Slag type optimization method for double-furnace continuous copper smelting process

Abstract

The invention relates to the technical field of copper smelting slag type optimization, in particular to a slag type optimization method for a double-furnace continuous copper smelting process. The method comprises the following steps: firstly, determining main slag types of the smelting slag and the converting slag according to the contents of main components of the smelting and converting slag, then calculating the viscosity of a slag system by regulating the amount of a slag former, drawing a slag system isotherm phase diagram by taking one of CaO, SiO2, MgO and Al2O3 in the smelting slag as a fixed amount or taking one of CaO and SiO2 in the converting slag as a fixed amount, and calculating the viscosity of the slag system according to the isotherm phase diagram. And finally, a result obtained through theoretical calculation and actual production are combined for analysis, and the slag type optimization method is obtained. Smelting and blowing processes of a double-furnace continuous copper smelting process are studied, simulation calculation and reality are effectively combined, slag has the advantages of being good in fluidity, high in copper direct recovery rate, high in yield, high in benefit and the like according to slag type components obtained through the method, and the production cost is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of copper smelting slag type optimization, and in particular to a slag type optimization method for a double-furnace continuous copper smelting process. Background Art

[0002] Slag making is an important link in copper smelting. Slag making refers to converting oxidative impurities such as oxides and sulfides of metallic copper into easily separable slag so as to separate copper from the slag. Slag making can not only improve the yield and smelting efficiency of copper, but also prevent unnecessary oxidation or volatilization losses during the smelting process, and protect the furnace body and reduce environmental pollution. By reasonably adjusting the copper slag components during smelting and blowing, and optimizing the slag type of smelting slag and blowing slag, the content of valuable metals in the slag can be reduced, thereby significantly improving the recovery rate of valuable metals such as copper, and also reducing the content of impurities such as arsenic and lead in the smelting process, thereby improving the purity and quality of the final copper product; at the same time, optimizing the slag type also helps to reduce energy consumption and emissions during the smelting process: reasonable slag type can reduce fuel consumption during the smelting process, while reducing the emission of harmful gases and dust, which is of great significance to environmental protection; in addition, by optimizing the slag type, the fluidity and separability of the smelting process can be improved, thereby accelerating the smelting process and improving production efficiency. The optimized slag can become a valuable resource in other industrial fields, realizing the recycling of resources.

[0003] At present, the copper concentrate smelting processes in operation in my country include flash smelting, oxygen bottom blowing smelting, oxygen-enriched double-side blowing smelting, silver method smelting, and TSL smelting; the copper matte blowing processes in operation include PS furnace blowing, flash blowing, oxygen bottom blowing, and multi-gun top blowing. The top-side blowing double-furnace continuous copper smelting process is a type of copper smelting process. From research and development to actual production application, this copper smelting process and smelting furnace have achieved the advantages of low energy consumption, low investment, low smoke rate, low copper content in blowing slag, low sulfur content in crude copper, high direct recovery rate, high yield and high efficiency for many years. Therefore, it is very important to optimize the slag shape of the smelting slag in the production of the top-side blowing double-furnace continuous copper smelting process. Summary of the invention

[0004] In order to make the smelting and blowing in the double-furnace continuous copper smelting process have better slag shape, reduce the copper entering the slag phase, and improve the direct recovery rate of copper, the present invention makes full use of the combination of thermodynamic calculation simulation and actual production, studies the thermodynamic influence of different slag-forming agents on the slag during the smelting and blowing processes in the double-furnace continuous copper smelting process under different process conditions, and proposes a slag shape optimization method for the double-furnace continuous copper smelting process.

[0005] A slag type optimization method for a double-furnace continuous copper smelting process comprises the following steps:

[0006] Step 1: According to the percentage of each component in the smelting slag or the blowing slag, determine the main quaternary slag type existing during smelting (i.e., smelting) or blowing under the composition;

[0007] Step 2: Calculate the viscosity of the smelting system or blowing system by changing the CaO, SiO 2 、MgO、Al 2 O 3 The mass proportion of the components and the melting temperature are such that the viscosity of the smelting slag is greater than 0.09Pa·s and less than or equal to 0.13Pa·s at the actual melting temperature ±10℃. Under this condition, the range of the smelting slag type is preliminarily determined; or the SiO2 content in the blowing slag system is changed. 2 , the mass proportion of CaO components and the blowing temperature, so that when the actual blowing temperature is ±10°C, the viscosity of the blowing slag is greater than 0.015Pa·s and less than or equal to 0.03Pa·s. Under this condition, the blowing slag type range is preliminarily determined;

[0008] Step 3: Separately mix CaO and SiO 2 、MgO、Al 2 O 3 The content of one of them is used as a quantitative measure to draw a quaternary isotherm projection phase diagram of the smelting slag system, or to separate SiO 2 ,CaO,Fe 3 O 4 The content of one of them is taken as a quantitative value to draw a quaternary isotherm projection phase diagram of the blowing slag system, and the smelting slag type or the blowing slag type range closest to or located in the slag liquid phase zone at the actual smelting temperature ±10°C or the actual blowing temperature ±10°C is obtained in the phase diagram.

[0009] Furthermore, in step 2, the viscosity of the smelting system or the blowing system is calculated using the Viscosity module of the FactSage thermodynamic software.

[0010] Furthermore, in step 2, the melting temperature or the blowing temperature is changed within the range of 1200°C-1400°C.

[0011] Furthermore, the temperature conditions for drawing the quaternary isotherm projection phase diagram in step 3 are 1000° C.-1600° C. and the pressure is 1.0-3.3 atm.

[0012] Furthermore, in step 3, the pressure condition for drawing the quaternary isotherm projection phase diagram of the smelting slag system is 1.0 atm, and the pressure condition for drawing the blowing slag system is 3.207 atm.

[0013] Furthermore, in the step 3, the smelting slag type is obtained under the condition of 1350±10°C in the quaternary isotherm projection phase diagram of the smelting slag system, and the blowing slag type is obtained under the condition of 1280±10°C in the quaternary isotherm projection phase diagram of the blowing slag system.

[0014] Furthermore, the smelting slag type range finally determined in step 3 is: CaO: 2.48%-3%, SiO 2 :19.5%-22%, MgO: 1.50%-1.75%, Al 2 O 3 :4.48%-5.0%,Fe / SiO 2 :1.95-2.2.

[0015] Furthermore, the blowing slag type range finally determined in step 3 is: CaO: 8.5%-9.5%, SiO 2 :1.37%-2.5%, Fe / CaO: 1.88-2.38.

[0016] The beneficial effects of the present invention are as follows: a thermodynamic study is conducted on the smelting slag and blowing slag in the top-side blowing double-furnace continuous copper smelting process. First, the viscosity of the slag system is calculated to ensure that its viscosity is within a reasonable range, and then the isotherm phase diagrams of the slag system are drawn separately, and finally the slag type range under the actual production temperature and pressure is determined to obtain the final optimized slag type. The present invention combines theory with production practice, reasonably adjusts the copper slag components during smelting and blowing, optimizes the slag type of smelting slag and blowing slag, can maximize the efficiency of copper smelting and product quality, and reduce environmental pollution. In addition, the method of the present invention is universal to the double-furnace continuous copper smelting process, and can obtain the optimized slag type composition without complicated experimental speculation, which is of great significance to the improvement of subsequent copper smelting processes and scientific and technological development. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The embodiments of the present invention are further described below with reference to the accompanying drawings, in which:

[0018] Figure 1 The MgO-SiO 2 -Al 2 O 3 -2.5%CaO isothermal liquidus projection diagram;

[0019] Figure 2 The CaO-SiO 2 -Al 2 O 3 -1.5%MgO isothermal liquidus projection diagram;

[0020] Figure 3 The CaO-MgO-SiO 2 -4.5%Al 2 O 3 Isothermal liquidus projection diagram;

[0021] Figure 4 The CaO-MgO-Al 2 O 3 -22%SiO 2 Isothermal liquidus projection diagram;

[0022] Figure 5 It shows that Fe in Example 2 3 O 4 -Cu 2 O-CaO-1.5%SiO 2 Isothermal liquidus projection diagram;

[0023] Figure 6 It shows that Fe in Example 2 3 O 4 -Cu 2 O-SiO 2 -8.5%CaO isothermal liquidus projection diagram;

[0024] Figure 7 It shows that the Cu 2 O-SiO 2 -CaO-24.7%Fe 3 O 4 Isothermal liquidus projection diagram. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly described, the present invention is further described in detail by specific embodiments in conjunction with the accompanying drawings. 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.

[0026] Example 1

[0027] Step 1: The main components of the smelting slag produced by a smelter using a top-side-blowing double-furnace continuous copper smelting process are: Fe 43%, SiO 2 22%, CaO 2.5%, MgO 1.5%, Al 2 O 3 4.5%, Cu 2.4%, S 0.5%, Pb 0.2%, Zn 1.25%, the smelting slag type is determined to be CaO-MgO-SiO 2 -Al 2 O 3 Quaternary slag type.

[0028] Step 2: Based on the provided smelting slag composition, the Viscosity module of FactSage thermodynamic software is used to calculate the smelting slag viscosity to study the effect of different slag-forming agent amounts on slag viscosity. In the double-furnace continuous copper smelting process, slag viscosity is an important parameter, which has a significant impact on the efficiency of copper smelting, metal recovery rate and the quality of the final product. The viscosity of the slag directly affects the separation efficiency of metal and slag, the efficiency of oxidation in the furnace, the transfer of heat in the furnace, and the stability of the smelting process. Therefore, in actual operation, accurately controlling the slag composition and temperature during the smelting process to adjust the viscosity of the slag is a key step in optimizing production efficiency and improving product quality.

[0029] (1) The mass proportion of CaO in the smelting slag was changed, and the viscosity of the smelting slag was calculated using FactSage software when the smelting temperature was 1200℃, 1250℃, 1300℃, 1350℃, and 1400℃, and the CaO content in the smelting slag was 2%, 2.5%, 3%, 3.5%, 4%, and 4.5%. When the mass proportion of CaO remained unchanged, the viscosity of the smelting slag gradually decreased with the increase of temperature. When the mass proportion of CaO was 2.5%, the viscosity of the smelting slag decreased from 0.29Pa·s to 0.101Pa·s when the temperature increased from 1200℃ to 1400℃, and the viscosity of the smelting slag was 0.128Pa·s at 1350℃; when the temperature remained unchanged, the viscosity of the smelting slag gradually decreased with the increase of the mass proportion of CaO. Therefore, in order to make the viscosity of the smelting slag greater than 0.09 Pa·s and less than or equal to 0.13 Pa·s within the range of 1350°C±10°C, the amount of CaO in the smelting slag is 2%-3%.

[0030] (2) The mass proportion of MgO in the smelting slag was changed, and the viscosity of the smelting slag was calculated using FactSage software when the smelting temperature was 1200℃, 1250℃, 1300℃, 1350℃, and 1400℃, and the MgO content in the smelting slag was 1%, 1.5%, 2%, 2.5%, 3%, and 3.5%. As the mass proportion of MgO increased, the viscosity of the smelting slag gradually decreased, and as the temperature increased, the viscosity of the smelting slag also decreased significantly. At 1200℃, the maximum viscosity was 0.3Pa·s, and at a temperature of 1400℃, the minimum viscosity was about 0.08Pa·s. Combined with the actual smelting temperature of 1350℃, as the mass proportion of MgO increased, the viscosity decreased from 0.132Pa·s to 0.118Pa·s. Therefore, in order to make the viscosity of the smelting slag greater than 0.09 Pa·s and less than or equal to 0.13 Pa·s within the range of 1350°C±10°C, the amount of MgO in the smelting slag is 1.5%-3.5%.

[0031] (3) Change the Al content in smelting slag 2 O 3The mass proportion of Al in the smelting slag was calculated using FactSage thermodynamic software at smelting temperatures of 1200℃, 1250℃, 1300℃, 1350℃, and 1400℃. 2 O 3 The viscosity of the smelting slag when the content is 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, and 6.0%. When the smelting temperature remains unchanged, as Al 2 O 3 As the mass ratio increases, the viscosity of the smelting slag gradually increases. 2 O 3 When the mass ratio remains unchanged, the viscosity of the smelting slag gradually decreases with the increase of the smelting temperature. At 1200℃, the maximum viscosity is 0.34Pa·s, and at 1400℃, the minimum viscosity is about 0.088Pa·s. 2 O 3 As the mass ratio increases, the viscosity increases from 0.111 Pa·s to 0.149 Pa·s. 2 O 3 When the mass ratio is 4.5%, the viscosity of the slag is 0.128Pa·s. Therefore, in order to make the viscosity of the slag greater than 0.09Pa·s and less than or equal to 0.13Pa·s within the range of 1350℃±10℃, the Al content in the slag should be 2 O 3 The amount is 4.0%-5.0%.

[0032] According to actual production experience, Al 2 O 3 The amount of slag should not be too much, as too much will lead to excessive viscosity of the smelting slag, thereby reducing the fluidity of the slag. 4.0%-5.0% is in the appropriate range. Whether it is smelting slag or blowing slag, excessive viscosity may cause process instability, energy waste, reduced smelting effect, equipment damage and other problems.

[0033] (4) Changing the iron-silicon ratio in the smelting slag, the iron-silicon ratio (Fe / SiO) of the smelting slag at smelting temperatures of 1200°C, 1250°C, 1300°C, 1350°C, and 1400°C was calculated using FactSage thermodynamic software. 2) is 2.69, 2.39, 2.15, 1.96, 1.79, and 1.65. When the smelting temperature remains unchanged, the viscosity of the smelting slag gradually decreases with the increase of the iron-silicon ratio. When the iron-silicon ratio remains unchanged, the viscosity of the smelting slag gradually decreases with the increase of the smelting temperature. When the iron-silicon ratio is about 2.0, the viscosity of the smelting slag decreases from 0.3Pa·s to about 0.1Pa·s with the increase of temperature. When the smelting temperature is 1200℃, with the increase of the iron-silicon ratio, the viscosity decreases from 0.48Pa·s to about 0.143Pa·s. Combined with the actual smelting temperature of about 1350℃, with the increase of the iron-silicon ratio, the viscosity gradually decreases from 0.3Pa·s to 0.07Pa·s. When the iron-silicon ratio is 1.96, the viscosity is 0.128Pa·s. Therefore, in order to make the viscosity of the smelting slag greater than 0.09 Pa·s and less than or equal to 0.13 Pa·s within the range of 1350°C±10°C, the iron-silicon ratio in the smelting slag is 2.0±0.20.

[0034] Step 3: Study the effects of different temperatures and different slag component contents on smelting slag, and fix CaO, MgO, SiO 2 、Al 2 O 3 The content of CaO-MgO-SiO is plotted at a temperature of 1000℃-1600℃ and a pressure of 1atm. 2 -Al 2 O 3 Phase diagram of quaternary slag system.

[0035] (1) Figure 1 As shown, CaO is fixed at 2.5% (the overall proportion in the smelting slag), and 2.5% CaO-MgO-SiO is plotted. 2 -Al 2 O 3 The quaternary slag phase diagram shows that as the smelting temperature continues to rise, the slag-liquid phase area continues to expand. According to the actual production smelting temperature of 1350°C, after fixing CaO at 2.5%, the composition of the remaining slag components closest to or located in the slag-liquid phase area as shown in the phase diagram is: MgO: 4.54%, Al 2 O 3 :23.16%,SiO 2 :72.29%, therefore, the content of copper concentrate smelting slag components is converted into: CaO:2.5%, MgO:1.27%, SiO 2 :20.24%、Al 2 O 3 :6.48%, iron-silicon ratio is 2.12.

[0036] (2) Figure 2As shown, the MgO content is fixed at 1.5%, and the CaO-1.5%MgO-SiO 2 -Al 2 O 3 The quaternary slag phase diagram shows that the phases in the slag system are oxide phase, slag liquid phase, protopyroxene phase, spinel phase, olivine phase and mullite phase. The initial melting point of the slag system is 1197.80℃. As the smelting temperature continues to rise, the slag liquid phase area continues to expand. The smelting temperature in actual production is 1350℃. At this time, according to the phase diagram, the composition of the remaining components of the slag system closest to or located in the slag liquid phase area is: CaO: 10.89%, Al 2 O 3 :24.25%,SiO 2 :64.85%, therefore, the content of copper concentrate smelting slag components is: CaO:3.16%, MgO:1.5%, SiO 2 :18.8%、Al 2 O 3 :7.03%, iron-silicon ratio is 2.29.

[0037] (3) Figure 3 As shown, fixed Al 2 O 3 The content is 4.5%, and the CaO-MgO-SiO 2 -4.5%Al 2 O 3 Phase diagram of quaternary slag system. The phases in the slag system are oxide phase, slag liquid phase, protopyroxene phase, spinel phase, olivine phase and mullite phase. The initial melting point of the slag system is 1224.28℃. The slag composition at this time is: CaO: 16.97%, MgO: 11.26%, SiO 2 :71.77%, therefore, the content of copper concentrate smelting slag components is: CaO:4.41%, MgO:2.93%, SiO 2 :18.66%、Al 2 O 3 :4.5%, iron-silicon ratio is 2.3. With the continuous increase of smelting temperature, the slag liquid phase area is constantly expanding. Combined with the actual production smelting temperature of 1350℃, fixed Al 2 O 3 The content is 4.5%. At this time, according to the phase diagram, the composition of the remaining components of the slag system closest to or located in the slag liquid phase area is: CaO: 8.15%, MgO: 5.75%, SiO 2 :71.4%、Al 2 O 3 :14.7%, therefore, the content of copper concentrate smelting slag components converted to actual smelting is: CaO:2.48%, MgO:1.75%, SiO2 :21.77%、Al 2 O 3 :4.48%, iron-silicon ratio is 1.98.

[0038] (4) Figure 4 As shown, fixed SiO 2 When the content is 22%, CaO-MgO-22%SiO is drawn. 2 -Al 2 O 3 According to the quaternary slag phase diagram, the phases in the slag system are oxide phase, slag liquid phase and mullite phase. As the smelting temperature continues to rise, the slag liquid phase area continues to expand. The smelting temperature in actual production is 1350℃. At this time, according to the phase diagram, the composition of the remaining components of the slag system closest to or located in the slag liquid phase area is: CaO: 8.15%, MgO: 5.05%, Al 2 O 3 :14.7%,SiO 2 :72.10%, therefore, the content of copper concentrate smelting slag components is: CaO:2.49%, MgO:1.54%, SiO 2 :22%、Al 2 O 3 :4.48%, iron-silicon ratio is 1.95.

[0039] From the above drawings, it can be seen that in the entire smelting slag quaternary slag system, SiO 2 It is the main slag-forming agent, SiO 2 It is an acidic oxide. If SiO 2 If the content is too low, the slag will be alkaline and the fluidity of the slag will be poor. 2 If the content is too high, it will corrode the smelting furnace and reduce the life of the furnace.

[0040] According to the phase diagram analysis of (1)-(4) above, in order to make the smelting slag have good fluidity and a large dominant area of ​​slag liquid phase, at a smelting temperature of 1350°C, the optimized smelting slag is CaO: 2.48%-3.16%; MgO: 1.27%-1.75%; SiO 2 :18.8%-22.0%;Al 2 O 3 : 4.48%-7.03%, iron-silicon ratio: 1.95-2.29.

[0041] Combined with the viscosity optimization slag type in step 2, the final optimized slag type of smelting slag is obtained: CaO: 2.48%-3.0%; MgO: 1.5%-1.75%; SiO 2 :19.5%-22.0%;Al 2 O 3: 4.48%-5.0%, iron-silicon ratio: 1.95-2.2.

[0042] In actual production experience, since the smelting slag is SiO 2 Acidic slag with high content, the main slag system is CaO-MgO-SiO 2 -Al 2 O 3 The melting temperature of the quaternary slag system smelting slag varies with the content of CaO, SiO 2 , MgO and Al 2 O 3 The content of MgO is most suitable when it is less than 5%. 2 O 3 When the content exceeds 9%-10%, the melting point of the slag will increase sharply. The viscosity of the slag decreases with the increase of the mass proportion of CaO and MgO. 2 O 3 、SiO 2 The optimized smelting slag type obtained by the method of the present invention conforms to the slag type range in actual production experience.

[0043] In order to further verify the obtained optimal slag shape control value and apply it to actual smelting, the simulation calculation results are comprehensively analyzed with the actual smelting results.

[0044] Table 1 lists the grades of matte and blister copper smelted within the mass proportion range of the slag-forming agent optimized by the smelting slag, to prove that the optimized slag type obtained by this method is feasible. The table is as follows:

[0045] Table 1 Main components of smelting slag and grade of smelted copper matte

[0046]

[0047] It can be seen from Table 1 that under the optimized slag ratio obtained by this method, the matte obtained by smelting has a higher grade, a higher copper recovery rate and a lower impurity content.

[0048] Example 2

[0049] Step 1: The main components of the slag from a smelter using a top-side-blowing double-furnace continuous copper smelting process are: Cu 2 O34%, CaO8.5%, Fe 24.7%, SiO 2 1.5%, Pb 1.4%, Zn 1.1%, MgO 0.2%, Al 2 O 3 0.4%, where Fe represents the iron content, with Fe 3 O 4 The slag type is Fe3 O 4 -Cu 2 O-CaO-SiO 2 .

[0050] The blowing process plays a key role in separation and extraction in copper smelting. It helps to remove impurities, regulate metal composition, improve smelting speed and efficiency, and ultimately produce copper metal products with higher purity. The main factors that have a greater impact on blowing slag and subsequent smelting are SiO 2 content, iron-calcium ratio (Fe / CaO), and the oxides FeO and Fe formed by iron in blowing slag 3 O 4 The content is particularly important. Because in the whole blowing slag, Fe 3 O 4 The content of is generally high, which will make the blowing slag roughly calcium ferrite slag type (Fe 3 O 4 -Cu 2 O-CaO-SiO 2 ), and the role of FeO is to react with SiO 2 For slag making, if SiO is added 2 If the content is insufficient, some FeO and SiO 2 It is impossible to form slag and will continue to be oxidized into high melting point Fe 3 O 4 The magnetite slag is generated. If it is slightly overblown, it will form copper ferrite with a lower melting point and better fluidity, which will increase the copper content of the slag and SiO 2 Too much will also deteriorate the slag shape and increase viscosity. In addition, inaccurate judgment of the blowing end point will also cause the melt to be overblown, thereby causing Cu 2 The content of O increases, which greatly increases the copper content in the slag. Therefore, slag shape control is the prerequisite for stable blowing furnace conditions and subsequent smelting. 3 O 4 -Cu 2 O-CaO-SiO 2 The study of quaternary slag system is of vital importance.

[0051] Step 2: Based on the provided blowing slag composition, the viscosity of the blowing slag is calculated using the Viscosity module of the FactSage thermodynamic software to study the effect of different slag-making dosages on the slag viscosity. It is crucial to study the effect of slag viscosity in the blowing process. The viscosity of the slag has a direct impact on its ability to absorb impurities. Slag with lower viscosity is easier to flow and can more effectively absorb and carry away impurities in the copper liquid, such as iron and sulfur. On the contrary, slag with high viscosity has poor fluidity and is difficult to fully contact the copper liquid, affecting the efficiency of impurity removal. The viscosity of the slag also affects the energy consumption of the entire blowing process. Low-viscosity slag is easy to flow and discharge, thereby reducing the energy required in the smelting process, while high-viscosity slag requires more energy to maintain its fluid state, thereby increasing energy consumption. Energy consumption is directly related to production costs and is an important consideration in the smelting process. In addition, the loss of copper in the slag is also related to the viscosity of the slag. Slag with lower viscosity can more effectively wrap and carry copper particles out of the furnace, reducing copper losses, while slag with high viscosity may cause more copper to be contained in the slag, thereby increasing copper losses. The sticky slag may also cause faster wear of the stirring device and other parts in contact with the molten material. The slag viscosity has an indirect effect on the purity and microstructure of copper. If the slag is not handled properly, it may cause more impurities to remain in the copper product, thereby affecting the electrical conductivity and mechanical properties of copper. Therefore, this method optimizes the slag type of the blowing slag based on the influence of the viscosity of the blowing slag.

[0052] (1) By changing the SiO content in blowing slag 2 The mass proportion of SiO in the blowing slag was calculated by using FactSage thermodynamic software at blowing temperatures of 1200℃, 1240℃, 1280℃, and 1320℃. 2 The viscosity of the blowing slag when the content is 1%, 1.5%, 2%, 2.5%, and 3%. The analysis and calculation results show that when the blowing temperature remains unchanged, as the SiO 2 As the SiO 2 When the mass proportion of SiO2 remains unchanged, the viscosity of the blowing slag gradually decreases with the increase of blowing temperature. 2 When the blowing slag is 1.5%, with the increase of temperature, the viscosity of the blowing slag gradually decreases from 0.04Pa·s to 0.02Pa·s, and the viscosity of the blowing slag is relatively small. When the blowing temperature is 1280℃, the viscosity of the blowing slag is 0.026Pa·s. In the blowing temperature range of 1280℃±10℃, in order to make the viscosity of the blowing slag greater than 0.015Pa·s and less than or equal to 0.03Pa·s, SiO 2 The amount is 1.0%-2.5%.

[0053] (2) By changing the mass proportion of CaO in the blowing slag, the viscosity of the blowing slag was calculated using FactSage thermodynamic software when the blowing temperature was 1200℃, 1240℃, 1280℃, and 1320℃, and the CaO content in the blowing slag was 7.5%, 8%, 8.5%, 9%, and 9.5%. When the blowing temperature remained unchanged, the viscosity of the blowing slag gradually increased with the increase of the mass proportion of CaO. When the mass proportion of CaO remained unchanged, the viscosity of the blowing slag gradually decreased with the increase of the blowing temperature. When the mass proportion of CaO was 8.5%, the viscosity of the blowing slag gradually decreased from 0.04Pa·s to 0.023Pa·s with the increase of temperature. When the blowing temperature was 1280℃, the viscosity of the blowing slag gradually increased from 0.025Pa·s to 0.028Pa·s. When the blowing temperature was 1280℃ and CaO was 8.5%, the viscosity of the blowing slag was 0.026Pa·s. In the blowing temperature range of ±10°C, in order to make the blowing slag viscosity greater than 0.015 Pa·s and less than or equal to 0.03 Pa·s, the amount of CaO is 7.5%-9.5%.

[0054] Step 3: Study the effects of different temperatures and different slag component contents on blowing slag, and fix SiO 2 ,CaO,Fe 3 O 4 When the temperature is controlled at 1000℃-1600℃ and the pressure is 3.207atm, the Fe 3 O 4 -Cu 2 O-CaO-SiO 2 Phase diagram of the quaternary slag system.

[0055] (1) Fixed SiO 2 The content is 1.5%. At this time, the phases present in the slag system are oxide phase, slag liquid phase and spinel phase. The initial melting point temperature of the slag system is 1069.07℃. At this time, the slag composition is: Fe 3 O 4 :40.74%, CaO:9.218%, Cu 2 O: 50%, therefore, when converted into the actual blowing process, the copper concentrate blowing slag component content is: Fe 3 O 4 :27.99%, CaO:6.33%, Cu 2 O: 34.35%, SiO 2 :1.5%, the blowing iron-calcium ratio is 3.20. As the smelting temperature continues to rise, the slag liquid phase area continues to expand. Combined with the actual production blowing temperature of 1280℃, the slag composition at this temperature read in the software is: FeO:11.53%, Fe 2 O 3:25.63%, CaO:19.08%, Cu 2 O: 41.76%, SiO 2 :2%, therefore, the content of copper concentrate blowing slag components converted into the actual blowing process is: FeO:7.92%, Fe 2 O 3 :17.61%, CaO:13.11%, Cu 2 O: 28.69%, SiO 2 :1.37%, and the blowing iron-calcium ratio is 1.41.

[0056] (2) The CaO content in the fixed blowing slag is 8.5%. At this time, the phases in the slag system are oxide phase, slag liquid phase and spinel phase. As the smelting temperature continues to increase, the slag liquid phase area continues to expand. Combined with the actual production blowing temperature of 1280℃, the slag composition at this time is: FeO: 20.750%, Fe 2 O 3 :29.22%、Cu 2 O: 47.64%, SiO 2 :2.38%. The content of copper concentrate blowing slag components is: FeO:12.49%, Fe 2 O 3 :17.59%, CaO:8.5%, Cu 2 O: 28.68%, SiO 2 :1.43%, and the blowing iron-calcium ratio is 2.59.

[0057] (3) The content of Fe in the fixed blowing slag is 24.7%, and the initial melting point of the slag system is 1070.15℃. As the smelting temperature continues to increase, the slag liquid phase area continues to increase. In actual production, the blowing temperature is 1280℃, and the slag composition is: FeO: 18.155%, Fe 2 O 3 :24.759%, CaO:12.611%, Cu 2 O: 40.496%, SiO 2 :3.943%, therefore, the content of copper concentrate blowing slag components is: FeO:12.47%, Fe 2 O 3 :17.01%, CaO:8.66%, Cu 2 O: 27.82%, SiO 2 :2.71%, and the blowing iron-calcium ratio is 2.49.

[0058] Combining steps 2 and 3, the final optimized slag type of blowing slag is determined as: CaO: 8.5%-9.5%, SiO 2:1.37%-2.5%, Fe / CaO: 1.88-2.38.

[0059] According to actual production experience, the main slag system in the blowing slag is Fe 3 O 4 -Cu 2 O-CaO-SiO 2 In the quaternary slag system, when the CaO content in the blowing slag exceeds 15% and is close to the iron content, the melting point of the blowing slag will increase rapidly. The viscosity of the blowing slag is smaller than that of the smelting slag. 2 The increase in mass proportion is combined with the calculation of the slag composition during actual blowing. It is found that as the blowing temperature increases from 1200℃ to 1280℃, the melt viscosity decreases from 0.03Pa·s to 0.026Pa·s. This shows that appropriately increasing the temperature and increasing the amount of slag-forming agent are helpful to improve the fluidity of the slag. The optimized blowing slag type obtained by this method is consistent with the judgment of production experience.

[0060] In order to further verify the obtained optimal slag shape control value and apply it to actual smelting, the simulation calculation results are comprehensively analyzed with the actual smelting results.

[0061] Table 2 lists the grade of crude copper smelted within the mass proportion range of the slag-forming agent optimized for the blowing slag, to prove that the optimized slag type obtained by this method is feasible. The table is as follows:

[0062] Table 2 Main components of blowing slag and smelted crude copper grade

[0063]

[0064] It can be seen from Table 2 that under the optimized slag ratio obtained by this method, the crude copper grade obtained by smelting is higher, the copper recovery rate is higher, and the impurity content is lower.

[0065] Some exemplary embodiments of the present invention are 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 scheme obtained thereby is 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 making creative work, that is, all modifications, equivalent substitutions and improvements made within the spirit and principles of this application, fall within the protection scope required by the present invention.

Claims

1. A slag type optimization method for a dual-furnace continuous copper smelting process, characterized in that: The following steps are involved: Step 1: According to the percentage of each component in the smelting slag or the blowing slag, determine the main quaternary slag type existing during smelting or blowing under the composition; Step 2: Calculate the viscosity of the smelting system or the blowing system, and change the mass proportion of CaO, SiO2, MgO, and Al2O3 components in the smelting slag system and the smelting temperature so that the viscosity of the smelting slag is greater than 0.09 Pa·s and less than or equal to 0.13 Pa·s when the actual smelting temperature is ±10°C. Under this condition, preliminarily determine the smelting slag type range; or change the mass proportion of SiO2 and CaO components in the blowing slag system and the blowing temperature so that the viscosity of the blowing slag is greater than 0.015 Pa·s and less than or equal to 0.03 Pa·s when the actual blowing temperature is ±10°C. Under this condition, preliminarily determine the blowing slag type range; Step 3: Taking the content of one of CaO, SiO2, MgO, and Al2O3 as a quantitative value, respectively, a quaternary isotherm projection phase diagram of the smelting slag system is drawn, or taking the content of one of SiO2, CaO, and Fe3O4 as a quantitative value, a quaternary isotherm projection phase diagram of the blowing slag system is drawn, and the smelting slag type or the blowing slag type range that is closest to or located in the slag liquid phase region at the actual smelting temperature ±10°C or the actual blowing temperature ±10°C is obtained in the phase diagram.

2. The slag type optimization method for a dual-furnace continuous copper smelting process according to claim 1, characterized in that: In step 2, the viscosity of the smelting system or the blowing system is calculated using the Viscosity module of the FactSage thermodynamic software.

3. The slag type optimization method for a dual-furnace continuous copper smelting process according to claim 1, characterized in that: In the step 2, the melting temperature or the blowing temperature is changed within the range of 1200°C-1400°C.

4. The slag type optimization method for a dual-furnace continuous copper smelting process according to claim 1, characterized in that: The temperature conditions for drawing the quaternary isotherm projection phase diagram in step 3 are 1000° C.-1600° C. and the pressure is 1.0-3.3 atm.

5. The slag type optimization method for a dual-furnace continuous copper smelting process according to claim 4, characterized in that: The pressure condition for drawing the quaternary isotherm projection phase diagram of the smelting slag system in step 3 is 1.0 atm, and the pressure condition for drawing the blowing slag system is 3.207 atm.

6. The slag type optimization method for a dual-furnace continuous copper smelting process according to claim 1, characterized in that: In the step 3, a smelting slag type is obtained under the condition of 1350±10°C in the quaternary isotherm projection phase diagram of the smelting slag system, and a blowing slag type is obtained under the condition of 1280±10°C in the quaternary isotherm projection phase diagram of the blowing slag system.

7. The slag type optimization method for a dual-furnace continuous copper smelting process according to claim 6, characterized in that: The smelting slag type range finally determined in step 3 is: CaO: 2.48%-3%, SiO2: 19.5%-22%, MgO: 1.50%-1.75%, Al2O3: 4.48%-5.0%, Fe / SiO2: 1.95-2.

2.

8. The slag type optimization method for a dual-furnace continuous copper smelting process according to claim 6, characterized in that: The blowing slag type range finally determined in step 3 is: CaO: 8.5%-9.5%, SiO2: 1.37%-2.5%, Fe / CaO: 1.88-2.38.

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