A method for constructing and applying a copper grade prediction model

Abstract

This invention provides a method for constructing a copper grade prediction model and its application. The method for constructing the copper grade prediction model includes step A1, determining the types of impurity metal elements Me in scrap copper raw materials; and step A2, establishing a copper grade prediction model based on the mass balance principle. The application of the copper grade prediction model includes step B1, selecting slag type and operating conditions for directional slag refining to prepare 3N copper based on the copper grade prediction model; and step B2, performing directional slag refining on the scrap copper raw materials based on the selected slag type and operating conditions, and verifying whether the copper grade of the product meets the 3N copper standard through the refining results. The copper grade prediction model of this invention can optimize slag type and operating conditions to improve the copper grade of the final product, ensuring that the copper grade of the product meets the 3N copper standard. In the application process, it enables the refined scrap copper raw materials to meet the 3N copper standard.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, specifically to a method for constructing and applying a copper grade prediction model. Background Technology

[0002] With the depletion of high-grade mineral resources and increasingly stringent environmental protection requirements, vigorously developing recycling technologies for copper-containing secondary resources such as scrap copper is an essential path for my country to address the copper resource and environmental crisis. Currently, there are two main processes for recycling scrap copper:

[0003] One method involves returning scrap copper to the copper smelting process, where it is smelted using reverberatory furnaces, blast furnaces, Kaldor furnaces, and top-blown furnaces, and finally cast into anode plates; high-grade copper is then obtained through electrolysis. This process of returning scrap copper to the copper smelting process has strong raw material adaptability, and the produced cathode copper can reach a grade of over 99.95%. However, this process is relatively long and energy-intensive.

[0004] Another method involves directly refining and removing impurities from scrap copper, then drawing it into copper rods to obtain copper products (FRHC direct rod production technology). This technology boasts a short process flow, simple equipment, and low energy consumption. Furthermore, it utilizes scrap copper containing 92%–96% copper to directly produce high-conductivity, low-oxygen copper rods, aligning with the metallurgical industry's trend towards short-process, low-energy-consumption technologies. To date, 20 FRHC furnaces worldwide utilize direct rod production technology, but the copper content of their products is mostly below 98.5%, failing to meet the 3N copper (Cu% ≥ 99.9%) standard achieved through electrolysis.

[0005] Therefore, it is very important to provide a method for constructing and applying a copper grade prediction model to ensure that the copper grade of the product meets the 3N copper standard. Summary of the Invention

[0006] The purpose of this invention is to provide a method for constructing and applying a copper grade prediction model. The specific technical solution is as follows:

[0007] In a first aspect, the present invention provides a copper grade prediction model, comprising the following steps:

[0008] Step A1: Determine the types of impurity metal elements Me in the scrap copper raw materials;

[0009] Step A2: Establish a copper grade prediction model based on the principle of mass balance.

[0010] Optionally, in step A2, the process of establishing the copper grade prediction model includes the following steps:

[0011] Step A2.1: Impurity metal element Me in waste copper raw material migrates from the metal phase to the slag phase through oxidation reaction. Therefore, it is necessary to determine the chemical reaction constant K corresponding to the oxidation reaction. The reaction formula of the oxidation reaction is shown in formula (1); the chemical reaction constant K is expressed by formula (2).

[0012]

[0013]

[0014] In equation (2), a Me Represents the activity of the impurity metal element Me; The activity of the oxide MeOx representing the impurity metal element Me; is the oxygen partial pressure; in equations (1) to (2), x represents the number of oxygen atoms in the oxide of the impurity metal element Me;

[0015] Step A2.2, if [n] T [] represents the total number of moles of single cation components in 100g of metal phase, expressed as (n T ) represents the total number of moles of single cation components in 100g of slag phase. Then, the activity of the impurity metal element Me is expressed by formula (3), and the oxide MeO x The activity is expressed by equation (4);

[0016] a Me =γ Me N Me =γ Me [Mewt%] / M Me [n T (3)

[0017]

[0018] In equations (3) to (4), γ Me This represents the activity coefficient of the impurity metal element Me; MeO represents oxide x Activity coefficient; N Me This indicates the mole fraction concentration of the impurity metal element Me; MeO represents oxide x mole fraction concentration; M Me [Me wt%] represents the relative atomic mass of the impurity metal element Me; [Me wt%] represents the mass fraction of the impurity metal element Me in the metallic phase under equilibrium conditions.

[0019] Step A2.3: Under thermodynamic equilibrium, determine the distribution coefficient L of the impurity metal element Me in the slag phase. s / m (Me); where L s / m(Me) is represented by equation (5);

[0020] L s / m (Me)=(Mewt%) / [Mewt%] (5)

[0021] In equation (5), (Mewt%) is the mass fraction of the impurity metal element Me in the slag phase under equilibrium conditions;

[0022] Equation (6) is obtained by simultaneously solving equations (1) to (5);

[0023]

[0024] In equation (6), [γ Me [] represents the activity coefficient of the impurity metal element Me in the metallic phase; MeO represents oxide x The activity coefficient in the slag phase; as can be seen from equation (6), the distribution coefficient L s / m (Me) is affected by temperature and oxygen partial pressure;

[0025] Step A2.4: By designing a high-temperature three-phase equilibrium experiment of metallic copper-slag-impurity metal elements, the distribution coefficient L of the impurity metal element Me under the corresponding equilibrium conditions is obtained. s / m (Me) and the mass fraction of copper w(Cu,sl) in the refined slag phase; wherein, the high temperature conditions used in the three-phase equilibrium high temperature experiment of metallic copper-slag-impurity metal elements are 1200~1350℃.

[0026] Assume that both metal Cu and impurity metal element Me enter the slag phase in the form of oxides, where Cu enters the slag phase in the form of Cu2O and impurity metal element Me enters the slag phase in the form of MeO;

[0027] The initial copper quantity is determined to be m. Cu °, initial slag volume is m slag °; Slag volume after the first refining of directional slag forming (m) (slag,after1) Equation (7) is used to represent:

[0028] m (slag,after1) =m slag °+m(Cu2O,sl)+∑m(MeO,sl) (7)

[0029] In equation (7), m(Cu2O,sl) is the mass of Cu2O in the slag phase after the first refining; m(MeO,sl) is the mass of the oxide MeO in the slag phase after the first refining.

[0030] The mass of the copper oxide Cu2O in the slag phase is expressed by formula (8):

[0031] m(Cu2O,sl)=m (slag,after1) ×w(Cu,sl) / w(Cu:Cu2O) (8)

[0032] The mass of the oxide MeO in the slag phase is expressed by equation (9):

[0033] m(MeO,sl)=m (slag,after1) ×(Mewt%) / w(Me:MeO) (9)

[0034] In equations (8) to (9), w(Cu:Cu2O) represents the mass fraction of metallic copper in Cu2O; w(Me:MeO) represents the mass fraction of impurity metal element Me in MeO; and w(Cu,sl) is the mass fraction of copper in the slag phase after the first refining.

[0035] Combining the above equations (7) to (9), the quality of the slag phase after the first refining of directional slag can be expressed as the following equation (10):

[0036]

[0037] In equation (10), (Mewt%) Cu,after1 This indicates the mass fraction of the impurity metallic element Me in the slag phase of metallic copper after the first refining.

[0038] The mass of metallic copper after the first refining is expressed by formula (11):

[0039] m (Cu,after1) =m Cu °-m (slag,after1) ×w(Cu,sl) (11)

[0040] According to the principle of mass balance, each impurity metal element Me is represented by equation (12):

[0041] m (slag,after1) ×(Mewt%) Cu,after1 +m (Cu,after1) ×[Mewt%] Cu,after1 =m Cu °×[Me] initial (12)

[0042] In equation (12), [Mewt%] Cu,after1 [Me] represents the mass fraction of the impurity metallic element Me in the metallic phase of copper after the first refining process. initial The initial content of the impurity metal element Me;

[0043] Based on the definition of the distribution coefficient in equation (5), equation (12) can be written in the form of equation (13):

[0044] m (slag,after1) ×[Mewt%] Cu,after1 ×L s / m (Me)+m (Cu,after1) ×[Mewt%] Cu,after1 =m Cu °×[Me] initial (13)

[0045] A copper grade prediction model is established using equations (1) to (13);

[0046] By combining equations (10), (11), and (13), the content of the impurity metal element Me in metallic copper after the first refining process [Mewt%] can be determined. Cu,after1 Then, the copper grade of the product after the first refining is calculated.

[0047] Optionally, in step A2, if the copper grade of the product after the first refining does not meet the 3N copper standard, the copper grade of the product after the second refining is calculated by analyzing the second refining and the principle of quality balance, and so on, until the 3N copper standard is met.

[0048] In the second refining process, the initial value used is the amount of copper m after the first refining. (Cu,after1) And the amount of slag after the first refining m (slag,after1) .

[0049] Optionally, in step A1, the scrap copper raw material is scrap copper with a copper grade of not less than 94%.

[0050] Optionally, in step A1, the impurity components in the waste copper raw material are impurity metal elements Me, including Ni, Sb, Fe, Sn, Zn and Pb.

[0051] In a second aspect, the present invention provides an application of a copper grade prediction model for the targeted slag refining of scrap copper raw materials to prepare 3N copper, which includes the following steps:

[0052] Step B1: Select the slag type and operating conditions for directional slag refining to prepare 3N copper based on the copper grade prediction model.

[0053] Step B2: Based on the selected slag type and operating conditions, carry out directional slag refining of waste copper raw materials, and verify whether the copper grade of the product meets the 3N copper standard through the refining results.

[0054] Optionally, in step B1, the slag type includes the slag type selected in the first slag making and the slag type selected in the second slag making; the operating conditions include the operating conditions for the first slag making and the operating conditions for the second slag making.

[0055] Optionally, the slag type selected in the first slag formation and the slag type selected in the second slag formation both include any one of CaO-Fe2O3-SiO2, CaO-Fe2O3-SiO2-Al2O3, and CaO-Fe2O3-SiO2-Na2O;

[0056] The mass ratio of CaO-Fe2O3-SiO2 is 25 / 25 / 50 and / or 25 / 35 / 40;

[0057] The mass ratio of CaO-Fe2O3-SiO2-Al2O3 is 30 / 5 / 55 / 10 and / or 30 / 15 / 45 / 10;

[0058] The mass ratio of CaO-Fe2O3-SiO2-Na2O is 20 / 15 / 60 / 5 and / or 20 / 25 / 50 / 5.

[0059] Optionally, the operating conditions for the first slag formation include an operating temperature of 1200–1350°C and an oxygen partial pressure of… The ratio of scrap copper to slag is 5:1 to 20:1.

[0060] The operating conditions for the second slag formation include an operating temperature of 1200–1350℃ and an oxygen partial pressure of… The ratio of copper content to slag content is 5:1 to 20:1.

[0061] Optionally, in step B2, the directional slag refining includes a first refining and a second refining;

[0062] The first refining is based on the slag type selected in the first slag making and the operating conditions of the first slag making. The waste copper raw material is refined for the first time to obtain first refined copper and first refined slag.

[0063] The second refining process is based on the slag type selected in the second slag formation and the operating conditions of the second slag formation. The copper from the first refining process is then refined a second time to obtain second refined copper and second refined slag.

[0064] The application of the technical solution of the present invention has at least the following beneficial effects:

[0065] (1) The method for constructing the copper grade prediction model described in this invention involves analyzing and determining the type and composition of Me in the scrap copper raw material in step A1, and then establishing the copper grade prediction model in step A2 based on the principle of mass conservation. This model can accurately predict the Me content and copper grade after refining the scrap copper raw material under the selected slag type and operating conditions. Furthermore, through the copper grade prediction model, the slag type and operating conditions (temperature, oxygen partial pressure, and slag-copper mass ratio) can be optimized to improve the copper grade of the final product, ensuring that the copper grade of the product meets the 3N copper standard.

[0066] (2) The application of the copper grade prediction model described in this invention involves step B1 to screen out the slag type and operating conditions for directional slag refining to prepare 3N copper; and step B2, based on the selected slag type and operating conditions, directional slag refining of scrap copper raw materials, and verifying whether the product copper grade meets the 3N copper standard through the refining results. Specifically, if the copper grade predicted by the copper grade prediction model does not meet the 3N copper standard after the first directional slag refining, a second refining is required. During the second refining process, the slag type and operating conditions are optimized based on the prediction results after the first refining (specifically, the copper from the first refining and the remaining impurities), and the ratio of slag quantity and metallic copper mass is appropriately adjusted to achieve the optimal scrap copper purification effect, thereby realizing the preparation of 3N copper. In the application of this invention to directional slag refining of scrap copper raw materials to prepare 3N copper, the content of the impurity metal element Me in the scrap copper raw materials can be effectively reduced, so that the refined scrap copper raw materials can meet the 3N copper standard.

[0067] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0068] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0069] Figure 1 This is a process flow diagram of the application of a copper grade prediction model in Embodiment 1 of the present invention. Detailed Implementation

[0070] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0071] Example 1:

[0072] A method for constructing a copper grade prediction model includes the following steps:

[0073] Step A1: Determine the types of impurity metal elements Me in the scrap copper raw material; specifically, in step A1, the scrap copper raw material is scrap copper with a copper grade of 94%, and the impurity components in the scrap copper raw material are impurity metal elements Me. Specifically, the impurity metal elements Me are Ni, Sb, Fe, Sn, Zn, and Pb, and the mass content of Ni, Sb, Fe, Sn, Zn, and Pb in the scrap copper raw material is all 1%.

[0074] Step A2: Establish a copper grade prediction model based on the principle of mass balance.

[0075] In step A2, the process of establishing the copper grade prediction model includes:

[0076] Step A2.1: Impurity metal element Me in waste copper raw material migrates from the metal phase to the slag phase through oxidation reaction. Therefore, it is necessary to determine the chemical reaction constant K corresponding to the oxidation reaction. The reaction formula of the oxidation reaction is shown in formula (1); the chemical reaction constant K is expressed by formula (2).

[0077]

[0078]

[0079] In equation (2), a Me Represents the activity of the impurity metal element Me; The activity of the oxide MeOx representing the impurity metal element Me; is the oxygen partial pressure; in equations (1) to (2), x represents the number of oxygen atoms in the oxide of the impurity metal element Me;

[0080] Step A2.2, if [n] T [] represents the total number of moles of single cation components in 100g of metal phase, expressed as (n T ) represents the total number of moles of single cation components in 100g of slag phase. Then, the activity of the impurity metal element Me is expressed by formula (3), and the oxide MeO x The activity is expressed by equation (4);

[0081] a Me =γ Me N Me =γ Me [Me wt%] / M Me [n T (3)

[0082]

[0083] In equations (3) to (4), γ Me This represents the activity coefficient of the impurity metal element Me; MeO represents oxide x Activity coefficient; N Me This indicates the mole fraction concentration of the impurity metal element Me; MeO represents oxide x mole fraction concentration; M Me [Me wt%] represents the relative atomic mass of the impurity metal element Me; [Me wt%] represents the mass fraction of the impurity metal element Me in the metallic phase under equilibrium conditions.

[0084] Step A2.3: Under thermodynamic equilibrium, determine the distribution coefficient L of the impurity metal element Me in the slag phase. s / m (Me); where L s / m (Me) is represented by equation (5);

[0085] L s / m (Me)=(Me wt%) / [Me wt%] (5)

[0086] In equation (5), (Me wt%) is the mass fraction of the impurity metal element Me in the slag phase under equilibrium conditions;

[0087] Equation (6) is obtained by simultaneously solving equations (1) to (5);

[0088]

[0089] In equation (6), [γ Me ] represents the activity coefficient of the impurity metal element Me in the metallic phase; (γ) MeOx ) represents the activity coefficient of oxide MeOx in the slag phase; from equation (6), it can be seen that the partition coefficient L s / m (Me) is affected by temperature and oxygen partial pressure (activity coefficient [γ]). Me ] and (γ MeOx It is also a function of temperature and oxygen partial pressure.

[0090] Step A2.4: By designing a high-temperature three-phase equilibrium experiment of metallic copper-slag-impurity metal elements, the distribution coefficient L of the impurity metal element Me under the corresponding equilibrium conditions is obtained. s / m (Me) and the mass fraction of copper w(Cu,sl) in the refined slag phase; wherein, the high temperature conditions used in the three-phase equilibrium high temperature experiment of metallic copper-slag-impurity metal elements are 1200~1350℃.

[0091] The high-temperature three-phase equilibrium experiment of copper-slag-impurity metal elements was conducted in a high-temperature quenching furnace. This furnace has a good sealing system and is equipped with mass flow meters for different gases, allowing the introduction of Ar, N2, CO, CO2, and H2 gases individually or simultaneously to conduct high-temperature three-phase equilibrium experiments of copper-slag-impurity metal elements under different atmospheres. The sample used in this experiment consisted of a fixed ratio of slag (0.125g), copper, and impurity metal powder (totaling 0.25g, with the following specific mass percentages: Cu 94%, Ni, Sb, Fe, Sn, Zn, and Pb each 1%). The impurity metal powder used was a metal powder reagent with a purity of 99.99% or higher.

[0092] After the high-temperature experiment of the three-phase equilibrium of metallic copper-slag-impurity metal elements, the sample was first quenched in an ice-water mixture by free fall, and then stored at room temperature in a phase coexistence state at the experimental set temperature (i.e., 1200-1350℃). Secondly, using SEM-EDS and EPMA analysis methods, the contents of each impurity metal element in the metallic copper and slag phases, and the content of copper in the slag, were determined under the three-phase equilibrium state of metallic copper-slag-impurity metal elements. Finally, the contents of the impurity metal elements under different conditions (temperature (1200-1350℃), oxygen partial pressure (P)) under this equilibrium condition can be calculated using formula (1). O2 =10 -6 ~10 -4 The distribution coefficients of slag type (specifically CaO-Fe2O3-SiO2, CaO-Fe2O3-SiO2-Al2O3, and CaO-Fe2O3-SiO2-Na2O; the mass ratio of CaO-Fe2O3-SiO2 is 25 / 25 / 50 and 25 / 35 / 40; the mass ratio of CaO-Fe2O3-SiO2-Al2O3 is 30 / 5 / 55 / 10 and 30 / 15 / 45 / 10; the mass ratio of CaO-Fe2O3-SiO2-Na2O is 20 / 15 / 60 / 5 and 20 / 25 / 50 / 5).

[0093] In the experimental study to obtain the distribution coefficients of various impurity metal elements, temperature, oxygen partial pressure and slag type were selected as variables. A database of impurity metal element distribution coefficients was constructed based on the results of multiple experiments, and these values ​​were applied to the calculation of the copper grade prediction model.

[0094] Assume that both metal Cu and impurity metal element Me enter the slag phase in the form of oxides, where Cu enters the slag phase in the form of Cu2O and impurity metal element Me enters the slag phase in the form of MeO;

[0095] The initial copper quantity is determined to be m. Cu °, initial slag volume is m slag °; Slag volume after the first refining of directional slag forming (m) (slag,after1) Equation (7) is used to represent:

[0096] m (slag,after1) =m slag °+m(Cu2O,sl)+∑m(MeO,sl) (7)

[0097] In equation (7), m(Cu2O,sl) is the mass of Cu2O in the slag phase after the first refining; m(MeO,sl) is the mass of the oxide MeO in the slag phase after the first refining.

[0098] The mass of the copper oxide Cu2O in the slag phase is expressed by formula (8):

[0099] m(Cu2O,sl)=m (slag,after1) ×w(Cu,sl) / w(Cu:Cu2O) (8)

[0100] The mass of the oxide MeO in the slag phase is expressed by equation (9):

[0101] m(MeO,sl)=m (slag,after1) ×(Mewt%) / w(Me:MeO) (9)

[0102] In equations (8) to (9), w(Cu:Cu2O) represents the mass fraction of metallic copper in Cu2O; w(Me:MeO) represents the mass fraction of impurity metal element Me in MeO; and w(Cu,sl) is the mass fraction of copper in the slag phase after the first refining.

[0103] Combining the above equations (7) to (9), the quality of the slag phase after the first refining of directional slag can be expressed as the following equation (10):

[0104]

[0105] In equation (10), (Mewt%) Cu,after1 This indicates the mass fraction of the impurity metallic element Me in the slag phase of metallic copper after the first refining.

[0106] The mass of metallic copper after the first refining is expressed by formula (11):

[0107] m (Cu,after1) =m Cu °-m (slag,after1) ×w(Cu,sl) (11)

[0108] According to the principle of mass balance, each impurity metal element Me is represented by equation (12):

[0109] m (slag,after1) ×(Mewt%) Cu,after1 +m (Cu,after1) ×[Mewt%] Cu,after1 =m Cu °×[Me] initial (12)

[0110] In equation (12), [Mewt%] Cu,after1 [Me] represents the mass fraction of the impurity metallic element Me in the metallic phase of copper after the first refining process. initial The initial content of the impurity metal element Me;

[0111] Based on the definition of the distribution coefficient in equation (5), equation (12) can be written in the form of equation (13):

[0112] m (slag,after1) ×[Mewt%] Cu,after1 ×L s / m (Me)+m (Cu,after1) ×[Mewt%] Cu,after1 =m Cu °×[Me] initial (13)

[0113] Specifically, the impurity metal elements Ni, Sb, Fe, Sn, Zn and Pb are represented by Equation (13) in sequence, as follows:

[0114]

[0115] A copper grade prediction model is established using equations (1) to (13);

[0116] By combining equations (10), (11), and (13), the content of the impurity metal element Me in metallic copper after the first refining process [Mewt%] can be determined. Cu,after1 Then, the copper grade of the product after the first refining is calculated.

[0117] In step A2, if the copper grade of the product after the first refining does not meet the 3N copper standard, the copper grade of the product after the second refining is calculated by analyzing the second refining and the principle of quality balance. This process continues until the copper grade of the product meets the 3N copper standard.

[0118] In the second refining process, the initial value used is the amount of copper m after the first refining. (Cu,after1) And the amount of slag after the first refining m (slag,after1) The amount of slag after the second refining is expressed by the following formula (14):

[0119]

[0120] The mass of the copper metal after the second refining is expressed by the following formula (15):

[0121] m (Cu,after2) =m (Cu,after1) -m (slag,after2) ×w(Cu,sl) after2 (15)

[0122] According to equation (13), for each impurity metal element Me after the second refining, the following relationship (16) holds:

[0123]

[0124] By combining equations (14) and (16), the content of the impurity metal element Me in metallic copper after the second refining [Mewt%] can be obtained. Cu,after2 The amount of slag after the second refining (m) (slag，after2) And the amount of copper m after the second refining (Cu，after2) .

[0125] Therefore, a model for predicting the copper grade of products was established.

[0126] See Figure 1 An application of a copper grade prediction model for the targeted slag refining of scrap copper raw materials to prepare 3N copper includes the following steps:

[0127] Step B1: Select the slag type and operating conditions for directional slag refining to prepare 3N copper based on the copper grade prediction model.

[0128] Step B2: Based on the selected slag type and operating conditions, the waste copper raw material is crushed, ground, and then subjected to directional slag refining. The refining results are used to verify whether the copper grade of the product meets the 3N copper standard.

[0129] In step B1, the slag type includes the slag type selected in the first slag making and the slag type selected in the second slag making; the operating conditions include the operating conditions for the first slag making and the operating conditions for the second slag making.

[0130] The slag type selected for the first slag formation is a mixed slag of CaO-Fe2O3-SiO2-Al2O3 (mass ratio: 30 / 5 / 55 / 10); the slag type selected for the second slag formation is a mixed slag of CaO-Fe2O3-SiO2 (mass ratio: 25 / 25 / 50).

[0131] The operating conditions for the first slag formation included an operating temperature of 1200℃ and an oxygen partial pressure of P. O2 =10 -4.5 The ratio of scrap copper to slag is 10:1.

[0132] The operating conditions for the second slag formation included an operating temperature of 1200℃ and an oxygen partial pressure of P. O2 =10 -4.5 The ratio of copper content to slag content is 10:1.

[0133] In step B2, the directional slag refining includes a first refining and a second refining;

[0134] The first refining process, based on the slag type and operating conditions selected in the first slag formation, involves feeding the scrap copper raw material into a refining furnace for the first refining, yielding first-refined copper and first-refined slag. EPMA analysis shows the content of remaining impurity metal elements in the metallic copper phase, as shown in Table 1. The copper grade after the first refining reaches 99.542%, while the copper grade prediction model predicts a grade of 99.575%, with an error of 0.033%. After discharging the slag obtained from the first refining, the copper from the first refining process continues to undergo a second refining in the refining furnace.

[0135] Table 1. Model-predicted and actual measured values ​​of copper grade and Me content after the first refining in directional slag forming process.

[0136]

[0137] The second refining process, based on the slag type and operating conditions selected in the second slag formation, involves feeding the first-refined copper into a refining furnace for a second refining, yielding second-refined copper and second-refined slag. EPMA analysis shows the remaining impurities in the metallic copper phase, as shown in Table 2. The copper grade after the second refining reaches 99.95%, i.e., 3N copper level. The copper grade prediction model predicts a copper grade of 99.95%, with an error value of 0.004%. The slag obtained from the second refining is first discharged, followed by the 3N copper product obtained from the second refining.

[0138] Table 2. Model-predicted and actual measured values ​​of copper grade and Me content after secondary refining with directional slag forming.

[0139]

[0140] As shown in Tables 1 and 2, the relative error between the prediction results of the copper grade prediction model and the actual detection results is less than 0.04%. This indicates that the prediction results and the detection results are in good agreement, demonstrating that the prediction data of the copper grade prediction model of the present invention is accurate and reliable. Furthermore, the copper grade of the product produced under the optimized slag type and operating conditions based on the copper grade prediction model can reach the 3N copper level.

[0141] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for constructing a copper grade prediction model, characterized in that, Includes the following steps: Step A1: Determine the types of impurity metal elements Me in the scrap copper raw materials; Step A2: Establish a copper grade prediction model based on the principle of mass balance; In step A2, the process of establishing the copper grade prediction model includes: Step A2.1: The migration of impurity metal element Me from the metal phase to the slag phase in the waste copper raw material requires an oxidation reaction. Determine the chemical reaction constant K corresponding to the oxidation reaction. The reaction formula of the oxidation reaction is shown in formula (1); the chemical reaction constant K is expressed by formula (2). In equation (2), a Me Represents the activity of the impurity metal element Me; The activity of the oxide MeOx representing the impurity metal element Me; is the oxygen partial pressure; in equations (1) to (2), x represents the number of oxygen atoms in the oxide of the impurity metal element Me; Step A2.2, if [n] T [] represents the total number of moles of single cation components in 100g of metal phase, expressed as (n T ) represents the total number of moles of single cation components in 100g of slag phase. Then, the activity of the impurity metal element Me is expressed by formula (3), and the oxide MeO x The activity is expressed by equation (4); a Me =c Me N Me =c Me [Mewt%] / M Me [n T ] (3) In equations (3) to (4), γ Me This represents the activity coefficient of the impurity metal element Me; MeO represents oxide x Activity coefficient; N Me This indicates the mole fraction concentration of the impurity metal element Me; MeO represents oxide x mole fraction concentration; M Me [Mewt%] represents the relative atomic mass of the impurity metal element Me; [Mewt%] represents the mass fraction of the impurity metal element Me in the metallic phase under equilibrium conditions. Step A2.3: Under thermodynamic equilibrium, determine the distribution coefficient L of the impurity metal element Me in the slag phase. s / m (Me); where L s / m (Me) is represented by equation (5); L s / m (Me)=(Death%) / [Death%] (5) In equation (5), (Mewt%) is the mass fraction of the impurity metal element Me in the slag phase under equilibrium conditions; Equation (6) is obtained by simultaneously solving equations (1) to (5); In equation (6), [γ Me [] represents the activity coefficient of the impurity metal element Me in the metallic phase; MeO represents oxide x The activity coefficient in the slag phase; as can be seen from equation (6), the distribution coefficient L s / m (Me) is affected by temperature and oxygen partial pressure; Step A2.4: By designing a high-temperature three-phase equilibrium experiment of metallic copper-slag-impurity metal elements, the distribution coefficient L of the impurity metal element Me under the corresponding equilibrium conditions is obtained. s / m (Me) and the mass fraction of copper w(Cu,sl) in the refined slag phase; wherein, the high temperature conditions used in the three-phase equilibrium high temperature experiment of metallic copper-slag-impurity metal elements are 1200~1350℃. Assume that both metal Cu and impurity metal element Me enter the slag phase in the form of oxides, where Cu enters the slag phase in the form of Cu2O and impurity metal element Me enters the slag phase in the form of MeO; The initial copper quantity is determined to be m. Cu °, initial slag volume is m slag °; The slag volume m after the first refining in directional slag forming (slag,after1) Equation (7) is used to represent: m (slag,after1) =m slag o +m(Cu2O,sl)+∑m(MeO,sl) (7) In equation (7), m(Cu2O,sl) is the mass of Cu2O in the slag phase after the first refining; m(MeO,sl) is the mass of the oxide MeO in the slag phase after the first refining. The mass of the copper oxide Cu2O in the slag phase is expressed by formula (8): m(Cu2O,sl)=m (slag,after1) ×w(Cu,sl) / w(Cu:Cu2O)(8) The mass of the oxide MeO in the slag phase is expressed by equation (9): m(MeO,sl)=m (slag,after1) ×(Me wt%) / w(Me:MeO)(9) In equations (8) to (9), w(Cu:Cu2O) represents the mass fraction of metallic copper in Cu2O; w(Me:MeO) represents the mass fraction of impurity metal element Me in MeO; and w(Cu,sl) is the mass fraction of copper in the slag phase after the first refining. Combining the above equations (7) to (9), the quality of the slag phase after the first refining of directional slag can be expressed as the following equation (10): In equation (10), (Me wt%) Cu,after1 This indicates the mass fraction of the impurity metallic element Me in the slag phase of metallic copper after the first refining. The mass of metallic copper after the first refining is expressed by formula (11): m (Cu,after1) =m Cu o -m (slag,after1) ×w(Cu,sl) (11) According to the principle of mass balance, each impurity metal element Me is represented by equation (12): m (slag,after1) ×(Death%) Cu,after1 +m (Cu,after1) ×[Death%] Cu,after1 =m Cu o ×[Me] initial (12) In equation (12), [Mewt%] Cu,after1 [Me] represents the mass fraction of the impurity metallic element Me in the metallic phase of copper after the first refining process. initial The initial content of the impurity metal element Me; Based on the definition of the distribution coefficient in equation (5), equation (12) can be written in the form of equation (13): m (slag,after1) ×[Death%] Cu,after1 ×L s / m (Me)+m (Cu,after1) ×[Death%] Cu,after1 =m Cu o ×[Me] initial (13) A copper grade prediction model is established using equations (1) to (13); By combining equations (10), (11), and (13), the content of the impurity metal element Me in metallic copper after the first refining process [Mewt%] can be determined. Cu,after1 Then, the copper grade of the product after the first refining is calculated.

2. The method for constructing the copper grade prediction model according to claim 1, characterized in that, In step A2, if the copper grade of the product after the first refining does not meet the 3N copper standard, the copper grade of the product after the second refining is calculated by analyzing the second refining and the principle of quality balance, and so on, until the 3N copper standard is met. In the second refining process, the initial value used is m. (Cu,after1) And the amount of slag after the first refining m (slag,after1) .

3. The method for constructing the copper grade prediction model according to claim 1, characterized in that, In step A1, the scrap copper raw material is scrap copper with a copper grade of not less than 94%.

4. The method for constructing the copper grade prediction model according to claim 1, characterized in that, In step A1, the impurity components in the waste copper raw material are impurity metal elements Me, including Ni, Sb, Fe, Sn, Zn and Pb.

5. An application of the copper grade prediction model according to any one of claims 1-4, characterized in that, The method for preparing 3N copper by directional slag refining of scrap copper raw materials includes the following steps: Step B1: Select the slag type and operating conditions for directional slag refining to prepare 3N copper based on the copper grade prediction model. Step B2: Based on the selected slag type and operating conditions, directional slag refining is carried out on the waste copper raw material, and the copper grade of the product is verified through the refining results to see if it meets the 3N copper standard.

6. The application according to claim 5, characterized in that, In step B1, the slag type includes the slag type selected in the first slag making and the slag type selected in the second slag making; the operating conditions include the operating conditions for the first slag making and the operating conditions for the second slag making.

7. The application according to claim 6, characterized in that, The slag type selected in the first slag formation and the slag type selected in the second slag formation both include any one of CaO-Fe2O3-SiO2, CaO-Fe2O3-SiO2-Al2O3 and CaO-Fe2O3-SiO2-Na2O; The mass ratio of CaO-Fe2O3-SiO2 is 25 / 25 / 50 and / or 25 / 35 / 40; The mass ratio of CaO-Fe2O3-SiO2-Al2O3 is 30 / 5 / 55 / 10 and / or 30 / 15 / 45 / 10; The mass ratio of CaO-Fe2O3-SiO2-Na2O is 20 / 15 / 60 / 5 and / or 20 / 25 / 50 / 5.

8. The application according to claim 7, characterized in that, The operating conditions for the first slag formation included an operating temperature of 1200–1350℃ and an oxygen partial pressure of P. O2 =10 -6 ～ 10 -4 The ratio of scrap copper to slag is 5:1 to 20:

1. The operating conditions for the second slag formation include an operating temperature of 1200–1350℃ and an oxygen partial pressure of P. O2 =10 -6 ~10 -4.5 The ratio of copper content to slag content is 5:1 to 20:

1.

9. The application according to claim 7, characterized in that, In step B2, the directional slag refining includes a first refining and a second refining; The first refining is based on the slag type selected in the first slag making and the operating conditions of the first slag making. The waste copper raw material is refined for the first time to obtain first refined copper and first refined slag. The second refining process is based on the slag type selected in the second slag formation and the operating conditions of the second slag formation. The copper from the first refining process is then refined a second time to obtain second refined copper and second refined slag.

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