Smelting method of cobalt-manganese polymetallic ore

Abstract

The invention provides a smelting method of cobalt-manganese polymetallic ore, and relates to the technical field of color metallurgy, the smelting method comprises the following steps: carrying out primary reduction on the cobalt-manganese polymetallic ore by adopting hydrogen or ammonia gas to obtain a first reduction material; the first reduction material is subjected to melt separation, and multi-element alloy containing cobalt, nickel and copper and manganese-rich slag containing manganese, silicon and iron are obtained; and carrying out secondary reduction on the manganese-rich slag containing the manganese-silicon iron at the reduction temperature of 1400-1700 DEG C by adopting hydrogen plasma or ammonia plasma to obtain the manganese-silicon alloy. According to the method provided by the invention, cobalt-manganese polymetallic ore reduction metallurgy is carried out by completely relying on hydrogen or ammonia gas and hydrogen plasma or ammonia plasma as a reducing agent, grouped and step-by-step reduction and extraction of nickel, cobalt, copper, manganese, iron and silicon are realized, and a multi-component alloy containing cobalt, nickel and copper and a low-carbon manganese-silicon alloy containing manganese, silicon and iron are obtained respectively; the problem of carbon emission is effectively solved, and zero carbon emission in cobalt-manganese polymetallic ore smelting is achieved.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metallurgy, and in particular to a method for smelting cobalt-manganese polymetallic ore. Background Technology

[0002] Cobalt-manganese polymetallic ores refer to polymetallic oxide ores rich in cobalt and manganese, and also containing other valuable metals such as nickel and copper. The most typical type is the complex polymetallic oxide ores distributed on the ocean floor, rich in multiple valuable elements such as cobalt, nickel, copper, manganese, and iron, including deep-sea polymetallic nodules (commonly known as manganese nodules) and cobalt-rich iron-manganese crusts. These ores are characterized by polymetallic association and low grade. Besides nickel, cobalt, and copper, they also contain large amounts of iron and manganese, with a total nickel, cobalt, and copper content of approximately 1%–3% and a manganese content of approximately 15%–30%. The ores are naturally porous, with a porosity as high as 60%. No similar ores have been discovered or used for production on land to date. Due to the complex mineral distribution characteristics, physical beneficiation cannot separate and enrich nickel, cobalt, and copper; direct smelting, including hydrometallurgy and pyrometallurgy, is required.

[0003] Pyrometallurgy has attracted much attention due to its large processing capacity and high efficiency. Patent application CN 1048286C discloses a smelting-leaching-extraction method for extracting polymetallic compounds from marine manganese nodules. This method involves pulverizing dried manganese nodules to 30-60 mesh, mixing them with coke powder and silica powder, forming 10-30 mm pellets, reducing them at 800-1000℃, and finally smelting the reduced material in a crucible furnace at 1300-1500℃, separating the slag and gold to obtain a nickel-cobalt-copper alloy and a manganese-rich slag. Patent application CN 1598007A discloses a pyrometallurgical enrichment method for valuable metals in cobalt-rich oceanic crusts. This method also requires grinding the ore to -60 mesh, mixing it with coke powder and a binder to form pellets. The difference is that this patent application uses high-silicon manganese ore instead of silica powder in the batching process. The pellets are then dried and sent to a DC electric arc furnace for reduction smelting. After smelting, the slag and gold are separated to obtain an alloy and a manganese-rich slag. Patent CN 111172412A discloses a method for the combined extraction of manganese and comprehensive recovery of nickel, cobalt, and copper from cobalt-manganese polymetallic oxide ore through beneficiation and smelting. The method involves first crushing and grinding the cobalt-manganese polymetallic oxide ore to a size smaller than 0.25 mm, then mixing it with carbonaceous reducing agents such as coal, coke, or biomass to form pellets. After drying, the pellets are metallized and reduced at 1000-1300℃. The reduced material is then crushed, finely ground, and separated by magnetic separation to obtain a nickel-cobalt-copper mixed concentrate and a manganese concentrate. This process also includes ore fine grinding, pelletizing, and the use of carbonaceous reducing agents. Patent application CN 109439895A discloses a method for reducing polymetallic nodules. This method involves mixing crushed and finely ground polymetallic nodules with carbonaceous reducing agents such as coal, coke powder, and biochar, as well as flux and binder to obtain carbon-containing pellets. These pellets are then reduced at 1100-1300℃. The reduction product is then placed in a melting furnace, carbon powder is added, and the mixture is reduced at 1500-1600℃ to obtain a polymetallic alloy.

[0004] Manganese-rich slag obtained by pyrometallurgy can be used for hydrometallurgical production of electrolytic manganese or pyrometallurgical production of ferromanganese alloys or ferromanganese alloys. However, to produce ferromanganese alloys or ferromanganese alloys using manganese-rich slag by pyrometallurgy, coke is required as a reducing agent to reduce manganese to a metallic state to obtain ferromanganese alloys or ferromanganese alloys.

[0005] The common characteristics of the above methods are as follows: Due to the high manganese and ferromanganese content of these cobalt-manganese polymetallic ores, with a total manganese and ferromanganese content as high as 30-40%, both smelting nickel-cobalt-copper multi-element alloys and further smelting manganese-silicon alloys require the use of large amounts of carbonaceous materials such as coke, coal, bio-coke, and petroleum coke as reducing agents. This not only easily leads to the over-reduction of manganese into the cobalt-nickel alloy, increasing the refining difficulty of the subsequent alloy, but also affects the grade of manganese-rich slag and the manganese recovery rate. The manganese recovery rate of the manganese-rich slag is only 91%-97%, and the manganese content in the alloy reaches 2%-10%. The ore needs to be ground first and then pelletized, which is not only energy-intensive, but also loses the natural porous reaction advantage of the seabed polymetallic oxide ores, which is not conducive to the reduction process. In addition, the use of carbonaceous materials such as coke, coal, bio-coke, and petroleum coke as reducing agents or energy sources will lead to a large amount of carbon emissions during the smelting process, resulting in high carbon emission pressure, which is inconsistent with the trend of low-carbon development. The adoption of low-carbon or even zero-carbon technologies is the development trend of the metallurgical industry. Summary of the Invention

[0006] This invention provides a smelting method for cobalt-manganese polymetallic ore, which solves the defects of low manganese recovery rate of manganese-rich slag, high manganese content of cobalt-nickel-copper multi-element alloy and large carbon emissions in the existing cobalt-manganese polymetallic ore smelting technology. Thus, it provides a deep-sea cobalt-manganese polymetallic ore smelting method with high manganese recovery rate of manganese-rich slag, low manganese content of cobalt-nickel-copper multi-element alloy and no carbon emissions.

[0007] This invention provides a method for smelting cobalt-manganese polymetallic ore, comprising the following steps: S1. The cobalt-manganese polymetallic ore is first reduced using hydrogen or ammonia to obtain the first reducing material; S2. The first reducing material is melted and separated to obtain a multi-element alloy containing cobalt, nickel, and copper, and a manganese-rich slag containing manganese and ferrosilicon. S3. The manganese-rich slag containing manganese ferrosilicon is subjected to a second reduction using hydrogen plasma or ammonia plasma at a reduction temperature of 1400~1700℃ to obtain a manganese-silicon alloy.

[0008] This invention provides a smelting method for cobalt-manganese polymetallic ore. Utilizing the differences in reducing power between hydrogen or ammonia and hydrogen plasma or ammonia plasma, selective stepwise reduction is achieved. Specifically, at a lower temperature, hydrogen or ammonia is used to selectively reduce cobalt, nickel, and copper in the ore to their elemental state, while iron and manganese exist as low-valence oxides. Subsequently, cobalt, nickel, and copper are separated from manganese and iron through smelting. Then, at a higher temperature, still using hydrogen or ammonia as the gas source, the strong reducing properties of hydrogen or ammonia plasma are used to deeply reduce and smelt the manganese-rich slag obtained from the smelting, removing harmful impurities and yielding a low-carbon manganese-silicon alloy containing manganese ferrosilicon. This method achieves cobalt-manganese polymetallic ore reduction metallurgy entirely relying on hydrogen or ammonia and hydrogen or ammonia plasma as reducing agents, enabling the stepwise reduction and extraction of nickel, cobalt, copper, manganese, iron, and silicon in groups. This yields a multi-element alloy containing cobalt, nickel, and copper, and a low-carbon manganese-silicon alloy containing manganese ferrosilicon, effectively solving the carbon emission problem and achieving zero-carbon emissions in cobalt-manganese polymetallic ore smelting.

[0009] The present invention provides a smelting method for cobalt-manganese polymetallic ore. In the process of hydrogen or ammonia reduction in step S1 and melting in step S2, natural alkalinity smelting is adopted without the addition of additional flux, which reduces the amount of smelting materials, improves the grade of manganese-rich slag, and reduces energy consumption and waste slag.

[0010] In the smelting method of cobalt-manganese polymetallic ore provided by the present invention, the reduction temperature of the second reduction is controlled at 1400~1700℃, which can ensure a sufficiently high temperature to maintain the molten state of the furnace charge and reduce the viscosity of the slag, which is conducive to slag-metal separation and improve the recovery rate of manganese-silicon alloy, while avoiding excessively high temperature leading to increased smelting energy consumption.

[0011] Preferably, in step S1, the cobalt-manganese polymetallic ore is crushed to a particle size ≤30mm, more preferably 5~30mm.

[0012] In step S1 of this scheme, the particle size of the cobalt-manganese polymetallic ore is controlled to be ≤30mm. The ore does not require high-energy-consuming grinding treatment. It can be smelted directly using the raw ore or after simple crushing. This reduces the grinding and re-agglomeration processes, greatly reducing energy consumption and process complexity. At the same time, it can make full use of the natural porous structure of the cobalt-manganese polymetallic ore to improve the diffusion and reduction efficiency of hydrogen or ammonia inside the ore, thus achieving efficient and clean metal recovery.

[0013] As a preferred option, cobalt-manganese polymetallic ores are classified using a 30mm sieve. Ores with a particle size less than 30mm are directly subjected to the first reduction, while ores larger than 30mm are crushed to 5-30mm and do not require grinding.

[0014] As a preferred option, ores larger than 30mm are crushed to 10-20mm and do not require grinding.

[0015] Preferably, in S1, when hydrogen is used to perform the first reduction of cobalt-manganese polymetallic ore, the reduction temperature is 400~1100℃, preferably 710~900℃. And / or, When the ammonia gas is used to perform the first reduction of cobalt-manganese polymetallic oxide ore, the reduction temperature is 400~600℃.

[0016] In the smelting method of cobalt-manganese polymetallic ore provided in this scheme, when hydrogen is used for the first reduction of the cobalt-manganese polymetallic ore, the reduction temperature is 400~1100℃. Controlling the reduction temperature within this range ensures that the cobalt, nickel, and copper in the ore are reduced to their elemental state at a sufficiently high temperature, while avoiding excessively high temperatures that would increase smelting energy consumption and prevent excessive reduction of iron, thereby obtaining an alloy with high nickel, cobalt, and copper content. When ammonia is used for the first reduction of the cobalt-manganese polymetallic ore, the reduction temperature is 400~600℃. Controlling the reduction temperature within this range ensures that the cobalt, nickel, and copper in the ore are reduced to their elemental state at a sufficiently high temperature, while avoiding excessively high temperatures that would increase smelting energy consumption and prevent excessively high temperatures that would lead to excessive reduction of iron, thereby obtaining an alloy with high nickel, cobalt, and copper content.

[0017] In step S1 of this scheme, when hydrogen is used to perform the first reduction of cobalt-manganese polymetallic ore, the reduction temperature is controlled at 710~900℃, so as to achieve selective reduction of nickel, cobalt and copper while ensuring a high reduction reaction rate, and obtain an alloy with high nickel, cobalt and copper content.

[0018] Preferably, in S1, hydrogen or ammonia is used to perform the first reduction of cobalt-manganese polymetallic ore in a low-temperature reduction furnace, wherein the low-temperature reduction furnace is selected from rotary kiln, fluidized bed, shaft furnace or vertical tube furnace.

[0019] Preferably, in S1, the cobalt-manganese polymetallic ore is one or a mixture of two of the following: polymetallic nodules and cobalt-rich iron-manganese crusts.

[0020] Preferably, in step S2, the first reducing material is heated to 1300-1500°C in an electric furnace for melting, wherein the electric furnace is selected from a submerged arc furnace or an electric arc furnace.

[0021] Preferably, in step S2, the melting temperature is 1300~1500℃.

[0022] In the smelting method of cobalt-manganese polymetallic ore provided by the present invention, the first reducing material is heated to 1300~1500℃ for melting and separation. Controlling the melting and separation temperature within this range can ensure that the reducing material is completely melted at a sufficiently high temperature, reduce the viscosity of the slag, improve the slag-gold separation efficiency, and avoid the increase in melting and separation energy consumption due to excessively high temperature.

[0023] This solution provides a smelting method for cobalt-manganese polymetallic ore. By combining the low-temperature reduction with hydrogen or ammonia in step S1 (hydrogen reduction temperature 710~900℃, ammonia reduction temperature 400~600℃) with the melting separation in step S2 (melting separation temperature 1300~1500℃), more than 98% of the manganese in the cobalt-manganese polymetallic ore is suppressed in the manganese-rich slag, and the manganese is prevented from entering the cobalt-nickel-copper multi-element alloy. This results in a high-quality cobalt-nickel-copper multi-element alloy with less than 2% manganese, achieving effective separation of cobalt, nickel, copper and manganese, improving the metal recovery rate (especially the manganese recovery rate of the manganese-rich slag) and product quality.

[0024] Preferably, in step S2, a multi-element alloy containing cobalt, nickel, and copper is sulfided and smelted to obtain nickel matte, which is a eutectic melt of metal sulfides containing nickel, cobalt, copper, and iron.

[0025] Preferably, the sulfiding agent used in the sulfidation is selected from one or more of calcium sulfate, sulfur, and pyrite, or a mixture thereof.

[0026] Preferably, the sulfidation also includes the addition of quartz to form slag.

[0027] Preferably, in step S3, when the hydrogen plasma is used to perform a second reduction on the manganese-rich slag containing manganese ferrosilicon, the volume concentration of hydrogen in the working gas of the hydrogen plasma reduction is 10%~80%, preferably 40%~80%, with the remainder being argon and / or nitrogen; when the ammonia plasma is used to perform a second reduction on the manganese-rich slag containing manganese ferrosilicon, the working gas of the ammonia plasma reduction is ammonia. Using ammonia as the gas source has a lower reduction temperature than hydrogen, thus saving energy and being easier to transport and store safely.

[0028] In the smelting method for cobalt-manganese polymetallic ore provided in this scheme, when the hydrogen plasma is used to perform a second reduction on the manganese-rich slag containing manganese ferrosilicon, the volume concentration of hydrogen in the working gas of the hydrogen plasma reduction is 10%~80%. Controlling the volume concentration of hydrogen in this range can ensure that there is enough hydrogen to reduce nickel, cobalt, and copper to elemental form, while avoiding excessive hydrogen leading to reduced hydrogen utilization and decreased plasma stability, thereby improving the reduction effect. When the ammonia plasma is used to perform a second reduction on the manganese-rich slag containing manganese ferrosilicon, the working gas of the ammonia plasma reduction is ammonia, that is, plasma obtained by ionizing ammonia through a plasma generator. Since ammonia is used as the working gas for plasma reduction, nitrogen is produced by ammonia ionization and thermal decomposition, so it is not necessary to add an inert gas to the working gas.

[0029] In step S3 of this scheme, in order to improve the utilization rate of hydrogen and obtain stable plasma, the volume concentration of hydrogen in the working gas for hydrogen plasma reduction is controlled to be 10%~80%, preferably 40%~80%.

[0030] Preferably, the working gas for hydrogen plasma reduction also includes at least one of argon and nitrogen.

[0031] Preferably, the working gas for the hydrogen plasma reduction is a mixture of hydrogen and argon.

[0032] Preferably, when using hydrogen plasma or ammonia plasma to perform a second reduction on the manganese-rich slag containing manganese ferrosilicon, the ternary basicity of the smelting slag is adjusted to 0.5~1, preferably 0.6~0.8.

[0033] When using hydrogen plasma or ammonia plasma to perform a second reduction on manganese-rich slag containing manganese ferrosilicon, the ternary basicity of the smelting slag is adjusted to 0.5~1 according to the smelting manganese-silicon alloy grade and the requirements for smelting slag-metal separation. This can reduce the viscosity of the slag, improve the slag-metal separation effect, promote manganese-silicon reduction, and improve the smelting recovery rate.

[0034] The alkalinity described in this scheme is the ratio of the mass percentage of basic oxides to acidic oxides. The ternary alkalinity is R3 = (CaO% + MgO%) / SiO2%. As a preferred option, the ternary basicity of the smelting slag is adjusted by one or more of the following: quartz, silica, calcium oxide, magnesium oxide, and dolomite.

[0035] Preferably, in S3, the hydrogen plasma or ammonia plasma is obtained by ionization via a plasma generator.

[0036] Preferably, in step S3, the manganese-silicon alloy is a low-carbon, low-phosphorus manganese-silicon alloy containing no more than 0.05% phosphorus and no more than 0.05% carbon.

[0037] Preferably, the reduction smelting of cobalt-manganese polymetallic ore using hydrogen and hydrogen plasma includes the following steps: S1. The cobalt-manganese polymetallic ore with a particle size of 10-20 mm was first reduced by hydrogen at 710-900℃ to obtain the first reducing material; S2. The first reducing material is melted and separated at 1300~1500℃ to obtain a multi-element alloy containing cobalt, nickel and copper and a manganese-rich slag containing manganese ferrosilicon. S3. Adjust the ternary basicity of the manganese-containing ferrosilicon slag to 0.6~0.8, and use hydrogen plasma to perform a second reduction on the manganese-containing ferrosilicon slag at a reduction temperature of 1400~1700℃. The volume concentration of hydrogen in the working gas of the hydrogen plasma reduction is 40%~80%, and manganese-silicon alloy is obtained.

[0038] Preferably, the reduction smelting of cobalt-manganese polymetallic ore using ammonia gas and ammonia plasma includes the following steps: S1. Ammonia gas is used to perform the first reduction of cobalt-manganese polymetallic ore with a particle size of 10-20 mm at 400-600℃ to obtain the first reducing material; S2. The first reducing material is melted and separated at 1300~1500℃ to obtain a multi-element alloy containing cobalt, nickel and copper and a manganese-rich slag containing manganese ferrosilicon. S3. Adjust the ternary basicity of the manganese-containing ferrosilicon slag to 0.6~0.8, and use ammonia plasma to perform a second reduction on the manganese-containing ferrosilicon slag at a reduction temperature of 1400~1700℃. The working gas for the ammonia plasma reduction is ammonia gas, and manganese-silicon alloy is obtained.

[0039] Preferably, in step S3, the manganese-silicon alloy is refined with refining additives at a temperature of 1300~1500°C to obtain a refined manganese-silicon alloy, wherein the refining additives include a calcium-based reducing agent and a slagging agent. Preferably, the calcium-based reducing agent is selected from one or more of silicon-calcium alloy, aluminum-calcium alloy, and silicon-calcium-manganese alloy; More preferably, the amount of calcium-based reducing agent added is 1% to 5% of the mass of the manganese-silicon alloy.

[0040] Preferably, the slag-forming agent is selected from one or more of calcium oxide, magnesium oxide, dolomite, and fluorite, or a mixture thereof. More preferably, the amount of slag-forming agent added is 5% to 10% of the mass of the manganese-silicon alloy.

[0041] The present invention provides a smelting method for cobalt-manganese polymetallic ore. Compared with the prior art, the features and beneficial effects of the present invention are as follows: (1) By reducing with low-temperature hydrogen or ammonia and reducing with high-temperature hydrogen plasma or ammonia plasma, the grouping and stepwise reduction of nickel, cobalt, copper, manganese, iron and silicon is achieved entirely by using hydrogen or ammonia as the reducing gas, so as to obtain multi-element alloys containing cobalt, nickel and copper and low-carbon manganese-silicon alloys containing manganese and silicon iron, thus achieving zero carbon emissions in the smelting of deep-sea cobalt-manganese polymetallic oxide ore; (2) It does not require fine grinding of the ore, and can be directly smelted from the raw ore or simply crushed to a fine powder. Smelting is carried out after 5~30mm, which reduces the grinding and re-agglomeration process, shortens the process, and reduces energy consumption. At the same time, the natural porous structure of deep-sea cobalt-manganese polymetallic oxide ore can be fully utilized to improve the diffusion and reduction efficiency of hydrogen or ammonia in the ore. (3) When carrying out hydrogen or ammonia reduction and smelting, natural alkalinity smelting without external flux is adopted, which reduces the amount of smelting material, improves the grade of manganese-rich slag, and reduces energy consumption. (4) Manganese is inhibited from entering the cobalt-nickel-copper multi-element alloy, and high-quality cobalt-nickel-copper multi-element alloy with less than 2% manganese is obtained, which improves the manganese recovery rate of manganese-rich slag. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the process flow of some embodiments of the deep-sea cobalt-manganese polymetallic ore smelting method of the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0045] All percentages of elements described in this invention are mass percentages.

[0046] Example 1 This embodiment provides a smelting method for cobalt-manganese polymetallic ore, the specific process flow of which is as follows: Figure 1 As shown, it includes the following steps: S1. Deep-sea polymetallic nodule ore containing 0.2% Co, 1.2% Ni, 1.1% Cu, 26.5% Mn, 6.5% Fe and 16.8% SiO2 was dried and placed in a vertical tube furnace at 800℃ and continuously reduced with hydrogen for 4 hours to obtain the first reducing material. S2. The obtained first reducing material is transferred into an electric furnace and heated to 1450℃ for melting. The slag is then separated from the alloy to obtain a cobalt-nickel-copper multi-element alloy and a manganese-rich slag containing manganese and ferrosilicon. The multi-element alloy contains 1.98% cobalt, 11.88% nickel, 10.67% copper, and 1.85% manganese. The manganese-rich slag contains 43.95% manganese with a manganese recovery rate of 99.3%. S3. The manganese-rich slag containing manganese ferrosilicon is transferred into a hydrogen plasma reduction furnace for smelting. Silica and dolomite are added, and the ternary basicity of the smelting slag is adjusted to 0.8. Hydrogen and argon are ionized into plasma by a plasma torch at a volume ratio of 4:1 (hydrogen volume concentration of 80%) to form a high-temperature plasma flame. The manganese-rich slag containing manganese ferrosilicon is smelted by hydrogen plasma reduction at 1600℃ for 2 hours. After smelting, the slag and metal are separated to obtain a manganese-silicon alloy containing 65% manganese, 25% silicon, and less than 0.05% carbon.

[0047] The manganese recovery rate is calculated as follows: Manganese recovery rate = .

[0048] Example 2 This embodiment provides a smelting method for seabed cobalt-manganese polymetallic ore, comprising the following steps: S1. Cobalt-rich crust ore containing 0.43% Co, 0.34% Ni, 0.16% Cu, 18.0% Mn and 15.4% Fe was dried and placed in a vertical tube furnace at 800℃, and hydrogen was continuously passed through it for 4 hours to obtain the first reducing material. S2. The obtained first reducing material is transferred into an electric furnace and heated to 1450℃ for melting. The slag is then separated from the alloy to obtain a cobalt-nickel-copper multi-element alloy and a manganese-rich slag containing manganese and ferrosilicon. The multi-element alloy contains 6.08% cobalt, 4.81% nickel, 2.22% copper, and 1.80% manganese. The manganese-rich slag contains 32.5% manganese with a manganese recovery rate of 99.3%. S3. The manganese-rich slag containing manganese ferrosilicon is transferred into a hydrogen plasma reduction furnace for smelting. Silica and dolomite are added, and the ternary basicity of the smelting slag is adjusted to 0.6. Hydrogen and argon are ionized into plasma by a plasma spray gun at a volume ratio of 4:1 (hydrogen volume concentration of 40%) to form a high-temperature plasma flame. The manganese-rich slag containing manganese ferrosilicon is smelted by hydrogen plasma reduction at 1600℃ for 2 hours. After smelting, the slag and metal are separated to obtain a manganese-silicon alloy containing 60% manganese and 14% silicon.

[0049] Example 3 This embodiment provides a smelting method for seabed cobalt-manganese polymetallic ore, comprising the following steps: S1. A polymetallic nodule containing 0.20% Co, 1.05% Ni, 0.86% Cu, 24.64% Mn and 7.18% Fe is crushed to 10-20 mm, washed with water, dried and placed in a vertical tube furnace at 500℃, and continuously reduced with hydrogen for 4 hours to obtain the first reducing material. S2. The obtained first reducing material is transferred into an electric furnace and heated to 1450℃ for melting. The slag is then separated from the alloy to obtain a cobalt-nickel-copper multi-element alloy and a manganese-rich slag containing manganese-silicon ferroalloy. The multi-element alloy contains 2.83% cobalt, 14.85% nickel, 11.91% copper, and 1.76% manganese. The manganese-rich slag contains 40.86% manganese with a manganese recovery rate of 99.5%.

[0050] S3. The manganese-rich slag containing manganese ferrosilicon is transferred into a hydrogen plasma reduction furnace for smelting. Silica and dolomite are added, and the ternary basicity of the smelting slag is adjusted to 0.8. Hydrogen and argon are ionized into plasma by a plasma spray gun at a volume ratio of 4:1 (hydrogen volume concentration of 80%) to form a high-temperature plasma flame. The manganese-rich slag containing manganese ferrosilicon is smelted by hydrogen plasma reduction at 1600℃ for 2 hours. After smelting, the slag and metal are separated to obtain a manganese-silicon alloy containing 65% manganese and 20% silicon.

[0051] Example 4 This embodiment provides a method for smelting cobalt-manganese polymetallic ore, comprising the following steps: S1. After drying, polymetallic nodule ore containing 0.19% Co, 1.3% Ni, 1.25% Cu, 29.5% Mn and 5.8% Fe was placed in a vertical tube furnace at 710℃ and continuously reduced with hydrogen for 4 hours to obtain the first reducing material. S2. The obtained first reducing material is transferred into an electric furnace and heated to 1450℃ for melting. The slag is then separated from the alloy to obtain a cobalt-nickel-copper multi-element alloy and a manganese-rich slag containing manganese and ferrosilicon. The multi-element alloy contains 2.35% cobalt, 16.09t nickel, 15.15% copper, and 1.84% manganese. The manganese-rich slag contains 44.4% manganese with a manganese recovery rate of 99.5%. S3. The manganese-rich slag containing manganese ferrosilicon is transferred into a plasma melting furnace for melting. Silica and dolomite are added, and the ternary basicity of the melting slag is adjusted to 0.8. Hydrogen and argon are ionized into plasma by a plasma torch at a volume ratio of 4:1 (hydrogen volume concentration of 80%) to form a high-temperature plasma flame. The manganese-rich slag containing manganese ferrosilicon is subjected to hydrogen plasma reduction melting at 1600℃ for 2 hours. After melting, the slag and metal are separated to obtain a manganese-silicon alloy containing 65% manganese, 27% silicon, and less than 0.05% carbon.

[0052] Example 5 This embodiment provides a smelting method for cobalt-manganese polymetallic ore, which differs from the smelting method for cobalt-manganese polymetallic ore provided in Embodiment 2 in that step S4 is added: S4. The manganese-silicon alloy obtained in step S3 of Example 2 is transferred into a refining furnace, and silicon-calcium alloy, calcium oxide, and fluorite are added. The amounts of silicon-calcium alloy, calcium oxide, and fluorite added are 5%, 5%, and 5% of the mass of manganese-silicon alloy, respectively. Then, the temperature is raised to 1500℃ and refined for 1 hour. The slag and gold are separated to obtain a refined manganese-silicon alloy containing 60% manganese and 17% silicon.

[0053] Example 6 This embodiment provides a method for smelting cobalt-manganese polymetallic ore, comprising the following steps: S1. The seabed polymetallic nodule ore containing 0.20% Co, 1.0% Ni, 0.91% Cu, 23.5% Mn and 7.2% Fe was crushed to 10-20 mm, washed with water, dried and placed in a vertical tube furnace at 500℃, and continuously reduced with hydrogen for 4 hours to obtain the first reducing material. S2. The obtained first reducing material is transferred into an electric furnace and heated to 1450℃ for melting. The slag is then separated from the alloy to obtain a cobalt-nickel-copper multi-element alloy and a manganese-rich slag containing manganese-silicon ferroalloy. The multi-element alloy contains 2.83% cobalt, 14.14% nickel, 12.61% copper, and 1.68% manganese. The manganese-rich slag contains 38.9% manganese and has a manganese recovery rate of 99.5%.

[0054] S3. The manganese-rich slag containing manganese ferrosilicon is transferred into a plasma melting furnace for melting. Silica and dolomite are added, and the ternary basicity of the melting slag is adjusted to 0.8. Hydrogen and argon are ionized into plasma by a plasma torch at a volume ratio of 4:1 (hydrogen volume concentration of 80%) to form a high-temperature plasma flame. The manganese-rich slag containing manganese ferrosilicon is subjected to hydrogen plasma reduction melting at 1600℃ for 2 hours. After melting, the slag and metal are separated to obtain a manganese-silicon alloy containing 65% manganese and 25% silicon.

[0055] S4. The cobalt-nickel-copper multi-element alloy obtained in step S2 is transferred into a sulfidation furnace. Calcium sulfate and sulfur are added as sulfiding agents, with the amounts of calcium sulfate and sulfur being 35% and 10% of the mass of the multi-element alloy, respectively. Quartz is added to form slag, with the amount of quartz being 35% of the mass of the multi-element alloy. The sulfidation and smelting are carried out at 1300℃ for 2 hours to obtain matte containing 3.95% cobalt, 19.8% nickel, and 17.7% copper.

[0056] Example 7 This embodiment provides a method for smelting cobalt-manganese polymetallic ore, comprising the following steps: S1. Deep-sea polymetallic nodule ore containing 0.2% Co, 1.2% Ni, 1.1% Cu, 26.5% Mn, 6.5% Fe and 16.8% SiO2 was dried and placed in a vertical tube furnace at 500℃ and continuously reduced with hydrogen for 4 hours to obtain the first reducing material. S2. The obtained first reducing material is transferred into an electric furnace and heated to 1300℃ for melting. The slag is then separated from the alloy to obtain a cobalt-nickel-copper multi-element alloy and a manganese-rich slag containing manganese and ferrosilicon. The multi-element alloy contains 3.1% cobalt, 18.6% nickel, 16.9% copper, and 1.7% manganese. The manganese-rich slag contains 43.9% manganese with a manganese recovery rate of 99.6%. S3. The manganese-rich slag containing manganese ferrosilicon is transferred into a hydrogen plasma reduction furnace. Quartz and dolomite are added, and the ternary basicity of the smelting slag is adjusted to 0.8. Hydrogen and argon are fed into the plasma torch at a volume ratio of 3:2 (hydrogen volume concentration of 60%). Under the action of high-frequency voltage and electric arc, the slag is ionized into plasma, forming a high-temperature plasma flame. The manganese-rich slag containing manganese ferrosilicon is reduced and smelted by hydrogen plasma at 1400℃. After smelting, the slag and metal are separated to obtain a manganese-silicon alloy containing 61% manganese and 21% silicon.

[0057] Example 8 This embodiment provides a method for smelting cobalt-manganese polymetallic ore, comprising the following steps: S1. Deep-sea polymetallic nodule ore containing 0.2% Co, 1.2% Ni, 1.1% Cu, 26.5% Mn, 6.5% Fe and 16.8% SiO2 was dried and placed in a vertical tube furnace at 1000℃ and continuously reduced with hydrogen for 4 hours to obtain the first reducing material. S2. The obtained first reducing material is transferred into an electric furnace and heated to 1500℃ for melting. The slag is then separated from the alloy to obtain a cobalt-nickel-copper multi-element alloy and a manganese-rich slag containing manganese and ferrosilicon. The multi-element alloy contains 1.8% cobalt, 10.9% nickel, 9.8% copper, and 1.2% manganese, while the manganese-rich slag contains 43.9% manganese with a manganese recovery rate of 99.5%. S3. The manganese-rich slag containing manganese ferrosilicon is transferred into a hydrogen plasma reduction furnace. Silica and dolomite are added, and the ternary basicity of the smelting slag is adjusted to 0.8. Hydrogen and argon are fed into the plasma torch at a volume ratio of 1:4 (hydrogen volume concentration of 20%). Under the action of high-frequency voltage and electric arc, the slag is ionized into plasma, forming a high-temperature plasma flame. The manganese-rich slag containing manganese ferrosilicon is smelted by hydrogen plasma reduction at 1700℃. After smelting, the slag and metal are separated to obtain a manganese-silicon alloy containing 65% manganese and 28% silicon.

[0058] Example 9 The smelting method for cobalt-manganese polymetallic ore provided in this embodiment differs from the smelting method for cobalt-manganese polymetallic ore provided in Example 1 in that the ternary basicity of the manganese-rich slag containing manganese ferrosilicon is adjusted to 0.5.

[0059] In this embodiment, a manganese-silicon alloy containing 60% manganese and 22% silicon was prepared.

[0060] Example 10 This embodiment provides a method for smelting cobalt-manganese polymetallic ore, comprising the following steps: S1. After drying, polymetallic nodule ore containing 0.2% Co, 1.2% Ni, 1.1% Cu, 26.5% Mn, and 6.5% Fe is placed in a vertical tube furnace at 500℃ and continuously reduced with ammonia gas for 4 hours to obtain the first reducing material. S2. The obtained first reducing material is transferred into an electric furnace and heated to 1450℃ for melting. The slag is then separated from the alloy to obtain a cobalt-nickel-copper multi-element alloy and a manganese-rich slag containing manganese and ferrosilicon. The multi-element alloy contains 2.48% cobalt, 14.85% nickel, 13.33% copper, and 1.98% manganese. The manganese-rich slag contains 43.9% manganese with a manganese recovery rate of 99.4%. S3. The manganese-rich slag containing manganese ferrosilicon is transferred into an ammonia plasma reduction furnace. Quartz and dolomite are added, and the ternary basicity of the smelting slag is adjusted to 0.8. Ammonia gas is sent into the plasma lance, where it is ionized into plasma under the action of high-frequency voltage and electric arc, forming a high-temperature plasma flame. The manganese-rich slag containing manganese ferrosilicon is smelted by ammonia plasma reduction at 1600℃. After smelting, the slag and metal are separated to obtain a manganese-silicon alloy containing 65% manganese, 25% silicon, and less than 0.05% carbon.

[0061] Example 11 This embodiment provides a method for smelting cobalt-manganese polymetallic ore, comprising the following steps: S1. Cobalt-rich crust ore containing 0.43% Co, 0.34% Ni, 0.16% Cu, 18.0% Mn and 15.4% Fe was dried and placed in a vertical tube furnace at 450℃ and continuously reduced with ammonia gas for 4 hours to obtain the first reducing material. S2. The obtained first reducing material is transferred into an electric furnace and heated to 1450℃ for melting. The slag is then separated from the alloy to obtain a cobalt-nickel-copper multi-element alloy and a manganese-rich slag containing manganese-silicon ferroalloy. The multi-element alloy contains 5.32% cobalt, 4.21% nickel, 1.94% copper, and 1.58% manganese. The manganese-rich slag contains 32.5% manganese and has a manganese recovery rate of 99.3%.

[0062] S3. The manganese-rich slag containing manganese ferrosilicon is transferred into an ammonia plasma reduction furnace. Quartz and dolomite are added, and the ternary basicity of the smelting slag is adjusted to 0.8. Ammonia gas is sent into the plasma lance, where it is ionized into plasma under the action of high-frequency voltage and electric arc, forming a high-temperature plasma flame. The manganese-rich slag containing manganese ferrosilicon is smelted by ammonia plasma reduction at 1600℃. After smelting, the slag and metal are separated to obtain a manganese-silicon alloy containing 60% manganese and 14% silicon.

[0063] Example 12 This embodiment provides a method for smelting cobalt-manganese polymetallic ore, comprising the following steps: S1. A polymetallic nodule containing 0.20% Co, 1.05% Ni, 0.86% Cu, 24.64% Mn and 7.18% Fe is crushed to 10-20 mm, washed with water, dried and placed in a vertical tube furnace at 500℃. After continuous ammonia reduction for 4 hours, the first reducing material is obtained. S2. The obtained first reducing material is transferred into an electric furnace and heated to 1450℃ for melting. The slag is then separated from the alloy to obtain a cobalt-nickel-copper multi-element alloy and a manganese-rich slag containing manganese-silicon ferroalloy. The multi-element alloy contains 2.64% cobalt, 13.86% nickel, 11.12% copper, and 1.64% manganese. The manganese-rich slag contains 40.82% manganese and has a manganese recovery rate of 99.4%.

[0064] S3. The manganese-rich slag containing manganese ferrosilicon is transferred into an ammonia plasma reduction furnace. Quartz and dolomite are added at the same time to adjust the ternary basicity of the smelting slag to 0.8. Ammonia gas is sent into the plasma lance and ionized into plasma under the action of high-frequency voltage and electric arc to form a high-temperature plasma flame. The manganese-rich slag containing manganese ferrosilicon is smelted by ammonia plasma reduction at 1600℃. After smelting, the slag and metal are separated to obtain a manganese-silicon alloy containing 65% manganese and 25% silicon.

[0065] Example 13 The difference between the smelting method of cobalt-manganese polymetallic ore provided in this embodiment and the smelting method of cobalt-manganese polymetallic ore provided in Embodiment 1 is that in step S2, the first reducing material is transferred into an electric furnace and heated to 1200°C for melting.

[0066] In step S2 of this embodiment, the obtained first reducing material is transferred into an electric furnace and heated to 1200°C for melting. Under this temperature condition, the material is not completely melted, and the resulting cobalt-nickel-copper multi-element alloy contains 1.13% cobalt, 7.2% nickel, 6.01% copper, and 8.85% manganese. The manganese-rich slag contains 41.95% manganese, with a manganese recovery rate of 95.0%. In this embodiment, a manganese-silicon alloy containing 65% manganese and 25% silicon was prepared.

[0067] Example 14 The difference between the smelting method of cobalt-manganese polymetallic ore provided in this embodiment and the smelting method of cobalt-manganese polymetallic ore provided in Embodiment 1 is that the deep-sea polymetallic nodule ore is dried and then placed in a vertical tube furnace at 400°C for hydrogen reduction.

[0068] The cobalt-nickel-copper multi-element alloy prepared in this embodiment contains 2.67% cobalt, 18.0% nickel, 14.67% copper, and 0.1% manganese. The manganese-rich slag contains 37.85% manganese and has a manganese recovery rate of 99.9%.

[0069] In this embodiment, a manganese-silicon alloy containing 63% manganese and 22% silicon was prepared.

[0070] Comparative Example 1 The smelting method for cobalt-manganese polymetallic ore provided in this embodiment differs from the smelting method for cobalt-manganese polymetallic ore provided in Example 1 in that the manganese-rich slag containing manganese ferrosilicon is subjected to hydrogen plasma reduction smelting at 1200°C.

[0071] In step S3 of this comparative example, manganese-rich slag containing manganese ferrosilicon was subjected to hydrogen plasma reduction smelting at 1200℃ for 2 hours. The material did not melt, and no manganese-ferrosilicon alloy was obtained.

[0072] Example 15 The difference between the smelting method of cobalt-manganese polymetallic ore provided in this embodiment and the smelting method of cobalt-manganese polymetallic ore provided in Example 10 is that the polymetallic nodule ore is dried and then placed in a vertical tubular furnace at 400°C for ammonia reduction.

[0073] The cobalt-nickel-copper multi-element alloy prepared in this embodiment contains 2.8% cobalt, 17.2% nickel, 15.03% copper, and 0.1% manganese. The manganese-rich slag contains 37.8% manganese and has a manganese recovery rate of 99.9%.

[0074] In this embodiment, a manganese-silicon alloy containing 63% manganese and 22% silicon was prepared.

[0075] Comparative Example 2 A conventional smelting method for cobalt-manganese polymetallic ore includes the following steps: (1) Deep-sea polymetallic nodules (containing 0.20% Co, 1.25% Ni, 1.20% Cu, 28.0% Mn and 6.5% Fe by mass) are crushed and finely ground (100% below 100 mesh and 65% below 200 mesh), mixed with coke powder to form pellets, with the amount of coke powder being 10% of the mass of the nodules. The pellets are then reduced at 1000℃ for 2 hours to obtain the first reducing material. (2) The first reducing material obtained is transferred into an electric furnace and heated to 1450℃ for melting. The slag is then separated from the alloy to obtain a nickel-cobalt-copper multi-element alloy containing 10.28% nickel, 1.7% cobalt, 9.42% copper, and 10.37% manganese, and a manganese-rich slag containing 42.9% manganese. (3) Add quartz and dolomite to the manganese-rich slag obtained by melting and separation to adjust the ternary basicity to 0.8, and add coke at 20% of the mass of the manganese-rich slag. Then, smelt at 1600℃. After smelting, slag and metal are separated to obtain a manganese-silicon alloy containing 65% manganese, 20% silicon and 1% carbon.

[0076] Although existing technologies can also prepare manganese-silicon alloys, they still require the addition of coke powder or coke for reduction in steps (1) and (3), which is not conducive to controlling carbon emissions. Moreover, the nickel-cobalt-copper multi-element alloy obtained from the first reduction-melting process has a high manganese content, which increases the difficulty of further smelting of the nickel-cobalt-copper multi-element alloy.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for smelting a cobalt-manganese polymetallic ore, characterized in that, Includes the following steps: S1. The cobalt-manganese polymetallic ore is first reduced using hydrogen or ammonia to obtain the first reducing material; S2. The first reducing material is melted and separated to obtain a multi-element alloy containing cobalt, nickel, and copper, and a manganese-rich slag containing manganese and ferrosilicon. S3. The manganese-rich slag containing manganese ferrosilicon is subjected to a second reduction using hydrogen plasma or ammonia plasma at a reduction temperature of 1400~1700℃ to obtain a manganese-silicon alloy.

2. The smelting method of cobalt-manganese polymetallic ore according to claim 1, wherein in step S1, the cobalt-manganese polymetallic ore is crushed to a particle size ≤30mm.

3. The smelting method for cobalt-manganese polymetallic ore according to claim 1 or 2, characterized in that, In S1, when the hydrogen gas is used to perform the first reduction of cobalt-manganese polymetallic ore, the reduction temperature is 400~1100℃, preferably 710~900℃. And / or, When the ammonia gas is used to perform the first reduction of cobalt-manganese polymetallic ore, the reduction temperature is 400~600℃.

4. The smelting method for cobalt-manganese polymetallic ore according to claim 1 or 3, characterized in that, In step S2, the melting temperature is 1300~1500℃.

5. The smelting method for cobalt-manganese polymetallic ore according to claim 1 or 4, characterized in that, In step S2, a multi-element alloy containing cobalt, nickel, and copper is sulfided and smelted to obtain nickel matte.

6. The smelting method for cobalt-manganese polymetallic ore according to claim 1 or 4, characterized in that, In step S3, when the hydrogen plasma is used to perform a second reduction on the manganese-rich slag containing manganese ferrosilicon, the volume percentage concentration of hydrogen in the working gas of the hydrogen plasma reduction is 10%~80%, preferably 40~80%; when the ammonia plasma is used to perform a second reduction on the manganese-rich slag containing manganese ferrosilicon, the working gas of the ammonia plasma reduction is ammonia.

7. The smelting method for cobalt-manganese polymetallic ore according to any one of claims 1 to 6, characterized in that, When using hydrogen plasma or ammonia plasma to perform a second reduction on the manganese-rich slag containing manganese ferrosilicon, the ternary basicity of the smelting slag is adjusted to 0.5~1, preferably 0.6~0.

8.

8. The smelting method for cobalt-manganese polymetallic ore according to claim 1 or 7, characterized in that, In step S3, the manganese-silicon alloy is refined with refining additives at 1300~1500℃ to obtain a refined manganese-silicon alloy. The refining additives include a calcium-based reducing agent and a slagging agent.

9. The smelting method for cobalt-manganese polymetallic ore according to claim 8, characterized in that, The calcium-based reducing agent is selected from one or more of the following: silicon-calcium alloy, aluminum-calcium alloy, and silicon-calcium-manganese alloy; Preferably, the amount of calcium-based reducing agent added is 1% to 5% of the mass of the manganese-silicon alloy.

10. The smelting method for cobalt-manganese polymetallic ore according to claim 8 or 9, characterized in that, The slag-forming agent is selected from one or more of calcium oxide, magnesium oxide, dolomite, and fluorite; Preferably, the amount of slag-forming agent added is 5% to 10% of the mass of the manganese silicon alloy.

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