A process for the treatment of copper nickel oxide ores

Abstract

The application provides a processing method of oxidized copper-nickel ore and relates to the technical field of metallurgical ore dressing. The method comprises the following steps: step S1, ore pretreatment; step S2, reduction and sulfidation of the mixture; step S3, low-nickel matte converting; step S4, slow cooling of smelting slag; and step S5, smelting slag ore dressing. Part of the oxidized copper-nickel ore is smelted into nickel matte, and the other part of the oxidized copper-nickel ore is modified into copper-nickel sulfide ore. Through a flotation process, nickel and copper metals are recovered in the form of nickel-copper sulfide, and the valuable metals are recycled.

Description

Technical Field

[0001] This invention relates to the field of metallurgical mineral processing technology, and more specifically, to a method for processing copper-nickel oxide ore. Background Technology

[0002] Copper and nickel are important non-ferrous metals in my country, playing a vital role in the national economy. my country's copper-nickel ore is mainly composed of sulfide copper-nickel ores, accounting for 86% of the country's total reserves. On the one hand, with the continuous and in-depth exploitation of my country's copper and nickel resources, easily beneficiated sulfide ores are becoming increasingly scarce; on the other hand, in copper-nickel ore resources, apart from some independent oxide copper-nickel deposits, most sulfide copper-nickel deposits have an oxidation zone in their upper part (surface layer). With the gradual depletion of sulfide copper-nickel ore resources, the development of oxide copper-nickel ores has attracted great attention from the mining industry, especially the development and utilization of difficult-to-benefit oxide copper-nickel ores, which has become a research focus. Commonly used beneficiation processes for sulfide copper-nickel ores include preferential flotation, mixed flotation, mixed-separation flotation, flash flotation, acid leaching activation-flotation, electrochemical controlled flotation, and bioleaching. As is well known, copper and nickel in copper-nickel oxide ores mainly exist in the form of oxide phase and silicate phase, making flotation recovery quite difficult. At present, there is little research on recovery processes for copper-nickel oxide ores, and the main methods are pyrometallurgy and hydrometallurgy. Summary of the Invention

[0003] The purpose of this invention is to provide a method for processing copper-nickel oxide ore, which can smelt part of the copper-nickel oxide ore into nickel matte, and modify another part of the copper-nickel oxide ore into copper-nickel sulfide ore. Through flotation, the nickel and copper metals are recovered in the form of nickel-copper sulfide phase, thus realizing the resource utilization of valuable metals.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] This application provides a method for processing copper-nickel oxide ore, comprising the following steps: S1: ore pretreatment; firstly, the copper-nickel oxide ore is crushed to a particle size of less than or equal to 30 mm, and then dry concentrate, limestone, and lump coal are added to the copper-nickel oxide ore and thoroughly mixed to form a furnace feed mixture; Step S2: reduction sulfidation of the mixture; the mixture of copper-nickel oxide ore, dry concentrate, and lump coal is fed into an electric furnace through a feeding port for smelting, the reduction sulfidation temperature is 1300-1500℃, and the holding time is 30-40 min. The reduction sulfidation reaction and phase fusion and separation processes are completed in the continuous phase of the melt in the smelting pool, ultimately forming two layers of melt: low-nickel matte and slag, which are then discharged from their respective discharge ports. Smelting pool; Step S3: Low-nickel matte blowing; When air or oxygen is blown into the converter, the low-nickel matte produced by the smelting electric furnace has a high iron content, making it easy to oxidize during blowing. At the same time, sulfur is also oxidized to produce sulfur dioxide gas, thereby further enriching copper and nickel into high-nickel matte containing 75% nickel and copper, less than 18% sulfur, and less than 1.2% iron; During the blowing process, a small amount of nickel is oxidized and remains in the slag. This part of the converter slag will be returned to the smelting electric furnace for further reduction and sulfidation; Step S4: Slow cooling of smelting slag; After the smelting slag is discharged into the ladle, it enters the slow cooling stage, which is divided into two stages: natural slow cooling and forced slow cooling by spray water. The temperature of the smelting slag that just comes out of the furnace is 1300-1500℃. It first undergoes natural slow cooling for 10-15 hours. When the surface crust temperature is below 300 or 400℃, it is then forced to cool slowly with spray water for 50-70 hours; Step S5: Smelting slag beneficiation: The cooled smelting slag is crushed and ground by a slag remover, crusher and ball mill. When the particle size is less than or equal to 45μm, the slurry mass concentration is adjusted to 32% to 40%. After adding xanthate collector and frother and stirring thoroughly, it is then subjected to one roughing, one cleaning and one scavenging to obtain a copper-nickel mixed concentrate product with a nickel content greater than 5%. The flotation tailings are discarded.

[0006] Furthermore, in this invention, the amount of dry concentrate added is 2% to 5% of the total mass of copper-nickel oxide ore, the amount of limestone added is 0.5% to 2% of the total mass of copper-nickel oxide ore, and the amount of lump coal added is 1% to 3% of the total mass of copper-nickel oxide ore; the main contents of the dry concentrate are 8% to 12% nickel, 5% to 10% copper, 30% to 35% iron, 28% to 33% sulfur, and the balance is other impurities.

[0007] Furthermore, in this invention, the electric furnace is an ultra-low frequency polarity controllable electric furnace, which has the characteristics of strong melt stirring effect, energy saving and consumption reduction, controllable electrode polarity, and ultra-low frequency power supply, which can make the molten furnace charge form a closed flow loop and have a circulating stirring function.

[0008] Furthermore, in this invention, step S5 above also includes combining the foam generated from one scavenging and the tailings from one fine selection and returning them to one roughing for further flotation.

[0009] Furthermore, in this invention, the xanthate collector is one or more of ethyl xanthate, butyl xanthate and pentyl xanthate, and the xanthate addition amount is 80-140 g / t; the foaming agent is one or more of pine oil, MIBC and J622, and the foaming agent addition amount is 30-90 g / t.

[0010] Furthermore, in this invention, the final products obtained are high-nickel matte containing about 75% nickel and copper in step S3 and flotation copper-nickel mixed concentrate containing more than 5% nickel in step S5. The comprehensive recovery rate of nickel and copper both reach more than 90%, and the nickel and copper content of the final waste slag is less than 0.07%, achieving zero emissions.

[0011] Compared with the prior art, the present invention has at least the following advantages or beneficial effects:

[0012] This invention can smelt some copper-nickel oxide ore into nickel matte, and modify another part of the copper-nickel oxide ore into copper-nickel sulfide ore. Through flotation, the nickel and copper metals are recovered in the form of nickel-copper sulfide phase, realizing the resource utilization of valuable metals. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0016] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0017] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0018] Example 1

[0019] This embodiment provides a method for processing oxidized copper-nickel ore, such as... Figure 1 As shown, it includes:

[0020] Step S1, Ore Pretreatment:

[0021] First, the copper-nickel oxide ore is crushed to a particle size ≤30mm. Then, a certain proportion of dry concentrate, limestone, and lump coal are added to the copper-nickel oxide ore and thoroughly mixed to form the furnace feed mixture. The amount of dry concentrate added is 2% to 5% of the total mass of the copper-nickel oxide ore, the amount of limestone added is 0.5% to 2% of the total mass of the copper-nickel oxide ore, and the amount of lump coal added is 1% to 3% of the total mass of the copper-nickel oxide ore.

[0022] Step S2, Reduction Vulcanization of the Mixture:

[0023] The mixture of copper-nickel oxide ore, dry concentrate, and lump coal is fed into the electric furnace through the feeding port for smelting. The reduction and sulfidation temperature is 1300-1500℃ and the holding time is 30-40 minutes. The reduction and sulfidation reaction and the fusion and separation of phases are completed in the continuous phase of the melt in the smelting pool, and finally two layers of melt, low-nickel matte and slag, are formed. They are then discharged from the smelting pool through their respective discharge ports.

[0024] Step S3, Low-nickel matte refining:

[0025] When low-nickel matte produced by the electric furnace is blown into the converter with air or oxygen, the iron content in the low-nickel matte is high, making it easy to oxidize during blowing. At the same time, sulfur is also oxidized to produce sulfur dioxide gas, which further enriches copper and nickel into high-nickel matte containing about 75% nickel and copper, less than 18% sulfur, and less than 1.2% iron. During the blowing process, a small amount of nickel is oxidized and remains in the slag. This part of the converter slag will be returned to the electric furnace for further reduction and sulfidation.

[0026] Step S4, slow cooling of smelting slag:

[0027] After the smelting slag is discharged into the ladle, it enters the slow cooling stage. The slow cooling stage is divided into two stages: natural slow cooling (air cooling) and forced slow cooling (water cooling) by spraying water. The temperature of the smelting slag that just came out of the furnace is 1300-1500℃. It first undergoes natural slow cooling for 10-15 hours. When the surface crust temperature is lower than 300-400℃, it is then forced slow cooling by spraying water for 50-70 hours. The purpose of slow cooling is to promote the aggregation and growth of nickel-copper phase molecules, which is beneficial to subsequent flotation operations.

[0028] Step S5, Smelting slag beneficiation:

[0029] After cooling, the smelting slag is crushed and ground by equipment such as slag remover, crusher, and ball mill. When the particle size reaches ≤45μm, the slurry mass concentration is adjusted to 32% to 40%. After adding xanthate and frother and stirring thoroughly, the slurry undergoes one roughing, one cleaning, and one scavenging process to obtain a copper-nickel mixed concentrate product with a nickel content greater than 5%. The flotation tailings are discarded.

[0030] In step S1 of this embodiment, the nickel and copper in the copper-nickel oxide ore are mainly oxides, existing primarily in the form of copper oxide phase, nickel oxide phase, copper silicate phase, and nickel silicate phase. The main contents of the dry concentrate are 8%–12% nickel, 5%–10% copper, 30%–35% iron, and 28%–33% sulfur, with the balance being other impurities.

[0031] In step S2 of this embodiment, the electric furnace is an ultra-low frequency polarity controllable electric furnace, which has the characteristics of strong melt stirring effect, energy saving and consumption reduction, controllable electrode polarity and ultra-low frequency power supply, which can make the molten furnace material form a closed flow loop and circulate stirring function.

[0032] In step S5 of this embodiment, the process includes one roughing, one cleaning, and one scavenging. It also includes combining the foam generated by the scavenging and the tailings from the cleaning process and returning them to the roughing process for further flotation.

[0033] In the processing after step S5 in this embodiment, the flotation copper-nickel concentrate product is concentrated and filtered to obtain copper-nickel concentrate filter cake, which can be sold as a product; the tailings are concentrated and discharged into the tailings pond as final waste.

[0034] Example 2

[0035] The main chemical composition (mass percentage) of a copper-nickel oxide ore from Gansu Province is as follows: Ni 0.82%, Cu 0.65%, Fe 15.78%, SiO2 34.21%, MgO 22.05%, CaO 4.05%, Al2O 36.44%. Copper mainly exists in the form of copper oxide, accounting for 73.85% of the total copper content. Nickel mainly exists in the form of nickel oxide and nickel silicate, accounting for 83.33% of the total nickel content.

[0036] Table 1. Chemical phase analysis results of nickel and copper elements in a copper oxide nickel ore in Gansu Province, %

[0037]

[0038] The following process steps of the present invention are used to process a copper-nickel oxide ore from Gansu:

[0039] Step (1) Ore pretreatment: First, crush the copper-nickel oxide ore to a particle size of ≤30mm. Then, add a certain proportion of dry concentrate, limestone and lump coal to the copper-nickel oxide ore and mix them thoroughly as the furnace feed mixture. The amount of dry concentrate added accounts for 3% of the total mass of copper-nickel oxide ore, the amount of limestone added accounts for 1% of the total mass of copper-nickel oxide ore, and the amount of lump coal added accounts for 1% of the total mass of copper-nickel oxide ore.

[0040] Step (2) Reduction sulfidation of the mixture: The mixture of copper-nickel oxide ore, dry concentrate and lump coal is fed into the electric furnace through the feeding port for smelting. The reduction sulfidation temperature is 1400℃ and the constant temperature time is 30min. The reduction sulfidation reaction and phase fusion and separation process are completed in the continuous phase of the melt in the smelting pool. Finally, two layers of melt, low nickel matte and slag, are formed and discharged from the smelting pool through their respective discharge ports.

[0041] Step (3) Low-nickel matte blowing: When air or oxygen is blown into the converter, the low-nickel matte produced by the smelting electric furnace has a high iron content and is easily oxidized during blowing. At the same time, sulfur is also oxidized to produce sulfur dioxide gas, which further enriches copper and nickel into high-nickel matte with a nickel-copper content of 74.81%. During the blowing process, a small amount of nickel is oxidized and exists in the slag. This part of the converter slag will be returned to the smelting electric furnace for further reduction and sulfidation.

[0042] Step (4) Slow cooling of smelting slag: After the smelting slag is discharged into the ladle, it enters the slow cooling stage. The slow cooling stage is divided into two stages: natural slow cooling (air cooling) and forced slow cooling (water cooling) by spraying water. The temperature of the smelting slag that just came out of the furnace is 1400℃. It first undergoes natural slow cooling for 12 hours. When the surface crust temperature is lower than 300℃, it is then forced slow cooling by spraying water for 60 hours.

[0043] Step (5) Smelting slag beneficiation: After cooling, the smelting slag is crushed and ground by equipment such as slag remover, crusher, and ball mill. When the particle size reaches ≤45μm, the slurry mass concentration is adjusted to 35%. 120g / t of butyl xanthate and 80g / t of pine oil are added and thoroughly mixed. After one roughing, one cleaning, and one scavenging, a copper-nickel mixed concentrate product containing 5.12% nickel and 5.09% copper is obtained. The flotation tailings contain 0.07% nickel and 0.04% copper.

[0044] After the above steps, the resulting products are shown in Table 2:

[0045] Table 2. Processing results of a copper-nickel oxide ore in Gansu Province, %

[0046]

[0047] Processing results: A copper-nickel oxide ore in Gansu Province contained 0.82% nickel and 0.65% copper. After processing with this method, high-nickel matte containing 74.81% nickel and copper and flotation concentrate containing 5.12% nickel and 5.09% copper were obtained. The nickel recovery rate was 92.08% and the copper recovery rate was 94.29%. The flotation tailings contained 0.07% nickel and 0.04% copper.

[0048] Example 3

[0049] The main chemical composition (mass percentage) of a copper-nickel oxide ore from Xinjiang is as follows: Ni 1.12%, Cu 0.78%, Fe 13.78%, SiO2 38.21%, MgO 20.85%, CaO 7.05%, Al2O3 2.49%. Copper mainly exists in the form of copper oxide, accounting for 84.83% of the total copper content. Nickel mainly exists in the form of nickel oxide and nickel silicate, accounting for 97.40% of the total nickel content.

[0050] Table 3. Chemical phase analysis results of nickel and copper elements in a copper oxide nickel ore in Xinjiang, %

[0051]

[0052] The following process steps of the present invention are used to process a copper-nickel oxide ore from Gansu:

[0053] Step (1) Ore pretreatment: First, crush the copper-nickel oxide ore to a particle size of ≤30mm. Then, add a certain proportion of dry concentrate, limestone and lump coal to the copper-nickel oxide ore and mix them thoroughly as the furnace feed mixture. The amount of dry concentrate added accounts for 3% of the total mass of copper-nickel oxide ore, the amount of limestone added accounts for 1% of the total mass of copper-nickel oxide ore, and the amount of lump coal added accounts for 1% of the total mass of copper-nickel oxide ore.

[0054] Step (2) Reduction sulfidation of the mixture: The mixture of copper-nickel oxide ore, dry concentrate and lump coal is fed into the electric furnace through the feeding port for smelting. The reduction sulfidation temperature is 1400℃ and the constant temperature time is 30min. The reduction sulfidation reaction and phase fusion and separation process are completed in the continuous phase of the melt in the smelting pool. Finally, two layers of melt, low nickel matte and slag, are formed and discharged from the smelting pool through their respective discharge ports.

[0055] Step (3) Low-nickel matte blowing: When air or oxygen is blown into the converter, the low-nickel matte produced by the smelting electric furnace has a high iron content and is easily oxidized during blowing. At the same time, sulfur is also oxidized to produce sulfur dioxide gas, which further enriches copper and nickel into high-nickel matte with a nickel-copper content of 73.68%. During the blowing process, a small amount of nickel is oxidized and exists in the slag. This part of the converter slag will be returned to the smelting electric furnace for further reduction and sulfidation.

[0056] Step (4) Slow cooling of smelting slag: After the smelting slag is discharged into the ladle, it enters the slow cooling stage. The slow cooling stage is divided into two stages: natural slow cooling (air cooling) and forced slow cooling (water cooling) by spraying water. The temperature of the smelting slag that just came out of the furnace is 1400℃. It first undergoes natural slow cooling for 12 hours. When the surface crust temperature is lower than 300℃, it is then forced slow cooling by spraying water for 60 hours.

[0057] Step (5) Smelting slag beneficiation: After cooling, the smelting slag is crushed and ground by equipment such as slag remover, crusher, and ball mill. When the particle size reaches ≤45μm, the slurry mass concentration is adjusted to 35%. 120g / t of butyl xanthate and 80g / t of pine oil are added and thoroughly mixed. After one roughing, one cleaning, and one scavenging, a copper-nickel mixed concentrate product containing 9.80% nickel and 6.49% copper is obtained. The flotation tailings contain 0.07% nickel and 0.07% copper.

[0058] After the above steps, the resulting products are shown in Table 4:

[0059] Table 4. Processing results of a copper-nickel oxide ore in Xinjiang, %

[0060]

[0061] Results: A copper-nickel oxide ore in Xinjiang contained 1.12% nickel and 0.78% copper. After processing using this method, high-nickel matte with 73.68% nickel and copper and flotation concentrate with 9.80% nickel and 6.49% copper were obtained. The nickel recovery rate was 94.17% and the copper recovery rate was 91.62%. The flotation tailings contained 0.07% nickel and 0.07% copper.

[0062] Example 4

[0063] A certain copper-nickel oxide ore has the following main chemical components (mass percentage): Ni 2.02%, Cu 1.52%, Fe 23.01%, SiO2 25.21%, MgO 18.63%, CaO 12.37%, Al2O3 4.53%. Copper mainly exists in the form of copper oxide, accounting for 74.35% of the total copper content. Nickel mainly exists in the form of nickel oxide and nickel silicate, accounting for 67.33% of the total nickel content.

[0064] Table 5. Chemical phase analysis results of nickel and copper elements in a certain copper oxide nickel ore, %

[0065]

[0066] The following process steps of the present invention are used to process a copper-nickel oxide ore from Gansu:

[0067] Step (1) Ore pretreatment: First, crush the copper-nickel oxide ore to a particle size of ≤30mm. Then, add a certain proportion of dry concentrate, limestone and lump coal to the copper-nickel oxide ore and mix them thoroughly as the furnace feed mixture. The amount of dry concentrate added accounts for 3.5% of the total mass of copper-nickel oxide ore, the amount of limestone added accounts for 2% of the total mass of copper-nickel oxide ore, and the amount of lump coal added accounts for 1% of the total mass of copper-nickel oxide ore.

[0068] Step (2) Reduction sulfidation of the mixture: The mixture of copper-nickel oxide ore, dry concentrate and lump coal is fed into the electric furnace through the feeding port for smelting. The reduction sulfidation temperature is 1400℃ and the constant temperature time is 30min. The reduction sulfidation reaction and phase fusion and separation process are completed in the continuous phase of the melt in the smelting pool. Finally, two layers of melt, low nickel matte and slag, are formed and discharged from the smelting pool through their respective discharge ports.

[0069] Step (3) Low-nickel matte blowing: When air or oxygen is blown into the converter, the low-nickel matte produced by the smelting electric furnace has a high iron content and is easily oxidized during blowing. At the same time, sulfur is also oxidized to produce sulfur dioxide gas, which further enriches copper and nickel into high-nickel matte with a nickel-copper content of 77.25%. During the blowing process, a small amount of nickel is oxidized and exists in the slag. This part of the converter slag will be returned to the smelting electric furnace for further reduction and sulfidation.

[0070] Step (4) Slow cooling of smelting slag: After the smelting slag is discharged into the ladle, it enters the slow cooling stage. The slow cooling stage is divided into two stages: natural slow cooling (air cooling) and forced slow cooling (water cooling) by spraying water. The temperature of the smelting slag that just came out of the furnace is 1400℃. It first undergoes natural slow cooling for 12 hours. When the surface crust temperature is lower than 300℃, it is then forced slow cooling by spraying water for 60 hours.

[0071] Step (5) Smelting slag beneficiation: After cooling, the smelting slag is crushed and ground by equipment such as slag remover, crusher, and ball mill. When the particle size reaches ≤45μm, the slurry mass concentration is adjusted to 35%. 120g / t of butyl xanthate and 80g / t of pine oil are added and thoroughly mixed. After one roughing, one cleaning, and one scavenging, a copper-nickel mixed concentrate product containing 7.85% nickel and 7.25% copper is obtained. The flotation tailings contain 0.06% nickel and 0.07% copper.

[0072] After the above steps, the resulting products are shown in Table 6:

[0073] Table 6. Results of processing a copper-nickel oxide ore, %

[0074]

[0075] Processing results: A copper-nickel oxide ore containing 2.02% nickel and 1.52% copper was processed using this method to obtain high-nickel matte containing 77.25% nickel and copper and flotation concentrate containing 7.85% nickel and 7.25% copper. The nickel recovery rate was 97.32% and the copper recovery rate was 95.83%. The flotation tailings contained 0.06% nickel and 0.07% copper.

[0076] In summary, the embodiments of the present invention provide a method for processing copper-nickel oxide ore, which has at least the following advantages or beneficial effects:

[0077] (1) The smelting equipment of the present invention adopts an ultra-low frequency polarity controllable electric furnace, which has the characteristics of strong melt stirring effect, energy saving and consumption reduction, controllable electrode polarity and ultra-low frequency power supply, so that the molten furnace charge forms a closed flow loop. The circulating stirring process can provide a high temperature dynamic condition and metallurgical kinetic reaction condition for the furnace charge to react with each other, so as to better complete the displacement, reduction and sulfidation reaction. The present invention solves the technical problems of uncontrollable temperature field distribution, poor melt stirring effect and insufficient reaction kinetics in traditional metallurgical furnaces and kilns, so that the furnace temperature field distribution is flexible and controllable, the melt stirring effect is strong, the smelting time is short, the furnace power factor is high, the operation is simple and the electrode consumption is low. The equipment has excellent technical and economic indicators. The process and technology design of the present invention are reasonable, easy to implement on-site industrial production, economical and environmentally friendly, and low cost.

[0078] (2) In the present invention, under molten and reducing conditions, a portion of copper-nickel oxide ore is smelted into nickel matte, and another portion of copper-nickel oxide ore is modified into copper-nickel sulfide ore. Through flotation process, nickel-copper metal is recovered in the form of nickel-copper sulfide phase, realizing the resource utilization of valuable metals.

[0079] Valuable metals in copper-nickel oxide ores mainly exist in the form of oxides or silicates. Utilizing the high-temperature reaction between the components in the slag and added fluxes, reducing agents, and sulfiding agents, reactions such as displacement, reduction, and sulfidation occur. Part of the copper and nickel metal forms nickel matte during smelting, while another part, due to the low nickel-copper content in the ore, undergoes controlled sulfidation under molten and reducing conditions, causing the nickel, copper, and a small amount of iron in the furnace charge to sulfide, forming nickel-copper and iron sulfides. This modifies the valuable metals into sulfides. Gangue forms silicates that enter the slag phase. Through flotation, nickel and copper are recovered as sulfided nickel-copper phases, thus achieving the resource utilization of valuable metals. The reduction sulfidation process involves a fairly complex chemical reaction, the main reactions of which are as follows: Fe3O4+C=3FeO+CO, FeO+C=Fe+CO, MSiO4+ CaO=MO+ CaSiO4 (M replaces Ni, Cu, Co, etc.), Cu2O+ Fe=2Cu+ FeO, NiO+ Fe=Ni+ FeO, CoO+ Fe=Co+ FeO, 2Cu+FeS=Cu2S+ Fe, 3Ni+ 2FeS=Ni3S2+2Fe, Co+ FeS=CoS+ Fe, 2Cu+ S=Cu2S, 3Ni+2S=Ni3S2, Co+S=CoS, S+O2=SO2.

[0080] (3) This invention uses an ultra-low frequency polar controllable electric furnace to process copper-nickel oxide ore. By optimizing the design of the components and proportions of the sulfiding agent, reducing agent and flux, a high-nickel matte product with about 45% nickel and 30% copper can be produced. During the smelting process, the nickel-copper mineral phase of the smelting slag is reconstructed to generate new mineral phases, realize slag flotation, and produce a flotation copper-nickel mixed concentrate with more than 5.0% nickel, thus achieving the purpose of resource utilization. The comprehensive recovery rate of nickel and copper reaches more than 90%, and the nickel and copper content of the final discarded slag is less than 0.07%, achieving double zero discharge.

[0081] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for processing copper-nickel oxide ore, characterized in that, Includes the following steps: S1: Ore pretreatment; First, crush the copper-nickel oxide ore to a particle size of less than or equal to 30mm. Then, add dry concentrate, limestone, and lump coal to the copper-nickel oxide ore and mix thoroughly as the furnace feed mixture. The main contents of the dry concentrate are nickel 8%–12%, copper 5%–10%, iron 30%–35%, and sulfur 28%–33%. S2: Mixed material reduction sulfidation; The mixed material is fed into the electric furnace for smelting. The reduction sulfidation temperature is 1300-1500℃, and the holding time is 30-40min. The reduction sulfidation reaction and phase fusion and separation process are completed in the continuous phase of the melt in the smelting pool, and finally two layers of melt, low nickel matte and slag, are formed, which are then discharged from the smelting pool through their respective discharge ports. S3: Low-nickel matte blowing; When air or oxygen is blown into the converter, the low-nickel matte produced by the smelting electric furnace has a high iron content and is easily oxidized during blowing. At the same time, sulfur is also oxidized to produce sulfur dioxide gas, which further enriches copper and nickel into high-nickel matte with a nickel content of not less than 75% copper, less than 18% sulfur, and less than 1.2% iron. S4: Slow cooling of smelting slag; After the smelting slag is discharged into the ladle, it enters the slow cooling stage for cooling. S5: Smelting slag beneficiation; After cooling, the smelting slag is crushed and ground by a slag remover, crusher, and ball mill. When the particle size is less than or equal to 45μm, the slurry mass concentration is adjusted to 32% to 40%. After adding xanthate collector and frother and stirring thoroughly, the slurry undergoes one roughing, one cleaning, and one scavenging process to obtain a copper-nickel mixed concentrate product with a nickel content greater than 5%. The flotation tailings are discarded.

2. The method for processing copper-nickel oxide ore according to claim 1, characterized in that, The dry concentrate is added at 2% to 5% of the total mass of copper-nickel oxide ore, the limestone is added at 0.5% to 2% of the total mass of copper-nickel oxide ore, and the lump coal is added at 1% to 3% of the total mass of copper-nickel oxide ore.

3. The method for processing copper-nickel oxide ore according to claim 1, characterized in that, During the smelting process, a small amount of nickel is oxidized and remains in the slag. This portion of the converter slag will be returned to the smelting electric furnace for further reduction and sulfidation.

4. The method for processing copper-nickel oxide ore according to claim 1, characterized in that, In step S5, the foam generated from the first scavenging and the tailings from the first fine selection are combined and returned to the first roughing for further flotation.

5. The method for processing copper-nickel oxide ore according to claim 1, characterized in that, The xanthate collector is one or more of ethyl xanthate, butyl xanthate, and pentyl xanthate, with an addition amount of 80-140 g / t; the foaming agent is one or more of pine oil, MIBC, and J622, with an addition amount of 30-90 g / t.

6. The method for processing copper-nickel oxide ore according to claim 1, characterized in that, In step S4, the slow cooling process is divided into two stages: natural slow cooling and forced slow cooling with spray water. The temperature of the smelting slag that just came out of the furnace is 1300-1500℃. It first undergoes natural slow cooling for 10-15 hours. When the surface crust temperature is below 300 or 400℃, it is then forced slow cooling with spray water for 50-70 hours.

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