Treatment method of copper nickel oxide ore

Abstract

The invention provides a treatment method for copper nickel oxide ore, and relates to the technical field of metallurgical ore dressing. The method comprises the following steps: S1, ore pretreatment; s2, reducing and vulcanizing the mixture; s3, low-nickel matte blowing; s4, smelted slag is slowly cooled; s5, smelting slag beneficiation; according to the method, part of the copper-nickel oxide ore can be smelted into nickel matte, the other part of the copper-nickel oxide ore is modified into the copper-nickel sulfide ore, nickel-copper metal is recycled in a nickel-copper sulfide phase mode through the flotation technology, and resource utilization of valuable metal is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgical mineral processing, and in particular to a method for processing copper-nickel oxide ore. Background Art

[0002] Copper and nickel are important nonferrous metals in my country, occupying a crucial position in the national economy. Sulfide copper-nickel ores are the primary source of copper-nickel ore in my country, accounting for 86% of the country's total reserves. With the continued intensive exploitation of copper-nickel resources in my country, easily beneficiated sulfide ores are becoming increasingly scarce. Furthermore, in addition to isolated oxide copper-nickel deposits, most sulfide copper-nickel deposits contain an oxidation zone in the upper (surface) layers. With the gradual decline of sulfide copper-nickel ore resources, the development of oxide copper-nickel ores has attracted significant attention in the mining industry, with the development and utilization of refractory oxide copper-nickel ores becoming a research priority. Common beneficiation processes for sulfide copper-nickel ores include preferential flotation, mixed flotation, mixed-separation flotation, flash flotation, acid leaching activation-flotation, electrochemically controlled flotation, and bioleaching. As we all know, the copper and nickel in copper-nickel oxide ore mainly exist in the form of oxide phase and silicate phase, and flotation recovery is quite difficult. Currently, there is little research on the recovery process of copper-nickel oxide ore, and the main methods are pyrometallurgy and wet leaching. Summary of the Invention

[0003] The object of the present invention is to provide a method for treating copper-nickel oxide ore, which can smelt part of the copper-nickel oxide ore into nickel matte, and modify the other part of the copper-nickel oxide ore into copper-nickel sulfide ore. Through the flotation process, the nickel-copper metal can be recovered in the form of nickel-copper sulfide phase, thereby realizing the resource utilization of valuable metals.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: The present application provides a method for processing copper-nickel oxide ore, which includes step S1: ore pretreatment; first, 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 fully mixed to form a furnace mixture; step S2: reduction and sulfidation of the mixture; the copper-nickel oxide ore, dry concentrate and lump coal mixture is fed into an electric furnace through a feed port for smelting, the reduction and sulfidation temperature is 1300-1500°C, the constant temperature time is 30-40 minutes, and the reduction and sulfidation reaction and the 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, and then discharged from their respective discharge ports. Smelting pool; Step S3: blowing low nickel matte; When the low nickel matte produced by the smelting furnace is blown into air or oxygen-enriched water in the converter, the iron content in the low nickel matte is high and it is easily oxidized during blowing. At the same time, sulfur is also oxidized to produce sulfur dioxide gas, thereby further enriching copper and nickel into a high nickel matte containing 75% nickel copper, less than 18% sulfur, and less than 1.2% iron; During the blowing process, a small amount of nickel is oxidized and stored in the slag. This part of the converter slag will be returned to the smelting furnace for further reduction and sulfidation; Step S4: slow cooling of the 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 spraying water. The temperature of the smelting slag just out of the furnace is 1300-1500℃ and it is first naturally slow cooled for 10-15h. When the surface crust temperature is lower than 300 or 400°C, spray water for forced slow cooling for 50-70 hours; Step S5: Smelting slag beneficiation: the cooled smelting slag is crushed and ground by a slag maker, a crusher, and a ball mill. When the particle size is less than or equal to 45 μm, the slurry mass concentration is adjusted to 32% to 40%, and a xanthate collector and a frother are added and fully stirred. After a roughing selection, a fine selection, and a scavenging selection, a copper-nickel mixed concentrate product containing more than 5% nickel is obtained, and the flotation tailings are used as waste slag.

[0005] Furthermore, in the present invention, the amount of the dry concentrate added is 2% to 5% of the total mass of the copper-nickel oxide ore, the amount of the limestone added is 0.5% to 2% of the total mass of the copper-nickel oxide ore, and the amount of the lump coal added is 1% to 3% of the total mass of the copper-nickel oxide ore; the main content of the dry concentrate is 8% to 12% nickel, 5% to 10% copper, 30% to 35% iron, and 28% to 33% sulfur, with the remainder being other impurities.

[0006] Furthermore, in the present invention, the above-mentioned 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.

[0007] Furthermore, in the present invention, the above step S5 further comprises combining the foam generated by the first scavenging and the tailings from the first cleaning and returning them to the first roughing for re-flotation.

[0008] Furthermore, in the present invention, the xanthate collector is a mixture of one or more of ethyl xanthate, butyl xanthate and amyl xanthate, and the amount of xanthate added is 80-140 g / t; the foaming agent is a mixture of one or more of pine oil, MIBC and J622, and the amount of foaming agent added is 30-90 g / t.

[0009] Furthermore, in the present 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 rates of nickel and copper both reach more than 90%, and the nickel and copper contents of the final waste slag are both less than 0.07%, achieving double zero emissions.

[0010] Compared with the prior art, the present invention has at least the following advantages or beneficial effects: The present invention can smelt part of the oxidized copper-nickel ore into nickel matte, and modify the other part of the oxidized copper-nickel ore into copper-nickel sulfide ore. Through the flotation process, the nickel-copper metal is recovered in the form of nickel-copper sulfide phase, thereby realizing the resource utilization of valuable metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0012] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0014] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0015] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0016] Example 1 This embodiment provides a method for processing copper-nickel oxide ore, such as Figure 1 As shown, it includes: Step S1, ore pretreatment: First, the copper-nickel oxide ore is crushed to a particle size of ≤30 mm, and then a certain proportion of dry concentrate, limestone and lump coal are added to the copper-nickel oxide ore and mixed thoroughly to form a furnace 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.

[0017] Step S2, reduction vulcanization of the mixture: The copper-nickel oxide ore, dry concentrate and lump coal mixture are fed into the electric furnace through the feeding port for smelting. The reduction and sulfidation temperature is 1300-1500℃ and the constant temperature time is 30-40min. The reduction and sulfidation reaction and the 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, and then discharged from the smelting pool through their respective discharge ports.

[0018] Step S3, low nickel matte blowing: When air or oxygen is blown into the converter into the low-nickel matte produced by the smelting furnace, the iron content in the low-nickel matte is high and it is easily oxidized during blowing. At the same time, the sulfur is also oxidized to produce sulfur dioxide gas, thereby further enriching copper and nickel into high-nickel matte containing about 75% nickel-copper, less than 18% sulfur, and less than 1.2% iron. 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 furnace for further reduction and sulfidation.

[0019] Step S4, slowly cooling the 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 by spraying water (water cooling). The temperature of the smelting slag just out of the furnace is 1300-1500℃. It is first naturally slow cooled for 10-15h. When the surface crust temperature is lower than 300-400℃, it is forced slow cooled by spraying water for 50-70h. The purpose of slow cooling is to promote the aggregation and growth of nickel-copper phase molecules, which is beneficial to subsequent flotation operations.

[0020] Step S5, smelting slag beneficiation: The cooled smelting slag is crushed and ground by slag breaker, crusher, ball mill and other equipment. When the particle size reaches ≤45μm, the slurry mass concentration is adjusted to 32%-40%. After adding xanthate and foaming agent and fully stirring, it goes through one roughing, one fine selection and one scavenging selection to obtain a copper-nickel mixed concentrate product with a nickel content of more than 5%. The flotation tailings are used as waste slag.

[0021] In step S1 of this embodiment, the nickel and copper in the copper-nickel oxide ore are primarily oxides, present primarily in the form of copper oxide phase, nickel oxide phase, copper silicate phase, and nickel silicate phase. The dry concentrate primarily contains 8% to 12% nickel, 5% to 10% copper, 30% to 35% iron, and 28% to 33% sulfur, with the remainder being other impurities.

[0022] 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. It can make the molten furnace charge form a closed flow loop and circulate stirring function.

[0023] In step S5 of this embodiment, the first roughing, the first cleaning and the first scavenging are performed, and the foam generated by the first scavenging and the tailings from the first cleaning are combined and returned to the first roughing for re-flotation.

[0024] In the process after step S5 of this embodiment, the flotation copper-nickel concentrate product is concentrated and then filtered to obtain a copper-nickel concentrate filter cake, which can be sold as a product; the tailings are concentrated and then discharged into the tailings pond to be the final waste.

[0025] Example 2 The main chemical components (mass percentage) of a copper-nickel oxide ore in Gansu are: Ni 0.82%, Cu 0.65%, Fe 15.78%, SiO2 34.21%, MgO 22.05%, CaO 4.05%, Al2O3 6.44%. Copper mainly exists in the form of copper oxide, accounting for 73.85% of the total copper. Nickel is mainly nickel oxide and nickel silicate, accounting for 83.33% of the total nickel.

[0026] Table 1 Chemical phase analysis results of nickel and copper elements in a copper-nickel oxide ore in Gansu, % The following process steps of the present invention are used to treat a copper-nickel oxide ore in Gansu: Step (1) ore pretreatment: first crush the copper-nickel oxide ore to a particle size of ≤30 mm, then add a certain proportion of dry concentrate, limestone and lump coal to the copper-nickel oxide ore and mix them thoroughly to form a furnace mixture, wherein the amount of dry concentrate added accounts for 3% of the total mass of the copper-nickel oxide ore, the amount of limestone added accounts for 1% of the total mass of the copper-nickel oxide ore, and the amount of lump coal added accounts for 1% of the total mass of the copper-nickel oxide ore.

[0027] Step (2) reduction sulfidation of the mixture: the copper-nickel oxide ore, dry concentrate and lump coal mixture are fed into the electric furnace through the feed port for smelting, the reduction sulfidation temperature is 1400°C and the constant temperature time is 30 minutes, the reduction sulfidation reaction and the 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, and then discharged from the smelting pool through their respective discharge ports.

[0028] Step (3) blowing of low-nickel matte: When air or oxygen-enriched gas is blown into the converter into the low-nickel matte produced by the smelting furnace, the iron content in the low-nickel matte is high and it is easily oxidized 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 74.81% nickel copper. During the blowing process, a small amount of nickel is oxidized and stored in the slag. This part of the converter slag will be returned to the smelting furnace for further reduction and sulfidation.

[0029] Step (4) Slow cooling of slag: After the 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 by spraying water (water cooling). The temperature of the slag just out of the furnace is 1400℃. It is first naturally slow cooled for 12 hours. When the surface crust temperature is lower than 300℃, it is forced to slow cooled by spraying water for 60 hours.

[0030] Step (5) smelting slag beneficiation: The cooled smelting slag is crushed and ground by a slag breaker, a crusher, a ball mill and other equipment. When the particle size reaches ≤45 μm, the slurry mass concentration is adjusted to 35%, 120 g / t of butyl xanthate and 80 g / t of pine oil are added and fully stirred. After a roughing selection, a fine selection and a scavenging selection, a copper-nickel mixed concentrate product containing 5.12% nickel and 5.09% copper is obtained, and the flotation tailings contain 0.07% nickel and 0.04% copper.

[0031] After the above steps, the obtained products are shown in Table 2: Table 2 Treatment results of a copper-nickel oxide ore in Gansu, % Treatment results: A copper-nickel oxide ore in Gansu contains 0.82% nickel and 0.65% copper. After treatment by this method, a high-nickel matte containing 74.81% nickel and copper and a 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.

[0032] Example 3 The main chemical components (mass percentage) of a copper-nickel oxide ore in Xinjiang are: Ni 1.12%, Cu 0.78%, Fe 13.78%, SiO2 38.21%, MgO 20.85%, CaO 7.05%, Al2O3 2.49%. Copper exists mainly in the form of copper oxide, accounting for 84.83% of the total copper. Nickel mainly exists in the form of nickel oxide and nickel silicate, accounting for 97.40% of the total nickel.

[0033] Table 3 Chemical phase analysis results of nickel and copper elements in a copper-nickel oxide ore in Xinjiang, % The following process steps of the present invention are used to treat a copper-nickel oxide ore in Gansu: Step (1) ore pretreatment: first crush the copper-nickel oxide ore to a particle size of ≤30 mm, then add a certain proportion of dry concentrate, limestone and lump coal to the copper-nickel oxide ore and mix them thoroughly to form a furnace mixture, wherein the amount of dry concentrate added accounts for 3% of the total mass of the copper-nickel oxide ore, the amount of limestone added accounts for 1% of the total mass of the copper-nickel oxide ore, and the amount of lump coal added accounts for 1% of the total mass of the copper-nickel oxide ore.

[0034] Step (2) reduction sulfidation of the mixture: the copper-nickel oxide ore, dry concentrate and lump coal mixture are fed into the electric furnace through the feed port for smelting, the reduction sulfidation temperature is 1400°C and the constant temperature time is 30 minutes, the reduction sulfidation reaction and the 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, and then discharged from the smelting pool through their respective discharge ports.

[0035] Step (3) blowing of low-nickel matte: When air or oxygen-enriched gas is blown into the converter into the low-nickel matte produced by the smelting furnace, the iron content in the low-nickel matte is high and it is easily oxidized 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 73.68% nickel copper. During the blowing process, a small amount of nickel is oxidized and stored in the slag. This part of the converter slag will be returned to the smelting furnace for further reduction and sulfidation.

[0036] Step (4) Slow cooling of slag: After the 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 by spraying water (water cooling). The temperature of the slag just out of the furnace is 1400℃. It is first naturally slow cooled for 12 hours. When the surface crust temperature is lower than 300℃, it is forced to slow cooled by spraying water for 60 hours.

[0037] Step (5) smelting slag beneficiation: The cooled smelting slag is crushed and ground by a slag maker, a crusher, a ball mill and other equipment. When the particle size reaches ≤45 μm, the slurry mass concentration is adjusted to 35%, 120 g / t of butyl xanthate and 80 g / t of pine oil are added and fully stirred. After a roughing selection, a fine selection and a scavenging selection, a copper-nickel mixed concentrate product containing 9.80% nickel and 6.49% copper is obtained, and the flotation tailings contain 0.07% nickel and 0.07% copper.

[0038] After the above steps, the obtained products are shown in Table 4: Table 4 Treatment results of a copper-nickel oxide ore in Xinjiang, % Treatment results: A copper-nickel oxide ore from Xinjiang containing 1.12% nickel and 0.78% copper was treated with this method to produce a high-nickel matte containing 73.68% nickel and copper, and a flotation concentrate containing 9.80% nickel and 6.49% copper. 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. Example 4 The main chemical components (mass percentage) of a copper-nickel oxide ore are: Ni 2.02%, Cu 1.52%, Fe 23.01%, SiO2 25.21%, MgO 18.63%, CaO 12.37%, and Al2O3 4.53%. Copper exists mainly in the form of copper oxide, accounting for 74.35% of the total copper. Nickel mainly exists in the form of nickel oxide and nickel silicate, accounting for 67.33% of the total nickel.

[0039] Table 5 Chemical phase analysis results of nickel and copper elements in a copper-nickel oxide ore, % The following process steps of the present invention are used to treat a copper-nickel oxide ore in Gansu: Step (1) Ore pretreatment: first crush the copper-nickel oxide ore to a particle size of ≤30 mm, then add a certain proportion of dry concentrate, limestone and lump coal to the copper-nickel oxide ore and mix them thoroughly to form a furnace mixture, wherein the amount of dry concentrate added accounts for 3.5% of the total mass of the copper-nickel oxide ore, the amount of limestone added accounts for 2% of the total mass of the copper-nickel oxide ore, and the amount of lump coal added accounts for 1% of the total mass of the copper-nickel oxide ore.

[0040] Step (2) reduction sulfidation of the mixture: the copper-nickel oxide ore, dry concentrate and lump coal mixture are fed into the electric furnace through the feed port for smelting, the reduction sulfidation temperature is 1400°C and the constant temperature time is 30 minutes, the reduction sulfidation reaction and the 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, and then discharged from the smelting pool through their respective discharge ports.

[0041] Step (3) blowing of low-nickel matte: When the low-nickel matte produced by the smelting furnace is blown into air or oxygen-enriched water in the converter, the iron content in the low-nickel matte is high and it is easily oxidized 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 77.25% nickel copper. During the blowing process, a small amount of nickel is oxidized and stored in the slag. This part of the converter slag will be returned to the smelting furnace for further reduction and sulfidation.

[0042] Step (4) Slow cooling of slag: After the 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 by spraying water (water cooling). The temperature of the slag just out of the furnace is 1400℃. It is first naturally slow cooled for 12 hours. When the surface crust temperature is lower than 300℃, it is forced to slow cooled by spraying water for 60 hours.

[0043] Step (5) smelting slag beneficiation: The cooled smelting slag is crushed and ground by a slag breaker, a crusher, a ball mill and other equipment. When the particle size reaches ≤45 μm, the slurry mass concentration is adjusted to 35%, 120 g / t of butyl xanthate and 80 g / t of pine oil are added and fully stirred. After a roughing selection, a fine selection and a scavenging selection, a copper-nickel mixed concentrate product containing 7.85% nickel and 7.25% copper is obtained, and the flotation tailings contain 0.06% nickel and 0.07% copper.

[0044] After the above steps, the obtained products are shown in Table 6: Table 6 Treatment results of a copper-nickel oxide ore, % Treatment results: A copper-nickel oxide ore containing 2.02% nickel and 1.52% copper was treated by this method to obtain a high-nickel matte containing 77.25% nickel and copper and a 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.

[0045] In summary, the embodiments of the present invention provide a method for treating copper-nickel oxide ore, which has at least the following advantages or beneficial effects: (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 charge forms a closed flow loop. The cyclic stirring process can provide the charge with a high-temperature dynamic condition and metallurgical kinetic reaction condition for mutual contact reaction, so as to better complete the replacement, reduction and sulfidation reactions; the present invention solves the technical difficulties of uncontrollable temperature field distribution, poor melt stirring effect, and insufficient reaction kinetics in traditional metallurgical furnaces, 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, the electrode consumption is low, and the equipment has excellent technical and economic indicators; the process and process design of the present invention are reasonable, on-site industrial production is easy to implement, economical and environmentally friendly, and low cost.

[0046] (2) The present invention smelts part of the oxidized copper-nickel ore into nickel matte in a molten state and under reducing conditions, and modifies the other part of the oxidized copper-nickel ore into copper-nickel sulfide ore. Through the flotation process, the nickel-copper metal is recovered in the form of nickel-copper sulfide phase, thereby realizing the resource utilization of valuable metals.

[0047] The valuable metals in the oxidized copper-nickel ore mainly exist in the form of oxides or silicates. The components in the slag at high temperature can react with the added flux, reducing agent and sulfiding agent to undergo replacement, reduction and sulfidation reactions. A part of the copper-nickel metal forms nickel matte during the smelting process. The other part, due to the low nickel-copper content in the ore, is sulfided by controlling the sulfidation in the molten state and under reducing conditions to form nickel-copper and iron sulfides, thereby modifying the valuable metals into sulfides; the gangue forms silicates and enters the slag phase. Through the flotation process, the nickel and copper are recovered in the form of nickel-copper sulfide phase, thereby realizing the resource utilization of valuable metals. The reduction sulfide process undergoes quite complex chemical reactions, the main reactions 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.

[0048] (3) The present invention adopts an ultra-low frequency polarity controllable electric furnace to treat oxidized copper-nickel ore. By optimizing the components and ratios of the sulfiding agent, reducing agent and flux, a high-nickel matte product containing about 45% nickel and 30% copper can be blown out. In the smelting process, the nickel-copper mineral phase of the smelting slag is reconstructed for resource utilization, a new mineral phase is generated, slag flotation is realized, and a flotation copper-nickel mixed concentrate containing more than 5.0% nickel is produced, achieving the purpose of resource utilization; the comprehensive recovery rate of nickel and copper reaches more than 90%, and the nickel and copper contents of the final waste slag are both less than 0.07%, achieving double zero emissions.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for treating copper-nickel oxide ore, characterized in that: The following steps are involved: S1: Ore pretreatment: first crush the copper-nickel oxide ore to a particle size of less than or equal to 30 mm, then add dry concentrate, limestone and lump coal to the copper-nickel oxide ore and mix thoroughly to prepare the furnace mixture; S2: Reduction and sulfidation of the mixed material: The mixed material is fed into the electric furnace for smelting at a reduction and sulfidation temperature of 1300-1500°C for 30-40 minutes. The reduction and sulfidation reaction and the fusion and separation of the phases 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 the smelting pool through their respective discharge ports. S3: Low-nickel matte blowing; when the low-nickel matte produced by the smelting furnace is blown into air or oxygen-enriched water in the converter, the iron content in the low-nickel matte is high and it is easily oxidized 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 not less than 75% nickel and copper, less than 18% sulfur, and less than 1.2% iron; S4: Slow cooling of slag: After being discharged into the ladle, the slag enters the slow cooling stage for cooling; S5: Smelting slag beneficiation; the cooled smelting slag is crushed and ground by a slag maker, a crusher, and a ball mill. When the particle size is less than or equal to 45 μm, the slurry mass concentration is adjusted to 32% to 40%. After adding xanthate collector and frother and fully stirring, after a roughing, a fine selection, and a scavenging selection, a copper-nickel mixed concentrate product with a nickel content of more than 5% is obtained, and the flotation tailings are used as waste slag.

2. The method for treating copper-nickel oxide ore according to claim 1, wherein: 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.

3. The method for processing copper-nickel oxide ore according to claim 1, wherein: 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 furnace for further reduction and sulfidation.

4. The method for treating copper-nickel oxide ore according to claim 1, wherein: In step S5, the foam generated by the first scavenging and the tailings from the first cleaning are combined and returned to the first roughing for re-floatation.

5. The method for treating copper-nickel oxide ore according to claim 1, wherein: The xanthate collector is a mixture of one or more of ethyl xanthate, butyl xanthate, and amyl xanthate, and the amount of xanthate added is 80-140 g / t; the foaming agent is a mixture of one or more of pine oil, MIBC, and J622, and the amount of foaming agent added is 30-90 g / t.

6. The method for treating copper-nickel oxide ore according to claim 1, wherein: The slow cooling process in step S4 is divided into two stages: natural slow cooling and forced slow cooling by spraying water. The temperature of the smelting slag just out of the furnace is 1300-1500℃ and it is first naturally slow cooled for 10-15 hours. When the surface crust temperature is lower than 300 or 400℃, it is forced to slow cool by spraying water for 50-70 hours.

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