Method for deeply recovering phosphorus and vanadium from molten iron containing phosphorus and vanadium
By injecting a mixed gas into molten iron containing phosphorus and vanadium through a spray gun, the problem of low vanadium recovery rate was solved, achieving efficient recovery of phosphorus and vanadium, reducing smelting costs and dust levels, and improving resource utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-07
- Publication Date
- 2026-04-14
AI Technical Summary
In the existing technology for treating vanadium-containing molten iron, the vanadium recovery rate is low and the cost is high, and phosphorus is removed simultaneously, resulting in resource waste and increased smelting costs.
The oxygen blowing method is used to treat molten iron containing phosphorus and vanadium. A mixed gas, including oxidizing gas and inert gas, is blown into the molten iron using a spray gun. The spray gun directly enters the molten iron, and the concentration of oxidizing gas is 18%-50%. No coolant or slag-forming agent is required, which increases the contact area between the gas and the molten iron and enhances the reaction efficiency.
It improves the oxidation rate of phosphorus and vanadium, reduces the dust rate, enhances the stirring performance of the molten pool, improves the recovery rate of phosphorus and vanadium, realizes full utilization of resources, and reduces costs and heat loss.
Smart Images
Figure CN121852647A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of phosphorus and vanadium recovery from molten iron, and more specifically to a method for deep recovery of phosphorus and vanadium from phosphorus-vanadium molten iron. Background Technology
[0002] Materials such as coal shale contain elements such as phosphorus and vanadium. Pyrometallurgical processing produces large quantities of phosphorus- and vanadium-containing molten iron. The smelting of high-phosphorus iron ore, vanadium-titanium magnetite, and other materials, whether alone or in combination, also produces large quantities of phosphorus-, vanadium-, and phosphorus- and vanadium-containing molten iron. Phosphorus and vanadium are valuable elements with high recycling and application value.
[0003] In the prior art, vanadium-containing molten iron and vanadium-phosphorus-containing molten iron are mostly produced by oxygen blowing to obtain vanadium-containing slag. However, during the oxygen blowing process, the phosphorus element is also removed simultaneously. Therefore, for molten iron containing elements such as phosphorus and vanadium, while vanadium is being recovered, the phosphorus element is also being removed or recovered into the vanadium-containing slag.
[0004] Phosphorus, a harmful element in molten iron, is typically removed by oxygen blowing. However, to ensure effective removal, coolants and slagging agents are added during this process. This leads to low vanadium content and low vanadium recovery in the vanadium-containing slag. Furthermore, the conventional converter method uses top-blown oxygen, with the lance positioned above the molten iron. The injected oxygen directly acts on the surface of the molten iron, resulting in extremely high contact temperatures. This causes significant amounts of iron, phosphorus, and vanadium to volatilize and enter the flue gas. Additionally, the small contact area leads to low reaction efficiency, necessitating the use of pure oxygen, which in turn results in high smelting costs and high heat loss rates during open-top converter smelting. Summary of the Invention
[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of low vanadium content and low vanadium recovery rate in the vanadium-containing slag obtained by oxygen blowing in the treatment of molten iron containing elements such as phosphorus and vanadium in the prior art, thereby providing a method for deep recovery of phosphorus and vanadium from phosphorus-vanadium molten iron to solve the above problems.
[0006] A method for deep recovery of phosphorus and vanadium from molten iron containing phosphorus and vanadium involves treating the molten iron with oxygen blowing. In this method, a mixed gas is directly blown into the molten iron using a spray gun. The mixed gas includes an oxidizing gas and an inert gas, and the volume concentration of the oxidizing gas is 18%-50%.
[0007] For example, the volume concentration of the oxidizing gas can be 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, etc.
[0008] As an optional configuration, the oxidizing gas is oxygen and / or carbon dioxide.
[0009] As an optional configuration, the mixed gas is compressed air or oxygen-enriched air.
[0010] As an optional configuration, in the oxygen blowing method, the smelting temperature during mixed gas injection is 1300℃-1650℃, preferably 1350℃-1550℃. For example, the smelting temperature during mixed gas injection can be 1300℃, 1350℃, 1400℃, 1450℃, 1500℃, 1550℃, 1600℃, 1650℃, etc.
[0011] As an optional setup, the oxygen blowing method includes at least one of side-blown smelting, bottom-blown smelting, and top-blown smelting.
[0012] As an optional configuration, the number of spray guns can be 2-100. For example, the number of spray guns can be 2, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, etc.
[0013] As an optional configuration, the nozzle of the spray gun is immersed in molten vanadium-phosphate iron at a height h above the surface of the molten vanadium-phosphate iron, with a total depth of H; 0.01 ≤ h / H ≤ 1. For example, the value of h / H can be 0.01, 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1, etc.
[0014] As an optional configuration, the smelting furnace used in the oxygen blowing method is a self-heating furnace.
[0015] As an optional configuration, the nozzle of the spray gun is evenly distributed in the molten iron containing phosphorus and vanadium.
[0016] The technical solution of this invention has the following advantages: This invention provides a method for deep recovery of phosphorus and vanadium from molten iron containing phosphorus and vanadium. The method involves treating the molten iron containing phosphorus and vanadium using an oxygen blowing method. In the oxygen blowing method, a mixed gas is directly blown into the molten iron using a spray gun. The mixed gas includes an oxidizing gas and an inert gas, and the volume concentration of the oxidizing gas is 18%-50%. The method of this invention eliminates the need for coolants and slag-forming agents. By directly injecting a mixed gas into the molten iron using a spray gun, it can efficiently recover phosphorus and vanadium from the molten iron. Specifically, the inert gas in the mixed gas cools the spray gun head, while the rising dust is captured by other molten materials, significantly reducing the dust rate. The oxidizing gas in the mixed gas directly enters the molten iron, greatly increasing the contact area between the gas and the molten iron, significantly improving the reaction efficiency, and simultaneously increasing the oxidation rate of phosphorus and vanadium in the molten iron, which can reach over 95%. Through the synergistic effect of the above measures, the reaction rate is accelerated, the dust rate is reduced, and the stirring performance of the molten pool is enhanced, thereby improving the phosphorus and vanadium recovery rate and obtaining phosphorus and vanadium-rich slag. This solves the shortcomings of existing phosphorus and vanadium-containing molten iron treatments, such as low vanadium content and low vanadium recovery rate in the vanadium-containing slag. It features low cost, short process, environmental friendliness, low carbon emissions, high heat utilization rate, and full utilization of resources. Attached Figure Description
[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the side-blown furnace in Embodiment 1 of the present invention.
[0019] Figure label: 1-Spray gun; 2-Phosphorus-vanadium molten iron. Detailed Implementation The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.
[0020] In the description of this invention, it should be noted that the terms "side," "upper," "lower," "top," "bottom," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0022] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.
[0023] Example 1 A method for deep recovery of phosphorus and vanadium from molten iron containing phosphorus and vanadium, such as Figure 1 As shown, it includes: (1) Obtaining phosphorus-vanadium-containing molten iron Phosphorus-vanadium molten iron was obtained in a melting furnace using conventional steelmaking smelting steps. The composition of the phosphorus-vanadium molten iron is shown in Table 1 below. Table 1. Composition of Phosphorus- and Vanadium-Containing Molten Iron (2) Method of oxygen blowing in molten iron containing phosphorus and vanadium Phosphorus-vanadium-containing molten iron is added to the smelting furnace via a converter. Compressed air is directly injected into the phosphorus-vanadium-containing molten iron 2 through a spray gun 1 located on the side or bottom of the smelting furnace. The oxygen in the air entering the molten iron selectively oxidizes most of the phosphorus, vanadium, silicon, calcium and other elements into oxides that enter the slag. A small amount of iron is oxidized into oxides and enters the slag, resulting in phosphorus-vanadium-rich slag, which is used for further processing to obtain phosphorus and vanadium products. The produced flue dust is mixed with the phosphorus-vanadium-rich slag to recover phosphorus and vanadium resources. The remaining molten iron is returned to the system as a collector or used in steelmaking.
[0024] The specific process of step (2) is as follows: The phosphorus-vanadium-containing molten iron in step (1) is selectively oxidized by blowing air into a side-blown furnace. The side-blown furnace has 20 spray guns, which are evenly distributed inside the phosphorus-vanadium-containing molten iron, and the positions of the spray gun nozzles are evenly distributed within the range of 0.01≤h / H≤1. The air consumption is 373 Nm³. 3 / t of phosphorus-vanadium molten iron, smelted at 1500℃, produces phosphorus-vanadium rich slag, molten iron and flue dust.
[0025] The phosphorus- and vanadium-rich slag produced contained 19.48% phosphorus and 13.07% vanadium and phosphorus, respectively. The total recovery rates of P and V in phosphorus- and vanadium-rich slag and flue dust were 98.12% and 97.78%, respectively. The remaining molten iron has a carbon content of 0.031%.
[0026] Example 2 A method for deep recovery of phosphorus and vanadium from molten iron containing phosphorus and vanadium differs from Example 1 in that the parameters for the oxygen blowing method in step (2) of the molten iron containing phosphorus and vanadium are different, as follows: (1) Obtaining phosphorus-vanadium-containing molten iron Phosphorus-vanadium molten iron was obtained in a melting furnace using conventional steelmaking smelting steps. The composition of the phosphorus-vanadium molten iron is shown in Table 1 above. (2) Method of oxygen blowing in molten iron containing phosphorus and vanadium Phosphorus-vanadium-containing molten iron is added to the smelting furnace via a converter. Compressed air is directly injected into the phosphorus-vanadium-containing molten iron 2 through a spray gun 1 located on the side or bottom of the smelting furnace. The oxygen in the air entering the molten iron selectively oxidizes most of the phosphorus, vanadium, silicon, calcium and other elements into oxides that enter the slag. A small amount of iron is oxidized into oxides and enters the slag, resulting in phosphorus-vanadium-rich slag, which is used for further processing to obtain phosphorus and vanadium products. The produced flue dust is mixed with the phosphorus-vanadium-rich slag to recover phosphorus and vanadium resources. The remaining molten iron is returned to the system as a collector or used in steelmaking.
[0027] The specific process of step (2) is as follows: The phosphorus-vanadium-containing molten iron in step (1) is selectively oxidized by blowing air into a side-blown furnace. The side-blown furnace has 20 spray guns, which are evenly distributed inside the phosphorus-vanadium-containing molten iron, and the positions of the spray gun nozzles are evenly distributed within the range of 0.01≤h / H≤1. The air consumption is 316 Nm³. 3 / t of phosphorus-vanadium molten iron, smelted at 1380℃, produces phosphorus-vanadium rich slag, molten iron and flue dust.
[0028] The phosphorus- and vanadium-rich slag produced contained 17.45% phosphorus and 11.58% vanadium and phosphorus, respectively. The total recovery rates of P and V in phosphorus- and vanadium-rich slag and flue dust were 96.76% and 93.53%, respectively. The remaining molten iron has a carbon content of 2.0%.
[0029] Example 3 A method for deep recovery of phosphorus and vanadium from molten iron containing phosphorus and vanadium differs from Example 1 in that the parameters for the oxygen blowing method in step (2) of the molten iron containing phosphorus and vanadium are different, as follows: (1) Obtaining phosphorus-vanadium-containing molten iron Phosphorus-vanadium molten iron was obtained in a melting furnace using conventional steelmaking smelting steps. The composition of the phosphorus-vanadium molten iron is shown in Table 1 above. (2) Method of oxygen blowing in molten iron containing phosphorus and vanadium Phosphorus-vanadium-containing molten iron is added to the smelting furnace via a converter. Compressed air is directly injected into the phosphorus-vanadium-containing molten iron 2 through a spray gun 1 located on the side or bottom of the smelting furnace. The oxygen in the air entering the molten iron selectively oxidizes most of the phosphorus, vanadium, silicon, calcium and other elements into oxides that enter the slag. A small amount of iron is oxidized into oxides and enters the slag, resulting in phosphorus-vanadium-rich slag, which is used for further processing to obtain phosphorus and vanadium products. The produced flue dust is mixed with the phosphorus-vanadium-rich slag to recover phosphorus and vanadium resources. The remaining molten iron is returned to the system as a collector or used in steelmaking.
[0030] The specific process of step (2) is as follows: The phosphorus-vanadium-containing molten iron in step (1) is selectively oxidized by blowing air into a side-blown furnace. The side-blown furnace has 20 spray guns, which are evenly distributed inside the phosphorus-vanadium-containing molten iron, and the positions of the spray gun nozzles are evenly distributed within the range of 0.01≤h / H≤1. The air consumption is 373 Nm³. 3 / t of phosphorus-vanadium molten iron, smelted at 1630℃, produces phosphorus-vanadium rich slag, molten iron and flue dust.
[0031] The phosphorus- and vanadium-rich slag produced contained 20.57% phosphorus and 13.51% vanadium and phosphorus, respectively. The total recovery rates of P and V in phosphorus- and vanadium-rich slag and flue dust were 99.78% and 99.0%, respectively. The remaining molten iron has a carbon content of 0.05%.
[0032] Example 4 A method for deep recovery of phosphorus and vanadium from molten iron containing phosphorus and vanadium differs from Example 1 in that the parameters for the oxygen blowing method in step (2) of the molten iron containing phosphorus and vanadium are different, as follows: (1) Obtaining phosphorus-vanadium-containing molten iron Phosphorus-vanadium molten iron was obtained in a melting furnace using conventional steelmaking smelting steps. The composition of the phosphorus-vanadium molten iron is shown in Table 1 above. (2) Method of oxygen blowing in molten iron containing phosphorus and vanadium Phosphorus-vanadium-containing molten iron is added to the smelting furnace via a converter. Compressed air is directly injected into the phosphorus-vanadium-containing molten iron 2 through a spray gun 1 located on the side or bottom of the smelting furnace. The oxygen in the air entering the molten iron selectively oxidizes most of the phosphorus, vanadium, silicon, calcium and other elements into oxides that enter the slag. A small amount of iron is oxidized into oxides and enters the slag, resulting in phosphorus-vanadium-rich slag, which is used for further processing to obtain phosphorus and vanadium products. The produced flue dust is mixed with the phosphorus-vanadium-rich slag to recover phosphorus and vanadium resources. The remaining molten iron is returned to the system as a collector or used in steelmaking.
[0033] The specific process of step (2) is as follows: The phosphorus-vanadium-containing molten iron in step (1) is selectively oxidized by blowing air into a side-blown furnace. The side-blown furnace has 50 spray guns, which are evenly distributed inside the phosphorus-vanadium-containing molten iron, and the positions of the spray gun nozzles are evenly distributed within the range of 0.01≤h / H≤1. The air consumption is 373 Nm³. 3 / t of phosphorus-vanadium molten iron, smelted at 1330℃, produces phosphorus-vanadium rich slag, molten iron and flue dust.
[0034] The phosphorus- and vanadium-rich slag produced contained 17.8% phosphorus and 11.7% vanadium and phosphorus, respectively. The total recovery rates of P and V in phosphorus- and vanadium-rich slag and flue dust were 98.6% and 96.5%, respectively. The remaining molten iron has a carbon content of 2.4%.
[0035] Example 5 A method for deep recovery of phosphorus and vanadium from molten iron containing phosphorus and vanadium differs from Example 1 in that the parameters for the oxygen blowing method in step (2) of the molten iron containing phosphorus and vanadium are different, as follows: (1) Obtaining phosphorus-vanadium-containing molten iron Phosphorus-vanadium molten iron was obtained in a melting furnace using conventional steelmaking smelting steps. The composition of the phosphorus-vanadium molten iron is shown in Table 1 above. (2) Method of oxygen blowing in molten iron containing phosphorus and vanadium Phosphorus-vanadium-containing molten iron is added to the smelting furnace via a converter. Compressed air is directly injected into the phosphorus-vanadium-containing molten iron 2 through a spray gun 1 located on the side or bottom of the smelting furnace. The oxygen in the air entering the molten iron selectively oxidizes most of the phosphorus, vanadium, silicon, calcium and other elements into oxides that enter the slag. A small amount of iron is oxidized into oxides and enters the slag, resulting in phosphorus-vanadium-rich slag, which is used for further processing to obtain phosphorus and vanadium products. The produced flue dust is mixed with the phosphorus-vanadium-rich slag to recover phosphorus and vanadium resources. The remaining molten iron is returned to the system as a collector or used in steelmaking.
[0036] The specific process of step (2) is as follows: The phosphorus-vanadium-containing molten iron in step (1) is selectively oxidized by blowing air into a bottom-blown furnace. The side-blown furnace has three spray guns, and the nozzles of the spray guns are all located at the bottom of the bottom-blown furnace, i.e., h / H=1. The spray guns are evenly distributed at the bottom of the bottom-blown furnace, and the air consumption is 373 Nm³. 3 / t of phosphorus-vanadium molten iron, smelted at 1500℃, produces phosphorus-vanadium rich slag, molten iron and flue dust.
[0037] The phosphorus- and vanadium-rich slag produced contained 17.88% phosphorus and 11.86% vanadium and phosphorus, respectively. The total recovery rates of P and V in phosphorus- and vanadium-rich slag and flue dust were 98.78% and 97.34%, respectively. The remaining molten iron has a carbon content of 0.03%.
[0038] Example 6 A method for deep recovery of phosphorus and vanadium from molten iron containing phosphorus and vanadium differs from Example 1 in that the parameters for the oxygen blowing method in step (2) of the molten iron containing phosphorus and vanadium are different, as follows: (1) Obtaining phosphorus-vanadium-containing molten iron Phosphorus-vanadium molten iron was obtained in a melting furnace using conventional steelmaking smelting steps. The composition of the phosphorus-vanadium molten iron is shown in Table 1 above. (2) Method of oxygen blowing in molten iron containing phosphorus and vanadium Phosphorus-vanadium-containing molten iron is added to the smelting furnace via a converter. Compressed air is directly injected into the phosphorus-vanadium-containing molten iron 2 through a spray gun 1 located on the side or bottom of the smelting furnace. The oxygen in the air entering the molten iron selectively oxidizes most of the phosphorus, vanadium, silicon, calcium and other elements into oxides that enter the slag. A small amount of iron is oxidized into oxides and enters the slag, resulting in phosphorus-vanadium-rich slag, which is used for further processing to obtain phosphorus and vanadium products. The produced flue dust is mixed with the phosphorus-vanadium-rich slag to recover phosphorus and vanadium resources. The remaining molten iron is returned to the system as a collector or used in steelmaking.
[0039] The specific process of step (2) is as follows: The phosphorus-vanadium-containing molten iron in step (1) is selectively oxidized by blowing air into a top-blown furnace. The side-blown furnace has 100 spray guns, all with their nozzles inserted into the phosphorus-vanadium-containing molten iron in the top-blown furnace. The nozzle positions satisfy h / H = 0.01, and the spray guns are evenly distributed at the top of the furnace. The air consumption is 373 Nm³. 3 / t of phosphorus-vanadium molten iron, smelted at 1500℃, produces phosphorus-vanadium rich slag, molten iron and flue dust.
[0040] The phosphorus- and vanadium-rich slag produced contained 19.6% phosphorus and 13.2% vanadium and phosphorus, respectively. The total recovery rates of P and V in phosphorus- and vanadium-rich slag and flue dust were 99.6% and 99.2%, respectively. The remaining molten iron has a carbon content of 0.04%.
[0041] Example 7 A method for deep recovery of phosphorus and vanadium from molten iron containing phosphorus and vanadium differs from Example 1 in that the parameters for the oxygen blowing method in step (2) of the molten iron containing phosphorus and vanadium are different, as follows: (1) Obtaining phosphorus-vanadium-containing molten iron Phosphorus-vanadium molten iron was obtained in a melting furnace using conventional steelmaking smelting steps. The composition of the phosphorus-vanadium molten iron is shown in Table 1 above. (2) Method of oxygen blowing in molten iron containing phosphorus and vanadium Phosphorus-vanadium-containing molten iron is added to the smelting furnace via a converter. Compressed air is directly injected into the phosphorus-vanadium-containing molten iron 2 through a spray gun 1 located on the side or bottom of the smelting furnace. The oxygen in the air entering the molten iron selectively oxidizes most of the phosphorus, vanadium, silicon, calcium and other elements into oxides that enter the slag. A small amount of iron is oxidized into oxides and enters the slag, resulting in phosphorus-vanadium-rich slag, which is used for further processing to obtain phosphorus and vanadium products. The produced flue dust is mixed with the phosphorus-vanadium-rich slag to recover phosphorus and vanadium resources. The remaining molten iron is returned to the system as a collector or used in steelmaking.
[0042] The specific process of step (2) is as follows: The phosphorus-vanadium-containing molten iron in step (1) is selectively oxidized by injecting a mixed gas into a side-blown furnace. The side-blown furnace has 20 lances, evenly distributed inside the molten iron, with the lance nozzles evenly distributed within a range of 0.01 ≤ h / H ≤ 1. The mixed gas contains 18% oxygen by volume, and nitrogen is the inert gas. The amount of mixed gas used is 373 Nm³. 3 / t of phosphorus-vanadium molten iron, smelted at 1500℃, produces phosphorus-vanadium rich slag, molten iron and flue dust.
[0043] The phosphorus- and vanadium-rich slag produced contained 19.25% phosphorus and 13.09% vanadium and phosphorus, respectively. The total recovery rates of P and V in phosphorus- and vanadium-rich slag and flue dust were 98.05% and 98.36%, respectively. The remaining molten iron has a carbon content of 0.045%.
[0044] Example 8 A method for deep recovery of phosphorus and vanadium from molten iron containing phosphorus and vanadium differs from Example 1 in that the parameters for the oxygen blowing method in step (2) of the molten iron containing phosphorus and vanadium are different, as follows: (1) Obtaining phosphorus-vanadium-containing molten iron Phosphorus-vanadium molten iron was obtained in a melting furnace using conventional steelmaking smelting steps. The composition of the phosphorus-vanadium molten iron is shown in Table 1 above. (2) Method of oxygen blowing in molten iron containing phosphorus and vanadium Phosphorus-vanadium-containing molten iron is added to the smelting furnace via a converter. Compressed air is directly injected into the phosphorus-vanadium-containing molten iron 2 through a spray gun 1 located on the side or bottom of the smelting furnace. The oxygen in the air entering the molten iron selectively oxidizes most of the phosphorus, vanadium, silicon, calcium and other elements into oxides that enter the slag. A small amount of iron is oxidized into oxides and enters the slag, resulting in phosphorus-vanadium-rich slag, which is used for further processing to obtain phosphorus and vanadium products. The produced flue dust is mixed with the phosphorus-vanadium-rich slag to recover phosphorus and vanadium resources. The remaining molten iron is returned to the system as a collector or used in steelmaking.
[0045] The specific process of step (2) is as follows: The phosphorus-vanadium molten iron in step (1) is selectively oxidized by injecting a mixed gas into a side-blown furnace. The furnace has 20 lances, evenly distributed inside the molten iron, with the lance nozzles positioned uniformly within a range of 0.01 ≤ h / H ≤ 1. The mixed gas contains 50% oxygen by volume, and nitrogen is used as the inert gas. The amount of mixed gas used is 373 Nm³. 3 / t of phosphorus-vanadium molten iron, smelted at 1500℃, produces phosphorus-vanadium rich slag, molten iron and flue dust.
[0046] The phosphorus- and vanadium-rich slag produced contained 19.92% phosphorus and 13.37% vanadium and phosphorus, respectively. The total recovery rates of P and V in phosphorus- and vanadium-rich slag and flue dust were 98.34% and 97.96%, respectively. The remaining molten iron has a carbon content of 0.056%.
[0047] Comparative Example 1 The difference between this comparative example and Example 1 is that the oxygen blowing method uses top blowing smelting, and the position of the lance nozzle in top blowing smelting is above the surface of the molten iron. Other conditions are the same as in Example 1.
[0048] (1) Obtaining phosphorus-vanadium-containing molten iron Phosphorus-vanadium molten iron was obtained in a melting furnace using conventional steelmaking smelting steps. The composition of the phosphorus-vanadium molten iron is shown in Table 1 above. (2) Method of oxygen blowing in molten iron containing phosphorus and vanadium Phosphorus-vanadium-containing molten iron from the melting furnace is added to the smelting furnace. Compressed air is directly sprayed onto the phosphorus-vanadium-containing molten iron 2 through a spray gun 1 set at the top of the smelting furnace. The oxygen in contact with the molten iron selectively oxidizes most of the phosphorus, vanadium, silicon, calcium and other elements into oxides that enter the slag. A small amount of iron is oxidized into oxides and enters the slag, resulting in phosphorus-vanadium-rich slag, which is used for further processing to obtain phosphorus and vanadium products. The produced flue dust is mixed with the phosphorus-vanadium-rich slag to recover phosphorus and vanadium resources. The remaining molten iron is returned to the system as a collector or used in steelmaking.
[0049] The specific process of step (2) is as follows: The phosphorus-vanadium-containing molten iron in step (1) is selectively oxidized using a top-blown smelting method. The smelting furnace has 20 lances evenly distributed above the phosphorus-vanadium-containing molten iron, and the air consumption is 373 Nm³. 3 / t of phosphorus-vanadium molten iron, smelted at 1500℃, produces phosphorus-vanadium rich slag, molten iron and flue dust.
[0050] The phosphorus- and vanadium-rich slag produced contained 19.7% phosphorus and 12.75% v phosphorus and v v, respectively. The total recovery rates of P and V in phosphorus- and vanadium-rich slag and flue dust were 95.1% and 92.02%, respectively. The remaining molten iron has a carbon content of 0.12%.
[0051] The results of the above embodiments and comparative examples show that the method of the present invention does not require the addition of coolant and slag-forming agent. By directly injecting a mixed gas including oxidizing gas and inert gas into the molten iron using a spray gun, phosphorus and vanadium in the molten iron can be efficiently recovered. Specifically, the inert gas in the mixed gas cools the spray gun head, and the smoke and dust are captured by other melts during the rising process, significantly reducing the smoke and dust rate. The oxidizing gas in the mixed gas directly enters the molten iron, greatly increasing the contact area between the gas and the molten iron, significantly improving the reaction efficiency, and increasing the oxidation rate of phosphorus and vanadium in the molten iron, which can reach over 95%. Through the synergy between the various features of the present invention, the effects of accelerating the reaction rate, reducing the smoke and dust rate, and enhancing the stirring performance of the molten pool are achieved, thereby improving the phosphorus and vanadium recovery rate and obtaining phosphorus and vanadium-rich slag. This solves the shortcomings of low vanadium content and low vanadium recovery rate in vanadium-containing slag after existing phosphorus and vanadium-containing molten iron treatment. It has the characteristics of low cost, short process, environmental friendliness, low carbon emissions, high heat utilization rate, and full utilization of resources.
[0052] Data from Examples 1-6 show that by injecting a mixed gas with a volume concentration of oxidizing gas of 18%-50% into the molten iron containing phosphorus and vanadium, and by increasing the amount of oxidizing gas introduced per ton of molten iron containing phosphorus and vanadium, the number of spray guns, the height h of the spray guns extending into the molten iron containing phosphorus and vanadium from the surface of the molten iron, and the smelting temperature, the recovery rate of phosphorus and vanadium in the molten iron containing phosphorus and vanadium is higher. In this invention, by further adjusting the above parameters, the recovery rate of phosphorus and vanadium in the molten iron containing phosphorus and vanadium can be increased to over 97%, or even over 99%.
[0053] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A method for deep recovery of phosphorus and vanadium from molten iron containing phosphorus and vanadium, comprising treating the molten iron containing phosphorus and vanadium using an oxygen blowing method, characterized in that, In the oxygen blowing method, a mixed gas is directly blown into the molten iron using a spray gun. The mixed gas includes an oxidizing gas and an inert gas, and the volume concentration of the oxidizing gas is 18%-50%.
2. The method according to claim 1, characterized in that, The oxidizing gas is oxygen and / or carbon dioxide.
3. The method according to claim 2, characterized in that, The mixed gas is compressed air or oxygen-enriched air.
4. The method according to any one of claims 1-3, characterized in that, In the oxygen blowing method, the smelting temperature during mixed gas injection is 1300℃-1650℃.
5. The method according to claim 4, characterized in that, The smelting temperature is 1350℃-1550℃.
6. The method according to any one of claims 1-5, characterized in that, The oxygen blowing method includes at least one of side-blowing smelting, bottom-blowing smelting, and top-blowing smelting.
7. The method according to claim 6, characterized in that, The number of spray guns is 2-100.
8. The method according to any one of claims 1-7, characterized in that, The nozzle of the spray gun is immersed in molten iron containing phosphorus and vanadium, at a height h above the surface of the molten iron containing phosphorus and vanadium, and the total depth of the molten iron containing phosphorus and vanadium is H; 0.01≤h / H≤1.
9. The method according to any one of claims 1-8, characterized in that, The smelting furnace used in the oxygen blowing method is a self-heating furnace.
10. The method according to any one of claims 1-9, characterized in that, The nozzle of the spray gun is evenly distributed in the molten iron containing phosphorus and vanadium.