Methods for predicting the concentration of valuable metals and methods for predicting the production volume of high-grade metals

Abstract

We provide technology that can accurately predict the concentration of valuable metals. [Solution] A method for predicting the concentration of valuable metals contained in incineration residue includes the steps of: measuring the mass and moisture content of the incineration residue; drying the incineration residue until the moisture content is 1% by mass or less; melting the incineration residue after the drying step by placing it in a graphite crucible and melting it in an electric melting furnace to separate it into a metal layer and a slag layer; recovering the metal layer and measuring its mass; analyzing the concentration of valuable metals contained in the metal layer; and predicting the concentration of valuable metals contained in the incineration residue before drying using the mass and moisture content of the incineration residue before drying, the mass of the metal layer, and the concentration of valuable metals contained in the metal layer.

Description

Technical Field

[0001] The present disclosure relates to a method for predicting the concentration of valuable metals.

Background Art

[0002] When incinerating waste such as municipal waste and industrial waste in an incineration facility, the incineration residue generated contains a small amount of valuable metals such as precious metals and copper. For example, in Patent Document 1, a method for recovering valuable metals from incineration residue using a reduction melting furnace has been proposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventors of the present application considered that by predicting the amount of valuable metals contained in the incineration residue, it can be used for price setting of the incineration residue and adjustment of the production amount of valuable metals produced from the incineration residue. However, conventionally, there has been no established method for analyzing the metals contained in the incineration residue. For example, in fact, an analytical sample is prepared from the incineration residue by referring to the methods described in JIS standards such as iron ore, sand, coal ash, etc., and the metal content is determined by performing wet analysis. According to such an analysis method, there is a problem that the numerical values of the analysis results vary greatly depending on the sample preparation conditions, and thus the reliability is lacking. Therefore, a technique capable of accurately predicting the concentration of valuable metals contained in the incineration residue is required.

Means for Solving the Problems

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to one embodiment of the present disclosure, a method for predicting the concentration of valuable metals contained in incineration residue is provided. This method for predicting the concentration of valuable metals contained in incineration residue includes the steps of: measuring the mass and moisture content of the incineration residue; drying the incineration residue until the moisture content is 1% by mass or less; melting the incineration residue after the drying step in a graphite crucible and melting it in an electric melting furnace to separate it into a metal layer and a slag layer; recovering the metal layer and measuring its mass; analyzing the concentration of valuable metals contained in the metal layer; and predicting the concentration of valuable metals contained in the incineration residue before drying using the mass and moisture content of the incineration residue before drying, the mass of the metal layer, and the concentration of valuable metals contained in the metal layer. According to this embodiment of the method for predicting the concentration of valuable metals contained in incineration residue, the concentration of valuable metals contained in the incineration residue can be predicted with high accuracy.

[0007] (2) In the method described in (1) above, the valuable metal may be copper. This method for predicting the concentration of valuable metals contained in incineration residue can accurately predict the concentration of copper contained in the incineration residue.

[0008] (3) In the method described in (1) or (2) above, in the melting step, the separated slag layer may be removed, and the incineration residue after the drying step may be added to the graphite crucible and melted again. This method for predicting the concentration of valuable metals contained in the incineration residue can increase the amount of metal layer formed, and thus the concentration of copper contained in the incineration residue can be predicted with greater accuracy.

[0009] (4) In the method described in any one of the above items (1) to (3), the step of analyzing the concentration of valuable metals contained in the metal layer may be performed using an X-ray fluorescence analyzer. This method for predicting the concentration of valuable metals contained in incineration residue makes it possible to easily predict the concentration of valuable metals contained in incineration residue.

[0010] (5) In the method described in any one of the above items (1) to (4), the melting temperature in the melting step may be 1200°C or more and 1600°C or less. This method for predicting the concentration of valuable metals contained in incineration residue can predict the concentration of valuable metals contained in incineration residue with greater accuracy.

[0011] (6) In the method described in any one of the above items (1) to (5), the capacity of the graphite crucible may be 250 mL or more and 1 L or less. This method for predicting the concentration of valuable metals contained in incineration residue can predict the concentration of valuable metals contained in incineration residue with greater accuracy.

[0012] (7) In the method described in any one of the above items (1) to (6), SiO2 and CaO may be mixed into the incineration residue subjected to the melting step such that the basicity CaO / SiO2 is 0.8 or more and 1.0 or less. This method for predicting the concentration of valuable metals contained in the incineration residue can promote the separation of the metal layer and the slag layer, and thus the concentration of valuable metals contained in the incineration residue can be predicted with greater accuracy.

[0013] (8) In other forms of the present disclosure, a method is provided for predicting the amount of high-grade metal to be produced from the incineration residue based on the concentration of the valuable metal predicted by the method of any one of the items (1) to (7) above. According to this form of method for predicting the amount of high-grade metal to be produced from the incineration residue, the amount of high-grade metal that can be produced from the incineration residue can be predicted with accuracy.

[0014] (9) In the method described in (8) above, if the valuable metal is copper, the amount y of high-grade metal produced from the incineration residue may be predicted by substituting the predicted concentration of copper contained in the incineration residue before drying, converted to mass, as x, into y = ax + b (where a is 0.4 or more and 0.6 or less, and b is 0.5 or more and 1.0 or less). This method for predicting the amount of high-grade metal produced from incineration residue allows for a more accurate prediction of the amount of high-grade metal that can be produced from the incineration residue.

[0015] (10) In the method described in (9) above, the value x obtained by converting the predicted concentration of copper in the incineration residue before drying to mass may be 5 tons or more. This method for predicting the amount of high-grade metal produced from incineration residue allows for a more accurate prediction of the amount of high-grade metal that can be produced from the incineration residue.

[0016] Furthermore, this disclosure can be implemented in various forms, for example, as an apparatus for manufacturing gold-containing materials, a control method for an apparatus for manufacturing gold-containing materials, a method for manufacturing gold and silver-containing materials, an apparatus for manufacturing gold and silver-containing materials, a control method for an apparatus for manufacturing gold and silver-containing materials, a method for recovering gold-containing materials from incinerated ash, and a method for recovering gold and silver-containing materials from incinerated ash. [Brief explanation of the drawing]

[0017] [Figure 1] This is a process diagram showing a method for predicting the concentration of valuable metals contained in incineration residue. [Figure 2] This is an explanatory diagram showing the method for preparing samples for wet analysis. [Figure 3] This diagram illustrates the relationship between the production volume of high-grade metals and the theoretical supply of copper calculated through melt analysis. [Figure 4] This diagram illustrates the relationship between the production volume of high-grade metals and the theoretical supply of copper calculated by wet analysis. [Modes for carrying out the invention]

[0018] A. Method for predicting the concentration of valuable metals in incineration residue. Figure 1 is a process diagram showing a method for predicting the concentration of valuable metals contained in incineration residue as one embodiment of the present disclosure. This method allows for accurate prediction of the amount of valuable metals contained in the incineration residue without performing melting in an actual reduction melting furnace. In this disclosure, "incineration residue" refers to the residue generated when waste such as municipal solid waste and industrial waste is incinerated at an incineration facility. Valuable metals are not particularly limited, but examples include precious metals, base metals, and rare metals. Precious metals are not particularly limited, but examples include gold, silver, platinum, palladium, and rhodium. Base metals are not particularly limited, but examples include copper, nickel, cobalt, zinc, and lead. Rare metals are not particularly limited, but examples include indium, gallium, tantalum, niobium, and various rare earth elements. The valuable metals preferably include at least one of gold, silver, and copper, and more preferably include copper.

[0019] The method for predicting the concentration of valuable metals contained in incineration residue according to this disclosure first involves preparing the incineration residue (step P110). Preferably, the incineration residue prepared in step P110 is sampled in accordance with JIS K0060:1992. Next, the mass and moisture content of the incineration residue are measured (step P120). The method for measuring the moisture content of the incineration residue is not particularly limited, but for example, it can be measured using an infrared moisture meter.

[0020] Next, the incineration residue is dried until the moisture content becomes 1% by mass or less (step P130). In the following description, step P130 is also referred to as the drying step. The method for drying the incineration residue in the drying step (step P130) is not particularly limited. For example, it can be dried using a constant temperature dryer. The drying temperature in the drying step (step P130) is not particularly limited, but from the viewpoint of suppressing elution of heavy metals and suppressing a decrease in drying efficiency, it is preferably 100°C or higher and 190°C or lower, more preferably 110°C or higher and 180°C or lower, still more preferably 120°C or higher and 170°C or lower, and even more preferably 130°C or higher and 160°C or lower. In the drying step (step P130), it is preferable to measure the moisture content at regular intervals and check whether it is 1% by mass or less, and repeat drying again when the moisture content exceeds 1% by mass. More specifically, for example, it is preferable to measure the moisture content every time drying is performed for 2 hours or more and 6 hours or less, and more preferably to measure the moisture content every time drying is performed for 3 hours or more and 5 hours or less.

[0021] Next, the incineration residue after the drying step (step P130) is placed in a graphite crucible and melted in an electric melting furnace to be separated into a metal layer and a slag layer (step P140). In the following description, step P140 is also referred to as the melting step. In the melting step (step P140), by using a graphite crucible and performing melting in an electric melting furnace, melting can be performed under conditions close to melting in a reduction atmosphere in an actual reduction melting furnace. The graphite crucible used in the melting step (step P140) is not particularly limited, but preferably has a capacity of 250 mL or more and 1 L or less, and more preferably 250 mL or more and 800 mL or less. The electric melting furnace used in the melting step (step P140) is not particularly limited, but for example, a small heater-type electric melting furnace can be used. By using a heater-type electric melting furnace, unlike when the actual reduction melting furnace is in operation, monitoring by a person is not required, so melting can be performed simply. Further, by using a heater-type electric melting furnace, melting can be performed by space heating, so it is possible to suppress the adhesion of the slag layer and the metal layer to the internal components of the apparatus. As a result, it is possible to suppress an error from occurring in the measurement result of the mass of the metal layer in step P150 described later, so it is possible to suppress a decrease in the prediction accuracy of the concentration of valuable metals contained in the incineration residue. The melting temperature in the melting step (step P140) is not particularly limited, but from the viewpoint of suppressing wear of the melting furnace and suppressing a decrease in melting efficiency, it is preferably 1200 °C or higher and 1600 °C or lower, more preferably 1300 °C or higher and 1500 °C or lower, and even more preferably 1400 °C or higher and 1500 °C or lower. The melting time in the melting step (step P140) is not particularly limited, but is preferably 2 hours or more and 12 hours or less, and more preferably 4 hours or more and 10 hours or less.

[0022] By the melting step (step P140), a slag layer is formed on the upper side and a metal layer is formed on the lower side in the graphite crucible. A plurality of types of metals are mixed in the metal layer, and among the metals contained in the metal layer, the heavier the specific gravity of the metal, the more it exists on the lower side, and the lighter the specific gravity of the metal, the more it exists on the upper side.

[0023] In the melting process (step P140), from the viewpoint of increasing the amount of metal layer formed, it is preferable to remove the separated slag layer and then add the incineration residue after the drying process to the graphite crucible and melt it again. By adding the incineration residue to the graphite crucible and melting it again, the metal layer can be concentrated. Furthermore, from the viewpoint of promoting the separation of the metal layer and the slag layer, SiO2 and CaO may be mixed into the incineration residue subjected to the melting process (step P140) so that the basicity CaO / SiO2 is between 0.8 and 1.0.

[0024] Next, the metal layer separated by the melting process (process P140) is recovered and its mass is measured (process P150). When recovering the metal layer in process P150, for example, the metal layer and slag layer can be cooled to room temperature, and then the slag layer can be broken using a hammer or the like to recover the metal layer.

[0025] Next, the concentration of valuable metals contained in the recovered metal layer is analyzed (step P160). For the analysis of the concentration of valuable metals contained in the metal layer, for example, an X-ray fluorescence analyzer can be used, and it is preferable to use an energy-dispersive X-ray fluorescence analyzer (EDX). By using an X-ray fluorescence analyzer, the measurement can be performed easily. When performing the analysis using an energy-dispersive X-ray fluorescence analyzer, the surface of the metal layer is flattened using a horizontal polishing machine or the like prior to the analysis. In the analysis of the concentration of valuable metals contained in the metal layer, it is preferable to take measurements at multiple locations, including at least one location on the top surface and one location on the bottom surface of the metal layer, and to calculate the average value.

[0026] Subsequently, the concentration of valuable metals in the incineration residue before drying is predicted using the mass and moisture content of the incineration residue before drying measured in step P120, the mass of the metal layer measured in step P150, and the concentration of valuable metals contained in the metal layer analyzed in step P160 (step P170). More specifically, for example, if the mass of the dried incineration residue used for melting is A (g), the moisture content of the incineration residue before drying is B (%), the mass of the recovered metal layer is C (g), and the concentration of valuable metals contained in the metal layer is D (%), the concentration of valuable metals contained in the incineration residue before drying can be calculated by substituting these values ​​into the following formula (1).

[0027] E(%)=D×{C×(100-B)÷100}÷A (1)

[0028] In the melting process (process P140), if the incineration residue is added to the graphite crucible and melted again, the total mass of the actually melted dried incineration residue is used as the mass A (g) of the dried incineration residue used for melting, and the total amount of moisture contained in the incineration residue before drying is used as the moisture content B (g) of the incineration residue before drying. Furthermore, if SiO2 and CaO are mixed with the incineration residue used in the melting process (process P140), the total mass F (g) of the mixed SiO2 and CaO is subtracted from the mass A (g) of the dried incineration residue used for melting in the calculation. More specifically, the concentration E (%) of valuable metals contained in the incineration residue before drying can be calculated using the following formula (2).

[0029] E(%)=D×{C×(100-B)÷100}÷(AF) ···(2)

[0030] The method for predicting the concentration of valuable metals in incineration residue, as described above, allows for a simplified melting process under conditions similar to those of an actual reduction melting furnace. Therefore, it is possible to accurately predict how much valuable metal is contained in the incineration residue. As a result, this can be used for pricing incineration residue and adjusting the production volume of valuable metals produced from incineration residue.

[0031] In contrast to the present invention, if a method is used in which analytical samples are prepared from incineration residues by referring to methods specified in JIS standards for iron ore, sand, coal ash, etc., and the metal content is determined by wet analysis, the numerical values ​​of the analytical results will vary greatly depending on the sample preparation conditions, thus lacking reliability.

[0032] In contrast, the method for predicting the concentration of valuable metals contained in incineration residue according to this embodiment can accurately predict the concentration of valuable metals contained in incineration residue, as shown in the examples described later.

[0033] B. Method for predicting the amount of high-grade metal produced from incineration residue. In other forms of this disclosure, a method is provided for predicting the amount of high-grade metal produced from incineration residue. This method predicts the amount of high-grade metal produced from incineration residue based on the concentration of valuable metals predicted by the method described above. In this disclosure, “high-grade metal” means a metal layer formed by the metal layer described above, having a relatively high concentration of valuable metals, and more specifically, a metal layer having a concentration of valuable metals of 50% by mass or more.

[0034] For example, if the valuable metal contained in the incineration residue is copper, the amount y of high-grade metal produced from the incineration residue can be predicted by substituting the predicted concentration of copper in the incineration residue before drying, converted to mass, as x, into equation (3) below. In equation (3) below, a is between 0.4 and 0.6, and b is between 0.5 and 1.0.

[0035] y = ax + b ... (3)

[0036] From the viewpoint of improving prediction accuracy, in formula (3) above, a is preferably 0.42 or more and 0.57 or less, more preferably 0.44 or more and 0.54 or less, and even more preferably 0.46 or more and 0.5 or less. Also from the viewpoint of improving prediction accuracy, in formula (3) above, b is preferably 0.55 or more and 0.95 or less, more preferably 0.6 or more and 0.9 or less, and even more preferably 0.65 or more and 0.85 or less. Also from the viewpoint of improving prediction accuracy, in formula (3) above, x is preferably 3 tons or more, more preferably 4 tons or more, and even more preferably 5 tons or more.

[0037] According to the method for predicting the amount of high-grade metal produced from incineration residue in this embodiment, as described above, the amount of high-grade metal produced from incineration residue is predicted based on the concentration of valuable metals predicted by performing a simplified melting process under conditions close to those of an actual reduction melting furnace. Therefore, the amount of high-grade metal that can be produced from incineration residue can be predicted with high accuracy. As a result, this can be used to adjust the production volume of high-grade metals produced from incineration residues. More specifically, for example, the blend of incineration residues to be used can be determined based on the predicted concentration of valuable metals for each incineration residue at each plant, according to the target production volume of high-grade metals. As a result, it is possible to suppress a decrease in the production efficiency of high-grade metals and to prevent the excessive production of high-grade metals. [Examples]

[0038] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. In the following description, "%" means mass%.

[0039] <Comparison of melt analysis and wet analysis> The copper content (%) in the incineration residue of factories A to L was calculated and compared based on the results of the melting analysis and wet analysis described below.

[0040] The melting analysis was performed using the following method. First, incineration residue from each plant was sampled in accordance with JIS K0060:1992. More specifically, approximately 1 kg was collected by scooping from two or more locations where the incineration residue was stored, placed in a bag, and mixed. The mass was then measured, and the moisture content was measured using an infrared benchtop moisture meter. Next, the wet incineration residue was dried using a constant-temperature dryer until the moisture content was 1% by mass or less. The drying conditions were 150°C for 4 hours, and this was repeated multiple times until the moisture content was 1% by mass or less. After confirming that the moisture content was 1% by mass or less, 200g to 300g of the incineration residue was placed in a 250mL graphite crucible, and the graphite crucible was placed in a small electric melting furnace with a heater. The melting conditions were 1400°C for 4.5 hours, and the residue was separated into a slag layer and a metal layer by melting. To obtain a measurable amount of metal layer using an X-ray fluorescence analyzer, the separated slag layer was removed after melting, and the incineration residue was added to the graphite crucible and melted again. If the separation of the metal layer and the slag layer was insufficient, SiO2 and CaO were mixed into the incineration residue during the second melting process so that the basicity CaO / SiO2 was between 0.8 and 1.0. Once it was determined that a measurable amount of metal layer had been obtained using an X-ray fluorescence analyzer, the graphite crucible was left overnight to cool to approximately room temperature. Subsequently, the slag layer surrounding the metal layer was broken with a hammer to recover the coin-shaped metal layer, and its mass was measured using an electronic balance. Then, the top and bottom surfaces of the metal layer were polished flat using a horizontal polishing machine, and the copper concentration was analyzed for both the top and bottom surfaces. For the analysis, an EDX7000 X-ray fluorescence analyzer (Shimadzu Corporation) was used, and the average value of the measurement results from one location on the top surface and one location on the bottom surface was calculated. Subsequently, the copper concentration in the incineration residue before drying was calculated using the mass and moisture content of the incineration residue before drying, corresponding to the amount of incineration residue used for melting, the mass of the recovered metal layer, and the copper concentration contained in the metal layer. Equation (2) above was used for the calculation.

[0041] Figure 2 is an explanatory diagram showing the preparation method of the wet analysis sample used in the example. This preparation method is an example of a conventional method used to analyze metals contained in incineration residue. First, incineration residue from each factory was sampled in accordance with JIS K0060:1992. After drying the entire amount using a constant temperature dryer, it was separated into under- and over-grade materials by sieving with a 4.75 mm sieve. The under- and over-grade materials were then separated into non-magnetic and magnetic materials by magnetic separation. From the non-magnetic under-grade and non-magnetic over-grade materials, crushable materials were selected and the entire amount was crushed to a size of 4.75 mm or less. Using this as the sample to be analyzed, the copper concentration (%) was analyzed by wet acid decomposition-ICP mass spectrometry. Subsequently, the copper concentration (%) contained in the incineration residue before drying was calculated using the following formula (4).

[0042] Copper content in incineration residue (%) = ICP mass spectrometry concentration (%) × Amount of analyte sample (g) ÷ Total amount of sieved incineration residue (g) × 100 ... (4)

[0043] Table 1 below shows the copper content (%) calculated using the results of melt analysis and the copper content (%) calculated using the results of wet analysis for the incineration residues of factories A to L.

[0044] [Table 1]

[0045] As shown in Table 1, some factories showed similar copper content values ​​when calculated using melt analysis, while others showed significant discrepancies when calculated using wet analysis.

[0046] <Relationship with melting results from an actual reduction melting furnace> The production volume of high-grade metal was determined on a monthly basis by continuously melting incineration residue using an actual reduction melting furnace. For melting, a mixture of incineration residues from factories A to L was used.

[0047] As a reduction melting furnace, it has a diameter of 3.3m, a depth of 1.8m, and a volume of 15.4m³. 3 An AC submerging electric furnace was used. The reduction melting furnace was equipped with three carbon electrodes that could be raised and lowered, positioned at the vertices of an equilateral triangle when viewed from above. The three electrodes were connected to a three-phase AC power supply. The voltage was set to a maximum of 275V and the current to 10,000A. The melting temperature was set to 1300℃ to 1500℃, and the melting time between metal layer recovery was set to 4.5 hours or more, with new incineration residue being added each time a metal layer was recovered. The mass of the recovered metal layer was measured and the copper concentration was analyzed. An EDX7000 X-ray fluorescence analyzer (manufactured by Shimadzu Corporation) was used for the analysis of the copper concentration.

[0048] The theoretical supply of copper for the current month (t) was calculated by multiplying the copper concentration (%) in the incineration residue of each plant, as determined by melting analysis, by the amount of incineration residue processed (t) at that plant for the current month, and then summing these values ​​for all plants. Similarly, the theoretical supply of copper for the current month (t) was calculated by multiplying the copper concentration (%) in the incineration residue of each plant, as determined by wet analysis, by the amount of incineration residue processed (t) at that plant for the current month, and then summing these values ​​for all plants.

[0049] Figure 3 is an explanatory diagram showing the relationship between the production volume of high-grade metal and the theoretical supply of copper calculated by melt analysis. Figure 4 is an explanatory diagram showing the relationship between the production volume of high-grade metal and the theoretical supply of copper calculated by wet analysis. In Figures 3 and 4, each plot represents the total amount of incineration residue processed in that month, the vertical axis represents the production volume of high-grade metal (t) for one month, and the horizontal axis represents the theoretical supply of copper (t) for that month.

[0050] Comparing Figures 3 and 4, it was found that the relationship between the theoretical supply of copper calculated by melt analysis (shown in Figure 3) and the production volume of high-grade metal had a larger coefficient of determination R² and a higher correlation than the relationship between the theoretical supply of copper calculated by wet analysis (shown in Figure 4). Therefore, the theoretical supply of copper calculated by melt analysis has a higher correlation with the actual production volume of high-grade metal than the theoretical supply of copper calculated by wet analysis, and is more suitable for predicting the production volume of high-grade metal. Furthermore, it is considered that the production volume of high-grade metal can be predicted with high accuracy by using the formula shown in Figure 3.

[0051] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features in each embodiment corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

Claims

1. A method for predicting the concentration of valuable metals contained in incineration residue, A step of measuring the mass and moisture content of the incineration residue, The incineration residue is dried until its moisture content is 1% by mass or less. The incineration residue after the drying process is placed in a graphite crucible and melted in an electric melting furnace to separate it into a metal layer and a slag layer in a melting process. A step of recovering the metal layer and measuring its mass, A step of analyzing the concentration of valuable metals contained in the metal layer, A step of predicting the concentration of valuable metals contained in the incineration residue before drying, using the mass and moisture content of the incineration residue before drying, the mass of the metal layer, and the concentration of valuable metals contained in the metal layer. Includes, The aforementioned valuable metal is one of gold, silver, and copper. method.

2. In the method according to claim 1, The aforementioned valuable metal is copper. method.

3. In the method according to claim 1, In the melting step, the separated slag layer is removed, and the incineration residue after the drying step is added to the graphite crucible and melted again. method.

4. In the method according to claim 1, In the step of analyzing the concentration of valuable metals contained in the metal layer, the analysis is performed using an X-ray fluorescence analyzer. method.

5. In the method according to claim 1, The melting temperature in the melting process is 1200°C or higher and 1600°C or lower. method.

6. In the method according to claim 1, The capacity of the graphite crucible is 250 mL or more and 1 L or less. method.

7. In the method according to claim 1, The incineration residue subjected to the melting process is given a basicity of CaO / SiO ２ SiO such that the ratio is between 0.8 and 1.0 ２ and mix with CaO, method.

8. A method for predicting the amount of high-grade metal produced from incineration residue based on the concentration of the valuable metal predicted by the method according to any one of claims 1 to 7.

9. In the method according to claim 8, The aforementioned valuable metal is copper, Let x be the predicted concentration of copper in the incineration residue before drying, converted to mass. By substituting into y = ax + b (where a is between 0.4 and 0.6, and b is between 0.5 and 1.0), the amount y of high-grade metal produced from the incineration residue is predicted. method.

10. In the method according to claim 9, The predicted concentration of copper in the incineration residue before drying, calculated by mass, is 5 tons or more. method.

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