Smelting stage optimization method of double-furnace continuous copper smelting process

Abstract

The invention relates to the technical field of copper smelting processes, in particular to a smelting stage optimization method of a double-furnace continuous copper smelting process. The method comprises the following steps: firstly, determining the types of raw materials entering a furnace during smelting of the double-furnace continuous copper smelting process, further determining the existing forms of Cu and Fe, and obtaining the mass or proportion of materials entering the furnace through theoretical calculation; the thermodynamic influence law of different slag types, oxygen enrichment concentrations and smelting temperatures on the copper content in smelting slag is studied, the equilibrium distribution law of Cu and Fe in slag / matte / gas phases in different slag systems is explored, and under the condition that the appropriate slag amount, the high matte yield, the high Cu content in the matte phase, the low impurity Fe content and the low Cu content in the slag phase are guaranteed, the copper content in the slag phase is increased, and the copper content in the slag phase is increased. And determining smelting process parameters. According to the method, multi-element phase equilibrium calculation in the copper smelting stage is carried out for different raw materials entering the furnace, accurate smelting parameters can be obtained, and the method has the advantages of improving production efficiency, reducing cost, reducing environmental pollution, improving product quality, enhancing process control and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of copper smelting processes, and specifically relates to an optimization method for the smelting stage of a double-furnace continuous copper smelting process. Background Art

[0002] During the development of copper smelting processes, the efficiency of the smelting stage and environmental pollution have always been the focus of research. In current copper smelting technologies, although significant progress has been made, especially in terms of the thermal efficiency and raw material utilization rate during the smelting process, there are still certain limitations. These limitations are mainly reflected in high energy consumption, large amounts of pollutant emissions, and insufficient raw material conversion rate during the smelting process. In order to improve the production efficiency of copper and environmental sustainable development, it is particularly important to carry out balance calculations and optimization research for the smelting stage.

[0003] In this regard, by using advanced calculation models and optimization algorithms to perform thermodynamic multi-phase equilibrium calculations for the copper smelting stage, a more accurate ratio of raw materials and energy can be achieved, and then the smelting parameters can be optimized to reduce energy consumption and environmental pollution. In addition, this method also helps to improve the metal recovery rate and raw material utilization efficiency, providing technical support for the sustainable development of copper smelting processes.

[0004] Therefore, the research on thermodynamic equilibrium calculations and process optimization for the copper smelting stage can not only optimize the production process and reduce production costs, but also has important environmental protection significance, having a profound impact on promoting technological progress and environmental protection in the copper smelting industry. Technological innovation and breakthroughs in this field will play a key role in the sustainable development of the copper smelting industry. Summary of the Invention

[0005] In order to improve the thermal efficiency, metal recovery rate, and raw material utilization rate of the copper smelting stage, and reduce energy consumption and pollutant emissions, the present invention proposes an optimization method for the smelting stage of a double-furnace continuous copper smelting process, and the specific steps are as follows:

[0006] Step 1: Determine the type of copper ore in the furnace feed and the existing forms of Cu and Fe in the copper ore, and calculate the theoretical values or mass percentages of the masses of each substance for the furnace feed according to fixed values;

[0007] Step 2: Change the oxygen enrichment concentration within the range of 55% - 100%, and use the method of minimizing the Gibbs free energy of the entire system for equilibrium calculations. Analyze the equilibrium distribution of Cu and Fe in the slag phase / matte / gas three-phase under different oxygen enrichment concentrations, ensuring that the slag amount is not higher than 480 kg, the matte amount is not lower than 300 kg, the Cu content in the matte phase is not lower than 68%, the Fe content is not higher than 10%, the Cu content in the slag phase is not higher than 3%, and the Fe content is not lower than 45%, and select the oxygen enrichment concentration range C;

[0008] Step 3: Under the condition of a pressure of 110 - 130 kPa, change the smelting temperature within the range of 1060 °C - 1380 °C, and use the method of minimizing the Gibbs free energy of the whole system for equilibrium calculation. Analyze the equilibrium distribution of Cu and Fe in the three phases of slag / matte / gas at different smelting temperatures, ensuring that the slag amount is not higher than 410 kg, the matte amount is not lower than 300 kg, the Cu content in the matte phase is not lower than 73%, the Fe content is not higher than 6%, the Cu content in the slag phase is not higher than 8%, and the Fe content is not lower than 40%. Select the smelting temperature range T;

[0009] Step 4: Under the conditions of smelting temperature T, a pressure of 110 - 130 kPa, and an oxygen enrichment concentration of C, respectively change the mass ratios of the slag-making agents CaO, MgO, Al 2 O 3 during smelting and the iron-silicon ratio, and use the method of minimizing the Gibbs free energy of the whole system for equilibrium calculation to obtain the thermodynamic laws of different slag type systems. At the same time, analyze the equilibrium distribution of Cu and Fe in the three phases of slag / matte / gas in different slag type systems, ensuring that the slag amount is not higher than 400 kg, the Cu content in the matte phase is not lower than 74%, and the Fe content is not higher than 3.8%. Determine the mass ratio ranges of CaO, MgO, Al 2 O 3 and SiO 2 .

[0010] Furthermore, in Step 4, change the mass ratio of CaO within the range of 0.5% - 6% for equilibrium calculation, ensuring that the Cu content in the slag phase is not higher than 7% and the Fe content is not lower than 40%, and determine the mass ratio range of CaO.

[0011] Furthermore, in Step 4, change the mass ratio of MgO within the range of 0.5% - 4% for equilibrium calculation, ensuring that the Cu content in the slag phase is not higher than 14.5% and the Fe content is not lower than 40%, and determine the mass ratio range of MgO.

[0012] Furthermore, in Step 4, change the mass ratio of Al 2 O 3 within the range of 0% - 8% for equilibrium calculation, ensuring that the Cu content in the slag phase is not higher than 7% and the Fe content is not lower than 40%, and the amount of spinel in the slag phase does not exceed 100 kg, and determine the mass ratio range of Al 2 O 3 .

[0013] Furthermore, in Step 4, change Fe / SiO 2 within the range of 1.7 - 3.0 for equilibrium calculation, ensuring that the Cu content in the slag phase is not higher than 14% and the Fe content is not lower than 40%, and determine the value range of Fe / SiO 2 and SiO 2The mass percentage range.

[0014] Advantages of the present invention: For the double-furnace continuous copper smelting process, by studying the thermodynamic influence laws of different slag types, oxygen enrichment concentrations, smelting temperatures, etc. on the copper content in the smelting slag, and analyzing the equilibrium distribution laws of copper (Cu) and iron (Fe) in the three phases of slag / matte / gas, the smelting parameters such as temperature, oxygen enrichment concentration, and the mass percentage of slag-forming agent can be controlled more precisely. Through the optimization method, not only the metal recovery rate can be predicted, but also the generation of by-products and wastes can be predicted, making the process more controllable and predictable. By optimizing the slag type and smelting temperature, the extraction efficiency of copper can be maximized, the loss of copper in the molten slag can be reduced, the purity of the final product can be improved, and thus the conductivity and other important physical properties of the copper product can be improved, directly increasing the recovery rate of valuable metals and economic benefits. At the same time, more effective process control means that better production results can be achieved with lower energy consumption. Optimizing the smelting conditions can reduce energy waste and production costs, which is particularly important in high-energy-consuming smelting operations. In addition, using this method to determine the smelting conditions can also reduce the content of harmful element iron in the slag and reduce the environmental pressure of treating these waste slags. At the same time, the optimization process helps to reduce the emissions of harmful gases and other pollutants, meeting more stringent environmental protection standards.

[0015] In summary, for different furnace feedstocks, without going through cumbersome multiple tests, through the optimization method of the present invention, the smelting parameters can be precisely controlled, the metal recovery rate can be increased, waste generation can be reduced, making the copper smelting process more efficient, economical and environmentally friendly, while improving product quality and market competitiveness. Specific embodiments

[0016] In order to describe the purpose, technical solutions and advantages of the present invention more clearly and understandably, the following further details the present invention through specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0017] Example 1

[0018] Step 1: Determine the type of copper ore in the furnace feedstock and the existing forms of Cu and Fe in the copper ore, and then calculate the mass percentage of each substance in the furnace feedstock according to a fixed furnace charge.

[0019] The content of the furnace feedstock in the smelting stage of a smelter adopting the double-furnace continuous copper smelting process is: Cu 23%, Fe 27%, S 30%, SiO 2 10%, CaO 1.5%, MgO 1.5%, Al 2 O 3 2%. The furnace feedstock is mainly chalcopyrite, and the copper in chalcopyrite mainly exists in the form of CuFeS 2exists in the form of, and iron mainly exists as CuFeS 2 and Fe 3 O 4 exists in the form of, or the furnace charge is calculated theoretically according to the furnace charge of 1t to obtain the mass of compounds in the furnace charge, and the masses of CuFeS 2 、FeS 2 、Fe 3 O 4 、SiO 2 、CaO, MgO, Al 2 O 3 are obtained.

[0020] Step 2: Determine the oxygen enrichment concentration:

[0021] In the copper smelting and smelting stage, the increase in the oxygen enrichment concentration can improve the combustion rate. An appropriate combustion rate can increase the furnace temperature, promote the melting of copper ore and the separation of impurities. The combustion efficiency is higher in an oxygen-enriched environment. A higher oxygen concentration can make the fuel react more completely with oxygen, reducing fuel waste and flue gas emissions. By adjusting the oxygen enrichment concentration, the furnace temperature can be better controlled. A reasonable temperature can ensure the smooth progress of the smelting reaction, while avoiding adverse effects on the equipment caused by too high or too low temperatures.

[0022] Change the oxygen enrichment concentration within the range of 55% - 100%, and use the Equilib equilibrium calculation module of the thermodynamic software to perform equilibrium calculations on the smelting stage of continuous copper smelting in a double furnace, and analyze the distribution of Cu and Fe in the slag phase, matte phase and gas phase.

[0023] As the oxygen enrichment concentration increases, the amount of generated gas shows a stable upward trend, rising from a total of 347.64 kg to 570.94 kg;

[0024] There is no direct linear relationship with the slag amount. When the oxygen enrichment concentration increases from 55% to 65%, the slag amount drops from 817.25 kg to 455.54 kg. When the oxygen enrichment concentration increases from 65% to 80%, the generated slag amount increases from 455.54 kg to 504.68 kg. When the oxygen enrichment concentration increases from 80% to 90%, the slag amount drops from 504.68 kg to 434.6 kg. When the oxygen enrichment concentration increases from 90% to 100%, the generated slag amount increases from 434.6 kg to 610.72 kg.

[0025] When the oxygen enrichment concentration increases from 55% to 65%, the matte amount rapidly increases from 146.15 kg to 353.9 kg. When the oxygen enrichment concentration increases from 65% to 100%, the matte amount gradually decreases from 353.9 kg to 153.124 kg; When the oxygen enrichment concentration is between 80% - 95%, a small amount of spinel begins to form, and its generated amount also shows a trend of increasing first and then decreasing.

[0026] As the oxygen enrichment concentration increases from 55% to 100%, the Fe content in the smelting slag phase as a whole first increases and then decreases. When the oxygen enrichment concentration increases from 55% to 80%, the Fe content in the slag increases from 33.01% to 51.537%. When the oxygen enrichment concentration increases from 80% to 100%, the Fe content in the slag decreases from 51.537% to 43.776%. The Cu content in the slag shows a trend of first decreasing and then increasing. When the oxygen enrichment concentration increases from 55% to 65%, the Cu content gradually decreases from 28.016% to 1.92%. When the oxygen enrichment concentration increases from 65% to 85%, the Cu content slowly increases from 1.92% to 2.192%. When the oxygen enrichment concentration increases from 85% to 100%, the Cu content in the slag rapidly increases from 2.192% to 14.823%.

[0027] In the matte phase, the Cu content increases with the increase of the oxygen enrichment concentration, while the Fe and S contents both show a trend of first increasing and then decreasing with the increase of the oxygen enrichment concentration. When the oxygen enrichment concentration increases from 55% to 100%, no matte is formed when the oxygen enrichment concentration is 55%. When the oxygen enrichment concentration increases from 55% to 60%, the Cu content in the matte phase rapidly increases from 0% to 61.789%. When the oxygen enrichment concentration is 60% - 100%, the Cu content slowly increases from 61.789% to 78.27%. The Fe content increases from 0% to 13.77% and then slowly decreases to 2.01%. The S content increases from 0% to 24.441% and then decreases to 18.786%.

[0028] To ensure that the slag amount is not higher than 480 kg, the matte amount is not lower than 300 kg, the Cu content in the matte phase is not lower than 68%, the Fe content is not higher than 10%, the Cu content in the slag phase is not higher than 3%, and the Fe content is not lower than 45%, so as to ensure the high grade of matte and the reasonable distribution of Fe and Cu in the slag, and no excessive Cu enters the slag phase. The oxygen enrichment concentration is most suitable at about 82% - 87%. Although a high oxygen enrichment concentration can increase the matte grade, it will also increase the Cu entering the slag and reduce the amount of slag generated, which is not suitable for subsequent smelting.

[0029] Step 3: Determine the smelting temperature:

[0030] The smelting temperature in copper smelting has an important impact on the quality and yield of copper. The smelting temperature significantly affects the purification efficiency of copper. An ideal smelting temperature can help separate copper from impurities such as sulfur, iron, and other non-metallic impurities. If the temperature is too low, these impurities may not be completely separated, resulting in a decrease in the purity of copper. On the contrary, too high a temperature may lead to excessive oxidation of copper, which also affects the quality of the final product. Finding the optimal smelting temperature, which can effectively separate impurities and reduce energy consumption, is an important consideration in the smelting process. Under high-temperature conditions, the long-term operation of smelting equipment may accelerate the wear and aging of the equipment, thus affecting the equipment life and operation safety. Therefore, an appropriate smelting temperature can also help extend the equipment service life and reduce maintenance costs. An appropriate smelting temperature helps improve production efficiency. In short, the control of the smelting temperature in the copper smelting process is crucial for ensuring product quality, reducing production costs, extending equipment life, improving production efficiency, and reducing environmental pollution. In actual operation, by precisely controlling the smelting temperature, the production efficiency and product quality of copper can be effectively improved.

[0031] Under the condition of changing the smelting temperature in the range of 1060°C - 1380°C and a pressure of 120 kPa, the Equilib equilibrium calculation module of the thermodynamic software was used to perform equilibrium calculations on the smelting process of continuous copper smelting in a double furnace, and analyze the distribution of Cu and Fe in the slag phase, matte phase, and gas phase.

[0032] Analysis of the calculation results shows that the generated amounts of Cu and Fe in the gas phase are at the 10 -9 -level, so the contents of Cu and Fe in the gas phase are almost zero. As the smelting temperature increases, the amount of generated gas shows a stable upward trend, rising from a total of 486.42 kg to 502.62 kg; the amount of slag also increases with the increase of the smelting temperature. When the temperature rises from 1060°C to 1380°C, the amount of slag rises from 291.79 kg to 413.82 kg; with the increase of temperature, the amount of generated matte increases from 261.18 kg to 353.9 kg, and the generated amount of spinel decreases from 238.74 kg to 117.65 kg.

[0033] As the smelting temperature rises from 1060°C to 1380°C, the contents of Fe and Cu in the smelting slag phase both show an upward trend. With the increase of the smelting temperature, the Fe content in the slag gradually increases from 32.16% to 44.213%, and the Cu content in the slag slowly increases from 4.15% to 8.12%.

[0034] In the matte phase, the content of Cu increases with the increase of smelting temperature, while the content of Fe decreases with the increase of smelting temperature, and the content of S hardly changes. When the smelting temperature rises from 1060 °C to 1380 °C, the Cu content in the matte phase increases from 72.064% to 76.064%, the Fe content decreases from 8.041% to 4.0409%, and the S content remains at about 19.895%. The amount of matte produced increases with the increase of smelting temperature.

[0035] The smelting temperature has little effect on the distribution of Cu, Fe and S in the matte, but has a significant impact on the content of the phases produced by smelting and the distribution of Cu and Fe in the slag. Under the conditions of ensuring that the slag amount is not higher than 410 kg, the matte amount is not lower than 300 kg, the Cu content in the matte phase is not lower than 73%, the Fe content is not higher than 6%, the Cu content in the slag phase is not higher than 8%, and the Fe content is not lower than 40%, the smelting temperature is selected as 1320 °C - 1340 °C. At this time, the amount of spinel produced is lower, the amount of matte is higher, and the Cu and Fe contents entering the matte phase and the slag phase are within a reasonable range, which is suitable for production.

[0036] Step 4: Determine the content of slag-forming agent:

[0037] Adding an appropriate amount of slag-forming agent can reduce the copper content in the slag and improve the direct recovery rate of copper metal. Therefore, by changing the mass ratio of the slag-forming agent and using the Equilib equilibrium calculation module of the thermodynamic software to analyze the addition of slag-forming agents CaO, MgO, Al 2 O 3 and SiO 2 the distribution of Cu and Fe in the slag phase, matte phase and gas phase.

[0038] According to Steps 2 and 3, select the conditions of smelting temperature of 1340 °C, pressure of 120 kPa, and oxygen enrichment concentration of 82% - 86%.

[0039] (1) First, change the mass ratio of CaO to 0.5% - 6% and perform equilibrium calculations.

[0040] According to the calculation results, as the mass ratio of CaO increases, the amount of gas generated only has a slight decreasing trend, and the total amount is about 500 kg. The generated amounts of Cu and Fe in the gas phase are at the order of 10 -5 and 10 -9 level, so the contents of Cu and Fe in the gas phase are almost 0;

[0041] The slag amount mainly shows a trend of first decreasing and then increasing. When the mass fraction of CaO increases from 0.5% to 4.5%, the slag amount decreases from 447.24 kg to 338.26 kg. When the mass fraction of CaO is increased from 4.5% to 6% again, the slag amount increases to 348.31 kg.

[0042] The generation amounts of spinel and matte both increase with the increase of the mass fraction of CaO. Among them, the change trend of the spinel amount with the increase of the mass fraction of CaO is obvious.

[0043] With the increase of the mass fraction of CaO, both Cu and Fe in the slag phase show a downward trend, and the downward trend of Fe is particularly obvious. The content of Cu decreases from 7.48% to 4.64%, and the content of Fe decreases from 46.15% to 30.91%.

[0044] In the whole matte phase, the main existing elements are Cu, Fe, and S. Among them, the contents of Cu and S account for a larger proportion compared with Fe. However, the content of Cu in the matte phase decreases with the increase of the mass fraction of CaO, while the contents of Fe and S show a slow upward trend with the increase of the mass fraction of CaO. When the mass fraction of CaO increases from 0.5% to 6%, the content of Cu in the matte phase decreases from 75.063% to 72.09%, the content of S increases from 19.895% to 20.126%, and the content of Fe increases from 2.02% to 4.43%.

[0045] In order to ensure that the slag amount is not higher than 400 kg, the content of Cu in the matte phase is not lower than 74%, the content of Fe is not higher than 3.8%, the content of Cu in the slag phase is not higher than 7%, and the content of Fe is not lower than 40%, to ensure the grade of matte, the distribution of Fe and Cu in the slag is reasonable, and too much Cu will not enter the slag phase. Finally, the mass fraction of CaO is determined to be 1.1% - 1.5%. At the same time, since too high an amount of CaO added will increase the viscosity of the smelting slag and reduce the melt fluidity, a lower mass fraction of CaO can be selected within this range.

[0046] (2) Change the mass fraction of MgO to 0.5% - 4% and conduct multi-component phase equilibrium calculations.

[0047] Through the analysis of the calculation results, it can be seen that the generation amounts of Cu and Fe in the gas phase are at the 10 -9 level. Therefore, the contents of Cu and Fe in the gas phase are almost zero. With the increase of the mass fraction of MgO, the generated gas amount only shows a slight decreasing trend, and the total amount is about 500 kg; the slag amount shows an obvious downward trend. When the mass fraction of MgO increases from 0.5% to 4%, the slag amount decreases from 456.16 kg to 353.38 kg. The generation amounts of spinel and matte both increase with the increase of the mass fraction of MgO. Among them, the change trend of the spinel amount is obvious.

[0048] As the mass fraction of MgO increases from 0.5% to 4%, the Fe content in the generated smelting slag phase gradually decreases from 45.27% to 36.12%, and the Cu content gradually increases from 14.02% to 14.83%.

[0049] In the matte phase, the Cu content decreases with the increase of the MgO amount, while the Fe and S contents show a slow upward trend with the increase of the MgO amount. When the MgO amount increases from 0.5% to 4%, the Cu content in the matte phase decreases from 75.11% to 72.91%, the S content increases from 19.736% to 20.136%, and the Fe content increases from 2.77% to 4.02%.

[0050] To ensure that the slag amount is not higher than 400 kg, the Cu content in the matte phase is not lower than 74%, the Fe content is not higher than 3.8%, the Cu content in the slag phase is not higher than 14.5%, and the Fe content is not lower than 40%, so as to ensure the grade of the matte and the reasonable distribution of Fe and Cu in the slag, and prevent excessive Cu from entering the slag phase. Finally, it is determined that the mass fraction of MgO is in the range of 1.0% - 1.5%. In addition, if the added amount of MgO is too high, it will increase the melt viscosity, raise the melting point of the entire smelting slag, and reduce the melt fluidity, which is not suitable for subsequent smelting. A lower MgO amount can be selected within this range.

[0051] (3) Change the mass fraction of Al 2 O 3 to be 0% - 8% and conduct thermodynamic multi-phase equilibrium calculations.

[0052] Through the analysis of the calculation results, it is found that the contents of Cu and Fe in the generated gas phase are almost 0. As the amount of Al 2 O 3 increases, the amount of the generated gas shows a slight decreasing trend, with a total amount of about 500 kg; the slag amount shows an obvious downward trend. When the amount of Al 2 O 3 increases from 0% to 8%, the slag amount decreases from 510.81 kg to 345.56 kg. When the mass fraction of Al 2 O 3 increases from 0% to 4%, the generated slag amount decreases rapidly. When the mass fraction of Al 2 O 3 increases from 4% to 8%, the decrease of the generated slag amount is relatively slow.

[0053] The generation amounts of spinel and matte both increase with the increase of the mass fraction of Al 2 O 3 . Among them, the matte phase increases from 241.58 kg to 256.18 kg, and the generated spinel amount increases from 20.369 kg to 254.69 kg. When the mass fraction of Al 2 O3 When the mass fraction increases from 0% to 4.5%, the amount of spinel in the smelting slag generated increases significantly.

[0054] With the increase of Al 2 O 3 When the mass fraction increases from 0% to 8%, the Fe content in the slag phase gradually decreases, and the Cu content shows a slight upward trend. Among them, the Fe content decreases from 49.951% to 32.154%, and the Cu content gradually increases from 6.98% to 7.1824%.

[0055] In the matte phase, the Cu content increases slowly with the increase of the mass fraction of Al 2 O 3 The Fe and S contents show a slow downward trend with the increase of the mass fraction of Al 2 O 3 In the matte phase, the Cu content increases from 72.02% to 75.48%, the S content decreases from 20.198% to 19.829%, and the Fe content decreases from 4.056% to 2.321%.

[0056] To ensure that the slag amount is not higher than 400 kg, the Cu content in the matte phase is not lower than 74%, the Fe content is not higher than 3.8%, the Cu content in the slag phase is not higher than 7%, and the Fe content is not lower than 40%, so as to make the generated slag and matte within a suitable range, ensure the high grade of matte, and the distribution of Fe and Cu in the slag is reasonable, and prevent too much Cu from entering the slag phase. Finally, it is determined that the mass fraction of Al 2 O 3 is 1.7% - 2.0%, and the maximum cannot exceed 2%. If it is greater than 2%, the amount of spinel generated will exceed 100 kg, the slag amount will decrease, and it is not suitable for production. Moreover, if the added amount of Al 2 O 3 is too high, it will also increase the melt viscosity and reduce the melt fluidity, which is not suitable for subsequent smelting.

[0057] (4) When changing Fe / SiO 2 to 1.7 - 3.0, perform thermodynamic multi-phase equilibrium calculations.

[0058] According to the calculation results, the generated amounts of Cu and Fe in the gas phase are at the order of 10 -9 . Therefore, the contents of Cu and Fe in the generated gas phase are almost 0. With the increase of the iron-silicon ratio, the amount of generated gas only shows a slight decreasing trend, and the total amount is about 500 kg; the slag amount shows an obvious downward trend. When the iron-silicon ratio increases from 1.7 to 3.0, the slag amount decreases from 617.18 kg to 359.2 kg. When the iron-silicon ratio increases from 2.0 to 3.0, the generated slag amount decreases rapidly. Among them, when the iron-silicon ratio increases from 1.7 to 2.0, the decrease of the generated slag amount is relatively slow.

[0059] The production amounts of spinel and matte both increase with the increase of the Fe / SiO₂ ratio. The amount of matte phase increases from 229 kg to 255 kg, and the amount of spinel produced increases from 0 kg to 173 kg. When the Fe / SiO₂ ratio increases from 1.7 to 2.0, the amount of spinel in the smelting slag produced is almost 0. When the Fe / SiO₂ ratio increases from 2 to 2.7, the amount of spinel in the smelting slag produced increases rapidly.

[0060] As the Fe / SiO₂ ratio increases from 1.7 to 3.0, the Fe content in the smelting slag gradually increases, and the Cu content also shows a slight upward trend. Among them, the Fe content increases from 40.13% to 43.12%, and the Cu content gradually increases from 13.81% to 14.38%.

[0061] In the matte phase, the contents of Cu and Fe increase with the increase of the Fe / SiO₂ ratio. Among them, the S content has a slight change trend of increasing first and then decreasing. The S content in the matte phase increases from 19.885% to 19.896% and then decreases to 19.894%. The Cu content increases from 72.078% to 74.965%, and the Fe content increases from 3.69% to 4.07%.

[0062] To ensure that the slag amount is not higher than 400 kg, the Cu content in the matte phase is not lower than 74%, the Fe content is not higher than 3.8%, the Cu content in the slag phase is not higher than 14%, and the Fe content is not lower than 40%, so as to make the produced slag, matte and spinel within a suitable range, ensure the high grade of matte, and the Fe and Cu in the slag are reasonably distributed, and there is no excessive Cu entering the slag phase. Finally, it is determined that Fe / SiO₂ 2 is 2.3 - 2.5. According to the Fe content in the raw materials during smelting, the addition amount of SiO₂ 2 is changed, and then the Fe / SiO₂ ratio is regulated. The Fe / SiO₂ ratio being too low is not feasible because when the Fe / SiO₂ ratio is low, that is, the added amount of SiO₂ 2 is large, when it is similar to the Fe content, too much SiO₂ 2 will corrode the furnace lining, reduce the furnace lining life, and is not suitable for subsequent smelting.

[0063] To sum up, for the types and element contents of the furnace charge in this embodiment, the specific optimized process parameters for smelting obtained by using this method are: the oxygen enrichment concentration is 82% - 87%; the smelting temperature is 1320 °C - 1340 °C; the mass ratio of CaO is 1.1% - 1.5%; MgO is 1.0% - 1.5%; Al 2 O 3 is 1.7% - 2.0%; Fe / SiO₂ 2 is 2.3 - 2.5.

[0064] To further verify the optimized results in the smelting stage, apply them to actual smelting, and comprehensively analyze by combining the simulation calculation results with actual smelting.

[0065] The smelting parameters selected within the optimized range and the matte grade obtained by smelting are listed in the following table to prove the feasibility of the optimized slag type obtained by this method. The table is as follows:

[0066] The following smelting conditions are the results obtained in the smelting stage when the smelting temperature is 1340 °C, 120 kPa, and the oxygen enrichment concentration is 84%:

[0067]

[0068] Some exemplary embodiments of the present invention have been described above. It can be understood that the above embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention. The features in these embodiments can be recombined in a suitable manner, and the solutions obtained thereby are still within the protection scope required by the present invention. Based on the above embodiments, all other embodiments obtained by those skilled in the art without creative efforts, that is, all modifications, equivalent replacements, and improvements made within the spirit and principle of this application, fall within the protection scope required by the present invention.

Claims

1. A method for optimizing the smelting stage of a dual-furnace continuous copper smelting process, characterized in that: The following steps are involved: Step 1: Determine the type of copper ore of the raw materials entering the furnace, as well as the existence forms of Cu and Fe in the copper ore, and calculate the theoretical value or mass proportion of each substance in the raw materials entering the furnace according to fixed values; Step 2: Change the oxygen enrichment concentration within the range of 55%-100%, use the method of minimizing the Gibbs free energy of the entire system to perform equilibrium calculations, analyze the equilibrium distribution of Cu and Fe in the slag phase / matte / gas phases under different oxygen enrichment concentrations, ensure that the slag amount is not higher than 480kg, the matte amount is not less than 300kg, the Cu content in the matte phase is not less than 68%, the Fe content is not more than 10%, the Cu content in the slag phase is not more than 3%, and the Fe content is not less than 45%, and select the oxygen enrichment concentration range C; Step 3: Under the condition of a pressure of 110-130 kPa, the smelting temperature is changed within the range of 1060°C-1380°C, and the method of minimizing the Gibbs free energy of the entire system is used for equilibrium calculation, and the equilibrium distribution of Cu and Fe in the slag phase / matte / gas at different smelting temperatures is analyzed to ensure that the slag amount is not higher than 410 kg, the matte amount is not less than 300 kg, the Cu content in the matte phase is not less than 73%, the Fe content is not more than 6%, the Cu content in the slag phase is not more than 8%, and the Fe content is not less than 40%, and the smelting temperature range T is selected; Step 4: Under the conditions of smelting temperature T, pressure of 110-130kPa, and oxygen enrichment concentration of C, the mass proportions of slag-forming agents CaO, MgO, and Al2O3 and the iron-silicon ratio during smelting are changed respectively, and the equilibrium calculation is performed using the method of minimizing the Gibbs free energy of the entire system to obtain the thermodynamic laws of different slag types. At the same time, the equilibrium distribution of Cu and Fe in the slag phase / matte / gas in different slag types is analyzed to ensure that the slag amount is not higher than 400kg, the Cu content in the matte phase is not lower than 74%, and the Fe content is not higher than 3.8%, and the mass proportion ranges of CaO, MgO, Al2O3, and SiO2 are determined.

2. The method for optimizing the smelting stage of a dual-furnace continuous copper smelting process according to claim 1, characterized in that: In step 4, the mass percentage of CaO is changed within the range of 0.5%-6% to perform a balance calculation to ensure that the Cu content in the slag phase is not higher than 7% and the Fe content is not lower than 40%, thereby determining the mass percentage range of CaO.

3. The method for optimizing the smelting stage of a dual-furnace continuous copper smelting process according to claim 1, characterized in that: In step 4, the mass percentage of MgO is changed within the range of 0.5%-4% to perform a balance calculation to ensure that the Cu content in the slag phase is not higher than 14.5%, and the Fe content is not lower than 40%, and the mass percentage range of MgO is determined.

4. The method for optimizing the smelting stage of a dual-furnace continuous copper smelting process according to claim 1, characterized in that: In step 4, the mass proportion of Al2O3 is changed within the range of 0%-8% for balance calculation to ensure that the Cu content in the slag phase is not higher than 7%, the Fe content is not lower than 40%, the amount of spinel in the slag phase does not exceed 100kg, and the mass proportion range of Al2O3 is determined.

5. The method for optimizing the smelting stage of a dual-furnace continuous copper smelting process according to claim 1, characterized in that: In step 4, Fe / SiO2 is changed within the range of 1.7-3.0 for equilibrium calculation to ensure that the Cu content in the slag phase is not higher than 14% and the Fe content is not lower than 40%, and the value range of Fe / SiO2 and the mass proportion range of SiO2 are determined.

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