A production and preparation method of high-purity high-performance metal manganese ingot

Abstract

The application relates to the technical field of metal material smelting, and particularly discloses a production and preparation method of high-purity and high-performance metal manganese ingot. The method comprises the following steps: deep purification of argon gas is carried out through a molecular sieve and a sponge titanium filler tower, and super-low-oxygen argon gas is obtained as a protective gas; manganese-iron raw materials are smelted under the protection of the argon gas; calcium carbide powder is sprayed into the molten metal for deep desulfurization; and the ingot is cast after static setting and slagging. The sulfur, oxygen and nitrogen contents in the manganese ingot can be effectively reduced to below 10 ppm, and the product purity and performance are significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of metal material smelting technology, specifically relating to a method for producing high-purity, high-performance manganese ingots. Background Technology

[0002] Metallic manganese, especially high-purity metallic manganese, is an important alloying additive in the steel industry, effectively improving the strength, hardness, wear resistance, and permeability of steel. However, impurities such as oxygen, sulfur, and nitrogen in steel can significantly deteriorate its mechanical and processing properties, causing hot brittleness and reducing toughness. Therefore, the production of high-quality special steel places extremely high demands on the purity of manganese ingot additives, especially requiring strict control of their sulfur, oxygen, and nitrogen content.

[0003] Currently, the industrial production of manganese ingots mainly employs electrolytic or thermal smelting methods. Thermal smelting is widely used due to its lower cost, but it generally suffers from the following technical drawbacks:

[0004] First, during the smelting process, the molten metal readily reacts with oxygen and nitrogen in the air, leading to an increase in the oxygen and nitrogen content in the final product and affecting the product's purity.

[0005] Secondly, to reduce costs, scrap iron with a high sulfur content (such as 0.12%-0.2% sulfur) is often used as raw material in production, which introduces a large amount of sulfur impurities. Traditional desulfurization methods (such as adding manganese-based desulfurizers) have limited efficiency and are difficult to stably reduce the sulfur content to below 10 ppm, and may introduce new impurities.

[0006] Third, existing protective gas purification technologies (such as molecular sieve adsorption) often cannot completely remove trace oxygen (e.g., down to the ppb level), resulting in a non-completely inert smelting environment and affecting the deep desulfurization effect. This is because dissolved oxygen preferentially reacts with the desulfurizing agent, reducing desulfurization efficiency.

[0007] Therefore, there is an urgent need in this field for a method that can systematically solve the above problems and achieve stable production of ultra-high purity, low sulfur, low oxygen, and low nitrogen manganese ingots. Summary of the Invention

[0008] To address the problems in existing manganese ingot production processes, such as high oxygen and nitrogen content due to insufficient purity of protective gas, and difficulty in consistently reducing sulfur content to ultra-low levels due to low desulfurization efficiency, this invention aims to provide a method for producing high-purity, high-performance manganese ingots. This method utilizes a systematic approach involving deep purification of the post-atmosphere gas, low-oxygen, low-nitrogen protective smelting, and highly efficient deep desulfurization processes to stably produce high-purity, high-performance manganese ingots with sulfur, oxygen, and nitrogen contents all below 10 ppm.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A method for producing high-purity, high-performance manganese ingots includes the following steps:

[0011] Argon purification stage: The raw argon gas is purified by passing it sequentially through a molecular sieve adsorption tower and a sponge titanium packed tower to obtain ultra-high purity argon gas with an oxygen content of less than 1 ppb, a water vapor content of less than 0.1 ppm, and a CO2 content of less than 1 ppm.

[0012] Melting and protection stage: The metal raw material is placed in the medium frequency furnace, and the ultra-high purity argon gas is introduced as a protective gas to replace the air in the furnace. Then the temperature is raised to 1300℃ for melting.

[0013] Desulfurization stage: The molten metal is transferred to a ladle, and calcium carbide powder is injected into the molten metal by a spraying method for desulfurization;

[0014] Settling and slag removal stage: Let the desulfurized molten metal stand for 3-5 minutes and remove the floating sulfide slag;

[0015] Casting and cooling stage: The molten metal is poured into the mold, cooled, demolded, and crushed to obtain high-purity manganese ingots.

[0016] Furthermore, the argon purification stage includes:

[0017] First, the raw material argon gas is passed through a molecular sieve adsorption tower to remove water and CO2, so that the water vapor content is <0.1ppm and the CO2 content is <1ppm.

[0018] The gas was then preheated to 300°C and passed into a packed tower filled with titanium sponge. An oxygen removal reaction was carried out at 800°C to obtain ultra-high purity argon gas with an oxygen content of less than 1 ppb.

[0019] Furthermore, the particle size of the sponge titanium in the sponge titanium packed tower is 0.5-3 mm, and the gas flow rate is 10 Nm. 3 / h.

[0020] Furthermore, during the smelting protection stage, the metal raw materials include 95-98% metallic manganese and 2-5% scrap iron. When ultra-high purity argon is introduced, the initial flow rate is 20 Nm³ / h for purging for 10 minutes, subsequently maintained at 5 Nm³ / h. 3 The flow rate is / h.

[0021] Furthermore, the heating rate during the melting protection stage is 100℃ / min, the temperature is held at 1300℃ for 30 minutes, and stirring is carried out during the melting process.

[0022] Furthermore, in the desulfurization stage, the particle size of the calcium carbide powder is 0.1-1.0 mm, the injection speed is 10 kg / h, and the injection time is 15 minutes.

[0023] Furthermore, in the desulfurization stage, high-purity argon gas is used as the carrier gas, and calcium carbide powder is sprayed into the depth of the molten metal through a spray gun.

[0024] Furthermore, after the settling and slag removal stages, the sulfur content in the molten metal is monitored. If the sulfur content is higher than 10 ppm, the desulfurization treatment is repeated.

[0025] Furthermore, during the molding stage, the mold is preheated before casting.

[0026] Furthermore, the argon gas used in the melting protection stage is collected, purified, and recycled after use.

[0027] The advantages of this invention compared to the prior art are as follows:

[0028] (1) Extremely high product purity: Through deep deoxygenation of sponge titanium packed tower, the oxygen content of protective argon is reduced to 1ppb level, which fundamentally cuts off the introduction of oxygen and nitrogen. Combined with efficient calcium carbide injection desulfurization technology, the sulfur and oxygen content in the final manganese ingot product can be stably controlled at an extremely low level of less than 10ppm.

[0029] (2) High desulfurization efficiency and stable effect: The calcium carbide powder is directly sent into the depth of the molten metal by injection, which greatly increases the reaction area and realizes deep desulfurization. The strategy of creating a low-oxygen environment before desulfurization avoids the preferential reaction between the desulfurizing agent and oxygen and ensures the desulfurization efficiency.

[0030] (3) Environmentally friendly and resource-saving: This invention effectively treats the sulfur brought in by the raw material scrap iron, avoids SO2 emissions, and realizes the recycling of inert protective gas, which meets the requirements of green manufacturing.

[0031] (4) Strong process synergy: This invention is not a simple superposition of multiple processes, but a synergistic design of "deep deoxygenation-low oxygen protection-high efficiency desulfurization". Each step is interconnected and mutually supportive, systematically solving the problem of impurity control in the preparation of high-purity manganese ingots. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0033] Figure 1 A flowchart illustrating the production and preparation method of high-purity, high-performance metallic manganese ingots provided by this invention. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0036] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0037] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0039] Please see Figure 1 As shown in the figure, this invention provides a method for producing high-purity, high-performance manganese ingots, comprising the following steps:

[0040] Step S101, Argon purification stage: The raw argon gas is purified by passing it sequentially through a molecular sieve adsorption tower and a sponge titanium packed tower to obtain ultra-high purity argon gas with an oxygen content of less than 1 ppb, a water vapor content of less than 0.1 ppm, and a CO2 content of less than 1 ppm.

[0041] Step S102, Melting Protection Stage: The metal raw material is placed in an intermediate frequency furnace, and the ultra-high purity argon gas is introduced as a protective gas to replace the air in the furnace. Then the temperature is raised to 1300°C for melting.

[0042] Step S103, Desulfurization stage: The molten metal is transferred to a ladle, and calcium carbide powder is injected into the molten metal by a spraying method for desulfurization;

[0043] Step S104, Settling and Slag Removal Stage: Let the desulfurized molten metal stand for 3-5 minutes and remove the floating sulfide slag.

[0044] Step S105, casting and cooling stage: The molten metal is poured into the mold, cooled, demolded, and crushed to obtain high-purity manganese metal ingots.

[0045] In step S101, the argon purification stage includes:

[0046] First, the raw material argon gas is passed through a molecular sieve adsorption tower to remove water and CO2, so that the water vapor content is <0.1ppm and the CO2 content is <1ppm.

[0047] The gas was then preheated to 300°C and passed into a packed tower filled with titanium sponge. An oxygen removal reaction was carried out at 800°C to obtain ultra-high purity argon gas with an oxygen content of less than 1 ppb.

[0048] The sponge titanium in the packed tower has a particle size of 0.5-3 mm and a gas flow rate of 10 Nm. 3 / h.

[0049] In step S102, the metal raw material includes 95-98% metallic manganese and 2-5% scrap iron. When ultra-high purity argon is introduced, the initial flow rate is 20 Nm³ / h for purging for 10 minutes, and then maintained at 5 Nm³ / h. 3 The flow rate is / h.

[0050] The heating rate during the melting protection stage is 100℃ / min, and the temperature is held at 1300℃ for 30 minutes, with stirring during the melting process.

[0051] The argon gas used in the smelting protection stage is collected, purified, and recycled after use.

[0052] In step S103, the particle size of the calcium carbide powder is 0.1-1.0 mm, the blowing speed is 10 kg / h, and the blowing time is 15 minutes.

[0053] The desulfurization stage uses high-purity argon as the carrier gas, and calcium carbide powder is sprayed into the depth of the molten metal through a spray gun.

[0054] In step S104, after the settling and slag removal stage, the sulfur content in the molten metal is monitored. If the sulfur content is higher than 10 ppm, the desulfurization treatment is repeated.

[0055] In step S105, during the molding stage, the mold is preheated before casting.

[0056] The production method of high-purity, high-performance metallic manganese ingots provided by the present invention will be described in detail below with reference to specific embodiments. The following description is intended to explain the present invention, but not to limit the scope of protection of the present invention.

[0057] This invention provides a method for producing high-purity, high-performance manganese ingots. The core of this method lies in achieving deep purification of the protective gas and efficient desulfurization of the molten metal through systematic process design. The specific steps are as follows:

[0058] I. Argon Purification Stage

[0059] The goal of this phase is to further purify commercial high-purity argon (purity ≥ 99.99%) to an ultra-high purity with trace oxygen content of less than 1 ppb.

[0060] 1. Molecular sieve dehydration and CO2 removal: Argon gas from the storage tank is pressurized by a gas compressor and then introduced into the molecular sieve adsorption tower from the top at a flow rate of 10 Nm³ / h. The tower is filled with aluminosilicate molecular sieves, which effectively adsorb water vapor and carbon dioxide from the argon gas. The treated gas must meet the following requirements: water vapor (H₂O) content <0.1 ppm (dew point <-76℃), CO₂ content <1 ppm. The system is equipped with an online monitoring instrument; if the standards are not met, the molecular sieve regeneration program will be initiated.

[0061] 2. Deep Deoxygenation with Titanium Sponge: Preliminary purified argon gas enters the preheater and is heated to 300℃. Subsequently, the gas enters from the bottom of a high-temperature alloy packed tower filled with titanium sponge. The titanium sponge is pre-crushed and sieved into uniform particles of 0.5-3mm to provide a large reaction surface area and low bed pressure drop. The packed tower is programmed to rise and stabilize at 800℃. Under these conditions, trace amounts of oxygen in the argon gas undergo an irreversible gas-solid reaction with the titanium sponge to generate titanium oxide, achieving deep deoxygenation. The ultra-high purity argon gas flowing from the top of the tower passes through a dust filter to ensure its oxygen content is consistently below 1ppb and its dew point is below -70℃. When the outlet oxygen content consistently exceeds the standard, the packing material must be replaced under inert gas protection.

[0062] II. Argon Gas Introduction and Protection Stage

[0063] 1. Feeding: Strictly inspect the raw materials, weigh 95%-98% of electrolytic manganese metal flakes and 2%-5% of Class II scrap iron (the sulfur content of the scrap iron is 0.12%-0.2%) according to the mass ratio, and then put the mixed raw materials into the medium frequency furnace.

[0064] 2. Establish a protective atmosphere: After loading is complete, immediately introduce the ultra-high purity argon gas prepared in the above steps into the furnace. Initially, introduce 20 Nm³ of this gas. 3 Purge the furnace for 10 minutes at a flow rate of / h to completely displace and remove air from the furnace. Afterward, reduce the argon flow rate to 5Nm. 3 The pressure is maintained at / h, and the pressure inside the furnace is controlled to be slightly higher than atmospheric pressure to effectively prevent air from entering.

[0065] 3. Melting: Under stable argon protection, start the medium-frequency furnace heating system and heat the furnace charge to 1300℃ at a heating rate of approximately 100℃ / min, and hold at this temperature for 30 minutes. During the melting process, start the stirring device as needed to promote homogenization of the composition and prevent segregation.

[0066] III. Desulfurization Stage of Calcium Carbide

[0067] This stage employs the injection method for deep desulfurization.

[0068] 1. Preparation: Prepare a high-temperature resistant and corrosion-resistant spray gun and a matching spraying system. Use high-purity argon as the carrier gas. Use dry calcium carbide powder (particle size 0.1-1.0mm) as the desulfurizing agent, and ensure that all equipment is strictly isolated from water sources. Ensure on-site ventilation and strictly prohibit smoking to prevent calcium carbide from reacting with water to generate acetylene and explode.

[0069] 2. Purge Operation: Pour molten manganese at 1300℃ into a ladle preheated to a red-hot state. Using a lifting mechanism, vertically insert the spray gun into the molten metal, with its tip approaching approximately 3 / 4 of the ladle's depth. First, open the carrier gas valve and purge with high-purity argon gas at a flow rate of 10 Nm³ / h for 2 minutes to prevent backflow of the molten metal and to initially agitate the melt. Then, open the calcium carbide feed valve and inject fluidized calcium carbide powder into the depths of the molten metal through the spray gun at a conveying speed of 10 kg / h, using the carrier argon gas. The purging process continues for 15 minutes, during which a stable "boiling" state is observed on the liquid surface, with a small amount of calcium carbide slag floating to the surface.

[0070] 3. Purging end: After the purging time is up, first close the feeding valve to stop the powder feeding, continue to purge with carrier gas for 2 minutes to clean the residual powder in the pipeline, then turn off the air source and smoothly remove the spray gun.

[0071] IV. Settling and Slag Removal Process

[0072] After the injection is complete, the ladle is left to stand for 3-5 minutes to allow the calcium sulfide (CaS) slag generated by the reaction to fully aggregate and float to the surface. Then, a slag removal tool is used to thoroughly and cleanly remove the high-sulfur waste slag from the surface to prevent "sulfur reversion." Immediately after slag removal, a sample is taken to test the sulfur content of the manganese solution (using spectroscopic analysis). If the sulfur content is ≤10 ppm, the process proceeds to the next step; otherwise, the desulfurization treatment must be repeated.

[0073] V. Casting and Cooling Process

[0074] Pure manganese liquid meeting the sulfur content requirements is poured into a preheated mold through a gating system (mold preheating prevents uneven solidification due to rapid cooling). After the mold cools naturally to room temperature in the air, it is demolded, and the resulting manganese ingot is crushed into the required particle size to finally obtain a high-purity, high-performance metallic manganese ingot product.

[0075] VI. Optional Step: Argon Recovery

[0076] To conserve resources, the used inert protective gas discharged from the intermediate frequency furnace can be collected in a storage tank. If the impurity content increases after testing, it can be reintroduced into the argon purification system of this invention for purification treatment, thus achieving recycling.

[0077] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0078] Furthermore, it should be noted that the scope of the methods and systems in the embodiments of the present invention is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0079] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A method for producing high-purity, high-performance metallic manganese ingots, characterized in that, Includes the following steps: Argon purification stage: The raw argon gas is purified by passing it sequentially through a molecular sieve adsorption tower and a sponge titanium packed tower to obtain ultra-high purity argon gas with an oxygen content of less than 1 ppb, a water vapor content of less than 0.1 ppm, and a CO2 content of less than 1 ppm. Melting and protection stage: The metal raw material is placed in the medium frequency furnace, and the ultra-high purity argon gas is introduced as a protective gas to replace the air in the furnace. Then the temperature is raised to 1300℃ for melting. Desulfurization stage: The molten metal is transferred to a ladle, and calcium carbide powder is injected into the molten metal by a spraying method for desulfurization; Settling and slag removal stage: Let the desulfurized molten metal stand for 3-5 minutes and remove the floating sulfide slag; Casting and cooling stage: The molten metal is poured into the mold, cooled, demolded, and crushed to obtain high-purity manganese ingots.

2. The method according to claim 1, characterized in that, The argon purification stage includes: First, the raw material argon gas is passed through a molecular sieve adsorption tower to remove water and CO2, so that the water vapor content is <0.1ppm and the CO2 content is <1ppm. The gas was then preheated to 300°C and passed into a packed tower filled with titanium sponge. An oxygen removal reaction was carried out at 800°C to obtain ultra-high purity argon gas with an oxygen content of less than 1 ppb.

3. The method according to claim 2, characterized in that, The sponge titanium in the packed tower has a particle size of 0.5-3 mm and a gas flow rate of 10 Nm. 3 / h.

4. The method according to claim 1, characterized in that, During the smelting protection stage, the metal raw materials include 95-98% metallic manganese and 2-5% scrap iron. When ultra-high purity argon is introduced, the initial flow rate is 20 Nm³ / h for purging for 10 minutes, followed by a maintenance flow rate of 5 Nm³ / h. 3 The flow rate is / h.

5. The method according to claim 1, characterized in that, The heating rate during the melting protection stage is 100℃ / min, and the temperature is held at 1300℃ for 30 minutes, with stirring during the melting process.

6. The method according to claim 1, characterized in that, In the desulfurization stage, the particle size of the calcium carbide powder is 0.1-1.0 mm, the injection speed is 10 kg / h, and the injection time is 15 minutes.

7. The method according to claim 1, characterized in that, The desulfurization stage uses high-purity argon as the carrier gas, and calcium carbide powder is sprayed into the depth of the molten metal through a spray gun.

8. The method according to claim 1, characterized in that, After the settling and slag removal stages, the sulfur content in the molten metal is monitored. If the sulfur mass fraction is higher than 10 ppm, the desulfurization treatment is repeated.

9. The method according to claim 1, characterized in that, During the molding stage, the mold is preheated before pouring.

10. The method according to claim 1, characterized in that, The argon gas used in the smelting protection stage is collected, purified, and recycled after use.

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