly in the electric arc furnace molten pool, and the reduction efficiency is lowFurther promoting the reduction of the oxides in the stainless steel dust by the carbon. (2) The outlet of the three-layer sleeve type spray gun is positioned below the liquid steel level, and gas and powder are directly sprayed into the molten pool, so that the stirring of the molten pool is enhanced, the slag-gold reaction balance is accelerated, and the further reduction of Cr in the slag is facilitated2O3And FeO content.
The invention has the beneficial effects that: (1) the chromium oxide, the nickel oxide and the iron oxide in the stainless steel dedusting ash are reduced to the stainless steel mother liquor or the nickel-chromium-iron alloy smelted by an electric arc furnace at high efficiency and low cost, so that the recovery and the utilization of valuable elements are realized, and the reduction rate of chromium, nickel and iron exceeds 90 percent; (2) the unreduced components in the stainless steel fly ash enter the electric arc furnace slag, so that the dangerous waste which is difficult to treat is converted into the electric arc furnace slag which is easy to treat; (3) injecting carbon powder to reduce Cr in slag in final reduction stage2O3The consumption of reducing agents such as ferrosilicon and the like is reduced, and the production cost is further reduced; (4) by adopting the three-layer sleeve type spray gun, powder such as carbon powder, stainless steel dedusting ash and the like is separated from oxygen and is respectively injected through different channels, so that the safety of the production process is ensured.
Drawings
FIG. 1 is a schematic view of the installation of a lance and a schematic view of the construction of the lance of an electric arc furnace according to the present invention;
in the figure: 1. the device comprises an electric arc furnace, 2, an electric arc furnace wall, 3, a steel liquid retaining surface, 4, a smelting liquid surface, 5, a three-layer sleeve type spray gun, 5-1, a central channel of the spray gun, 5-2, a first circular seam channel of the spray gun, 5-3 and a second circular seam channel of the spray gun.
Detailed Description
The method for treating stainless steel dedusting ash by using the electric arc furnace comprises the following steps of adding a first carrier gas, carbon powder, oxygen and a first protective gas in a melting stage; in the melting reduction stage, adding a second carrier gas, stainless steel dedusting ash, carbon powder, oxygen and a second protective gas; in the final reduction stage, adding a third carrier gas, carbon powder, oxygen and a third protective gas; finishing the treatment of stainless steel dedusting ash; all the above steps are carried out in an electric arc furnace.
According to the invention, the stainless steel dedusting ash is treated in the electric arc furnace, only carbon powder is used, no other solid is added, under the action of protective gas and carrier gas, chromium oxide, nickel oxide and iron oxide in the stainless steel dedusting ash are reduced to stainless steel mother liquor or nickel-chromium-iron alloy smelted in the electric arc furnace at high efficiency and low cost, and the recycling of valuable elements is realized.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
On the contrary, the invention is intended to cover alternatives, modifications, equivalents and alternatives which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, certain specific details are set forth in order to provide a better understanding of the present invention. It will be apparent to one skilled in the art that the present invention may be practiced without these specific details.
The invention utilizes a three-layer sleeve type spray gun to add carrier gas, carbon powder, protective gas or stainless steel dedusting ash and oxygen into an electric arc furnace, concretely, referring to attached figure 1, a three-layer sleeve type spray gun 5 is arranged on a furnace wall 2 of the electric arc furnace 1, an outlet of the spray gun is positioned between a molten steel remaining liquid level 3 and a smelting liquid level 4, and the spray gun is an existing product and comprises a central channel 5-1, a first circular seam channel 5-2 and a second circular seam channel 5-3; in the process of smelting stainless steel mother liquor or nickel-chromium-iron alloy, carbon powder, mixed powder of carbon powder and stainless steel dedusting ash fine powder are injected into a central channel in stages, oxygen is injected into a first annular gap channel, protective gas is injected into a second annular gap channel, a high-temperature high-carbon reaction zone is formed near the outlet of a spray gun, and the melting and reduction of the stainless steel dedusting ash are accelerated; the granularity of the stainless steel dedusting ash treated by the method is 50-200 meshes.
Example 1
The invention is applied to an electric arc furnace for smelting stainless steel mother liquor with the nominal capacity of 100t, the electric arc furnace takes stainless steel scrap, carbon steel scrap, ferrochrome, ferronickel, dephosphorized molten iron and the like as main raw materials, and provides the stainless steel mother liquor with proper components, weight and temperature for the AOD converter through conventional batching and smelting, thereby being the prior art; the electric arc furnace is provided with two identical three-layer sleeve type spray guns which are symmetrically arranged on two sides of a furnace door of the electric arc furnace respectively, outlets of the spray guns are positioned between a steel liquid level and a smelting liquid level, the diameter of a central channel of each spray gun is 14mm, the width of a first circular seam channel is 2mm, and the width of a second circular seam channel is 1 mm.
The stainless steel fly ash is the smoke dust collected by an electric arc furnace and AOD converter dust removal system, and the T.Fe content, the Ni content and the Cr content in the fly ash are respectively 46%, 0.8% and 9% according to mass percentage; the stainless steel dust removal fine powder is conveyed into a storage bin of an electric arc furnace powder spraying system by utilizing the existing pneumatic conveying mode.
The specific converting steps in this example are as follows:
(1) before charging in the electric arc furnace, the liquid level in the furnace is the tapping liquid level, the outlet of the spray gun is in a naked state, the central channel of the spray gun sprays nitrogen with the flow rate of 100Nm3The first annular gap channel is used for blowing nitrogen with the flow rate of 50Nm3The second annular gap channel is used for blowing nitrogen with the flow rate of 40Nm3/h；
(2) During the charging process of the electric arc furnace, the liquid level in the furnace rises, and in order to avoid the blockage of the spray gun, the central channel of the spray gun injects nitrogen with the flow rate of 300Nm3The first annular gap channel is used for blowing nitrogen with the flow rate of 200Nm3The second annular gap channel is used for blowing nitrogen with the flow rate of 60Nm3/h；
(3) After the charging is finished, smelting is started, carbon powder is blown by a central channel of a spray gun by taking nitrogen as carrier gas in the melting stage of raw materials such as scrap steel, and the flow rate of the nitrogen is 400Nm3The flow rate of the carbon powder is 40kg/min, the first annular gap channel is used for blowing oxygen, and the flow rate is 400Nm3The second annular gap channel is injected with natural gas with the flow rate of 60Nm3/h；
(4) When the scrap steel is completely melted down, the temperature of a molten pool reaches more than 1550 ℃, and the carbon content of the molten pool reaches more than 0.5wt%, blowing to enter a melting reduction stage, and blowing stainless steel dedusting ash fine powder and carbon powder by taking nitrogen as carrier gas through a central channel of a spray gunNitrogen flow 400Nm3The flow rate of stainless steel dedusting ash is 30kg/min, the flow rate of carbon powder is 10kg/min, oxygen is injected into the first annular gap channel, and the flow rate is 300Nm3The second annular gap channel is injected with natural gas with the flow rate of 60Nm3/h；
(5) The melting reduction stage lasts for 15min, the temperature of a molten pool reaches 1650 ℃, blowing enters the final reduction stage, the central channel of the spray gun uses nitrogen as carrier gas to blow carbon powder, and the flow rate of the nitrogen is 400Nm3The flow rate of the carbon powder is 40kg/min, the first annular gap channel is used for blowing oxygen, and the flow rate is 300Nm3The second annular gap channel is injected with natural gas with the flow rate of 60Nm3/h；
(6) The final reduction stage lasts for 5min, temperature measurement and sampling are carried out, tapping is carried out, the stainless steel liquid of the electric arc furnace prepared by using the stainless steel dedusting ash is obtained, nitrogen is injected into a central channel of a spray gun in the tapping process, and the flow rate is 300Nm3The first annular gap channel is used for blowing nitrogen with the flow rate of 200Nm3The second annular gap channel is used for blowing nitrogen with the flow rate of 60Nm3/h；
(7) After tapping, the liquid level in the furnace is recovered to the tapping liquid level, the outlet of the spray gun is exposed, slag intermittently covers the outlet of the spray gun by tilting the electric arc furnace back and forth, and the slag is adhered to the periphery of the spray gun by utilizing the condensation effect of nitrogen injected by the spray gun, so that the spray gun and the refractory materials around the spray gun are protected.
The flow rate in the blowing step is a blowing flow rate per one lance, and the above steps are performed in this order.
After the method is adopted, about 900kg of stainless steel fly ash can be processed in each furnace, according to field collection, the recovery rate of chromium in the fly ash can reach 92 percent, the recovery rate of nickel can reach 98 percent, the recovery rate of iron can reach 97 percent, and Cr in the slag at the smelting end point of the electric arc furnace can be obtained2O3The content is reduced by 2 percent.
By adopting the same method, 10 heats of stainless steel fly ash are respectively treated, the result fluctuation of each heat is small, the recovery rates of chromium element, nickel element and iron element in the fly ash are within 3 percent, and the Cr of the slag at the smelting end point of the electric arc furnace is found2O3The content is reduced by the difference ofWithin 2 percent.
Example 2
The invention is applied to an electric arc furnace for smelting stainless steel mother liquor with the nominal capacity of 50t, the electric arc furnace takes stainless steel scrap, carbon steel scrap, ferrochrome, ferronickel and the like as main raw materials, and provides stainless steel mother liquor with proper components, weight and temperature for an AOD converter through conventional proportioning and smelting, the electric arc furnace is provided with a three-layer sleeve type spray gun which is arranged on the right side of a furnace door of the electric arc furnace, an outlet of the spray gun is positioned between a steel remaining liquid level and a smelting liquid level, the diameter of a central channel of the spray gun is 16mm, the width of a first circular seam channel is 2mm, and the width of a second circular seam channel is 1 mm.
The stainless steel fly ash is the smoke dust collected by an electric arc furnace and AOD converter dust removal system, the content of T.Fe in the fly ash is about 48%, the content of Ni is about 0.9% and the content of Cr is about 10% by mass percent, and the fine powder of the stainless steel fly ash is conveyed into a storage bin of the electric arc furnace dust removal system by a pneumatic conveying mode.
The specific converting steps in this example are as follows:
(1) before charging in the electric arc furnace, the liquid level in the furnace is the tapping liquid level, the outlet of the spray gun is in a naked state, the central channel of the spray gun sprays nitrogen with the flow rate of 100Nm3The first annular gap channel is used for blowing nitrogen with the flow rate of 50Nm3The second annular gap channel is used for blowing nitrogen with the flow rate of 50Nm3/h；
(2) During the charging process of the electric arc furnace, the liquid level in the furnace rises, and in order to avoid the blockage of the spray gun, the central channel of the spray gun injects nitrogen with the flow of 400Nm3The first annular gap channel is used for blowing nitrogen with the flow rate of 300Nm3The second annular gap channel is used for blowing nitrogen with the flow rate of 80Nm3/h；
(3) After the charging is finished, smelting is started, carbon powder is blown by a central channel of a spray gun by taking nitrogen as carrier gas in the melting stage of the scrap steel, and the flow rate of the nitrogen is 500Nm3The flow rate of the carbon powder is 50kg/min, the first annular gap channel is used for blowing oxygen, and the flow rate is 400Nm3The second annular gap channel is used for blowing nitrogen with the flow rate of 100Nm3/h；
(4) When all the scrap steel is completely melted downWhen the temperature of the molten pool reaches more than 1550 ℃ and the carbon content of the molten pool reaches more than 0.5 percent, the blowing enters a melting reduction stage, the central channel of the spray gun uses nitrogen as carrier gas to blow fine powder and carbon powder of stainless steel dedusting ash, and the nitrogen flow is 500Nm3The flow rate of fine powder of stainless steel dedusting ash is 42kg/min, the flow rate of carbon powder is 14kg/min, oxygen is injected into the first annular gap channel, and the flow rate is 400Nm3The second annular gap channel is sprayed with natural gas with the flow rate of 80Nm3/h；
(5) The melting reduction stage lasts for 12min, the temperature of a molten pool reaches 1650 ℃, blowing enters the final reduction stage, the central channel of the spray gun uses nitrogen as carrier gas to blow carbon powder, and the flow rate of the nitrogen is 400Nm3The flow rate of the carbon powder is 40kg/min, the first annular gap channel is used for blowing oxygen, and the flow rate is 300Nm3The second annular gap channel is used for blowing nitrogen with the flow rate of 100Nm3/h；
(6) The final reduction stage lasts for 5min, temperature measurement and sampling are carried out, steel tapping is carried out, nitrogen is injected into a central channel of a spray gun in the steel tapping process, and the flow rate is 400Nm3The first annular gap channel is used for blowing nitrogen with the flow rate of 300Nm3The second annular gap channel is used for blowing nitrogen with the flow rate of 80Nm3/h；
(7) After tapping, the liquid level in the furnace is recovered to the tapping liquid level, the outlet of the spray gun is exposed, slag intermittently covers the outlet of the spray gun by tilting the electric arc furnace back and forth, and the slag is adhered to the periphery of the spray gun by utilizing the condensation effect of nitrogen injected by the spray gun, so that the spray gun and the refractory materials around the spray gun are protected.
After the method is adopted, about 500kg of stainless steel fly ash can be processed in each furnace, the recovery rate of chromium in the fly ash can reach 91 percent, the recovery rate of nickel can reach 97 percent, the recovery rate of iron can reach 98 percent, and Cr in the slag at the smelting end point of the electric arc furnace can be obtained2O3The content is reduced by 1.8 percent.
Comparative example
The electric arc furnace, the smelting raw materials and the stainless steel fly ash of the embodiment 2 are adopted, the step (4) is modified, and the rest is unchanged, and the method specifically comprises the following steps:
(4) when the scrap steel is completely melted down, the temperature of the molten pool reaches more than 1500 ℃, and the carbon content of the molten pool reaches 0.3when the weight percent is higher than the reference value, blowing the mixture into a melting reduction stage, blowing fine stainless steel dedusting ash powder and carbon powder by taking nitrogen as carrier gas in a central channel of a spray gun, wherein the nitrogen flow is 500Nm3The flow rate of fine powder of stainless steel dedusting ash is 42kg/min, the flow rate of carbon powder is 8kg/min, oxygen is injected into the first annular gap channel, and the flow rate is 400Nm3The second annular gap channel is sprayed with natural gas with the flow rate of 80Nm3H is used as the reference value. Because the initial temperature in the melting reduction stage is reduced, the initial carbon content is reduced, and the flow of the injected carbon powder is small, the heat in a molten pool is insufficient, a reducing agent is insufficient, the thermodynamic condition for reducing the fly ash is poor, a part of the fly ash cannot be effectively reduced due to the lack of the reducing agent, the recovery rate of chromium in the fly ash is only 62%, the recovery rate of nickel is only 71%, and the recovery rate of iron is only 82%; in addition, the chemical energy of the electric arc furnace smelting is reduced due to the reduction of the sprayed amount of the carbon powder, and the power consumption is increased by 9kwh/t steel.
The method for blowing the dedusting ash into the electric arc furnace is not available at present, and the dedusting ash and other materials are mixed and pressed into balls and thrown into the electric arc furnace. The working procedures are complex, the working procedure cost is increased, the reaction kinetic condition of adding the spherical fly ash into the submerged arc furnace or the electric furnace is poor, the slag-gold is difficult to reach a balanced state, the yield of the fly ash is low, and Cr in the slag is low2O3The content is high, and the consumption of reducing agents such as ferrosilicon and the like is large; in addition, the pelletizing process and the transportation process have the problem of secondary pollution.
The stainless steel dedusting ash has more heavy metals, wherein the metal elements with recovery value mainly comprise iron, chromium and nickel, the metal elements exist in the form of oxides or composite oxides, are all toxic heavy metal elements, particularly hexavalent chromium, the stainless steel dedusting ash is treated by a reduction method in the prior art, the problems of complex early treatment, high energy consumption, damage to refractory materials in a furnace and the like exist, particularly, the metal recovery fluctuation is large, the stainless steel dedusting powder is creatively and directly added into an electric arc furnace, the pelletizing is not needed, the raw material proportion is not changed, the stainless steel dedusting ash is reduced in the smelting process, the iron, chromium and nickel are stably and efficiently recovered, the refractory materials are protected, particularly, no metal reducing agent is added, and the technical problem that the existing electric arc furnace is not suitable for the stainless steel dedusting ash reduction due to complex smelting environment and many influencing factors is solved through the process control, the reduction product is not required to be smelted again, the whole smelting process is realized by adopting one-step reaction, and the reduction is really direct reduction, namely valuable metal is directly returned to the stainless steel by one-step reduction without additional equipment.
Claims (6)
1. A method for treating stainless steel dedusting ash by using an electric arc furnace is characterized by comprising the following steps:
(1) installing a three-layer sleeve type spray gun on the furnace wall of the electric arc furnace, wherein the outlet of the spray gun is positioned between the retained steel liquid level and the smelting liquid level; the spray gun comprises a central passage, a first annular seam passage and a second annular seam passage;
(2) in the process of smelting stainless steel mother liquor or nickel-chromium-iron alloy by using an electric arc furnace, the central channel stage-by-stage injects mixed powder of carbon powder, carbon powder and stainless steel dedusting ash fine powder, the first annular gap channel injects oxygen, and the second annular gap channel injects protective gas; realizing the melting and reduction of the stainless steel dedusting ash and finishing the treatment of the stainless steel dedusting ash;
the step of jetting the mixed powder of carbon powder, carbon powder and stainless steel dedusting ash fine powder by stages comprises the following steps:
(1) in the scrap steel melting stage of the electric arc furnace, a first carrier gas and carbon powder are injected into a central channel, oxygen is injected into a first annular seam channel, and a first protective gas is injected into a second annular seam channel;
(2) in the melting reduction stage, the central channel injects a mixed powder of a second carrier gas, carbon powder and stainless steel dedusting ash fine powder, the first annular gap channel injects oxygen, and the second annular gap channel injects a second protective gas; in the melting reduction stage, the solid-gas ratio of the central channel is 3-10; the mass flow ratio of the central channel carbon powder to the central channel stainless steel dedusting ash fine powder to the first annular seam oxygen is (30-50) to 100 to (20-40);
(3) in the final reduction stage, a third carrier gas and carbon powder are injected into the central channel, oxygen is injected into the first annular gap channel, and a third protective gas is injected into the second annular gap channel;
(4) in the non-converting stage, nitrogen is blown through the central passage, the first annular gap passage and the second annular gap passage.
2. The method for treating the stainless steel fly ash by using the electric arc furnace according to claim 1, wherein the method is suitable for 30-300 tons of electric arc furnaces for smelting stainless steel mother liquor or nickel-chromium-iron alloy; 1-5 three layers of sleeve type spray guns are arranged on the electric arc furnace; the granularity of the fine stainless steel dedusting ash powder is 50-200 meshes.
3. The method of processing stainless steel fly ash with an electric arc furnace of claim 1 wherein the conditions for the start of the smelting reduction stage are: the scrap steel in the electric arc furnace is completely melted down, the temperature of a molten pool is higher than 1550 ℃, and the carbon content of the molten pool is higher than 0.5%.
4. The method for treating stainless steel fly ash by using an electric arc furnace according to claim 1, wherein the first carrier gas is any one or a mixture of any two or more of carbon monoxide, hydrogen, nitrogen, methane and propane; the second carrier gas is any one or a mixture of any two or more of carbon monoxide, hydrogen, nitrogen, methane and propane; the third carrier gas is any one or a mixed gas of any two or more of carbon monoxide, hydrogen, nitrogen, methane and propane.
5. The method for treating stainless steel fly ash using electric arc furnace according to claim 1, wherein the first shielding gas is any one of gaseous hydrocarbon and nitrogen or a mixture thereof, the second shielding gas is gaseous hydrocarbon, and the third shielding gas is any one of gaseous hydrocarbon and nitrogen or a mixture thereof.
6. The method of processing stainless steel fly ash using an electric arc furnace as claimed in claim 1, wherein the lance outlet is exposed to the liquid surface after tapping of the electric arc furnace, and the slag intermittently covers the lance outlet by tilting the electric arc furnace back and forth.
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| CN113862551B (en) * | 2021-12-06 | 2022-03-04 | 北京科技大学 | Process control method for smelting stainless steel by blowing stainless steel dedusting ash in argon oxygen refining furnace |
| CN114835502A (en) * | 2022-04-06 | 2022-08-02 | 瑞泰科技股份有限公司 | Method for improving smelting quality of fusion-cast refractory material |
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