Short-process continuous smelting method for nickel-containing copper concentrate

Abstract

The invention discloses a short-process continuous smelting method for nickel-containing copper concentrate. The method comprises the following steps: 1) smelting nickel-containing copper concentrate to obtain smelting slag and high-nickel copper matte which are layered up and down; (2) the high-nickel copper matte is subjected to suspension blowing, and nickel-copper blowing slag and crude copper which are layered up and down are obtained; and (3) the nickel-copper converting slag is subjected to reduction smelting, and vertically-layered reducing slag and copper-nickel alloy are obtained. By adjusting the reaction kinetics condition and the slag type structure of the blowing section, copper and nickel elements in the high-nickel copper concentrate are efficiently separated in the blowing section, the produced crude copper can meet the requirements of subsequent fire refining and electrolytic refining, a nickel removal link does not need to be added at the rear end, the smelting process is shortened, and the production cost is reduced. And the application of the high-nickel copper concentrate to large-scale continuous copper smelting becomes possible. The nickel-copper converting slag is reduced into the copper-nickel alloy, the link of returning the converting slag to be mixed in a traditional process is omitted, short-process recovery of the Ni element is achieved, the problem of circulating enrichment of the Ni element in a system is solved, and the method is a brand-new technical route for widening the application range of raw materials, reducing cost and improving efficiency in a copper smelting plant.

Description

Technical Field

[0001] The invention belongs to the field of nonferrous metal smelting, and in particular relates to a method for short-process continuous smelting of nickel-containing copper concentrate. Background Art

[0002] Copper is the second most produced metal among the ten nonferrous metals. Due to its good electrical conductivity, thermal conductivity, ductility and corrosion resistance, it is widely used in electrical, mechanical, transportation, electronics, aerospace and other fields. At present, the raw material for primary copper metal smelting is mainly copper concentrate. my country's self-sufficiency rate of copper concentrate is less than 30%, and it is heavily dependent on imports. With the rise in the price of imported copper concentrate and the tightening of processing fee space, the supply of high-grade high-quality copper concentrate is becoming increasingly tight. It is an inevitable trend that the impurity content in copper smelting raw materials will increase in the future.

[0003] Metallic nickel is one of the common associated elements in copper concentrate. In the pyrometallurgical process that dominates the field of copper smelting, nickel usually enters the electrolytic system along the path of concentrate-copper matte-blister copper-anode copper. When the initial content is not high (generally 0.01-0.02%), Ni has little effect on the pyrometallurgical smelting system itself. However, if the raw material contains a high nickel content (>1%), Ni is enriched in the matte during the smelting process, which will affect the slag formation in the matte blowing process. Since the anode furnace refining process commonly used in the industry has almost no removal effect on the Ni element, most of the Ni in the blister copper enters the anode plate, which has a significant impact on the production of cathode copper in the electrolytic refining process. During the electrolysis process of high-nickel copper anodes, problems such as anode passivation, difficulty in anode mud sedimentation, and granulation and easy oxidation and blackening of the cathode copper surface are prone to occur.

[0004] Technical personnel in the industry have conducted some statistics and research on the migration law of the Ni element in the smelting process of nickel-containing copper concentrates, and found that during the smelting process, since FeS exists in the copper matte product, NiO in the slag is easily sulfided and dissolved into the copper matte. Therefore, more than 90% of the Ni element in this process enters the blowing process with the copper matte, and it is difficult to remove it by slag making. The impact of different processes in the blowing process on the distribution of the Ni element varies greatly. For example, in the flash blowing process, 70% of the Ni element is distributed in the crude copper, which is difficult to remove effectively. Although the Ausmelt blowing furnace can oxidize 70% of the Ni element into the slag, it cannot reduce the nickel content of the crude copper to a reasonable range when the nickel content of the raw material is high. A certain enterprise has developed a unique processing technology for high-nickel secondary copper concentrate. After top blowing, it uses the Kaldo furnace refining process to deeply blow and remove nickel from the nickel-containing crude copper, which can reduce the Ni content in the crude copper to 0.6%, meeting the requirements of subsequent processes. However, the obvious disadvantage of this process is that the process is long, resulting in multiple material transfers, and the Kaldo furnace has a small processing capacity and is a periodic operation, making it difficult to adapt to large-scale continuous copper smelting systems. Therefore, achieving short-process and continuous smelting of high-nickel copper concentrate is a technical problem that needs to be solved in the industry. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method for short-process continuous smelting of nickel-containing copper concentrate based on the reaction principle of oxidation smelting and blowing of nickel-containing copper concentrate and the melting characteristics of high-nickel slag. The method aims to achieve copper-nickel separation by continuous blowing process in an oxygen-enriched molten pool without increasing the complexity of the smelting process, so that the high-nickel copper concentrate can be applied to large-scale continuous industrial production, thereby improving the adaptability of copper smelting enterprises to low-quality complex raw materials.

[0006] The method for short-process continuous smelting of nickel-containing copper concentrate provided by the present invention comprises the following steps:

[0007] 1) Adding the raw material nickel-containing copper concentrate, fuel and acid flux into a smelting furnace, blowing in oxygen-enriched air, adjusting the ratio of oxygen to fuel, and adjusting the reaction atmosphere to an oxidizing atmosphere for smelting, and obtaining upper and lower layered smelting slag and high-nickel copper matte after the smelting is completed;

[0008] 2) introducing the high-nickel copper matte obtained in step 1) into a converting furnace, then adding a mixed flux to form slag, and blowing an oxygen-enriched gas flow for suspension converting, and obtaining nickel-copper converting slag and crude copper in upper and lower layers after the converting;

[0009] 3) The nickel-copper converted slag obtained in step 2) is introduced into a depletion furnace, and then oxygen-enriched air and fuel are blown in. By adjusting the ratio of oxygen to fuel, the reaction atmosphere is adjusted to a weak reducing atmosphere for reduction smelting. After the reduction smelting is completed, upper and lower layered reduction slag and copper-nickel alloy are obtained.

[0010] During the smelting stage of step 1), most of the main impurity Fe element in the raw material is converted into oxides, which react with the flux and enter the slag phase, while absorbing Al2O3, PbO, ZnO, etc. into the slag; the sulfur element is partially oxidized to produce SO2 and enter the flue gas; Cu and the remaining S element are deposited in the lower layer in the form of Cu2S, and most of the Ni3S2 and a small amount of FeS are dissolved to form high-nickel copper matte.

[0011] In the suspended blowing stage of step 2), the high-nickel copper matte is regularly discharged from the discharge port at the bottom of the smelting furnace, and then flows into the blowing furnace through the chute, and then the oxygen-rich gas flow is blown in. Under the vigorous stirring of the oxidizing gas, most of the Fe and Ni in the high-nickel copper matte are converted into oxidized phases. These oxidized phases slag with the mixed flux and float on the upper layer of the furnace. The Cu element generates metallic copper through the interactive reaction of Cu2S and Cu2O and sinks to the lower layer of the furnace to form a copper liquid layer (blister copper); Ni3S2 reacts with Cu2O to generate part of metallic nickel and dissolves in the blister copper. In the later stage of blowing, due to the decrease in the activity of metallic nickel in the blister copper, Cu and Ni will be synchronously oxidized into the slag phase, and the S element will be oxidized into SO2 and enter the flue gas. The qualified blister copper produced at the end of blowing enters the conventional pyro-refining process to manufacture anode copper, and the nickel-copper blowing slag produced enters the next step of depletion and recovery.

[0012] In the reduction smelting stage of step 3), the nickel-copper converting slag is regularly discharged from the slag outlet of the converting furnace, and then flows into the depletion furnace through the chute, and then oxygen-enriched air and pulverized coal are blown in. By adjusting the ratio of oxygen to fuel, the reaction atmosphere is adjusted to a weak reducing atmosphere for reduction smelting. The Cu, Ni and a small amount of Fe elements in the nickel-copper converting slag are reduced to metal elements to form a copper-nickel alloy melt and sink to the lower layer, which is regularly discharged from the lower outlet and sold as a raw material for the preparation of copper-nickel alloy; the Fe element is converted into a low-valent oxide, and the slag system is converted from a pentacyclic slag to a ternary slag system, which is regularly discharged from the slag outlet and can be directly quenched in water as a raw material for the preparation of building materials.

[0013] Preferably, in step 1), the nickel-containing copper concentrate contains 8-10% H2O, 20-26% Cu, 1-2% Ni, 28-32% S and 25-35% Fe on a dry basis.

[0014] In order to maintain the stability of the charge structure, nickel-containing copper concentrates are generally mixed from different batches and types of nickel-containing copper concentrates. Here, different batches and types of nickel-containing copper concentrates refer to copper concentrates with different nickel contents used by production enterprises. Through ore blending and mixing, the composition of the mixed material falls within the above range.

[0015] Preferably, in step 1), the fuel is granular coal, which is widely available and has low cost.

[0016] Preferably, in step 1), the process conditions involved in smelting include: oxygen concentration of 80-90%, oxygen-to-material ratio controlled at 300Nm 3 / t, coal rate is 1-2%, flux rate is 5-8%, smelting temperature is maintained at 1250-1300℃, smelting time is 2.5-3h. The oxygen-to-charge ratio here refers to the ratio of oxygen flow rate to mixed charge mass, coal rate refers to the ratio of fuel mass to mixed charge mass, flux rate refers to the ratio of flux mass to mixed charge mass.

[0017] Preferably, in step 1), the acidic flux is silica. During the smelting process, most of the Fe element in the raw material is oxidized to FeO and Fe3O4, and these oxides slag with SiO2 in the acidic flux to form smelting slag. The Fe / SiO2 in the smelting slag is controlled at 1.8-2.0, and the slag contains 1.5-2% Cu and 0.2-0.3% Ni. After the smelting is completed, the smelting slag is discharged from the slag outlet and sent to the slow cooling slag selection to recover the Cu therein.

[0018] Preferably, in step 1), the high nickel copper matte contains 68-72% Cu, 4-6% Ni and 1-3% Fe.

[0019] Preferably, the smelting furnace in step 1) is an oxygen-enriched side-blown smelting furnace; the oxygen-enriched side-blown smelting furnace includes a furnace body; the furnace body is a rectangular structure, and a solid charge feeding port and a flue are arranged on the top thereof, and the rear end of the flue is connected to a flue gas treatment system; a plurality of submerged side-blowing air ports are arranged in the middle part of the furnace side wall; a secondary air port is arranged on the upper part of the furnace side wall; a slag port is arranged in the middle part of the end wall, and a matte port is arranged in the lower part; the oxygen-enriched side-blown smelting furnace is connected to the feeding port of the blowing furnace through a chute. The solid charge feeding port is used to add nickel-containing copper concentrate mixture and flux, block fuel, etc.; the flue gas treatment system can recover waste heat and capture smoke dust; the plurality of submerged side-blowing air ports are used to blow in oxygen-enriched air of different concentrations, and the oxygen partial pressure in the furnace is flexibly controlled by adjusting the ratio of oxygen to fuel; the secondary air port is used to ignite sulfur and other combustible components in the flue gas to inhibit slagging in the flue.

[0020] Preferably, in step 2), the process conditions involved in suspension blowing include: oxygen enrichment concentration of 25-30%, oxygen-to-material ratio controlled at 150 Nm 3 / t, flux rate is 4-6%, blowing temperature is maintained at 1250-1300℃, blowing time is 14-16h. The oxygen-to-material ratio here refers to the ratio of oxygen flow rate to the mass of hot copper matte, and the flux rate refers to the ratio of flux mass to the mass of hot copper matte.

[0021] Suspension blowing has two main advantages: 1) Hot materials are continuously fed in and out, eliminating the need for material transfer between multiple devices, making full use of the physical heat of the hot copper matte, saving energy, and continuous operation is conducive to large-scale production; 2) The oxygen lance of suspension blowing is not immersed in the molten pool, and the life of the oxygen lance can be effectively extended.

[0022] Preferably, in step 2), the mixed flux is a mixture of limestone and silica. During the blowing process, the high-pressure oxygen flow rapidly undergoes a violent oxidation reaction with Fe, Ni, and Cu in the high-nickel copper matte to generate FeO, Fe3O4, NiO, Cu2O and other oxides, which react with CaO and SiO2 in the mixed flux to form slag, eventually forming Cu2O-NiO-Fex O-CaO-SiO2 quinary copper-nickel converting slag. The CaO / Fe in the copper-nickel converting slag is controlled at 0.2-0.4, the SiO2 / Fe is controlled at 0.5-0.7, and the slag contains 25-35% Cu and 18-20% Ni. The copper-nickel converting slag floats on the upper layer of the converting furnace, overflows and discharges regularly, and is added to the depletion furnace through a chute for reduction smelting.

[0023] Preferably, in step 2), the copper content in the blister copper is controlled to be Cu≥98.5%, Ni≤0.6%, and S≤0.1% at the end of the blowing process. The blister copper is continuously discharged through the siphon port at the bottom of the blowing furnace and sent to a conventional anode furnace for refining to prepare anode plates. The continuous blowing process is in an overheated state, and no fuel needs to be added. Solid copper such as residual anode can be added according to the furnace conditions to adjust the furnace temperature.

[0024] Preferably, in step 2), the converting furnace is a multi-gun top-blowing continuous converting furnace; the converting furnace comprises a furnace body, wherein the cross section of the furnace body is a rectangular structure; a copper water jacket is provided in the molten pool slag line area of ​​the converting furnace, and a white copper matte inlet, a crude copper discharge port, a slag discharge port and an emergency discharge port are provided on the furnace wall; a plurality of top-blowing spray guns are provided on the top of the furnace, the gun bodies can be raised and lowered and rotated, and high-pressure oxygen-rich air can be blown in to perform suspended converting above the liquid surface; a flue and a solid charge feeding port are provided on the top of the furnace, and the flue is connected to the furnace body and the waste heat boiler. The solid charge feeding port can be used to add flux, solid charge, etc.

[0025] Preferably, in step 3), the fuel is pulverized coal or natural gas. Pulverized coal or natural gas is widely available and is easy to spray with a spray gun.

[0026] Preferably, in step 3), the process conditions of reduction smelting include: weak reducing atmosphere means controlling the volume ratio of CO / (CO+CO2) in the atmosphere to be 50-70%; coal rate is 10-15%, oxygen excess coefficient is controlled at 0.65-0.75, the temperature of reduction smelting is controlled at 1300-1350°C, and the time of reduction smelting is 1-3h. The coal rate here refers to the ratio of the mass of the fuel to the mass of the blowing slag. Under the reduction smelting conditions, Cu and Ni in the copper-nickel blowing slag are reduced to metal elements to form a copper-nickel alloy and sink to the lower layer, the iron oxide in the slag is reduced to FeO, and the slag is transformed into a FeO-CaO-SiO2 ternary reduction slag, and the reduction slag contains Cu≤0.4% and Ni≤0.1%. The reduction slag is regularly discharged from the slag outlet and sold after water quenching as a raw material for building material preparation. The copper-nickel alloy can be directly sold after casting, and further refined to produce copper-nickel alloy products of different grades.

[0027] Preferably, in step 3), the depletion furnace is a side-blown reduction furnace; the side-blown reduction furnace includes a furnace body, which is a rectangular structure, with a liquid charging port on the upper part of one side end wall, a solid charge charging port and a flue on the top, and a flue connected to a flue gas treatment system at the rear end; a plurality of submerged side-blowing spray guns are provided at the lower part of the furnace side wall, and the spray guns are made of multiple layers of concentric sleeves; a secondary air port is provided at the upper part of the furnace side wall; a slag discharge port and a siphon port are provided on the furnace end wall. The solid charge charging port is used to add flux, block fuel, etc.; the flue gas treatment system is used to recover waste heat and capture smoke dust; the plurality of submerged side-blowing spray guns can be used to simultaneously blow in oxygen-enriched air and fuels such as pulverized coal / natural gas; the secondary air port is used to ignite combustible components such as CO in the flue gas.

[0028] Preferably, the flue gas generated in steps 1) and 2) contains SO2, so it is sent to the acid making process after waste heat recovery, dust collection and purification.

[0029] Preferably, the flue gas generated in step 3) is discharged after waste heat recovery, dust collection, and purification to meet the standards.

[0030] The beneficial effects of the present invention are as follows: 1) By adjusting the reaction kinetic conditions and slag structure of the blowing section, the copper and nickel elements in the high-nickel copper concentrate can be efficiently separated in the blowing section, and the crude copper produced can meet the requirements of subsequent pyro-refining and electrolytic refining. There is no need to add periodically operated nickel removal equipment at the back end, shortening the smelting process, reducing the number of times the charge is transported, and making it possible to apply the high-nickel copper concentrate to large-scale continuous copper smelting. 2) The high-nickel and high-copper blowing slag is reduced to a copper-nickel alloy, eliminating the link of returning the blowing slag to the ingredients in the traditional process, realizing the short-process recovery of the Ni element, and solving the problem of the circulation and enrichment of the Ni element in the system with the slag. 3) The main smelting equipment of the process is basically the same as that of the conventional molten pool copper smelting production line. It only needs to add a blowing slag depletion furnace on the original basis to realize the comprehensive recovery of copper-nickel raw materials. Therefore, the engineering application difficulty is relatively low, and it is a new technical route for copper smelters to broaden the scope of raw material application, reduce costs and increase efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a process flow chart of short-process continuous smelting of nickel-containing copper concentrate in Example 1. DETAILED DESCRIPTION

[0032] Example 1

[0033] according to Figure 1 In the process shown, nickel-copper concentrate mixed charge and granular coal are added into the oxygen-enriched side-blown smelting furnace through the upper charging port via a belt conveyor, wherein the nickel-copper concentrate mixed charge contains 10% H2O, 26% Cu, 1.8% Ni, 30% S, and 35% Fe on a dry basis. Oxygen-enriched air is blown in from the side-blown tuyere for smelting, with an oxygen concentration of 85% and an oxygen-to-charge ratio controlled at 300Nm3 / t, coal rate is 1.5%, and silica flux is added from the upper charging port to make slag. The flux rate is 6.5%, the smelting temperature is 1250℃, and the smelting is 3h to obtain smelting slag and high-nickel copper matte. The high-nickel copper matte contains Cu 68.9%, Ni 4.9%, and Fe 3%; the Fe / SiO2 in the smelting slag is 2.0, and the slag contains Cu1.6% and Ni 0.2%. After the smelting is completed, the slag is discharged from the slag port and sent to the slow cooling slag selection to recover the Cu. The high-nickel copper matte flows into the charging port of the multi-gun top-blown furnace through the chute for suspended blowing. During blowing, oxygen-enriched air is blown in through the spray gun installed on the top of the furnace. The oxygen-enriched concentration is 25%, and the oxygen-to-material ratio is controlled at 150Nm 3 / t, blowing temperature 1300 ℃, at the same time, limestone and silica flux are added into the furnace through the charging port set on the top of the furnace to make slag, wherein the mass of limestone accounts for 1.8% of the mass of high nickel copper matte, and the mass of silica accounts for 3.8% of the mass of high nickel copper matte. The oxygen in the oxygen-enriched air quickly reacts violently with Fe, Ni and Cu in the high nickel copper matte to finally form Cu2O-NiO-Fe x O-CaO-SiO2 quinary system blowing slag, CaO / Fe=0.2, SiO2 / Fe=0.6, slag contains Cu 30%, Ni 19%, after the blowing slag is discharged, it is added to the depletion furnace through the chute for reduction smelting. The lower layer generates metallic copper liquid (blister copper) containing Cu 98.5%, Ni 0.6%, S 0.1%. The blister copper is continuously discharged through the lower siphon port and sent to the conventional anode furnace for refining and preparation of anode plates. Cu2O-NiO-Fe x After the O-CaO-SiO2 quinary blowing slag is added to the side-blowing reduction furnace, oxygen-enriched air and pulverized coal are blown into the furnace by the side-blowing lance, the ratio of oxygen to pulverized coal is adjusted, the volume ratio of CO / (CO+CO2) in the atmosphere is controlled to be 55%, the coal rate is 15%, and the reduction temperature is 1350℃. The Cu and Ni in the slag are reduced to liquid copper-nickel alloy, and the iron oxide in the slag is reduced to FeO. The slag is transformed into FeO-CaO-SiO2 ternary reduction slag, and the reduction slag contains 0.36% Cu and 0.08% Ni. The recovery rates of Cu and Ni are both >99%. The copper-nickel alloy can be sold externally and further refined to produce copper-nickel alloy products of different grades.

[0034] Example 2

[0035] according to Figure 1 In the process shown, nickel-copper concentrate mixed charge and granular coal are added to the oxygen-enriched side-blown smelting furnace through the upper charging port via a belt conveyor, wherein the nickel-copper concentrate mixed charge contains 9% H2O, 24% Cu, 1.6% Ni, 29% S, and 35% Fe on a dry basis. Oxygen-enriched air is blown in from the side-blown tuyere for smelting, with an oxygen concentration of 85% and an oxygen-to-charge ratio controlled at 300Nm 3 / t, coal rate is 1.6%, and silica flux is added from the upper charging port to make slag at the same time. The flux rate is 7%, the smelting temperature is 1260℃, and the smelting is 3h to obtain smelting slag and high-nickel copper matte. The high-nickel copper matte contains Cu 70%, Ni 4.5%, and Fe 2.8%; the Fe / SiO2 in the smelting slag is 2.0, and the slag contains Cu 1.7% and Ni 0.2%. After the smelting is completed, the slag is discharged from the slag port and sent to the slow cooling slag selection to recover the Cu. The high-nickel copper matte flows into the charging port of the multi-gun top-blown furnace through the chute for suspended blowing. During blowing, oxygen-enriched air is blown in through the spray gun installed on the top of the furnace. The oxygen-enriched concentration is 27%, and the oxygen-to-material ratio is controlled at 150Nm 3 / t, blowing temperature 1300 ℃, at the same time, limestone and silica flux are added into the furnace through the charging port set on the top of the furnace to make slag, wherein the mass of limestone accounts for 1.6% of the mass of high nickel copper matte, and the mass of silica accounts for 3.6% of the mass of high nickel copper matte. The oxygen in the oxygen-enriched air quickly reacts violently with Fe, Ni and Cu in the high nickel copper matte to finally form Cu2O-NiO-Fe x O-CaO-SiO2 quinary system blowing slag, CaO / Fe=0.2, SiO2 / Fe=0.58, slag contains Cu 31%, Ni 18%, after the blowing slag is discharged, it is added to the depletion furnace through the chute for reduction smelting. The metallic copper liquid (blister copper) generated in the lower layer contains Cu 98.8%, Ni 0.58%, and S 0.08%. The blister copper is continuously discharged through the lower siphon port and sent to the conventional anode furnace for refining and preparation of anode plates. Cu2O-NiO-Fe x After the O-CaO-SiO2 quinary blowing slag is added to the side-blowing reduction furnace, oxygen-enriched air and pulverized coal are blown into the furnace by the side-blowing lance, the ratio of oxygen to pulverized coal is adjusted, the volume ratio of CO / (CO+CO2) in the atmosphere is controlled to be 55%, the coal rate is 15%, and the reduction temperature is 1350℃. The Cu and Ni in the slag are reduced to liquid copper-nickel alloy, and the iron oxide in the slag is reduced to FeO. The slag is transformed into FeO-CaO-SiO2 ternary reduction slag, and the reduction slag contains 0.38% Cu and 0.09% Ni. The recovery rates of Cu and Ni are both >99%. The copper-nickel alloy can be sold and further refined to produce copper-nickel alloy products of different grades.

[0036] Example 3

[0037] according to Figure 1 In the process shown, nickel-copper concentrate mixed charge and granular coal are added to the oxygen-enriched side-blown smelting furnace through the upper charging port via a belt conveyor, wherein the nickel-copper concentrate mixed charge contains 8% H2O, 21% Cu, 1.4% Ni, 28% S, and 33% Fe on a dry basis. Oxygen-enriched air is blown in from the side-blown tuyere for smelting, with an oxygen concentration of 85% and an oxygen-to-charge ratio controlled at 300Nm 3 / t, coal rate is 1.8%, and silica flux is added from the upper charging port to make slag. The flux rate is 7.5%, the smelting temperature is 1280℃, and the smelting is 3h to obtain smelting slag and high-nickel copper matte. The high-nickel copper matte contains Cu 72%, Ni 4.2%, and Fe 2.5%; the Fe / SiO2 in the smelting slag is 2.0, and the slag contains Cu 1.9% and Ni 0.3%. After the smelting is completed, the slag is discharged from the slag port and sent to the slow cooling slag selection to recover the Cu. The high-nickel copper matte flows into the charging port of the multi-gun top-blown furnace through the chute for suspended blowing. During blowing, oxygen-enriched air is blown in through the spray gun installed on the top of the furnace. The oxygen-enriched concentration is 29%, and the oxygen-to-material ratio is controlled at 150Nm 3 / t, the blowing temperature is 1280℃, and limestone and silica flux are added into the furnace through the charging port set on the top of the furnace to make slag, wherein the mass of limestone accounts for 1.5% of the mass of high-nickel copper matte, and the mass of silica accounts for 3.2% of the mass of high-nickel copper matte. The oxygen in the oxygen-enriched air quickly reacts violently with Fe, Ni, and Cu in the high-nickel copper matte to finally form Cu2O-NiO-Fe x O-CaO-SiO2 quinary system blowing slag, CaO / Fe=0.21, SiO2 / Fe=0.53, slag contains Cu 34%, Ni 19.5%, after the blowing slag is discharged, it is added to the depletion furnace through the chute for reduction smelting. The lower layer generates metallic copper liquid (blister copper) containing Cu 98.9%, Ni 0.55%, S 0.07%. The blister copper is continuously discharged through the lower siphon port and sent to the conventional anode furnace for refining and preparation of anode plates. Cu2O-NiO-Fe x After the O-CaO-SiO2 quinary blowing slag is added to the side-blowing reduction furnace, oxygen-enriched air and pulverized coal are blown into the furnace by the side-blowing lance, the ratio of oxygen to pulverized coal is adjusted, the volume ratio of CO / (CO+CO2) in the atmosphere is controlled to be 55%, the coal rate is 15%, and the reduction temperature is 1300℃. The Cu and Ni in the slag are reduced to liquid copper-nickel alloy, and the iron oxide in the slag is reduced to FeO. The slag is transformed into FeO-CaO-SiO2 ternary reduction slag, and the reduction slag contains 0.4% Cu and 0.1% Ni. The recovery rates of Cu and Ni are both >99%. The copper-nickel alloy can be sold and further refined to produce copper-nickel alloy products of different grades.

[0038] Comparative Example 1

[0039] According to the current conventional nickel-containing copper concentrate smelting process, an immersed single-lance top-blown furnace is usually used for self-heating smelting (this process is recorded in Chapter 9 of "China Nickel-Cobalt Metallurgy"), the smelting temperature is 1250℃, and the resulting crude copper contains 91% Cu, 4% Ni, and 3% S. Since the anode furnace has almost no effect on the removal of Ni, the crude copper needs to be periodically oxidized and blown by the Kaldo furnace to remove nickel, oxidize the crude copper into crude copper containing 98.5% Cu, 0.6% Ni, and 0.06% S, and then enter the anode furnace for refining. The Kaldo furnace in this process has an operating cycle of 2-2.5h, and the loading capacity of each furnace is only about 15t. It is suitable for processing small-scale production lines and is difficult to cooperate with the current large-scale and continuous production. At the same time, the gas-liquid mixed dynamic conditions of the single-gun top-blown furnace autothermal smelting are not good, making it difficult to achieve deep removal of the Ni element in the crude copper. The produced slag contains 10% Cu and 5% Ni, which needs to be returned to the smelting link, resulting in the cyclic enrichment of the Ni element in the system, which increases the pressure of nickel removal in the subsequent smelting sulfur-making and blowing copper-making processes.

[0040] The present invention achieves efficient separation of copper and nickel elements in nickel-containing copper concentrate in the blowing section by adjusting the reaction kinetic conditions and slag structure of the blowing section, without adding periodically operated nickel removal equipment at the back end, which not only shortens the smelting process, but also makes it possible to apply high-nickel copper concentrate to large-scale continuous copper smelting. At the same time, the high-nickel and high-copper blowing slag is reduced to copper-nickel alloy, eliminating the link of returning the blowing slag to the ingredients in the traditional process, realizing the short-process recovery of Ni elements, and solving the problem of Ni elements circulating and enriching in the system with the slag.

[0041] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

Claims

1. A method for short-process continuous smelting of nickel-containing copper concentrate, comprising the following steps: 1) Adding the raw material nickel-containing copper concentrate, fuel and acid flux into a smelting furnace, blowing in oxygen-enriched air, adjusting the ratio of oxygen to fuel, and adjusting the reaction atmosphere to an oxidizing atmosphere for smelting, and obtaining upper and lower layered smelting slag and high-nickel copper matte after the smelting is completed; 2) introducing the high-nickel copper matte obtained in step 1) into a converting furnace, then adding a mixed flux to form slag, and blowing an oxygen-enriched gas flow for suspension converting, and obtaining nickel-copper converting slag and crude copper in upper and lower layers after the converting; 3) The nickel-copper converted slag obtained in step 2) is introduced into a depletion furnace, and then oxygen-enriched air and fuel are blown in. By adjusting the ratio of oxygen to fuel, the reaction atmosphere is adjusted to a weak reducing atmosphere for reduction smelting. After the reduction smelting is completed, upper and lower layered reduction slag and copper-nickel alloy are obtained.

2. The method according to claim 1, characterized in that In step 1), the nickel-containing copper concentrate contains 8-10% H2O, 20-26% Cu, 1-2% Ni, 28-32% S and 25-35% Fe on a dry basis.

3. The method according to claim 1, characterized in that: In step 1), the fuel is granular coal; the acidic flux is silica.

4. The method according to claim 1, characterized in that: In step 1), the process conditions involved in smelting include: oxygen concentration of 80-90%, oxygen-to-material ratio controlled at 300Nm 3 / t, coal rate is 1-2%, flux rate is 5-8%, smelting temperature is maintained at 1250-1300℃, and smelting time is 2.5-3h.

5. The method according to claim 1, characterized in that In step 1), the Fe / SiO2 in the smelting slag is controlled at 1.8-2.0, the slag contains Cu 1.5-2%, Ni 0.2-0.3%; the high-nickel copper matte contains Cu 68-72%, Ni 4-6%, and Fe 1-3%.

6. The method according to claim 1, characterized in that In step 2), the process conditions involved in suspension blowing include: oxygen enrichment concentration of 25-30%, oxygen-to-material ratio controlled at 150Nm 3 / t, the flux rate is 4-6%, the blowing temperature is maintained at 1250-1300℃, and the blowing time is 14-16h.

7. The method according to claim 1, characterized in that In step 2), the mixed flux is a mixture of limestone and silica.

8. The method according to claim 1, characterized in that: In step 2), the CaO / Fe in the copper-nickel blowing slag is controlled at 0.2-0.4, the SiO2 / Fe is controlled at 0.5-0.7, the slag contains Cu 25-35%, Ni 18-20%; the crude copper contains Cu≥98.5%, Ni≤0.6%, and S≤0.1%.

9. The method according to claim 1, characterized in that: In step 3), the fuel is pulverized coal or natural gas; the process conditions of the reduction smelting include: a weak reducing atmosphere refers to controlling the volume ratio of CO / (CO+CO2) in the atmosphere to be 50-70%; the coal rate is 10-15%, the oxygen excess coefficient is controlled at 0.65-0.75, the reduction smelting temperature is controlled at 1300-1350°C, and the reduction smelting time is 1 to 3 hours.

10. The method according to claim 1, characterized in that In step 3), the reducing slag contains Cu≤0.4% and Ni≤0.1%.

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