Enhanced smelting method for complex heavy non-ferrous metals

Abstract

The invention belongs to the technical field of non-ferrous metal smelting, and particularly relates to an enhanced smelting method for complex heavy non-ferrous metal. The smelting method comprises the following steps: mixing raw materials in a furnace, a flux and fuel to obtain a mixture; designing a slag system according to the components of the charging raw materials, and establishing a low-melting-point slag type according to a multi-component phase equilibrium theory; matching a furnace profile according to the melting point of the low-melting-point slag profile; smelting the mixture in a matched furnace profile to obtain metal matte; oxygen-enriched air is blown in the smelting process. According to the method, systematic design is carried out, through precise burdening, slag system design, furnace profile adaptation, three-field cooperation and reaction five-in-one chaotic flow dynamic uniform flow state enhanced smelting, a low-melting-point slag type is designed, the slag-gold separation effect is improved, and metal contained in slag is obviously reduced; and oxygen-enriched air, a temperature field, a concentration field and a flow field are blown for cooperation and multi-phase reaction, a chaotic flow uniform flow state strengthens molten pool stirring, reaction heat release is fully utilized, the fuel adding amount is remarkably reduced, and finally efficient and clean utilization of complex heavy non-ferrous metal resources is achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of non-ferrous metal smelting, and particularly relates to a reinforced smelting method for complex heavy non-ferrous metals. BACKGROUND

[0002] Copper, nickel, lead, tin, zinc and other heavy non-ferrous metals are widely used in the fields of electric power, daily consumption and electronic communication, and have a high demand. In contrast, high-quality resources are gradually decreasing, and low-quality ores with low main metal grade, high gangue composition and complex ore phase structure are introduced into the smelting system, and secondary resources such as urban mines and cutting waste are gradually attracting attention.

[0003] At present, the smelting system has defects such as low utilization rate of complex resources and insufficient utilization of mixed ores when processing complex heavy non-ferrous metal resources such as copper, nickel, lead, tin and zinc, because the ore phase structure is complex, the ore ratio and flux addition in the production process depend on manual experience, resulting in unstable furnace operation, low smelting efficiency, low yield of heavy non-ferrous metals, unreasonable slag design, insufficient utilization of heat energy, high coal blending rate, high metal content in slag, insufficient stirring in the furnace, dead zones, low product qualification rate (low main metal content and high impurity element content) and other problems. SUMMARY

[0004] Therefore, the present application aims to provide a reinforced smelting method for complex heavy non-ferrous metals. The smelting method provided by the present application has high yield of heavy non-ferrous metals, and heat energy can be fully utilized with a low coal blending rate.

[0005] The present application provides a smelting method for complex heavy non-ferrous metals, comprising the following steps: Mixing the furnace charging raw material, flux and fuel to obtain a mixture; the furnace charging raw material comprises natural ores and secondary resources thereof; the mass ratio of total Fe to SiO2 in the mixture is (1.2-1.8):1, the mass ratio of CaO to SiO2 is (0.2-2.0):1, and the mass percentage content of MgO is less than 9.0%; Designing a slag system according to the composition of the furnace charging raw material, the slag system comprising an iron-silicon binary slag, an iron-calcium binary slag, an iron-silicon-calcium ternary slag or an iron-silicon-calcium-magnesium quaternary slag; adjusting the contents of SiO2, Fe3O4 and CaO in the slag according to the multi-component phase equilibrium theory to establish a low-melting-point slag type, so that the melting point temperature of copper smelting slag is lower than 1250℃, the melting point temperature of nickel smelting slag is lower than 1350℃, the melting point temperature of lead smelting slag is lower than 1100℃, the melting point temperature of tin smelting slag is lower than 1150℃, and the melting point temperature of zinc smelting slag is lower than 1200℃; According to the melting point and industrial applicability of the low-melting-point slag type, a furnace type of a smelting process is matched; a top-blown furnace, a bottom-blown furnace or a flash furnace is selected for a copper smelting process, a top-blown furnace or a side-blown furnace is selected for a nickel smelting process, a bottom-blown furnace, a side-blown furnace or a flash furnace is selected for a lead smelting process, a top-blown furnace is selected for a tin smelting process, and a closed blast furnace is selected for a zinc smelting process; The mixed material is smelted in a matched furnace type to obtain metal matte; and oxygen-enriched air is blown during the smelting process.

[0006] Preferably, the mass percentage of the main metal in the furnace-feeding raw material is 15-30%.

[0007] Preferably, the flux includes one or more of silicon dioxide, calcium oxide and magnesium oxide.

[0008] Preferably, the mass ratio of the flux to the furnace-feeding raw material is (0.05-0.08):1.

[0009] Preferably, the fuel includes fossil fuel or biomass fuel.

[0010] Preferably, the mass ratio of the fuel to the mixed material is (0.007-0.01):1.

[0011] Preferably, the mass ratio of total Fe to SiO2 in the iron-silicon binary slag is (1.2-1.8):1. The mass ratio of total Fe to CaO in the iron-calcium binary slag is (2.0-4.0):1. The mass ratio of total Fe to SiO2 in the iron-silicon-calcium ternary slag is (1.2-2.0):1, and the mass ratio of CaO to SiO2 is (0.1-0.8):1. The mass ratio of total Fe to SiO2 in the iron-silicon-calcium-magnesium quaternary slag is (1.2-2.0):1, the mass ratio of CaO to SiO2 is (0.1-0.8):1, and the mass percentage of MgO is less than 9.0%.

[0012] Preferably, the melting point temperature of the copper smelting slag is 1205℃, and the melting point temperature of the nickel smelting slag is 1281℃.

[0013] Preferably, the oxygen concentration in the oxygen-enriched air is 22-99 vol.%.

[0014] Preferably, the smelting temperature is 1100-1400℃.

[0015] Compared with the prior art, the present application has the following beneficial effects: The application provides a complex heavy non-ferrous metal strengthening smelting method. The application is designed in view of the defects of the existing smelting process in processing complex heavy non-ferrous metal resources, and through five-in-one chaotic flow dynamic uniform flow state strengthening of batching, slag system, furnace type, three fields and reaction, finally realizes efficient and clean utilization of complex heavy non-ferrous metal resources, stable furnace operation and high smelting efficiency. The smelting method provided by the application has at least the following advantages: (1) Under the condition of systematic design of batching-slag system-furnace type-three fields-reaction chaotic strengthening smelting, the smelting efficiency of complex mineral resources is significantly improved by applying the smelting method of the application; the application adjusts the adding proportion of multiple ores by taking the parameters of the grade of main metal in mixed ore, iron and sulfur content, iron-silicon ratio (mass ratio of total Fe to SiO2 in slag), iron-calcium ratio (mass ratio of total Fe to CaO in slag) as the benchmark, and ensures the maximum utilization of low-grade complex minerals.

[0016] (2) The melting point of the slag is greatly reduced by using the multi-component phase equilibrium relationship, the slag-gold separation effect is improved, and the metal content in the slag is significantly reduced; By adjusting the iron-silicon ratio and iron-calcium ratio of the slag through the phase equilibrium theory, low-melting-point slag is obtained, and the heat carried away by the slag is low and the heat energy is fully utilized; By adjusting the content of Fe3O4, MgO and Al2O3 in the slag and the parameters such as iron-silicon ratio and iron-calcium ratio in the slag, the metal settling and separation effect in the slag is improved.

[0017] (3) Reasonably selecting the furnace type, such as bottom blowing furnace, top blowing furnace, flash furnace, etc., through three-field cooperation and multi-phase reaction, using chaotic flow uniform flow state to strengthen the stirring of the molten pool, so that the molten bath in the furnace is fully stirred and there is no dead zone, the reaction heat is fully utilized, and the fuel addition amount in the smelting process is significantly reduced. In the copper concentrate smelting process, the fuel addition amount is generally 3-5% of the mass of the mixed ore, and the application can reduce it to 0.7-1%. DETAILED DESCRIPTION

[0018] The application provides a complex heavy non-ferrous metal strengthening smelting method, which comprises the following steps: Mixing the furnace raw material, flux and fuel to obtain a mixed material; the furnace raw material includes natural ore and secondary resources; the mass ratio of total Fe to SiO2 in the mixed material is (1.2-1.8):1, the mass ratio of CaO to SiO2 is (2.0-0.2):1, and the mass percentage content of MgO is less than 9.0%; The slag system is designed according to the composition of the raw materials fed into the furnace. The slag system includes iron-silicon binary slag, iron-calcium binary slag, iron-silicon-calcium ternary slag, or iron-silicon-calcium-magnesium quaternary slag. According to the multi-component phase equilibrium theory, the contents of SiO2, Fe3O4, and CaO in the slag are adjusted to establish a low-melting-point slag type, so that the melting point temperature of copper smelting slag is lower than 1250℃, the melting point temperature of nickel smelting slag is lower than 1350℃, the melting point temperature of lead smelting slag is lower than 1100℃, the melting point temperature of tin smelting slag is lower than 1150℃, and the melting point temperature of zinc smelting slag is lower than 1200℃. Based on the melting point and industrial applicability of the low-melting-point slag, the furnace type for the smelting process is matched; the copper smelting process uses a top-blown furnace, a bottom-blown furnace, or a flash furnace; the nickel smelting process uses a top-blown furnace or a side-blown furnace; the lead smelting process uses a bottom-blown furnace, a side-blown furnace, or a flash furnace; the tin smelting process uses a top-blown furnace; and the zinc smelting process uses a closed blast furnace. The mixture is smelted in a matching furnace to obtain matte metal; oxygen-enriched air is blown in during the smelting process.

[0019] Unless otherwise specified, all materials and equipment used in this invention are commercially available products in the field.

[0020] This invention mixes raw materials, flux, and fuel in a furnace to obtain a mixture.

[0021] In this invention, the complex heavy non-ferrous metal includes one or more of copper, nickel, lead, tin, and zinc.

[0022] In this invention, the natural ore is a natural ore (primary ore) of copper, nickel, lead, tin, or zinc. The natural ore includes low-quality ore, which refers to minerals with low main metal grade, high impurity content, fine particle size (less than 74 μm), and complex phases. Taking low-quality copper concentrate as an example, the copper content is only 14% by mass, and the impurities aluminum, magnesium, lead, and arsenic have mass percentages of 3.67%, 0.22%, 0.87%, and 1.61%, respectively. The phases include bornite (Cu5FeS4), chalcopyrite (CuFe2S3), and arsenopyrite (Cu...). 12 As4S 13 ), malachite / CuCO3·Cu(OH)2, etc.

[0023] In this invention, the secondary resources are materials with recycling value generated during the smelting and processing process, including slag, dust, waste plates, electrolytic floating matter, cutting waste, or municipal waste containing copper, nickel, lead, zinc, and tin.

[0024] In this invention, the raw materials fed into the furnace may specifically include complex copper concentrate, smelting dust generated during the smelting process, and oxide slag generated during the blowing stage. In the embodiments of this invention, the preferred mass ratio of the three types of complex copper concentrate (A, B, and C), oxide slag, and smelting dust is 4:4:10:2:1.

[0025] In this invention, the mass percentage of the main metal in the raw material fed into the furnace is preferably 5-30%. Specifically, when smelting copper, the mass percentage of Cu in the raw material fed into the furnace can be 18.4%.

[0026] In this invention, the flux preferably includes one or more of silicon dioxide, calcium oxide, and magnesium oxide. The amount of flux added ensures that the mass ratio of total Fe to SiO2 in the mixture is (1.2~1.8):1, and the mass ratio of CaO to SiO2 is (0.2~2.0):1.

[0027] In this invention, the fuel preferably includes fossil fuels or biomass fuels, and the fossil fuels preferably include coal or natural gas, with the coal preferably in pulverized coal form. The mass ratio of the fuel to the mixture is preferably (0.007~0.01):1.

[0028] In this invention, when the raw materials, flux and fuel are mixed, the content error of each component is preferably controlled within ±3% of the set value.

[0029] This invention designs slag systems based on the composition of the raw materials fed into the furnace. These slag systems include iron-silicon binary slag, iron-calcium binary slag, iron-silicon-calcium ternary slag, or iron-silicon-calcium-magnesium quaternary slag. Based on the multi-component phase equilibrium theory, the content of SiO2, Fe3O4, and CaO in the slag is adjusted to establish a low-melting-point slag type, resulting in a melting point temperature below 1250℃ for copper slag, below 1350℃ for nickel slag, below 1100℃ for lead slag, below 1150℃ for tin slag, and below 1200℃ for zinc slag. The slag is the component obtained after smelting. After smelting, oxides such as FeO, SiO2, CaO, and Fe3O4 enter the slag. This invention adjusts the slag composition by precisely batching and adding fluxes such as SiO2 and CaO.

[0030] In this invention, the slag system is designed based on the composition of the raw materials fed into the furnace, specifically based on the gangue components and impurity element content of the raw materials fed into the furnace, such as iron, silicon, calcium, and magnesium. The mass ratio of total Fe to SiO2 in the iron-silicon binary slag is (1.2~1.8):1; the total Fe refers to the total Fe element content in the slag, including the Fe element content of different phases such as 2FeO·SiO2 and Fe3O4; The mass ratio of total Fe to CaO in the iron-calcium binary slag is (2.0~4.0):1; The mass ratio of total Fe to SiO2 in the iron-silicon-calcium ternary slag is (1.2~2.0):1, and the mass ratio of CaO to SiO2 is (0.1~0.8):1. The mass ratio of total Fe to SiO2 in the iron-silicon-calcium-magnesium quaternary slag is (1.2~2.0):1, the mass ratio of CaO to SiO2 is (0.1~0.8):1, and the mass percentage of MgO is less than 9.0%.

[0031] In this invention, the melting point of the copper smelting slag is preferably 1205℃, and the melting point of the nickel smelting slag is preferably 1281℃.

[0032] The present invention matches the furnace type of the smelting process according to the melting point of the low melting point slag.

[0033] In this invention, a suitable furnace type is matched to the smelting process based on the selected slag type and melting point, including a top-blown furnace, a side-blown furnace, a bottom-blown furnace, or a flash furnace. For slag melting points below 1250°C, a top-blown furnace, a bottom-blown furnace, or a flash furnace can be selected.

[0034] After the furnace type is matched, the present invention smelts the mixture in the matched furnace type to obtain metal matte; oxygen-enriched air is blown in during the smelting process.

[0035] In this invention, the oxygen-enriched air is preferably blown in by a variable frequency flow jet, and more preferably blown in by a spray gun in a swirling motion; the oxygen concentration in the oxygen-enriched air is preferably 22~99 vol.%, specifically 71 vol.%.

[0036] This invention introduces oxygen-enriched air, which stirs the melt in the furnace. The flow pattern of the oxygen-enriched bubbles is controlled by the spray gun and the frequency conversion of the oxygen enrichment, so that the oxygen-enriched bubbles and melt in the furnace enter a dynamic and uniform flow state. This promotes the uniformity of the melt concentration field, temperature field and flow field in the furnace. The three fields work together to enhance the stirring of the melt by the bubble group, thereby efficiently entraining and dispersing the mineral material.

[0037] In this invention, the smelting temperature is preferably 1100~1400℃, specifically 1255℃ or 1315℃. The smelting time needs to be determined comprehensively based on smelting parameters such as the effective volume of different furnace types, ore quantity, gas flow rate, and oxygen concentration, and can be 35 minutes or 55 minutes. The metal matte includes copper matte or low-nickel matte, and preferably, slag and flue gas are also obtained after the smelting.

[0038] During the smelting process, the oxygen-enriched air blown in undergoes multiphase reactions with the molten metal, including the oxidation of metal sulfides, the reduction of metal oxides, matte formation (such as copper matte and nickel matte), and slag formation. Examples of these reactions are listed below (Me refers to Cu, Ni, Pb, Sn, and Zn):

[0039] This invention utilizes the oxygen-enriched air injected into the furnace to undergo multiphase exothermic reactions with the molten components, such as matte formation, metal formation, and slag formation. This provides the necessary heat for the smooth smelting process in the furnace and reduces the amount of coal used.

[0040] In this invention, the smelting process also yields: slag and flue gas; the slag is preferably subjected to slag depletion, specifically electric furnace depletion or flotation depletion; the dust in the flue gas is preferably returned to the bottom blown furnace.

[0041] This invention enables the intensified smelting of complex heavy non-ferrous metal resources such as copper, nickel, lead, tin, and zinc using chaotic flow dynamic uniform flow mode. It employs a five-in-one approach—precise batching, slag system design, furnace type adaptation, three-field synergy, and multiphase reaction—systematically designing the entire process from batching to smelting. This method can be used for copper matte, nickel matte, lead matte, and slag formation. The smelting method of this invention offers advantages such as high utilization rate of complex heavy non-ferrous metal resources, high production efficiency, and good product quality.

[0042] To further illustrate the present invention, the following detailed description of the enhanced smelting method for complex heavy non-ferrous metals provided by the present invention is provided in conjunction with embodiments, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0043] In the following examples or comparative examples, unless otherwise specified, % content refers to mass percentage content.

[0044] Example 1 This embodiment takes the smelting section in copper pyrometallurgical smelting as an example.

[0045] Based on the known content of Cu, Fe, and S elements in three complex copper concentrates (A, B, and C) and smelting dust and blowing oxide slag, precise batching was performed. Then, through the principle of multi-component phase equilibrium, the slag was designed as a low-melting-point slag system of iron-silicon-calcium ternary structure with a melting point of 1205℃, containing 33.4% total Fe, 23.4% SiO2, and 3.8% CaO. Based on this, a bottom-blown furnace was selected. In addition, oxygen-enriched air with a concentration of 71 vol.% was blown in through a swirling spray gun to ensure that the concentration field, temperature field, and flow field were in a uniform state, achieving a dynamic uniform flow state of chaotic flow within the furnace. The system design was also made full use of the exothermic reaction of the melt to systematically design the smelting process of complex copper resources. Ultimately, a smelting efficiency of approximately 80 tons per hour was achieved for complex copper concentrates (A, B, and C), oxide slag, and smelting dust. The process fully utilized the exothermic reaction of the molten metal, reducing the coal blending rate to 0.7%, yielding high-grade matte with 73.5% Cu, 18.3% S, 4.5% Fe, and 3.7% impurities. The direct copper recovery rate was 90.3%, and after processing the slag and dust, the overall copper recovery rate reached 98.1%. The specific steps are as follows: 1) Precise batching: The ore fed into the furnace consists of three complex copper concentrates (A, B, and C), smelting dust, and oxide slag generated during the smelting process, with the following composition: The composition of mineral A is Cu 17.7%, Fe 30.8%, S 37.9%, O 2.1%, Si 1.3%, Ca 0.6%, and other impurities 9.6%; The composition of ore B is Cu 22.4%, Fe 26.7%, S 22.5%, O 17.4%, Si 3.5%, Ca 2.0%, and other impurities 5.5%. The composition of the propylene ore is Cu 14.2%, Fe 21.7%, S 18.5%, O 21.4%, Si 10.2%, Ca 6.4%, and other impurities 7.6%. The composition of the oxidation slag is Cu 23.7%, Fe 23.8%, S 0.4%, O 25.1%, Si 8.6%, Ca 2.8%, and other impurities 15.7%. The composition of the flue dust was Cu 17.8%, Fe 5.3%, S 7.7%, Si 1.1%, Ca 0.4%, O 20.0%, and other impurities 47.7%.

[0046] Based on the batching calculations, three complex copper concentrates (A, B, and C), oxide slag, and flue dust were mixed in a mass ratio of 4:4:10:2:1. The resulting mixed ore composition was Cu 18.4%, Fe 25.0%, S 21.8%, O 18.1%, Si 7.0%, Ca 4.0%, and other impurities 10.8%, totaling 76.6 tons. 3.83 tons of SiO2 flux and 0.54 tons of pulverized coal were added as fuel, with a pulverized coal to mixed ore mass ratio of 0.007:1. The mass ratio of total Fe to SiO2 in the material was 1.25:1, and the mass ratio of CaO to SiO2 was 0.38:1.

[0047] 2) Slag system design: Based on the gangue composition of iron, silicon, calcium and other minerals in the raw materials fed into the furnace, the smelting slag system is designed as an iron-silicon-calcium ternary slag system. Based on multi-component phase equilibrium calculations, a low-melting-point slag type is established with total Fe 33.4%, SiO2 23.4%, and CaO 3.8%, and the melting point of this slag type is 1205℃.

[0048] 3) Furnace type adaptation: According to the designed iron-silicon-calcium ternary slag system, the matching furnace type is bottom blowing furnace.

[0049] 4) Three-field synergy: Based on the smelting furnace type determined in the previous step, oxygen-enriched air is blown in through a spray gun in a swirling motion. The oxygen content in the oxygen-enriched air is 71 vol.%, which chaotically stirs the melt inside the furnace and regulates the flow pattern of the oxygen-enriched bubbles. This allows the oxygen-enriched bubbles and melt inside the furnace to enter a dynamic and uniform flow state, promoting a uniform state of the melt concentration field, temperature field, and flow field inside the furnace. This strengthens the stirring of the melt by the bubble group, thereby efficiently entraining and dispersing the ore.

[0050] The oxygen-enriched air is introduced via variable frequency flow, conforming to the following formula:

[0051] in, , For instantaneous flow, The instantaneous flow rate at the previous moment. Maximum flow rate; Instantaneous flow rate × Maximum flow rate = 4 × Instantaneous flow rate of the previous moment - 4 × Instantaneous flow rate of the previous moment 2 .

[0052] The time for introducing oxygen-enriched air is determined based on the amount of ore fed into the furnace, generally 10-15 standard cubic meters of oxygen per ton of ore, with an oxygen concentration of 60-75%.

[0053] 5) Multiphase reaction: Using oxygen-enriched air blown in by the oxygen lance, it reacts with the melt, including the decomposition of complex sulfides and the oxidation of metal sulfides, to form copper matte and slag. The smelting temperature is controlled at 1255℃. After smelting for 55 minutes, the slag and copper matte are discharged.

[0054] The chemical composition of the obtained copper matte includes: Cu 73.5%, S 18.3%, Fe 4.5%, and other impurities 3.7%; the chemical composition of the slag includes: Cu 3.1%, total Fe 32.5%, CaO 3.8%, SiO2 23.4%, and other impurities 37.2%; the chemical composition of the flue gas includes: Cu 19.2%, S 10.3%, Fe 6.0%, SiO2 3.3%, CaO 1.4%, and other impurities 59.8%.

[0055] Calculations show that the direct copper recovery rate from copper matte is 90.3%. The slag is depleted by flotation to recover the copper matte; the flue dust is returned to the bottom-blown furnace to recover valuable components; and the depleted slag is used as building material. Material balance calculations show that the overall copper recovery rate reaches 98.1%.

[0056] Example 2 This embodiment takes the smelting section in nickel pyrometallurgical process as an example.

[0057] This embodiment precisely proportions the feedstock based on the known contents of Cu, Fe, and S in three complex nickel concentrates (A, B, and C), settling furnace tailings, and blowing oxide slag. Then, using the principle of multi-component phase equilibrium, the slag is designed as a low-melting-point slag system of iron-silicon-calcium-magnesium quaternary elements with a melting point of 1285℃, containing 32.0% total Fe, 34.9% SiO2, 10.5% CaO, and 9.0% MgO. Based on this, a top-blown furnace is selected. Furthermore, oxygen-enriched air with a concentration of 71 vol.% is injected through a swirling spray gun to achieve a uniform concentration field, temperature field, and flow field, realizing a dynamic uniform flow state within the furnace. The system design fully utilizes the exothermic reaction of the melt and other features specific to the smelting process of complex heavy metal resources. Ultimately, a smelting efficiency of approximately 110 tons per hour was achieved for complex nickel concentrates (A, B, and C), settling furnace tailings, and blowing oxide slag. The process fully utilized the exothermic reaction of the melt oxidation, with a coal blending rate as low as 0.01%, yielding low-nickel matte with Ni 29.8%, Cu 19.9%, S 18.7%, Fe 24.1%, and impurities 7.5%. The specific steps are as follows: 1) Precise batching: The ore fed into the furnace consists of three complex nickel concentrates (A, B, and C), settling furnace tailings, and oxide slag generated during the blowing stage.

[0058] Ore A has the following composition: Ni 5.6%, Cu 4.5%, Fe 32.7%, S 36.3%, SiO2 8.1%, CaO 0.4%, MgO 5.7%, and other impurities 6.7%. The composition of ore B is Ni 6.0%, Cu 4.8%, Fe 30.2%, S 23.2%, SiO 27.5%, CaO 1.8%, MgO 6.2%, and other impurities 20.2%. The composition of C ore is Ni 3.34%, Cu 2.0%, Fe 21.4%, S 17.9%, SiO2 10.2%, CaO 3.0%, MgO 9.1%, and other impurities 33.0%. The composition of the settling furnace tailings is Ni 0.34%, Cu 0.24%, Fe 33.9%, S 0.9%, SiO2 33.1%, CaO 3.5%, MgO 11.1%, and other impurities 16.9%. The composition of the oxide slag is Ni 12.1%, Cu 18.7%, Fe 28.6%, S 0.7%, SiO2 21.8%, CaO 5.6%, MgO 4.6%, and other impurities 7.9%.

[0059] Based on the batching calculations, three types of complex nickel concentrates (A, B, and C), settling furnace tailings, and oxide slag generated during the blowing stage were mixed in a ratio of 4:4:10:1:2. The resulting composition was Ni 5.2%, Cu 4.8%, Fe 27.8%, S 21.0%, SiO2 12.0%, CaO 2.7%, MgO 8.0%, and other impurities 18.5%, totaling 63.8 tons. 11.1 tons of SiO2 and 4.1 tons of CaO were added as flux; 0.64 tons of pulverized coal were used as fuel, with a mixed ore to pulverized coal mass ratio of 1:0.007. The mass ratio of total Fe to SiO2 in the mixture was 0.94:1, and the mass ratio of CaO to SiO2 was 0.31:1.

[0060] 2) Slag system design: Based on the gangue composition of iron, silicon, calcium, magnesium and other elements in the raw materials fed into the furnace, the smelting slag system is designed as an iron-silicon-calcium-magnesium quaternary slag system. Based on multi-component phase equilibrium calculations, a low-melting-point slag type is established with total Fe 32.7%, SiO2 34.6%, CaO 10.7%, and MgO 8.7%, and the melting point of this slag type is 1281℃.

[0061] 3) Furnace type adaptation: Based on the designed iron-silicon-calcium-magnesium quaternary slag system, the matching furnace type is a top-blown furnace.

[0062] 4) Three-field synergy: Based on the smelting furnace type determined in the previous step, the melt in the oxygen-enriched air chaotic stirring furnace is injected through the spray gun in a swirling flow. The oxygen content in the oxygen-enriched air is 71 vol.%, and the flow pattern of the oxygen-enriched air bubbles is controlled to make the oxygen-enriched air bubbles and melt in the furnace enter a dynamic and uniform flow state, so as to promote the uniformity of the melt concentration field, temperature field and flow field in the furnace; strengthen the stirring of the melt by the bubble group, and thus efficiently entrain and disperse the ore.

[0063] 5) Multiphase reaction: Using oxygen-enriched air blown in by an oxygen lance, the air reacts with the melt, including the decomposition of complex sulfides and the oxidation of metal sulfides, to form nickel matte and slag. The smelting temperature is controlled at 1315℃, and after smelting for 35 minutes, the slag and nickel matte are discharged.

[0064] The chemical composition of the obtained low-nickel matte product includes: Ni 29.8%, Cu 19.9%, S 18.7%, Fe 24.1%, S 18.7%, and other impurities 7.5%; the chemical composition of the slag includes: Ni 1.2%, Cu 3.6%, total Fe 32.7%, SiO2 34.6%, CaO 10.7%, MgO 8.7%, and other impurities 8.5%; the flue dust includes: Ni 6.2%, Cu 5.7%, S 14.2%, Fe 7.3%, SiO2 2.9%, CaO 1.8%, MgO 8.4%, and other impurities 53.5%.

[0065] Calculations show that the direct recovery rate of nickel in low-nickel matte is 90.5%, and the direct recovery rate of copper is 90.8%. The slag is depleted by flotation to recover the nickel matte; the flue dust is returned to the top-blown furnace to recover valuable components; the depleted slag is used as building material. Material balance calculations show that the overall recovery rates of nickel and copper reach 97.6% and 98.3%, respectively.

[0066] Comparative Example 1 Methods for smelting copper sulfide concentrate into matte: The difference between this comparative example and Example 1 is that, relying on manual experience, three complex copper concentrates (A, B, and C), oxide slag, and flue dust were mixed in a mass ratio of 2:2:14:2:1, resulting in 76.1 tons of mixed ore. The mixed ore composition was Cu 17.2%, Fe 23.6%, S 19.4%, O 20.4%, Si 8.5%, Ca 5.0%, and other impurities 10.8%. The fuel was pulverized coal, with a pulverized coal to ore mass ratio of 0.03:1. The total Fe to SiO2 mass ratio in the raw materials fed into the furnace was 1.0:1, and the CaO to SiO2 mass ratio was 0.4:1.

[0067] The furnace type selected is a top-blown furnace, with oxygen-enriched air containing 60 vol.% oxygen directly blown in by the lance. After smelting for 75 minutes, slag and copper matte are discharged.

[0068] The chemical composition of the obtained copper matte includes: Cu 60.2%, S 21.5%, Fe 12.7%, and other impurities 5.6%; the chemical composition of the slag includes: Cu 6.3%, total Fe 30.0%, CaO 7.1%, SiO2 27.6%, and the remainder 29.0%, with a slag melting point of 1241℃; the chemical composition of the flue gas includes: Cu 23.3%, S 13.7%, Fe 8.4%, SiO2 5.3%, CaO 3.8%, and other impurities 45.5%.

[0069] Calculations show that the smelting efficiency is 60.9 tons per hour, the direct copper recovery rate from the copper matte is 84.0%, and the copper-containing components are recovered through post-treatment of the slag and flue gas, resulting in a comprehensive copper recovery rate of 94.1%. The treated secondary slag is used as building material.

[0070] The smelting efficiency, copper-nickel direct recovery rate, and other smelting indicators of complex resources in Examples 1-2 and Comparative Example 1 are shown in Table 1 below.

[0071] Table 1 Smelting Indicators such as Smelting Efficiency and Direct Copper-Nickel Recovery Rate for Complex Resources

[0072] Comparing Example 1 and Comparative Example 1, the proportion of minerals added in Comparative Example 1 was determined based on manual experience, resulting in fewer sulfur-containing phases and lower exothermic reactions of sulfides. Therefore, more pulverized coal was needed to provide heat. The slag melting point in Comparative Example 1 was higher than in the Example 1, and the use of a top-blown furnace, among other factors, led to low smelting efficiency, high copper content in the slag, and low direct copper recovery. Table 1 shows that, using the smelting method of this invention, under the systematic design of batching, slag system, furnace type, three-field, and reaction-chaotic enhanced smelting conditions, the smelting efficiency of complex mineral resources is significantly improved. The multi-component phase equilibrium relationship significantly reduces the slag melting point, improves slag-gold separation, and significantly reduces the copper / nickel content in the slag. Through three-field synergy and multi-phase reactions, the chaotic flow uniformity enhances the stirring of the molten pool, fully utilizing the exothermic reaction and significantly reducing the amount of fuel added during the smelting process. Ultimately, efficient and clean utilization of complex heavy non-ferrous metal resources is achieved.

[0073] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, not all embodiments. People can obtain other embodiments based on the present invention without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for smelting complex heavy non-ferrous metals, characterized in that, Includes the following steps: Raw materials, flux, and fuel are mixed to obtain a mixture; the raw materials include natural ores and their secondary resources, the natural ores contain metals, and the metals include one or more of copper, nickel, lead, tin, and zinc; the mass ratio of total Fe to SiO2 in the mixture is (1.2~1.8):1, the mass ratio of CaO to SiO2 is (0.2~2.0):1, and the mass percentage of MgO is less than 9.0%; The slag system is designed according to the composition of the raw materials fed into the furnace. The slag system includes iron-silicon binary slag, iron-calcium binary slag, iron-silicon-calcium ternary slag, or iron-silicon-calcium-magnesium quaternary slag. According to the multi-component phase equilibrium theory, the contents of SiO2, Fe3O4, and CaO in the slag are adjusted to establish a low-melting-point slag type, so that the melting point temperature of copper smelting slag is lower than 1250℃, the melting point temperature of nickel smelting slag is lower than 1350℃, the melting point temperature of lead smelting slag is lower than 1100℃, the melting point temperature of tin smelting slag is lower than 1150℃, and the melting point temperature of zinc smelting slag is lower than 1200℃. Based on the melting point and industrial applicability of the low-melting-point slag type, the furnace type for the smelting process is matched; for copper smelting, a top-blown furnace, a bottom-blown furnace, or a flash furnace is selected; for nickel smelting, a top-blown furnace or a side-blown furnace is selected; for lead smelting, a bottom-blown furnace, a side-blown furnace, or a flash furnace is selected; for tin smelting, a top-blown furnace is selected; and for zinc smelting, a closed blast furnace is selected. The mixture is smelted in a matching furnace to obtain matte metal; oxygen-enriched air is blown in during the smelting process.

2. The smelting method according to claim 1, characterized in that, The main metal content in the raw materials fed into the furnace is 15-30% by mass.

3. The smelting method according to claim 1, characterized in that, The flux includes one or more of silicon dioxide, calcium oxide, and magnesium oxide.

4. The smelting method according to claim 1 or 3, characterized in that, The mass ratio of the flux to the raw materials fed into the furnace is (0.05~0.08):

1.

5. The smelting method according to claim 1, characterized in that, The fuels include fossil fuels or biomass fuels.

6. The smelting method according to claim 1 or 5, characterized in that, The mass ratio of the fuel to the mixture is (0.007~0.01):

1.

7. The smelting method according to claim 1, characterized in that, The mass ratio of total Fe to SiO2 in the iron-silicon binary slag is (1.2~1.8):1; The mass ratio of total Fe to CaO in the iron-calcium binary slag is (2.0~4.0):1; The mass ratio of total Fe to SiO2 in the iron-silicon-calcium ternary slag is (1.2~2.0):1, and the mass ratio of CaO to SiO2 is (0.1~0.8):

1. The mass ratio of total Fe to SiO2 in the iron-silicon-calcium-magnesium quaternary slag is (1.2~2.0):1, the mass ratio of CaO to SiO2 is (0.1~0.8):1, and the mass percentage of MgO is less than 9.0%.

8. The smelting method according to claim 1, characterized in that, The melting point of the copper smelting slag is 1205℃, and the melting point of the nickel smelting slag is 1281℃.

9. The smelting method according to claim 1, characterized in that, The oxygen concentration in the oxygen-enriched air is 22-99 vol.%.

10. The smelting method according to claim 1, characterized in that, The smelting temperature is 1100~1400℃.

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