Method for reconstructing slow cooling copper slag ore phase coupling thermal-mass circulation through limestone-FeS-carbon powder

Abstract

The invention relates to a limestone-FeS-carbon powder reconstructed slow-cooling copper slag ore phase coupling heat-mass circulation method, and belongs to the field of high-temperature copper slag waste heat recovery and valuable metal circulation extraction. According to the method, the slaked lime and the iron silicate phase in the copper slag are reconstructed to form the iron oxide and the calcium silicate phase, the iron oxide is reduced into the metallic iron or the ferroferric oxide under the action of the coke and the CO reducing agent, the metallic iron phase in the copper slag is separated through magnetic separation, the copper-containing phase of the copper slag is reconstructed, and the cuprous sulfide phase is enriched; and conditions are created for efficient flotation recovery of copper-containing phases. And finally, a calcium silicate phase in the copper slag reacts with CO2 to form a calcium carbonate phase, the energy storage effect of waste heat in a low-temperature area in the copper slag is achieved, and the stability of the copper slag is also improved. The invention provides a new process for reconstructing a copper slag ore phase by limestone and coke, the method can meet the crystallization growth effect of a copper-containing phase in the slow cooling process of the liquid copper slag, and meanwhile, efficient energy storage of copper slag waste heat is realized through a limestone decomposition reaction and a coke reduction reaction.

Description

Technical Field

[0001] The invention belongs to the field of waste heat recovery of high-temperature copper slag and cyclic extraction of valuable metals, and relates to a method for coupling heat-mass cycle of limestone-FeS-carbon powder reconstruction of slowly cooled copper slag ore. Background Art

[0002] Developing efficient waste heat recovery and utilization technologies for the slow-cooling process of copper slag is imperative. Developing a process for efficient, high-quality recovery of waste heat from slow-cooling copper slag across the entire temperature range, coupled with the synergistic extraction of valuable metals from the slag, is poised to become a key breakthrough for copper smelting companies.

[0003] At present, copper smelting enterprises mostly use wet leaching processes for the extraction of valuable metals from copper slag (such as invention patent CN119685604A, etc.). Although the above invention patents can extract valuable metals such as Cu and Fe from copper slag at a high rate, they do not consider the problem of copper slag waste heat recovery and the above process is not compatible with the slow cooling copper slag treatment process of copper smelting enterprises, making the process difficult to promote. In order to design a more compatible copper slag resource recovery process, the team of Academician Chai Liyuan of Central South University proposed the idea of ​​using CaO hot high-temperature reconstruction of copper slag ore phase to achieve copper and iron separation (such as invention patent CN119592784A, etc.). The formation of magnetic Fe3O4 ore phase is achieved by reconstructing the iron silicate phase through the CaO ore phase, and the separation of copper and iron valuable metals is achieved through magnetic separation recovery. However, the team did not systematically consider the problem of waste heat from slow cooling copper slag, and the subsequent carbonation problem of calcium silicate phase in copper tailings inhibits volume expansion, which directly restricts the feasibility of large-scale utilization of tailings. Based on this, our research group proposed a process of injecting limestone, ferrous sulfide and carbon powder at the copper slag outlet. The mixed copper slag completes the mineral phase reconstruction and chemical energy storage coupling of waste heat in a closed slag tank.

[0004] In view of the problems existing in the existing copper slag treatment process, the new process needs to solve the following problems:

[0005] (1) The problem of thermal reconstruction uniformity of the ferrous silicate phase in the slowly cooled copper slag. The copper slag flow rate must match the limestone injection rate, and the injection volume must exceed the theoretical limestone addition amount. The endothermic decomposition process of limestone inevitably absorbs sensible heat from the high-temperature zone of the copper slag and produces CO2 gas. The slag tank is densely enclosed to achieve a reducing atmosphere during the reconstruction reaction process and prevent deep oxidation of the copper-containing phase.

[0006] (2) The mixed slaked lime and the ferric silicate phase undergo a reconstruction reaction to form a calcium silicate phase and iron oxide. The iron oxide continues to undergo a reduction reaction with the carbon powder to produce metallic iron or magnetic ferroferric oxide phase. At this time, the sensible heat in the high temperature zone continues to realize chemical energy storage through the reduction reaction.

[0007] (3) The cuprous oxide phase in the copper slag reacts with FeS to form the cuprous sulfide phase. In addition, the waste heat in the low-temperature zone of the copper slag reconstructs the calcium silicate phase through CO2 to form the calcium carbonate phase, further improving the stability of the tailings. This provides technical support for the large-scale utilization of copper tailings as cement and building materials. Summary of the Invention

[0008] In response to the above-mentioned technical problems in the existing copper smelting field in the coupling of copper slag waste heat recovery and precious metal resource circulation, the present invention proposes a new process for reconstructing the copper slag mineral phase with limestone and coke. This method can not only meet the crystallization and growth effect of the copper-containing phase during the slow cooling process of liquid copper slag, but also realize the efficient energy storage of copper slag waste heat through the limestone decomposition reaction and coke reduction reaction. In addition, by reconstructing the iron silicate phase in the copper slag with slaked lime to form iron oxide and calcium silicate phases, the iron oxide is reduced to metallic iron or ferroferric oxide under the action of coke and CO reducing agents, and the metallic iron phase in the copper slag is separated by magnetic separation, the copper-containing phase of the copper slag is reconstructed and enriched into a cuprous sulfide phase, creating conditions for the efficient flotation recovery of the copper-containing phase. Finally, the calcium silicate phase in the copper slag reacts with CO2 to form a calcium carbonate phase, realizing the energy storage effect of the waste heat in the low temperature zone of the copper slag and improving the stability of the copper slag.

[0009] A method for reconstructing a slowly cooled copper slag phase coupled heat-mass cycle using limestone, FeS, and carbon powder comprises the following steps:

[0010] Step 1: preparing limestone, FeS and carbon powder as a slow-cooling copper slag reconstructor, mixing the slow-cooling copper slag reconstructor and then blowing it into the copper smelting slag through carrier gas N2 at a pressure of 0.5MPa-1MPa to obtain a slow-cooling copper slag to be treated;

[0011] Step 2: After the slag pot receives the slow-cooled copper slag to be processed, it is covered with a closed fume hood to achieve a CO-CO2 atmosphere protection effect. After standing for 10-12 hours, it is poured with water to continue cooling to ambient temperature;

[0012] Step 3: After crushing and grinding the slow-cooling copper slag, the metallic iron and magnetically separated Fe3O4 in the slow-cooling copper slag are extracted through a magnetic separation recovery process, achieving an iron recovery rate of over 90%;

[0013] Step 4: The tailings after copper and iron separation are enriched and recovered by flotation to achieve the copper-containing phase enrichment and recovery, so that the copper-containing phase grade of the copper tailings before flotation is less than 0.17%; the slowly cooled copper tailings after flotation can be used as a large amount of construction materials or road construction materials, realizing the effect of turning waste from copper smelters into treasure.

[0014] Furthermore, the particle size of the limestone, FeS and carbon powder in step 1 is less than 5 mm, wherein the amount of limestone is 200 kg / t-280 kg / t, the amount of FeS is 2 kg / t-8 kg / t, and the amount of carbon powder is 40 kg / t-100 kg / t.

[0015] Furthermore, the copper smelting slag composition in step 1 contains 30%-45% iron by weight, of which more than 70% is in the form of fayalite (Fe2SiO4) and 20%-30% is magnetite (Fe3O4).

[0016] Furthermore, the mass ratio of the slowly cooled copper slag reconstructor to the copper smelting slag in step 1 is (0.24-0.4):1.

[0017] Furthermore, the temperature of the slowly cooled copper slag to be treated in step 1 is 1200°C-1500°C.

[0018] Furthermore, the magnetic separation intensity range in the magnetic separation recovery process described in step 3 is 0.15T-0.3T.

[0019] Furthermore, the diameter of the copper slag that is crushed, ground and slowly cooled in step 3 is 10 μm to 5 mm.

[0020] Furthermore, in the entire limestone-FeS-carbon powder reconstruction slow-cooling copper slag phase coupled heat-mass cycle method, the waste heat of the copper slag is stored through chemical reaction endothermicity, and the energy storage efficiency is calculated to be 50%-80%.

[0021] Compared with the existing technology, the patent of this invention has the following beneficial effects and innovations:

[0022] (1) The slow-cooling copper slag is used in situ to realize the transformation of the iron-containing phase into the magnetic iron-containing phase, the copper-containing phase into the Cu2S phase, and the calcium silicate phase of the tailings into the calcium carbonate phase during the reconstruction process of the limestone-FeS-carbon powder mineral phase. At the same time, the waste heat of the copper slag in the slow cooling process is efficiently converted through chemical energy storage.

[0023] (2) By using the limestone-FeS-carbon powder mineral phase to reconstruct the slow-cooling copper slag, not only can the valuable metals in the copper slag be efficiently recovered and the stability of the tailings be improved, but also the waste heat chemical conversion of the slow-cooling process of the copper slag can be achieved in situ.

[0024] (3) The slow cooling copper slag process is reconstructed using the limestone-FeS-carbon powder mineral phase, which is more compatible with the existing copper slag treatment process of copper smelters and requires less modification to the original process.

[0025] (4) The slow cooling copper slag process is reconstructed by using limestone-FeS-carbon powder mineral phase, which can connect with the existing copper slag slow cooling process and match the treatment cycle.

[0026] (5) The slow-cooling copper slag process is reconstructed using the limestone-FeS-carbon powder mineral phase, resulting in a high recovery rate of the iron-containing phase and the conversion of the copper-containing phase to the cuprous sulfide phase. In addition, since the metallic mineral phase of the copper-containing tailings is completely converted to the calcium carbonate phase, the grindability and porosity of the slow-cooling copper slag are improved.

[0027] The recovery of waste heat from slow-cooling copper slag is an important research area for energy conservation and emission reduction in copper smelting enterprises, and is a key measure to achieve waste heat recovery and utilization in all links of copper smelting enterprises. The present invention adopts a limestone-FeS-carbon powder ore phase to reconstruct the slow-cooling copper slag process, which improves the chemical reaction to achieve chemical energy storage of waste heat, while coupling to achieve magnetization treatment of the iron-containing phase and sulfurization reconstruction of the copper-containing phase, providing high-quality raw materials for subsequent magnetic separation and flotation processes. In addition, the copper tailings are transformed into a calcium carbonate phase due to the calcium silicate phase, which improves the stability of the tailings, and solves the safety hazards of stability for the large-scale use of tailings as building materials or road construction materials. The present invention realizes the separation of valuable metals copper and iron in copper slag while coupling the consideration of the chemical energy storage of copper slag waste heat, as well as the stability problem of the resource utilization process of copper tailings in large quantities. The process method is an innovative process for in-situ treatment of slow-cooling copper slag and coupling to achieve copper slag heat-mass cycle, which fundamentally solves the problem of the high-efficiency heat-mass recycling process of copper smelting slag from top to bottom, and provides a new idea for energy conservation, environmental protection, quality improvement and efficiency enhancement of enterprises, with broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a process flow chart of the method for reconstructing slowly cooled copper slag by coupling heat and mass cycle with limestone-FeS-carbon powder according to the present invention. DETAILED DESCRIPTION

[0029] In the embodiment of the process for reconstructing the slowly cooled copper slag using the limestone-FeS-carbon powder mineral phase, the purity of the limestone, FeS and carbon powder purchased from the market exceeds 98%;

[0030] In the embodiment of the process of reconstructing the slowly cooled copper slag using the limestone-FeS-carbon powder mineral phase, the blowing system blows the powder into the copper slag melt through the carrier gas N2 at a pressure of 0.5MPa to 1MPa.

[0031] In the embodiment of the present invention, molten copper slag is used as liquid slag from a copper smelting site, and the initial temperature is about 1500°C.

[0032] During the entire process of slow cooling copper slag waste heat through mineral phase reconstruction, the waste heat of copper slag is stored through chemical reaction and heat absorption. The energy storage efficiency is calculated to be 50%-80%. The calculation formula is as follows:

[0033]

[0034] Where: Q 铜渣 =cmΔt (c, m, Δt represent the specific heat capacity, mass, and temperature difference of copper slag, respectively)

[0035] In the above-mentioned method of coupling the limestone-FeS-carbon powder reconstructed slow-cooling copper slag mineral phase to achieve heat and mass circulation, the mineral phases such as iron silicate and copper oxide in the copper slag particles undergo the following chemical reaction. The specific reaction equation is as follows:

[0036] CaCO3 = CaO + CO2 (2)

[0037] 2CaO + Fe2SiO4 =2FeO + Ca2SiO4 (3)

[0038] Ca2SiO4 + 2CO2 = 2CaCO3 + SiO2 (4)

[0039] Cu2O+FeS=Cu2S+FeO(5) (5)

[0040] C+FeO=Fe+CO(6) (6)

[0041] CO+FeO=Fe+CO2 (7)

[0042] Assuming a total iron content of 30-40% in slow-cooled copper slag, with 70% iron in the fayalite phase, 25% in magnetite, and 2-5% in hematite, the fayalite phase accounts for 21-28% of the total iron content. Furthermore, the copper oxide phase accounts for 0.02-0.08% of the copper-bearing phase. Complete reconstitution of one ton of slow-cooled copper slag requires a total limestone content of 200-280 kg / t. Based on a carbon-iron ratio of 2:1, the addition of coke as a reducing agent would range from 40 kg / t to 100 kg / t. The FeS addition amount is 2 kg / t to 8 kg / t. One ton of molten, slow-cooled copper slag at 1450°C is poured out of the slag chute via a pouring device. Simultaneously, a powder injection system sprays a limestone-FeS-carbon powder mixture into the slow-cooled molten copper slag. After receiving the mixed copper slag, the slag pot is slow-cooled in a closed hood for 10-12 hours. Water is then applied to enhance cooling of the slow-cooled copper slag to room temperature. The copper slag is crushed and ground to a particle size of less than 5mm. The magnetic iron-containing phase in the copper slag is recovered through magnetic separation. The processed slag after copper and iron separation is subjected to a flotation process to recover the cuprous sulfide phase. The tailings are used in large quantities as road construction materials.

[0043] Generally speaking, the specific heat capacity of copper slag is 200-500 J / kg℃ (300 J / kg℃ is used for calculation). The sensible heat released when 1 ton of copper slag is cooled from 1500℃ to 25℃ is:

[0044] Q 渣 =CMΔt=44.25×10 7 J

[0045] When the temperature of copper slag is between 1500℃ and 25℃, limestone absorbs heat and decomposes to form slaked lime (the specific heat of limestone is 0.59kJ / kg℃, the specific heat of slaked lime is 0.248kJ / kg℃, and the specific heat of coke is 0.8kJ / kg℃-1.4kJ / kg℃). The heat absorbed by the powder is:

[0046] Q 石灰石 =CMΔt=1.03-1.44×10 8 JQ 石灰 =CMΔt=1.67-2.33×10 7 J

[0047] Q 焦炭 =CMΔt=6.6-16.5×10 7 JΔH 石灰石 =0.6298-0.882×10 7 J

[0048] The calculated chemical energy storage efficiency of the waste heat of the slowly cooled copper slag is: η = 43.4% - 77.1%.

[0049] Example 1

[0050] The total iron content of the slow-cooling copper slag sampled from a domestic copper smelter A is 30%, of which the iron content in the fayalite phase accounts for 70%, the magnetite phase accounts for 25%, and the hematite phase accounts for 21% of the total iron content of the slow-cooling copper slag. In addition, the copper oxide phase accounts for 0.05% of the copper-containing phase. The total amount of limestone required for the complete reconstruction of 1 ton of slow-cooling copper slag is 280 kg / t. Based on the carbon-iron ratio of 2:1, the reducing agent coke is added, and the coke addition amount is 40 kg / t; the FeS addition amount is 6 kg / t. Figure 1 As shown:

[0051] Step 1: One ton of 1500°C molten slowly cooled metallurgical copper slag is poured out of the slag slot through a pouring device. Simultaneously, a powder spraying system sprays a limestone-FeS-carbon powder mixture into the slowly cooled molten copper slag.

[0052] Step 2: After the slag pot receives the mixed copper slag, it is slowly cooled in a closed cover for 10-12 hours, and then water is poured to enhance cooling and slowly cool the copper slag to room temperature;

[0053] Step 3: crushing and grinding the copper slag to a particle size of less than 5 mm, and recovering the magnetic iron-containing phase in the copper slag by magnetic separation (magnetic separation intensity 0.2 T);

[0054] Step 4: After the separation of copper and iron, the treated slag is subjected to a flotation process to recover the cuprous sulfide phase, and the tailings are used in large quantities as road construction materials.

[0055] Generally speaking, the specific heat capacity of copper slag is 200J / kg℃-500J / kg℃ (300J / kg℃ is used for calculation). The sensible heat released when 1 ton of copper slag is cooled from 1500℃ to 25℃ is:

[0056] Q 渣 =CMΔt=44.25×10 7 J

[0057] When the temperature of copper slag is between 1500℃ and 25℃, limestone absorbs heat and decomposes to form slaked lime (the specific heat of limestone is 0.59kJ / kg℃, the specific heat of slaked lime is 0.248kJ / kg℃, and the specific heat of coke is 0.8kJ / kg℃-1.4kJ / kg℃). The heat absorbed by the powder is:

[0058] Q 石灰石 =CMΔt=1.44×10 8 JQ 石灰 =CMΔt=2.33×10 7 J

[0059] Q 焦炭 =CMΔt=6.6×10 7 JΔH 石灰石 =0.882×10 7 J

[0060] The calculated chemical energy storage efficiency of the waste heat of the slowly cooled copper slag is: η = 54%

[0061] This embodiment shows that after one ton of slowly cooled copper slag at a temperature of 1500° C. is treated by the method of the present invention, the waste heat recovery rate of the copper slag can reach 54%, the magnetic separation recovery rate of metallic iron is higher than 95%, and the cuprous sulfide enrichment rate is increased by 30%.

[0062] Example 2

[0063] Slow-cooled copper slag sampled from a domestic copper smelter, B, contained 40% total iron. Of this, 70% was iron in the fayalite phase, 25% was magnetite, and 2%-5% was hematite. Therefore, the fayalite phase accounted for 28% of the total iron content in the slow-cooled copper slag. Furthermore, the copper oxide phase accounted for 0.02% of the copper-bearing phase. Complete reconstruction of one ton of slow-cooled copper slag requires a total limestone content of 280 kg / t. Based on a carbon-iron ratio of 2:1, the addition of reducing coke is 100 kg / t. The FeS addition is 8 kg / t.

[0064] Step 1: One ton of 1500°C molten slowly cooled metallurgical copper slag is poured out of the slag slot through a pouring device. Simultaneously, a powder spraying system sprays a limestone-FeS-carbon powder mixture into the slowly cooled molten copper slag.

[0065] Step 2: After the slag pot receives the mixed copper slag, it is slowly cooled in a closed cover for 10-12 hours, and then water is poured to enhance cooling and slowly cool the copper slag to room temperature;

[0066] Step 3: crushing and grinding the copper slag to a particle size of less than 5 mm, and recovering the magnetic iron-containing phase in the copper slag by magnetic separation (magnetic separation intensity 0.25 T);

[0067] Step 4: After the separation of copper and iron, the treated slag is subjected to a flotation process to recover the cuprous sulfide phase, and the tailings are used in large quantities as road construction materials.

[0068] The specific heat capacity of copper slag is 200J / kg℃-500J / kg℃ (ignoring the change of specific heat capacity with temperature). The heat released when 1 ton of copper slag is cooled from 1500℃ to 25℃ is:

[0069] Q 渣 =CMΔt=44.25×10 7 J

[0070] When the temperature of copper slag is between 1500℃ and 25℃, limestone absorbs heat and decomposes to form slaked lime (the specific heat of limestone is 0.59kJ / kg℃, the specific heat of slaked lime is 0.248kJ / kg℃, and the specific heat of coke is 0.8J / kg℃-1.4kJ / kg℃). The heat absorbed by the powder is:

[0071] Q 石灰石 =CMΔt=1.44×10 8 JQ 石灰 =CMΔt=2.33×10 7 J

[0072] Q 焦炭 =CMΔt=16.5×10 7 J ΔH 石灰石 =0.882×10 7 J

[0073] The calculated chemical energy storage efficiency of the waste heat of the slowly cooled copper slag is: η = 77.1%

[0074] This embodiment shows that after one ton of slowly cooled copper slag at a temperature of 1500° C. is treated by the method of the present invention, the waste heat recovery rate of the copper slag can reach 77.1%, the magnetic separation recovery rate of metallic iron is higher than 96%, and the cuprous sulfide enrichment rate is increased by 25.5%.

[0075] Example 3

[0076] Sample C of slow-cooled copper slag from a domestic copper smelter contained 40% total iron, of which 70% was iron in the fayalite phase, 25% was magnetite, and 5% was hematite. The fayalite phase accounted for 28% of the total iron content in the slow-cooled copper slag. Furthermore, the copper oxide phase accounted for 0.048% of the copper-bearing phase. Complete reconstruction of one ton of slow-cooled copper slag requires a total limestone content of 280 kg / t. Based on a carbon-iron ratio of 2:1, the addition of reducing coke is 60 kg / t. The FeS addition is 4 kg / t.

[0077] Step 1: One ton of 1500°C molten slowly cooled metallurgical copper slag is poured out of the slag slot through a pouring device. Simultaneously, a powder spraying system sprays a limestone-FeS-carbon powder mixture into the slowly cooled molten copper slag.

[0078] Step 2: After the slag pot receives the mixed copper slag, it is slowly cooled in a closed cover for 10-12 hours, and then water is poured to enhance cooling and slowly cool the copper slag to room temperature;

[0079] Step 3: crushing and grinding the copper slag to a particle size of less than 5 mm, and recovering the magnetic iron-containing phase in the copper slag by magnetic separation (magnetic separation intensity 0.18 T);

[0080] Step 4: After the separation of copper and iron, the treated slag is subjected to a flotation process to recover the cuprous sulfide phase, and the tailings are used in large quantities as road construction materials.

[0081] Generally speaking, the specific heat capacity of copper slag is 200J / kg℃-500J / kg℃ (ignoring the change of specific heat capacity with temperature). The sensible heat released by 1 ton of copper slag when it cools from 1500℃ to 25℃ is:

[0082] Q 渣 =CMΔt=44.25×10 7 J

[0083] When the temperature of copper slag is between 1500℃ and 25℃, limestone absorbs heat and decomposes to form slaked lime (the specific heat of limestone is 0.59kJ / kg℃, the specific heat of slaked lime is 0.248kJ / kg℃, and the specific heat of coke is 0.8J / kg℃-1.4kJ / kg℃). The total heat absorbed by the powder is:

[0084] Q 石灰石 =CMΔt=1.44×10 8 JQ 石灰 =CMΔt=2.33×10 7 J

[0085] Q 焦炭 =CMΔt=9.7×10 7 J ΔH 石灰石 =0.882×10 7 J

[0086] The calculated chemical energy storage efficiency of the waste heat of the slowly cooled copper slag is: η = 61.7%

[0087] This embodiment shows that after one ton of slowly cooled copper slag at a temperature of 1500° C. is treated by the method of the present invention, the waste heat recovery rate of the copper slag can reach 61.72%, the magnetic separation recovery rate of metallic iron is higher than 94%, and the cuprous sulfide enrichment rate is increased by 35%.

Claims

1. A method for reconstructing a slowly cooled copper slag phase coupled heat-mass cycle using limestone-FeS-carbon powder, characterized in that: The following steps are involved: Step 1: preparing limestone, FeS and carbon powder as a slow-cooling copper slag reconstructor, mixing the slow-cooling copper slag reconstructor and then blowing it into the copper smelting slag through carrier gas N2 at a pressure of 0.5MPa-1MPa to obtain a slow-cooling copper slag to be treated; Step 2: After the slag pot receives the slow-cooled copper slag to be processed, it is covered with a closed fume hood to achieve a CO-CO2 atmosphere protection effect. After standing for 10-12 hours, it is poured with water to continue cooling to ambient temperature; Step 3: After crushing and grinding the slow-cooling copper slag, the metallic iron and magnetically separated Fe3O4 in the slow-cooling copper slag are extracted through a magnetic separation recovery process, achieving an iron recovery rate of over 90%; Step 4: The tailings after copper and iron separation are enriched and recovered by flotation to achieve the copper-containing phase enrichment and recovery, so that the copper-containing phase grade of the copper tailings before flotation is less than 0.17%; the slowly cooled copper tailings after flotation can be used as a large amount of construction materials or road construction materials, realizing the effect of turning waste from copper smelters into treasure.

2. The method for reconstructing a slowly cooled copper slag phase coupled heat-mass cycle using limestone-FeS-carbon powder according to claim 1, characterized in that: The particle size of the limestone, FeS and carbon powder in step 1 is less than 5 mm, wherein the amount of limestone is 200 kg / t-280 kg / t, the amount of FeS is 2 kg / t-8 kg / t, and the amount of carbon powder is 40 kg / t-100 kg / t.

3. The method for reconstructing a slowly cooled copper slag phase coupled heat-mass cycle using limestone-FeS-carbon powder according to claim 1, characterized in that: The copper smelting slag described in step 1 contains 30%-45% iron by weight, of which more than 70% exists in the form of fayalite and 20%-30% exists in the form of magnetite.

4. The method of claim 1, wherein the method comprises: The mass ratio of the slowly cooled copper slag reconstructor to the copper smelting slag in step 1 is (0.24-0.4):

1.

5. The method of claim 1, wherein the method comprises: The temperature of the slowly cooled copper slag to be treated in step 1 is 1200° C.-1500° C.

6. The method of claim 1, wherein the method comprises: The magnetic separation intensity range in the magnetic separation recovery process described in step 3 is 0.15T-0.3T.

7. The method of claim 1, wherein the method comprises: The diameter of the copper slag after crushing, grinding and slow cooling in step 3 is 10 μm to 5 mm.

8. The method of claim 1 for reconstructing a slowly cooled copper slag phase coupled heat-mass cycle using limestone, FeS, and carbon powder, characterized in that: In the entire limestone-FeS-carbon powder reconstruction slow-cooling copper slag phase coupled heat-mass cycle method, the waste heat of the copper slag is stored through chemical reaction endothermicity, and the energy storage efficiency is calculated to be 50%-80%.

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