Vanadium-iron alloy smelting slag-gold separation control method

Abstract

The present application relates to a vanadium-iron alloy smelting slag-gold separation control method, which comprises: a. mixing and smelting vanadium-iron alloy smelting raw materials including vanadium-containing materials, reducing agents, iron materials and slag characteristic regulators, and the first mass percentage of iron materials is used in step a; b. after the vanadium-iron alloy smelting raw materials are completely melted to form a molten pool, the smelting system is maintained in a molten state by power supply until the vanadium mass fraction in the molten slag is reduced by less than a predetermined value, and then slagging is performed; c. adding the second mass percentage of iron materials to the surface of the molten pool, and continuously supplying power for a predetermined time; d. after the reaction product is cooled, the slag-gold is separated to obtain a vanadium-iron alloy and a smelting corundum slag. The present application approximates the settlement of vanadium-iron alloy molten particles in the molten slag as free settlement in an infinite fluid, and based on this theory, the influencing factors of the slag-gold separation efficiency in the aluminum thermal reduction vanadium-iron alloy smelting process are obtained, the conditions of the alloy settlement conditions are effectively improved, and the efficient separation of the molten slag-gold is promoted.

Description

Technical Field

[0001] This invention belongs to the field of metallurgy, specifically relating to a method for controlling the separation of gold from vanadium-iron alloy smelting slag. Background Technology

[0002] Vanadium in steel can combine with carbon and nitrogen to form fine and dispersed carbonitrides, exhibiting a dual strengthening mechanism of fine-grain strengthening and precipitation strengthening, thus improving the strength and wear resistance of steel. Therefore, vanadium-containing steel is widely used in construction, aerospace, and road and bridge industries. It is mainly added to steel as a vanadium-containing master alloy. Ferrovanadium alloy is currently the most widely used vanadium-containing microalloying steel additive. Its preparation method mainly uses vanadium oxide as raw material and metallic aluminum as a reducing agent, employing an aluminothermic self-propagating smelting process. According to the charging system and furnace function, its smelting methods mainly include one-step, two-step, and multi-stage methods. The most important technical and economic indicators in the production of ferrovanadium alloys include smelting yield, smelting efficiency, product quality, and the comprehensive utilization rate of vanadium-containing secondary resources.

[0003] Patent CN 104532105 A discloses a method for producing ferrovanadium using a large tilting furnace electrothermal process. This method combines multi-stage smelting with stepped aluminum blending, offering advantages such as convenient operation, reduced aluminum consumption, and high ferrovanadium yield. Patent CN109825704 A discloses a smelting method for ferrovanadium alloys. This method employs a two-step reduction process—one-step reduction followed by ladle refining—which significantly reduces waste slag TV, improves product quality, and enables continuous smelting. Patent CN 114293081A discloses a method for smelting ferrovanadium in a straight-cylinder furnace. This method is characterized by the mutual tilting of the molten slag and alloy in two straight-cylinder furnaces to promote slag-alloy mixing, thereby maximizing aluminum utilization efficiency and obtaining a qualified ferrovanadium alloy.

[0004] Based on the publicly available technologies, current optimization of ferrovanadium alloy smelting processes mainly focuses on improving smelting yield and efficiency. The principles of slag inclusions and gold coating in slag during ferrovanadium alloy smelting, and their impact on smelting yield and product quality, have not yet been thoroughly studied.

[0005] Therefore, existing technologies still need improvement. Summary of the Invention

[0006] The purpose of this invention is to solve the quality and yield problems caused by gold inclusion in slag and alloy slag inclusion in the current vanadium-iron alloy smelting process. It provides a slag-gold separation control method based on the theory of free settling of infinite fluids. This method aims to realize the practical application of Stokes' settling equation in the industrial production of vanadium-iron alloys, thereby promoting the efficient separation of gold from molten slag in the vanadium-iron alloy smelting process.

[0007] Specifically, the present invention provides a method for controlling the separation of vanadium-iron alloy smelting slag and gold, comprising the following steps: a. smelting vanadium-iron alloy smelting raw materials by mixing them, wherein the vanadium-iron alloy smelting raw materials include vanadium-containing materials, reducing agents, iron materials, and slag characteristic regulators, and a first mass percentage of the iron materials is used in step a; b. after the vanadium-iron alloy smelting raw materials have completely melted to form a molten pool, maintaining the molten state of the smelting system by applying electricity until the vanadium mass fraction in the slag decreases by less than a predetermined value, at which point the slag is discharged; c. adding a second mass percentage of the iron materials to the surface of the molten pool and continuously applying electricity for a predetermined time; and d. cooling the reaction product obtained in step c and separating the slag and gold to obtain vanadium-iron alloy and smelting corundum slag.

[0008] In embodiments of the present invention, the vanadium-containing material includes at least one of vanadium oxide, vanadium-containing dust, and vanadium-containing enriched material, and the vanadium oxide accounts for not less than 90% of the total vanadium-containing material (by weight of vanadium), wherein the vanadium oxide includes vanadium trioxide and vanadium pentoxide; the reducing agent includes metallic aluminum; the ferrous material includes ferrous material with metallic iron as the main component, and its effective component (by weight of metallic iron) is not less than 95%; the slag characteristic regulator includes pre-calcined lime, and its effective component (by weight of CaO) is not less than 90%.

[0009] In the embodiments of the present invention, the theoretical aluminum consumption of the vanadium-containing materials is 485 kg / t V2O5 and 360 kg / t V2O3, respectively.

[0010] In an embodiment of the present invention, in step a, the first mass percentage is 80% to 95%, and in step c, the second mass percentage is 5% to 20%.

[0011] In an embodiment of the present invention, in step b, the predetermined value is 0.01% / min, the slag discharge rate is 50% of the total slag amount, and the slag discharge rate is 50% to 90% of the theoretical slag production rate. The theoretical slag production rate is the alumina produced by the thermal reduction of vanadium oxide divided by the mass percentage of alumina in the slag.

[0012] In embodiments of the present invention, the ferrovanadium alloy includes FeV50 or FeV80, and the vanadium to iron weight ratio of the vanadium-containing material and the iron material in the ferrovanadium alloy smelting raw materials required for smelting FeV50 and FeV80 is 50:45-48 and 80:46-48, respectively.

[0013] In an embodiment of the present invention, in step c, the predetermined time is 10 min to 60 min.

[0014] In an embodiment of the present invention, in step a, the amount of vanadium-containing material and reducing agent added to the vanadium-iron alloy smelting raw material is based on 1.05 to 1.10 times the theoretical aluminum consumption of vanadium oxide, and the amount of slag characteristic regulator added to the vanadium-iron alloy smelting raw material is 5% to 25% of the theoretical slag production.

[0015] In the embodiments of the present invention, the mixing principle of the vanadium-containing materials and the iron materials is based on meeting the vanadium to iron weight ratio corresponding to different grades of vanadium-iron alloys in the GBT / 4139-2012 standard.

[0016] In embodiments of the present invention, the method is applicable to mainstream aluminothermic self-propagating reduction processes for preparing ferrovanadium alloys, including the straight-tube furnace aluminothermic one-step reduction method and the tilting furnace multi-stage reduction method.

[0017] This invention approximates the settling of ferrovanadium alloy molten particles in slag as free settling in an infinitely large fluid. Based on this theory, the theoretical settling and floating velocities of alloys with different particle sizes under different temperature conditions during the aluminothermic reduction of ferrovanadium alloy smelting process were obtained, as well as the influencing factors on the slag-gold separation efficiency of the process. Based on a thorough study of these influencing factors, the technical solution of this invention was obtained, realizing the practical application of the Stokes settling equation in the industrial production of ferrovanadium alloys. This effectively improves the alloy settling conditions during the ferrovanadium alloy smelting process and promotes the efficient separation of molten slag and gold. Attached Figure Description

[0018] Figure 1 The diagram shows a flow chart of a method for controlling the separation of vanadium-iron alloy smelting slag and gold, provided by an embodiment of the present invention. Detailed Implementation

[0019] It should be understood that the embodiments of the invention shown in the exemplary embodiments are merely illustrative. Although only a few embodiments have been described in detail in this invention, those skilled in the art will readily recognize that various modifications are possible without substantially departing from the teachings of the invention. Accordingly, all such modifications should be included within the scope of the invention. Other substitutions, modifications, variations, and deletions can be made to the design, operating conditions, and parameters of the following exemplary embodiments without departing from the spirit of the invention.

[0020] This invention approximates the settling of ferrovanadium alloy molten particles in slag as free settling in an infinitely large fluid. Based on this theory, the theoretical settling and floating velocities of alloys with different particle sizes under different temperature conditions during the aluminothermic reduction of ferrovanadium alloy smelting process were obtained, as well as the influencing factors on the slag-gold separation efficiency of the process. Based on a thorough study of these influencing factors, the technical solution of this invention was obtained, realizing the practical application of the Stokes settling equation in the industrial production of ferrovanadium alloys. This effectively improves the alloy settling conditions during the ferrovanadium alloy smelting process and promotes the efficient separation of molten slag and gold.

[0021] According to the present invention, a method for controlling the separation of gold from vanadium-iron alloy smelting slag is provided, such as... Figure 1 As shown, it includes the following steps:

[0022] a. The vanadium-iron alloy smelting raw materials are mixed and then smelted, wherein the vanadium-iron alloy smelting raw materials include vanadium-containing materials, reducing agents, iron materials and slag characteristic modifiers, and a first mass percentage of the iron materials is used in step a;

[0023] b. After the vanadium-iron alloy smelting raw materials have been completely melted to form a molten pool, electricity is applied to maintain the molten state of the smelting system until the vanadium mass fraction in the slag decreases by less than a predetermined value, at which point the slag is discharged.

[0024] c. Add the second mass percentage of the iron material to the surface of the molten pool and continue to energize for a predetermined time; and

[0025] d. After cooling the reaction product obtained in step c, separate the slag and gold to obtain ferrovanadium alloy and smelting corundum slag.

[0026] In embodiments of the present invention, the vanadium-containing material includes at least one of vanadium oxide, vanadium-containing dust, and vanadium-enriched material, and the vanadium oxide accounts for no less than 90% of the total vanadium-containing material (by weight of vanadium), wherein the vanadium oxide includes vanadium trioxide and vanadium pentoxide; the reducing agent includes metallic aluminum with a purity of no less than 99%; the ferrous material includes ferrous material with metallic iron as the main component, and its effective component (based on metallic iron) is no less than 95%; the slag characteristic regulator includes pre-calcined lime, and its effective component (based on CaO) is no less than 90%.

[0027] In the embodiments of the present invention, the theoretical aluminum consumption of the vanadium-containing materials is 485 kg / t V2O5 and 360 kg / t V2O3, respectively.

[0028] In embodiments of the present invention, the factor affecting the alloy particle size is the probability of alloy phase aggregation and growth. A non-uniform iron distribution mode is used to control the alloy particle size, and the iron material addition ratio before and after smelting is in the range of 80:20 to 95:5. Therefore, in step a, the first mass percentage is 80% to 95%, and in step c, the second mass percentage is 5% to 20%.

[0029] In an embodiment of the present invention, in step b, the predetermined value is 0.01% / min, and the slag discharge is 50% of the total slag discharge. Reducing the slag layer thickness is beneficial to shortening the alloy settling path. Factors affecting the slag layer thickness include the slag production per unit alloy and the slag discharge parameters after different stages of smelting. In the actual smelting process, the slag discharge is 50% to 90% of the theoretical slag production.

[0030] In embodiments of the present invention, the ferrovanadium alloy includes FeV50 or FeV80, and the vanadium to iron weight ratio of the vanadium-containing material and the iron material in the ferrovanadium alloy smelting raw materials required for smelting FeV50 and FeV80 is 50:45-48 and 80:46-48, respectively.

[0031] In embodiments of the present invention, factors affecting the slag-gold cooling rate include energizing time and heat preservation measures. In actual smelting processes, the energizing time is continuously 10 to 60 minutes after smelting, and an insulation cover is added for protective cooling after energizing. Therefore, in step c, the predetermined time is 10 to 60 minutes.

[0032] In an embodiment of the present invention, in step a, the amount of vanadium-containing materials and reducing agent added to the vanadium-iron alloy smelting raw materials is based on 1.05 to 1.10 times the theoretical aluminum consumption of vanadium oxide. Furthermore, slag characteristics mainly include slag viscosity and slag melting point. The addition of slag characteristic regulators can effectively reduce the slag melting point and viscosity. In actual smelting processes, the amount of slag characteristic regulator added to the vanadium-iron alloy smelting raw materials is 5% to 25% of the theoretical slag production.

[0033] In the embodiments of the present invention, the mixing principle of the vanadium-containing materials and the iron materials is based on meeting the vanadium to iron weight ratio corresponding to different grades of vanadium-iron alloys in the GBT / 4139-2012 standard.

[0034] In embodiments of the present invention, the method is applicable to mainstream aluminothermic self-propagating reduction processes for preparing ferrovanadium alloys, including the straight-tube furnace aluminothermic one-step reduction method and the tilting furnace multi-stage reduction method.

[0035] The present invention will be illustrated below through specific embodiments:

[0036] Example 1

[0037] All vanadium-containing materials (vanadium pentoxide TV (total vanadium) 55.0% by weight, vanadium trioxide TV 64.0% by weight), all metallic aluminum (aluminum particle purity 99.0% by weight, actual aluminum particle addition 1.5 times theoretical addition), 95% iron material (effective component 99.0%), and all lime (effective component 90% by weight) were mixed. The vanadium mixture was then uniformly loaded into a smelting electric furnace for smelting. After the vanadium-iron smelting mixture was completely melted to form a molten pool, the smelting system was kept in a molten state by power until the vanadium mass fraction of the slag decreased by less than 0.01% / min. At this point, slag was discharged (50% of the total slag). The remaining 5% of iron material was uniformly added to the surface of the molten pool, and power was continuously supplied for 10 minutes. After the smelting was completed, an insulation cover was added to the upper surface of the furnace for air cooling. After the reaction products were completely cooled, the slag and gold were separated to obtain vanadium-iron alloy and smelting corundum slag.

[0038] Implementation results: Under the above smelting conditions, the TV content of the waste slag was 1.5%, the gold encapsulation rate in the slag was 0.8%, the slag inclusion rate in the alloy cake was 2.3%, the corresponding vanadium smelting yield was 96.7%, and the first-pass yield of the product was 97.7%.

[0039] Example 2

[0040] All vanadium-containing materials (vanadium pentoxide TV of 55.0% by weight, vanadium trioxide TV of 64.0% by weight), all metallic aluminum (aluminum particle purity of 99.0% by weight, actual addition of aluminum particles is 1.5 times the theoretical addition), 90% iron material (effective component of 99.0%), and all lime (effective component of 90% by weight) were mixed together. The vanadium mixture was then uniformly loaded into a smelting electric furnace for smelting. After the vanadium-iron smelting mixture was completely melted to form a molten pool, the smelting system was kept in a molten state by power until the vanadium mass fraction of the slag decreased by less than 0.01% / min. At this point, slag was discharged (70% of the total slag). The remaining 10% of iron material was uniformly added to the surface of the molten pool and the smelting was continued for 30 minutes. After the smelting was completed, an insulation cover was added to the upper surface of the furnace for air cooling. After the reaction products were completely cooled, the slag and gold were separated to obtain vanadium-iron alloy and smelting corundum slag.

[0041] Implementation results: Under the above smelting conditions, the TV content of the waste slag was 1.1%, the gold encapsulation rate in the slag was 0.5%, the slag inclusion rate in the alloy cake was 1.5%, the corresponding vanadium smelting yield was 97.6%, and the first-pass yield of the product was 98.5%.

[0042] Example 3

[0043] All vanadium-containing materials (vanadium pentoxide TV of 55.0% by weight, vanadium trioxide TV of 64.0% by weight), all metallic aluminum (aluminum particle purity of 99.0% by weight, actual addition of aluminum particles 1.5 times the theoretical addition), 80% iron material (effective component of 99.0%), and all lime (effective component of 90% by weight) were mixed together. The vanadium mixture was then uniformly loaded into a smelting electric furnace for smelting (the smelting method was one-step). After the vanadium-iron smelting mixture was completely melted to form a molten pool, the smelting system was kept in a molten state by power until the vanadium mass fraction of the slag decreased by less than 0.01% / min. At this point, slag was discharged (the amount of slag discharged was 90% of the total slag). The remaining 20% ​​of iron material was uniformly added to the surface of the molten pool and the smelting was continued for 60 minutes. After the smelting was completed, an insulation cover was added to the upper surface of the furnace for air cooling. After the reaction products were completely cooled, the slag and gold were separated to obtain vanadium-iron alloy and smelting corundum slag.

[0044] Implementation results: Under the above smelting conditions, the TV content of the waste slag was 0.9%, the gold encapsulation rate in the slag was 0.3%, the slag inclusion rate in the alloy cake was 0.8%, the corresponding vanadium smelting yield was 98.0%, and the first-pass yield of the product was 99.2%.

[0045] Comparative Example 1

[0046] All vanadium-containing materials (vanadium pentoxide TV of 55.0% by weight, vanadium trioxide TV of 64.0% by weight), metallic aluminum (aluminum particle purity of 99.0% by weight, actual addition of aluminum particles 1.5 times the theoretical addition), iron materials (effective component of 99.0%), and lime (effective component of 90% by weight) were mixed and uniformly loaded into a smelting electric furnace for smelting. After the vanadium-iron smelting mixture was completely melted to form a molten pool, the smelting system was kept in a molten state by powering on until the vanadium mass fraction of the slag decreased by less than 0.01% / min. Then the powering was stopped and air cooling was performed. After the reaction products were completely cooled, the slag and gold were separated to obtain vanadium-iron alloy and smelting corundum slag.

[0047] Implementation results: Under the above smelting conditions, the TV content of the waste slag was 1.7%, the gold encapsulation rate in the slag was 1.1%, the slag inclusion rate in the alloy cake was 2.6%, the corresponding vanadium smelting yield was 96.3%, and the first-pass yield of the product was 97.4%.

[0048] Test Example 1

[0049] The main technical indicators of test examples 1-3 and comparative example 1 are shown in Table 1.

[0050] The formula for calculating vanadium smelting yield is: Vanadium smelting yield = Vanadium mass fraction in smelting slag × Slag amount ÷ Vanadium content in raw material × 100%.

[0051] The formula for calculating the first pass rate is: First pass rate = 1 - Slag inclusion rate × 100%.

[0052] Table 1

[0053]

[0054] As shown in Table 1, compared with the prior art, the method described in this invention can achieve a higher vanadium smelting yield and a higher first-pass yield.

[0055] This invention approximates the settling behavior of molten ferrovanadium alloy particles in low-density slag during aluminothermic reduction as free settling in an infinitely large fluid. Based on this theory, the theoretical settling and floating velocities of alloys with different particle sizes under different temperature conditions during the aluminothermic reduction of ferrovanadium alloy smelting process are obtained. The main influencing factors on the slag-metal separation efficiency of this process include slag characteristics, slag layer thickness, slag-metal cooling rate, and alloy particle size. Furthermore, these process parameters are optimized and controlled during actual production, resulting in significant social and economic benefits.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications or equivalent substitutions made to the present invention without departing from the spirit and scope thereof should be covered within the protection scope of the claims of the present invention.

Claims

1. A method for controlling the separation of vanadium-iron alloy slag and gold, characterized in that, The method is based on the theory of free settling of an infinite fluid, and the method includes the following steps: a. The vanadium-iron alloy smelting raw materials are mixed and then smelted, wherein the vanadium-iron alloy smelting raw materials include vanadium-containing materials, reducing agents, iron materials and slag characteristic modifiers, and 80% to 95% of the iron materials are used in step a; b. After the vanadium-iron alloy smelting raw materials have completely melted and formed a molten pool, electricity is applied to maintain the molten state of the smelting system until the vanadium mass fraction in the slag decreases by less than 0.01% / min, at which point the slag is discharged. The amount of slag discharged is 50% to 90% of the theoretical slag production. c. Add 5% to 20% of the iron material to the surface of the molten pool and continuously apply electricity for a predetermined time; and d. After cooling the reaction product obtained in step c, separate the slag and gold to obtain ferrovanadium alloy and smelting corundum slag.

2. The method for controlling the separation of vanadium-iron alloy smelting slag and gold according to claim 1, characterized in that, The vanadium-containing material includes at least one of vanadium oxide, vanadium-containing dust, and vanadium-enriched material, and the vanadium oxide accounts for no less than 90% of the total vanadium-containing material by weight of vanadium, wherein the vanadium oxide includes vanadium trioxide and vanadium pentoxide; the reducing agent includes metallic aluminum; the ferrous material includes ferrous material with metallic iron as the main component, and its effective component based on metallic iron is no less than 95%; the slag characteristic regulator includes pre-calcined lime, and its effective component based on CaO is no less than 90%.

3. The method for controlling the separation of vanadium-iron alloy smelting slag and gold according to claim 2, characterized in that, The theoretical aluminum consumption of the vanadium-containing materials is 485 kg / t V2O5 and 360 kg / t V2O3, respectively.

4. The method for controlling the separation of vanadium-iron alloy smelting slag and gold according to claim 1, characterized in that, Ferrovanadium alloys include FeV50 or FeV80. The vanadium to iron weight ratios of vanadium-containing materials and iron materials in the ferrovanadium alloy smelting raw materials required for smelting FeV50 and FeV80 are 50:45~48 and 80:46~48, respectively.

5. The method for controlling the separation of vanadium-iron alloy smelting slag and gold according to claim 1, characterized in that, In step c, the predetermined time is 10 min to 60 min.

6. The method for controlling the separation of vanadium-iron alloy slag and gold according to claim 1, characterized in that, In step a, the amount of vanadium-containing materials and reducing agents added to the vanadium-iron alloy smelting raw materials is based on 1.05 to 1.10 times the theoretical aluminum consumption of vanadium oxide, and the amount of slag characteristic regulator added to the vanadium-iron alloy smelting raw materials is 5% to 25% of the theoretical slag production.

7. The method for controlling the separation of vanadium-iron alloy slag and gold according to claim 1, characterized in that, The mixing principle of the vanadium-containing materials and iron materials is based on meeting the vanadium to iron weight ratio corresponding to different grades of vanadium-iron alloys in the GBT / 4139-2012 standard.

8. The method for controlling the separation of vanadium-iron alloy smelting slag and gold according to claim 1, characterized in that, The method is applicable to mainstream aluminothermic self-propagating reduction processes for preparing ferrovanadium alloys, including the straight-tube furnace aluminothermic one-step reduction method and the tilting furnace multi-stage reduction method.

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