Smelting process and device for treating high-nickel copper concentrate

Abstract

The invention discloses a smelting process and device for treating high-nickel copper concentrate. The smelting process comprises four stages of smelting, blowing, anode refining and slag dilution. In the smelting stage, the high-nickel copper concentrate is added into a smelting furnace to be smelted, and high-nickel matte, flue gas and smelting slag are produced; the high-nickel matte produced in the smelting stage is fed into a converting furnace for converting, and crude copper, flue gas and converting slag are produced by adopting a new calcium-silicon slag type; the crude copper directly flows into an anode furnace for anode refining to produce an anode plate; and blowing slag flows into a dilution furnace for dilution to produce high-grade nickel matte. The method solves the problem that the high-nickel copper concentrate cannot be treated on a large scale in current industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal smelting, and particularly relates to a smelting process and device for treating high-nickel copper concentrate. Background Art

[0002] Copper in nature mainly exists in the form of sulfides, often associated with harmful metals such as arsenic, antimony, bismuth, lead, cadmium, and mercury, and also associated with precious and rare metals such as gold, silver, platinum, and palladium. During the smelting process, generally, precious and rare metals and some lead and bismuth enter the anode slime and are recovered; other impurities are removed in processes such as tail slag, sulfuric acid purification, and electrolytic purification, and finally high-purity cathode copper and other valuable metals are obtained.

[0003] Sulfide copper ores are also accompanied by nickel sulfides. Trace amounts of nickel can be recovered as nickel sulfate by evaporation crystallization or freeze crystallization during the purification of the electrolyte. If the nickel content increases and exceeds 0.3%, it belongs to the category of nickel sulfide ores. Nickel sulfide ores with a nickel content higher than 3% are called rich ores and can be directly smelted without beneficiation. Nickel sulfide ores are often accompanied by copper sulfide ores, so they are often called "nickel sulfide ores" (Ni / Cu>1), and their smelting theory and practice are similar to those of copper sulfide concentrate.

[0004] Existing technologies only have processes for treating nickel sulfide concentrate, such as the nickel flash furnace + converter process in Jinchuan and the Ausmelt furnace process in Jilin Jien Nickel Industry Co., Ltd., and there is no process for directly treating high-nickel copper concentrate. Currently, in industrial production, high-nickel copper concentrate is mixed with low-nickel copper concentrate in a certain proportion so that the nickel content in the mixed copper concentrate reaches less than 0.5% before smelting. During the smelting process of high-nickel copper concentrate, most of the nickel enters the copper phase and a small amount enters the slag phase. Since the properties of copper and nickel are similar, during the electrolytic refining stage, the anode plate is passivated and the electrolytic process cannot proceed normally. Summary of the Invention

[0005] In view of the deficiencies of the existing technology, the present invention provides a smelting process and device for treating high-nickel copper concentrate.

[0006] As the first aspect of the present invention, it lies in providing a smelting process for treating high-nickel copper concentrate, including the following steps:

[0007] S1, smelting: Mix the high-nickel copper concentrate with the flux quartz sand, add it to the smelting furnace, react with oxygen-enriched air, and complete slag formation with the flux quartz sand to produce matte.

[0008] In the embodiment of the present invention, the high-nickel copper concentrate contains 0.5 - 5% nickel, 15 - 30% copper, and the nickel-copper ratio is 0.02 - 0.33.

[0009] Preferably, in step S1, the mass ratio of the high-nickel copper concentrate to the quartz sand is 1:0.1 - 1:0.25.

[0010] Preferably, in step S1, the concentration of oxygen-enriched air is 60%-90%.

[0011] In step S1, the main reactions include the decomposition, oxidation of sulfide ore, the formation of matte and slag-making process. Preferably, in step S1, the matte produced contains 55-70% copper and 1-10% nickel, which is high-nickel matte.

[0012] S2, Blowing: Feed the high-nickel matte produced in step S1 into a blowing furnace for blowing, adopt a new calcium-silicate slag type to produce blister copper and blowing slag.

[0013] In the embodiment of the present invention, the molten matte obtained in step S1 is granulated, dried and ground finely, with a particle size: -325 mesh > 45%. It enters the blowing furnace together with oxygen-enriched air, and at the same time, slag-making fluxes limestone (calcium oxide) and quartz sand are added to make a large amount of nickel enter the slag phase, controlling (CaO + SiO2) / (Fe + Ni) ≥ 1 in the slag,

[0014] (Cu + SiO2 + CaO / Ni + Fe) ≥ 1.6, and the slag temperature is 1280°C - 1350°C.

[0015] Preferably, in step S2, the mass ratio of matte:SiO2:CaO is about 10:1:0.3.

[0016] Preferably, in step S2, the concentration of oxygen-enriched air can be 60%, 90% or any concentration between 60% - 90%.

[0017] The main reactions in the blowing process include the oxidation reaction in the reaction tower, copper-making and slag-making reactions in the settling tank; preferably, in step S2, the blowing slag contains 20-25% copper, 30-40% CaO + SiO2, and 4-8% nickel, and enters the impoverishment furnace for impoverishment; the blister copper contains less than 0.8% nickel and 98-99% copper.

[0018] S3, Anode refining: The blister copper obtained in step S2 directly flows into the anode furnace for anode refining to produce anode plates, and the blowing slag flows into the impoverishment furnace for impoverishment to produce high-grade nickel matte.

[0019] Preferably, in step S3, it includes the first-stage impoverishment process in the first-stage impoverishment furnace and the second-stage impoverishment process in the second-stage impoverishment furnace; coke and sulfiding agent are added in the first-stage impoverishment furnace to carry out reduction and sulfidation reactions; slag-making fluxes are added in the second-stage impoverishment furnace to remove most of the iron in the low-grade nickel matte and produce high-grade nickel matte with 70-80% nickel + copper. The high-grade nickel matte is further processed to recover copper and nickel. The process parameters of the first-stage impoverishment: The mass ratio of pyrite to slag is 1:5 - 1:4, the mass ratio of coke to slag is 1-2:50, and the temperature is controlled at 1280-1320°C. The process parameters of the second-stage impoverishment: The mass ratio of quartz sand to low-grade nickel matte is 1-2:20, and the temperature is controlled at 1280-1320°C.

[0020] During the stage of converting slag impoverishment, reduction and sulfidation reactions occur in the impoverishment furnace to produce high-grade nickel matte with nickel + copper content of 70 - 80%, and the copper and nickel are further processed and recovered.

[0021] As the second aspect of the present invention, there is provided a smelting device for processing high-nickel copper concentrate, including, arranged in sequence:

[0022] A smelting furnace for generating matte, selected from flash furnace, side-blown furnace or bottom-blown furnace;

[0023] A converting furnace for producing blister copper and converting slag, selected from flash furnace, top-blown furnace or PS converter;

[0024] An anode furnace for anodic refining to produce anode plates, selected from rotary furnace, reverberatory furnace or tilting furnace;

[0025] An impoverishment furnace for generating high-grade nickel matte, the impoverishment furnace includes a first-stage impoverishment furnace and a second-stage impoverishment furnace connected in sequence, selected from side-blown furnace, electric furnace or bottom-blown furnace.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. The present invention provides a process for processing high-nickel copper concentrate; during the converting stage of this process, through new slag type and parameter control, most of the nickel enters the converting slag instead of the blister copper, avoiding the problem of anode passivation in the subsequent electrolytic refining process.

[0028] 2. The present invention solves the problem that high-nickel copper concentrate cannot be processed on a large scale in current industrial production.

[0029] 3. Through the smelting stage of the present invention, high-nickel matte containing about 60 - 70% copper and 3 - 10% nickel is obtained; the high-nickel matte is completed in a flash converting furnace during the converting stage, and by adding CaO and SiO2 to make slag, blister copper with a nickel content of about 0.8% and liquid converting slag with a nickel content of 5 - 10% are obtained; the blister copper is anodically refined in the anode furnace to obtain anode plates containing 0.6% nickel and more than 99% copper.

[0030] 4. The present invention sulfidizes and reduces the high-nickel matte converting slag in the first-stage impoverishment furnace to obtain low-nickel matte with a copper + nickel content of about 60%, and the low-nickel matte is further blown and slagged in the second-stage impoverishment furnace to generate high-grade nickel matte; the high-grade nickel matte is ground and flotated to obtain secondary copper concentrate and secondary nickel concentrate, and then copper and nickel are recovered respectively by traditional processes.

[0031] 5. The present invention realizes continuous operation, has a large processing capacity, and a single furnace can process more than 2000t of matte per day, and can also process relatively low-grade matte. Description of the Drawings

[0032] The accompanying drawings of the specification, which form a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0033] Figure 1 The smelting process flow chart provided for the present invention. Detailed implementation manners

[0034] It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanations of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0035] The connection relationship of the embodiments of the present invention based on the smelting device is as follows:

[0036] The smelting device for processing high-nickel copper concentrate includes a smelting furnace, a converting furnace, and an anode furnace arranged in sequence. The converting furnace is also sequentially provided with a first-stage matte smelting furnace and a second-stage matte smelting furnace.

[0037] In the embodiments of the present invention, the main components of the high-nickel copper concentrate are as follows:

[0038] Element Cu S Fe <![CDATA[SiO2]]> Ni Content (%) 26.5 28.5 33.8 3.5 2.5

[0039] This smelting process includes four stages: smelting, converting, anode refining, and slag cleaning. The process flow is as Figure 1 shown.

[0040] S1, smelting stage:

[0041] Add the high-nickel copper concentrate to the smelting furnace for smelting to produce matte, flue gas, and smelting slag. The smelting furnace can be any one of flash furnaces, side-blown furnaces, bottom-blown furnaces, etc.

[0042] Embodiment 1

[0043] Adopt the flash smelting process. After the high-nickel copper concentrate (particle size: -200 mesh, >80%) and the flux quartz sand are proportioned according to a mass ratio of 1:0.21, and after drying (including pneumatic drying, steam drying, etc.), the water content reaches less than 0.3%. Then it enters the flash smelting furnace through the concentrate nozzle and reacts with oxygen-enriched air (oxygen content 60%-90%) in the furnace. In this embodiment, the oxygen consumption per ton of ore is 143.58 Nm 3 / t, with a process oxygen concentration of 87.1%, a series of decomposition, oxidation, and reduction reactions occur, and slag formation is completed with the flux quartz sand to produce matte (containing 60% copper and 5% nickel). Target control parameters: slag temperature (i.e., smelting furnace temperature) 1300 °C, iron-silicon ratio in the slag 1.3, copper content in matte 60%. During the smelting stage, nickel mainly enters the matte in the form of nickel sulfide, and the smelting slag contains 0.35% nickel (analyzed by X-ray fluorescence analysis). After flotation, it is returned to the smelting furnace to recover copper and nickel.

[0044] By controlling the amount of quartz sand added, the iron-silicon ratio in the slag is controlled between 1.1 - 1.4 to ensure smooth slag discharge.

[0045] Preferably, the range of the oxygen-enriched air concentration can be 60% - 90%, and the oxygen consumption per ton of ore is between 140 - 190 Nm 3 / t; by controlling the oxygen consumption per ton of ore, the copper content in the matte is controlled. The oxygen-enriched air concentration is used to adjust the smelting temperature.

[0046] The flash smelting process is completed instantaneously when the concentrate and oxygen-enriched air enter the flash furnace.

[0047] Example 2

[0048] Using the oxygen-enriched side-blowing process, after the high-nickel copper concentrate is mixed with the flux quartz sand, it enters the side-blowing furnace and undergoes a series of decomposition, oxidation, and reduction reactions with the oxygen-enriched air (oxygen enrichment 60% - 90%) in the furnace, and slag formation is completed with the flux quartz sand to produce matte (containing 60% copper and 5% nickel). Target control parameters: slag temperature 1300 °C, iron-silicon ratio in the slag 1.23, copper content in matte 60%. During the smelting stage, nickel mainly enters the matte in the form of nickel sulfide and a small amount enters the furnace slag. After flotation, a concentrate with 18% copper and 0.32% nickel is obtained from the slag concentrate and returned to the smelting furnace.

[0049] The side-blowing furnace process is similar to the flash smelting in Example 1. The difference is that the material does not need to be dried and the oxygen concentration is higher at 90%. The advantages are less slag volume, higher direct recovery rates of copper and nickel, and higher recovery rates under the condition of a certain copper and nickel content in the tail slag.

[0050] The main reactions during smelting are as follows:

[0051] (1) Decomposition of sulfide ore:

[0052]

[0053] (2) Oxidation of sulfide:

[0054]

[0055] FeS2 + 8O2 = Fe3O4 + 6SO2

[0056] S2 + 2O2 → SO2↑

[0057] 2Cu2S + 3O2 → 2Cu2O + 2SO2↑

[0058] 2FeS + 3O2 → 2FeO + 2SO2↑

[0059] FeS + 3Fe3O4 → 10FeO + SO2

[0060] (3) Making matte:

[0061] FeS + Cu2O → Cu2S + FeO

[0062] (4) Making slag:

[0063] FeO + SiO2 → (FeO)2·SiO2

[0064] FeS + 3Fe3O4 + 5SiO2 → 5(2FeO·SiO2) + SO2↑

[0065] CaO + SiO2 → CaO·SiO2.

[0066] S2 Blowing stage:

[0067] The matte produced in the smelting stage is sent to the blowing furnace for blowing to produce blister copper, flue gas and blowing slag. The blister copper directly flows into the anode furnace for anode refining to produce anode plates, and the blowing slag flows into the impoverishment furnace for impoverishment. The blowing furnace can be any one of the flash furnace, top-blown furnace and PS converter.

[0068] Example 3

[0069] Adopting the flash blowing process, the molten matte obtained in Example 1 is granulated and then enters the matte mill for drying and grinding. The particle size: -325 mesh > 45%. It is stored in the matte furnace top bin and enters the blowing furnace together with oxygen-enriched air (oxygen enrichment 60% - 90%) through the matte nozzle. At the same time, the slag-making flux limestone (calcium oxide) and quartz sand are added to make a large amount of nickel enter the slag phase, controlling (CaO + SiO2) / (Fe + Ni) ≥ 1 and (Cu + SiO2 + CaO / Ni + Fe) ≥ 1.6 in the slag, and the slag temperature is 1280°C - 1350°C.

[0070] In this example, the oxygen consumption per ton of matte is 184.18 Nm 3 / t, and the oxygen concentration is 69.5%. Matte:SiO2:CaO is approximately 10:1:0.3.

[0071] In other examples, the oxygen-enriched air concentration can be 60%, 90% or any concentration between 60% - 90%.

[0072] Specific indicators: the copper content in the slag is 20 - 25%, the content of CaO + SiO2 is 30 - 40%, the nickel content is 4 - 8%, and it enters the de-silting furnace for de-silting. The nickel content in the blister copper is below 0.8%, and the copper content is 98 - 99%. It enters the anode furnace for refining to obtain an anode plate with a copper content of over 99% and a nickel content of about 0.6%.

[0073] Example 4

[0074] Adopt the top-blown converter smelting process. Under the same other conditions, the matte obtained in Example 1 and oxygen-enriched air (oxygen enrichment 60% - 90%) enter the converter together. At the same time, slag-making fluxes such as limestone (calcium oxide) and quartz sand are added, so that a large amount of nickel enters the slag phase. The slag contains 22% copper, 6.5% nickel, 25% SiO2, 7.5% CaO, the slag temperature is 1320 °C, the nickel content in the blister copper is below 0.8%, and the copper content is 98 - 99%. It enters the anode furnace for refining to obtain an anode plate with a copper content of over 99% and a nickel content of about 0.6%.

[0075] The main reactions during the smelting process are as follows:

[0076] (1) Oxidation reaction in the reaction tower:

[0077] 2FeS + 3O2 = 2FeO + 2SO2

[0078] 3FeS + 5O2 = Fe3O4 + 3SO2

[0079] 2Fe3O4 + 1 / 2O2 = 3Fe2O3

[0080] Cu2S + O2 = 2Cu + SO2

[0081] 2Cu2S + 3O2 = 2Cu2O + 2SO2

[0082] 2Ni3S2 + 7O2 = 6NiO + 4SO2

[0083] (2) Copper-making and slag-making reactions in the settling tank:

[0084] 2Cu2O + Cu2S = 6Cu + SO2

[0085] Cu2S + Fe2O3 = 2Cu + SO2 + 4FeO

[0086] Fe2O3 + CaO = CaFe2O4

[0087] SiO2 + 2CaO = Ca2SiO4

[0088] SiO2 + 2FeO = Fe2SiO4

[0089] SiO2 + 2NiO = Ni2SiO4

[0090] The crude copper obtained in Example 3 is directly fed into the anode furnace for anode refining to produce anode plates, and the converting slag is fed into the matte smelting furnace for matte smelting.

[0091] S3, Matte smelting stage:

[0092] Coke and sulfiding agent are added into the first-stage matte smelting furnace. The sulfiding agent can be sulfur or pyrite (pyrite is preferred), and a low-grade nickel matte with about 60% copper + nickel content is produced. The first-stage matte smelting furnace is preferably a side-blown furnace.

[0093] Reduction and sulfidation reactions occur in the matte smelting furnace, that is, mainly metal oxides are converted into metal sulfides and a small amount of metallic copper.

[0094] Cu2O + FeS = Cu2S + FeO

[0095] NiO + FeS = NiS + FeO

[0096] 2Cu2O + C = 4Cu + CO2.

[0097] The process parameters of the first-stage matte smelting: the mass ratio of pyrite to slag is 1:5 - 1:4, the mass ratio of coke to slag is 1 - 2:50, and the temperature is controlled at 1300 °C.

[0098] Example 5:

[0099] Using a side-blown furnace, the molten converting slag (Cu 18%, Ni 6%, Fe 21.45%) is added at a rate of 26.2 t / h, pyrite at 5.3 t / h, coke at 1.1 t / h, and oxygen at 6 t / h, producing low-grade nickel matte (Cu 45%, Ni 14.8%, Fe 13.5%, S 23.8%) at a rate of 10.1 t / h, and the operating temperature is 1297 °C.

[0100] Flux for slag formation is added into the second-stage matte smelting furnace, preferably quartz sand, to remove most of the iron in the low-grade nickel matte and produce high-grade nickel matte with nickel + copper content of 70 - 80%. The high-grade nickel matte is further processed to recover copper and nickel. The second-stage matte smelting furnace can be a side-blown furnace, bottom-blown furnace or top-blown furnace, etc., and the bottom-blown furnace is preferred.

[0101] The process parameters of the second-stage matte smelting: the mass ratio of quartz sand to low-grade nickel matte is 1 - 2:20, and the temperature is controlled at 1300 °C.

[0102] Example 6:

[0103] Using a bottom-blown furnace, adding low-grade nickel matte (with the same composition as the low-grade nickel matte produced in Example 5) at 10.1 t / h, quartz sand at 0.72 t / h, and oxygen at 2.1 t / h, producing high-grade nickel matte (Cu 56.2%, Ni 19.1%, Fe 4.1%, S 20.8%) at 8.3 t / h, and the operating temperature is 1302 °C.

[0104] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A smelting process for treating high-nickel copper concentrate, characterized in that, It includes the following steps: S1, Smelting: Charge high-nickel copper concentrate and flux quartz sand, add them into a smelting furnace, react with oxygen-enriched air, and complete slag formation with the flux quartz sand to produce matte. The high-nickel copper concentrate contains 0.5 - 5% nickel, 15 - 30% copper, and the nickel-copper ratio is 0.02 - 0.

33. S2, Converting: Feed the matte produced in step S1 into a converting furnace for converting to produce blister copper and converting slag. S3, The blister copper obtained in step S2 directly flows into an anode furnace for anode refining to produce anode plates, and the converting slag flows into a slag cleaning furnace for slag cleaning.

2. The smelting process for treating high-nickel copper concentrate according to claim 1, characterized in that, In step S1, the mass ratio of the high-nickel copper concentrate to quartz sand is 1:0.1 - 1:0.

25.

3. The smelting process for treating high-nickel copper concentrate according to claim 1, characterized in that, In steps S1 - S3, the concentration of oxygen-enriched air is 60% - 90%.

4. The smelting process for treating high-nickel copper concentrate according to claim 1, characterized in that, In step S1, the matte produced contains 55 - 70% copper and 1 - 10% nickel.

5. The smelting process for treating high-nickel copper concentrate according to claim 1, characterized in that, In step S2, the molten matte obtained in step S1 is granulated, dried and ground finely, with a particle size: -325 mesh > 45%. It enters the converting furnace together with oxygen-enriched air, and at the same time, slag-forming fluxes limestone and quartz sand are added. Control (CaO + SiO2) / (Fe + Ni) ≥ 1 and (Cu + SiO2 + CaO / Ni + Fe) ≥ 1.6 in the slag, and the slag temperature is 1280℃ - 1350℃.

6. The smelting process for treating high-nickel copper concentrate according to claim 1, characterized in that, In step S2, the mass ratio of matte:SiO2:CaO is 10:1:0.

3.

7. The smelting process for treating high-nickel copper concentrate according to claim 1, characterized in that, In step S2, the converting slag contains 20 - 25% copper, 30 - 40% CaO + SiO2, and 4 - 8% nickel, and enters the slag cleaning furnace for slag cleaning; the blister copper contains less than 0.8% nickel and 98 - 99% copper.

8. The smelting process for treating high-nickel copper concentrate according to claim 1, characterized in that, In step S3, it includes a primary slag cleaning process in the primary slag cleaning furnace and a secondary slag cleaning process in the secondary slag cleaning furnace; coke and sulfiding agent are added in the primary slag cleaning furnace to carry out reduction and sulfidation reactions; slag-forming fluxes are added in the secondary slag cleaning furnace to produce high-grade nickel matte with nickel + copper at 70 - 80%; the high-grade nickel matte is further processed to recover copper and nickel.

9. The smelting process for treating high-nickel copper concentrate according to claim 8, characterized in that, Primary slag cleaning process parameters: The mass ratio of pyrite to slag is 1:5 - 1:4, the mass ratio of coke to slag is 1 - 2:50, and the temperature is controlled at 1280 - 1320℃; secondary slag cleaning process parameters: The mass ratio of quartz sand to low-grade nickel matte is 1 - 2:20, and the temperature is controlled at 1280 - 1320℃. In the stage of converting slag cleaning, reduction and sulfidation reactions occur in the slag cleaning furnace to produce high-grade nickel matte with nickel + copper at 70 - 80%, which is further processed to recover copper and nickel.

10. A smelting device for processing high-nickel copper concentrate, characterized in that, It includes, arranged in sequence: A smelting furnace for producing matte, selected from a flash furnace, a side-blown furnace or a bottom-blown furnace; A converting furnace for producing blister copper and converting slag, selected from a flash furnace, a top-blown furnace or a PS converter; An anode furnace for anode refining to produce anode plates, selected from a rotary furnace, a reverberatory furnace or a tilting furnace; A slag cleaning furnace for producing high-grade nickel matte. The slag cleaning furnace includes a primary slag cleaning furnace and a secondary slag cleaning furnace connected in sequence, and is selected from a side-blown furnace, an electric furnace or a bottom-blown furnace.

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