Aging processing method of steel making slag and production method of slag material

Abstract

To provide an aging processing method of a steel making slag and a production method of a slag material, capable of easily grasping a progress state of aging processing in an inner layer without requiring installation and recovery of a measuring facility in the inner layer of a laminated steel making slag.SOLUTION: An aging processing method of a steel making slag to carry out aging processing for the steel making slag has: a moisture supply start process of starting supplying moisture from a moisture supply device to the steel making slag; a specific resistance value calculation process of calculating a specific resistance value of the steel making slag by using an electric current electrode and a potential electrode installed on a surface of the steel making slag; and a progress state determination process of determining a progress state of the aging processing based on the specific resistance value calculated in the specific resistance value calculation process.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an aging treatment method for steelmaking slag used as roadbed material or coarse aggregate for concrete, and a method for producing slag material. [Background technology]

[0002] The steel slag produced in integrated steelworks includes blast furnace slag, which is produced when iron ore is melted and reduced in a blast furnace, and steelmaking slag, which is produced at the steelmaking stage when pig iron is refined. The steel slag produced is then piled up in a cooling yard and cooled slowly by natural cooling and the supply of an appropriate amount of moisture. It is then crushed and sieved, and aged as necessary, before being used as roadbed material or coarse aggregate for concrete.

[0003] Among iron and steel slags, steelmaking slag contains free lime (free CaO) and / or free MgO (hereinafter referred to as "free lime, etc."). When steelmaking slag containing free lime, etc. is used as road base material or coarse aggregate for concrete, the free lime contained in the steelmaking slag reacts with water, etc., causing volume expansion, which leads to the collapse of the road base material or coarse aggregate for concrete.

[0004] For this reason, it is necessary to sufficiently remove free lime and the like at the stage of the aging treatment of steelmaking slag. In other words, it is necessary to supply moisture to the stacked steelmaking slag during the aging treatment and promote the reaction between the free lime and the like that cause expansion collapse and the moisture (water flow or steam), thereby promoting the stabilization of the steelmaking slag. Furthermore, research has been conducted on technology to grasp the progress of the aging treatment of steelmaking slag stacked in a cooling yard during the aging treatment.

[0005] Non-Patent Document 1 discloses a method for managing the aging time of steelmaking slag in a steam aging treatment of steelmaking slag by installing a thermocouple on the top of the slag layer and grasping the progress of the aging treatment based on the temperature measured by the thermocouple. Patent Document 1 discloses a heat-insulating cover for steam aging of steelmaking slag having a hole for inserting a thermocouple. Patent Document 2 discloses a method for controlling the amount of steam supply based on the measurement values ​​of multiple thermometers buried inside the slag layer in a steam aging treatment of steelmaking slag. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 7120841 [Patent Document 2] Japanese Patent Application Publication No. 4-175250 [Non-patent literature]

[0007] [Non-Patent Document 1] Development of steam aging treatment for steelmaking slag, Sasaki et al., Nippon Steel & Sumitomo Metal Techniques, 399 (2014), p.21 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the techniques disclosed in Non-Patent Document 1 and Patent Document 1 make it possible to measure the temperature of the outer layer of steelmaking slag by installing a thermocouple on the surface of the outer layer of steelmaking slag, but it is difficult to measure the temperature in the inner layer of steelmaking slag. Therefore, even if the techniques disclosed in Non-Patent Document 1 and Patent Document 1 are used, it is not possible to grasp temperature information in the inner layer of steelmaking slag, i.e., the progress of the aging treatment in the inner layer, and it is difficult to perform an accurate aging treatment taking into account the progress.

[0009] In addition, the technology disclosed in Patent Document 2 makes it possible to measure the temperature of the inner layer of steelmaking slag by embedding multiple thermometers in the inner layer of the steelmaking slag, but it requires a lot of effort to install and remove the multiple thermometers in the inner layer before and after the aging treatment.

[0010] Furthermore, the techniques disclosed in Non-Patent Document 1 and Patent Documents 1 and 2 are based on measurements by installing a thermometer in the outer or inner layer of steelmaking slag, and the measured value is temperature information at a specific position in the outer or inner layer of steelmaking slag, and is local temperature information. Therefore, it is difficult to grasp the overall progress of the aging treatment in the outer or inner layer of steelmaking slag, and it is difficult to control the amount of moisture supply based on the progress of the aging treatment in the inner layer and to accurately calculate the treatment time required for the aging treatment.

[0011] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a method for aging steelmaking slag and a method for producing slag material, which makes it possible to easily grasp the progress of the aging treatment in the inner layer of stacked steelmaking slag without the need to install and recover measuring equipment in the inner layer. [Means for solving the problem]

[0012] [1] A method for aging treatment of steelmaking slag, comprising: a moisture supply starting step of starting the supply of moisture from a moisture supply device to the steelmaking slag; a resistivity calculation step of calculating the resistivity of the steelmaking slag using a current electrode and a potential electrode installed on the surface of the steelmaking slag; and a progress determination step of determining the progress of the aging treatment based on the resistivity calculated in the resistivity calculation step. [2] The method of aging treatment of steelmaking slag described in [1], wherein the progress determination process determines the end of the aging treatment based on the resistivity value calculated by the resistivity value calculation process becoming less than a threshold value. [3] The aging treatment method for steelmaking slag described in [2], wherein the threshold value is 700 Ω·m. [4] The method for aging steelmaking slag described in [1], further comprising, after the progress status determination process, an additional processing time calculation process for calculating the additional processing time required for the aging treatment or a control process for controlling the moisture supply device. [5] A method for producing a slag material, comprising producing a slag material by the method for aging steelmaking slag according to any one of [1] to [4]. Effect of the Invention

[0013] According to the present invention, the progress of the aging treatment in the inner layer of stacked steelmaking slag can be easily grasped without the need to install and recover measuring equipment in the inner layer. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing a schematic configuration as an example of an electrical exploration (resistivity method). [Diagram 2] FIG. 1 is a diagram illustrating a schematic configuration of an example of a progress status determination device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, "upper layer" means the uppermost layer of the stacked steel slag. "Lower layer" means the lowermost layer of the stacked steel slag. "Middle layer" means any layer in the vertical direction of the stacked steel slag, excluding the "upper layer" and "lower layer". Furthermore, "upper surface" means the upper surface of the stacked steel slag. "Side" means the lateral surface of the stacked steel slag. "Lower surface" means the lower surface of the stacked steel slag. "Surface" collectively refers to the upper surface, side surface, and lower surface of the stacked steel slag. Furthermore, "outer layer" includes the surface (upper surface, side surface, and lower surface) of the stacked steel slag and means the surface layer of the steel slag having a predetermined thickness toward the center of the stacked steel slag. "Inner layer" means any inner layer of the stacked steel slag, excluding the outer layer.

[0016] A configuration for measuring resistivity values ​​based on electrical exploration (resistivity method) used in this embodiment is shown in Fig. 1. Electrical exploration is a type of physical exploration in which a current (I) is passed from a pair of current electrodes provided on the surface of the outer layer of the steelmaking slag to be measured, and a potential difference (V) is measured between another pair of potential electrodes to grasp the electrical properties of the steelmaking slag and to investigate the progress of the aging treatment inside (inner layer) of the steelmaking slag.

[0017] As shown in Figure 1, electrical exploration uses a pair of current electrodes A and a pair of potential electrodes V. Then, a current is passed through the steelmaking slag S by the pair of current electrodes A, and a voltage is applied to the steelmaking slag S by the pair of potential electrodes V, thereby forming an electric field in the inner layer of the steelmaking slag S.

[0018] Thereafter, with an electric field formed in the inner layer of the steelmaking slag S, the resistivity value of a measurement point N in the inner layer of the steelmaking slag S between a pair of current electrodes A and a pair of potential electrodes V is calculated. The measurement point N is located inside the formed electric field. The calculated resistivity value is then taken as a value (resistance value) related to the electrical resistor in the inner layer between the pair of current electrodes A and the pair of potential electrodes V, and the distribution state of the substance (moisture) contained in the electrical resistor (steelmaking slag S) can be grasped. Specifically, when the steelmaking slag S contains a lot of moisture, the resistivity value is small. On the other hand, when the steelmaking slag S contains a lot of coarse particles and little moisture, the resistivity value is large.

[0019] Here, taking into consideration the distance between the surface of the outer layer of the steelmaking slag S and the measurement point N in the inner layer of the steelmaking slag S, it is preferable to set the distance between the pair of current electrodes A and the pair of potential electrodes V to 1 m. For the same reason, it is also preferable to set the distance between the pair of current electrodes A and the pair of potential electrodes V to 1 m.

[0020] As shown in FIG. 1, the distance D (m) between the midpoint C between the pair of current electrodes A and the pair of potential electrodes V and the measurement point N located inside the electric field is expressed by the following equation (1). D = (a × n + a) / 2 (1) Here, a represents the distance (m: meters) between the pair of current electrodes A and the pair of potential electrodes V, and n represents the value obtained by dividing the distance between the pair of current electrodes A and the pair of potential electrodes V by a. For ease of measurement, n is preferably set to "n=1".

[0021] When a pair of current electrodes A and a pair of potential electrodes V are installed on the surface of the upper layer of the steelmaking slag S, the position of the electric field formed in the depth direction of the inner layer of the steelmaking slag S can be changed by changing the distance between the pair of current electrodes A and the pair of potential electrodes V, or the distance between the pair of current electrodes and the pair of potential electrodes. Specifically, by reducing the distance between the pair of current electrodes A and the pair of potential electrodes V, or the distance between the pair of current electrodes and the pair of potential electrodes, an electric field can be formed in the inner layer of the steelmaking slag S at a position (shallow position) closer to the upper layer of the steelmaking slag S. On the other hand, by increasing the distance between the pair of current electrodes A and the pair of potential electrodes V, or the distance between the pair of current electrodes and the pair of potential electrodes, an electric field can be formed in the inner layer of the steelmaking slag S at a position (deep position) closer to the lower layer of the steelmaking slag S.

[0022] Therefore, by applying electrical exploration (resistivity method) using a pair of current electrodes A and a pair of potential electrodes V, it is possible to calculate the resistivity values ​​at various positions in the depth direction of the inner layer of the steelmaking slag S, and the progress of the aging treatment (moisture penetration status) at various positions in the depth direction of the inner layer of the steelmaking slag S can be grasped.

[0023] Furthermore, by providing an electrode configuration involving a combination of a pair of current electrodes A and a pair of potential electrodes V at multiple locations on the surface of the outer layer of the steelmaking slag S, and calculating the resistivity values ​​in the inner layer of the steelmaking slag S using all of the electrode configurations, the two-dimensional distribution of the progress of the aging treatment can be grasped.

[0024] In addition, on the surface of the outer layer of the steelmaking slag S, electrode configurations involving combinations of a pair of current electrodes A and a pair of potential electrodes V are provided at multiple locations, and the spacing between the pair of current electrodes A and the pair of potential electrodes V, or the spacing between the pair of current electrodes and the pair of potential electrodes, is changed for each of these multiple electrode configurations, and the resistivity values ​​are calculated using all of the electrode configurations, making it possible to grasp the three-dimensional distribution of the progress of the aging treatment.

[0025] When a pair of current electrodes A and a pair of potential electrodes V are installed on the surface of the upper or lower layer of the steelmaking slag S, in order to accurately calculate the resistivity value in the inner layer of the steelmaking slag S, it is preferable that the distance between the pair of current electrodes A and the pair of potential electrodes V, or the distance between the pair of current electrodes and the pair of potential electrodes, is equal to or less than the height of the loaded steelmaking slag S (see arrow T in Figure 2). This is because if the distance between the pair of current electrodes A and the pair of potential electrodes V, or the distance between the pair of current electrodes and the pair of potential electrodes, is larger than the height of the steelmaking slag S, the position of the electric field formed in the depth direction of the inner layer of the steelmaking slag S will be deeper than the thickness of the steelmaking slag S, and the resistivity value in the inner layer of the steelmaking slag S will not be accurately calculated.

[0026] The pair of current electrodes A and the pair of potential electrodes V may also be installed on the side of the steelmaking slag S. In this case, in order to accurately calculate the resistivity value in the inner layer of the steelmaking slag S, it is preferable that the distance between the electrodes or the distance between the pair of current electrodes and the pair of potential electrodes is equal to or less than the width (see arrow W in FIG. 2) or depth distance (see arrow Q in FIG. 2) of the steelmaking slag S. The depth distance means the length of the loaded steelmaking slag S in the depth direction of the drawing.

[0027] Furthermore, the pair of current electrodes A and the pair of potential electrodes V may be installed on the surface of the upper or lower layer of the steelmaking slag S, and may also be installed on the side of the steelmaking slag S. In this case, with respect to the pair of current electrodes A and the pair of potential electrodes V installed on the surface of the upper or lower layer of the steelmaking slag S, it is preferable that the distance between the electrodes or the distance between the pair of current electrodes and the pair of potential electrodes is equal to or less than the height of the steelmaking slag S (see arrow T in Figure 2). In addition, with respect to the pair of current electrodes A and the pair of potential electrodes V installed on the side of the steelmaking slag S, it is preferable that the distance between the electrodes or the distance between the pair of current electrodes and the pair of potential electrodes is equal to or less than the width (see arrow W in Figure 2) or depth distance (see arrow Q in Figure 2) of the steelmaking slag S to be loaded.

[0028] In addition, although the configuration of the current electrode A and the potential electrode V shown in Fig. 1 as an embodiment is a 4-pole arrangement in a dipole-dipole configuration, any configuration of the current electrode and the potential electrode is possible as long as it is possible to calculate the resistivity value in the inner layer of the steelmaking slag S. In other words, the present invention can be applied to a 2-pole arrangement in a pole-pole configuration, a 3-pole arrangement in an equally spaced CPP configuration, and other 4-pole arrangements such as the Wenner arrangement, the Eltlan arrangement, and the Schlumberger arrangement. In view of the accuracy of the calculation of the resistivity value, the dipole-dipole arrangement (4-pole arrangement) is preferable.

[0029] Next, an embodiment of the steelmaking slag aging treatment method according to the present invention will be described with reference to Fig. 2. Fig. 2 shows a schematic configuration diagram of an example of a progress determination device 20. The progress determination device 20 has a moisture supplying device 12, a current electrode A, a potential electrode V, a control device 13, and a storage device 14.

[0030] In this embodiment, the current electrode A and the potential electrode V are provided on the surface of the upper layer ST, which is a part of the outer layer of the steelmaking slag S stacked in the aging treatment site 11, which is the aging site. In the present invention, the current electrode A and the potential electrode V may be installed on any surface of the outer layer of the steelmaking slag S. That is, the current electrode A and the potential electrode V may be installed on any surface of the upper surface, side surface, or lower surface of the stacked steelmaking slag S. Furthermore, the current electrode A and the potential electrode V may be installed in a surface range from the upper surface to the side surface, a surface range from the side surface to the lower surface, or on the upper and lower surfaces. The moisture supplying device 12 receives a control signal from the control device 13 and is capable of supplying moisture to the lower layer SB of the steelmaking slag S based on the control signal. The moisture supplying device 12 is capable of supplying moisture to the lower layer SB of the steelmaking slag S as a water flow, steam, or pressurized steam.

[0031] The control device 13 is composed of a general-purpose information processing device such as a personal computer or a workstation. The control device 13 is, for example, a CPU, and is connected to be able to receive current information and voltage information related to the measurement from the current electrode A and the potential electrode V. The control device 13 reads out a program stored in the storage device 14 into a working area of ​​the main storage unit, and executes the program to realize various processes. The control device 13 receives current information and voltage information related to the measurement from the current electrode A and the potential electrode V, and performs processes based on the information. The control device 13 is connected to be able to generate a control signal based on the processed information and transmit the control signal to the moisture supply device 12. The storage device 14 is, for example, an information recording medium such as an updatable flash memory, a built-in hard disk or a memory card connected via a data communication terminal, and a read / write device for the information recording medium. The storage device 14 previously stores programs for realizing various functions related to the aging process of the slag, data used during the execution of the programs, and the like.

[0032] In this embodiment, the aging treatment method for steelmaking slag may be carried out using the configuration shown in Fig. 2. That is, the aging treatment method for steelmaking slag may include a moisture supply starting step of starting the supply of moisture from the moisture supplying device 12 to the steelmaking slag S, and a resistivity calculation step of calculating the resistivity of the steelmaking slag S using a current electrode A and a potential electrode V installed on the surface of the outer layer of the steelmaking slag S. Then, a progress determination step of determining the progress of the aging treatment based on the resistivity calculated in the resistivity calculation step may be carried out.

[0033] Therefore, by carrying out the steelmaking slag aging treatment method of the present invention, it is possible to easily grasp the progress of the aging treatment in the inner layer of the steelmaking slag S by using the current electrode A and potential electrode V installed on the surface of the outer layer of the steelmaking slag S, without the need to install and remove measuring equipment in the inner layer of the stacked steelmaking slag S.

[0034] Here, before the aging treatment of the steelmaking slag S, the steelmaking slag S to be subjected to the aging treatment may be stacked in the aging treatment plant 11. The steelmaking slag S may be stacked in an amount of 3000 t at a time. It is preferable to stack the steelmaking slag S in an amount of 100 to 10000 t at a time. The steelmaking slag S may be stacked to a height of 3 m using a wheel loader. Although there is no limit to the height of the stack of the steelmaking slag S, it is preferable to set it to 3 m or less from the viewpoint of work safety. The surface of the stacked steelmaking slag S may be leveled in consideration of the installation of the electrodes. It is not necessary to level the surface of the steelmaking slag S if there is no problem with the installation of the electrodes. The method of stacking the steelmaking slag S is not important as long as the above-mentioned amount and stack height can be tolerated.

[0035] First, in the moisture supply starting step, the control device 13 may transmit a control signal to the moisture supplying device 12 to start supplying moisture to the lower layer SB of the steelmaking slag S. The moisture supply may be a water flow supply to the lower layer SB of the steelmaking slag S, a steam supply, or a pressurized steam supply. The moisture may be supplied at a supply rate of 1 t / h at the start of the supply. Taking into account a predetermined processing time required for the aging treatment, the moisture supply rate is preferably set to 5 t / h or more at the start of the supply. In the resistivity value calculation step, the current electrode A and the potential electrode V may measure current information and voltage information in the inner layer of the steelmaking slag S and transmit the measured current information and voltage information to the control device 13. Furthermore, the control device 13 may calculate the resistivity value in the inner layer of the steelmaking slag S based on the received current information and voltage information.

[0036] Furthermore, the current electrode A and the potential electrode V may start measuring current information and voltage information in the inner layer of the steelmaking slag S at the same time as the supply of moisture from the moisture supplying device 12 to the steelmaking slag S, and may continue to periodically measure the current information and voltage information and transmit it to the control device 13. The control device 13 may then continue to periodically calculate the resistivity value in the inner layer of the steelmaking slag S based on the current information and voltage information received periodically.

[0037] Measurement of current information and voltage information in the inner layer of steelmaking slag S, or calculation of the resistivity value in the inner layer of steelmaking slag S, is preferably performed periodically at time intervals of less than one hour in order to capture changes in the resistivity value over time, and more preferably every 10 minutes.

[0038] In the progress determination step, the control device 13 may determine the progress of the aging treatment based on the resistivity value calculated in the resistivity value calculation step. Specifically, the control device 13 may determine whether the water penetration state of the steelmaking slag S that is the target of the aging treatment is sufficient or insufficient based on the result of comparing the calculated resistivity value with a preset threshold value, taking into account past operating records.

[0039] The preset threshold value may be set as an index that can determine, based on past operating results, that the moisture penetration state in the steelmaking slag S is sufficient and the aging treatment can be terminated during the aging treatment of the steelmaking slag S. The preset threshold value may be stored in the memory device 14. In the progress determination process, the control device 13 may read out the preset and stored threshold value from the memory device 14 and perform processing. The resistivity value calculated in the resistivity value calculation process is useful as information that is affected by the distribution state of the substance (moisture) contained in the steelmaking slag S, so the progress of the aging treatment can be easily grasped based on the calculated resistivity value.

[0040] Alternatively, in the progress status determination step, the control device 13 may estimate the amount of permeated water in the steelmaking slag S based on the correspondence relationship between the resistivity value calculated in the resistivity value calculation step and the amount of permeated water in the steelmaking slag S. Specifically, the control device 13 may estimate the amount of permeated water in the inner layer of the steelmaking slag S based on correspondence information indicating the correspondence relationship between the resistivity value and the amount of permeated water in the inner layer of the steelmaking slag S (a value indicating the permeation status of moisture in the inner layer of the steelmaking slag S). In this case, the correspondence information between the resistivity value and the amount of permeated water may be stored in the storage device 14 in advance. The control device 13 may read out the correspondence information between the resistivity value and the amount of permeated water from the storage device 14 and perform processing during the permeated water amount estimation step.

[0041] In the progress status determination step, the control device 13 may perform a control step of controlling the moisture supplying device or may determine the end of the aging treatment when the resistivity value calculated in the resistivity value calculation step becomes less than a preset threshold value. Specifically, the control device 13 may transmit a control signal to the moisture supplying device 12 to reduce the rate at which moisture is supplied to the steelmaking slag S. Alternatively, in the progress status determination step, the control device 13 may determine the end of the aging treatment based on the resistivity value calculated in the resistivity value calculation step becoming less than 700 Ω·m. The "end" of the aging treatment means the stop of the supply of moisture to the steelmaking slag S.

[0042] When the supply of moisture to the lower layer SB of the stacked steelmaking slag S is started, the moisture penetrates from the lower layer SB to the middle layer SM and upper layer ST in order. Then, when the moisture penetrates into the middle layer SM of the steelmaking slag S, the resistivity value calculated from the measurements made by the pair of current electrodes A and the pair of potential electrodes V becomes less than 700 Ω·m. Therefore, the resistivity value in the inner layer of the steelmaking slag S becomes less than 700 Ω·m. Then, when the resistivity value becomes less than 700 Ω·m, the control device 13 may determine the end of the aging treatment in the progress determination step. This makes it possible to improve the quality of the slag material after the aging treatment (specifically, to reduce the expansion rate in a water immersion expansion test).

[0043] In the progress status determination step, when the resistivity value calculated in the resistivity value calculation step is equal to or greater than a preset threshold value, the control device 13 may perform a control step of controlling the moisture supplying device or an additional processing time calculation step of calculating an additional processing time required for the aging treatment. Specifically, the control device 13 may transmit a control signal to the moisture supplying device 12 to increase the supply rate of moisture to the steelmaking slag S. Alternatively, the control device 13 may calculate the additional processing time required for the aging treatment based on the difference between the calculated resistivity value and a preset threshold value.

[0044] That is, the steelmaking slag aging treatment method of the present invention may further include, after the progress status determination step, an additional treatment time calculation step of calculating the additional treatment time required for the aging treatment or a control step of controlling the moisture supplying device.

[0045] Furthermore, slag material may be produced by using the above-described aging method for steelmaking slag according to the present invention. That is, as a method for producing slag material, the aging method for steelmaking slag according to the present invention may be used to produce slag material of improved quality that can be used as roadbed material or coarse aggregate for concrete. In this case, the slag material produced preferably has a resistivity measured after treatment of less than 700 Ω·m, due to the fact that it is produced using the aging method for steelmaking slag according to the present invention.

[0046] As described above, the control device 13 may determine the end of the aging treatment when the calculated resistivity value is less than 700 Ω·m. Instead of less than 700 Ω·m, the effective resistivity value for the moisture penetration state in the inner layer of the steelmaking slag S is preferably 500 Ω·m or less, and more preferably 200 Ω·m or less. This makes it possible to further improve the quality of the slag material after the aging treatment (specifically, to reduce the expansion rate in a water immersion expansion test).

[0047] As mentioned above, by providing an electrode configuration that combines a pair of current electrodes A and a pair of potential electrodes V at multiple locations on the surface of the outer layer of the steelmaking slag S, it is possible to grasp the two-dimensional or three-dimensional distribution of the progress of the aging treatment in the inner layer of the steelmaking slag S.

[0048] In this case, the resistivity value based on the actual measurement value calculated from the information (current information and voltage information) measured at each position may be corrected based on the resistivity values ​​at multiple locations. Specifically, the resistivity value calculated for each position of the inner layer of the steelmaking slag S is a local value that does not take into account the surrounding conditions of each position to be measured. For this reason, when the steelmaking slag S contains impurities, the resistivity value based on the actual measurement value will show an extreme value. On the other hand, since the moisture that penetrates into the inner layer of the steelmaking slag S has linearity in two and three dimensions, it is not preferable to directly apply the resistivity value based on the actual measurement value in order to accurately grasp the progress of the aging treatment.

[0049] Therefore, in order to accurately grasp the two-dimensional or three-dimensional distribution of the progress of the aging treatment in the inner layer of the steelmaking slag S, the resistivity values ​​based on the actual measured values ​​at each position may be corrected by performing an approximation process (inverse analysis) using multiple resistivity values ​​collected in two or three dimensions.

[0050] From the above, when grasping the two-dimensional or three-dimensional distribution of the progress of the aging treatment in the inner layer of the steelmaking slag S, in the resistivity calculation step, the resistivity may be calculated based on the actual measured value and the resistivity may be corrected based on the calculated actual measured value. Then, the end of the aging treatment may be determined based on the corrected resistivity value being less than 700 Ω·m. Moreover, instead of making the corrected resistivity value less than 700 Ω·m, it is preferable to make it 500 Ω·m or less, and more preferably 200 Ω·m or less. This makes it possible to further improve the quality of the slag material after the aging treatment (specifically, to reduce the expansion rate in a water immersion expansion test). EXAMPLES

[0051] Next, the results of aging treatment of steelmaking slag by the steelmaking slag aging treatment method according to the present invention will be described. The examples were carried out for various steelmaking slag, with 10 to 10,000 tons of steelmaking slag stacked to a height of 1 to 3 m in the aging treatment plant shown in Fig. 2. The width of the stacked steelmaking slag was 20 m, and the depth was 10 m.

[0052] The water was supplied to the steel slag in the form of a water flow, steam, or pressurized steam. The water supply rate was set at 0.0 to 20.0 t / h when the aging treatment of the steel slag was started. The electrode configuration relating to the combination of a pair of current electrodes and a pair of potential electrodes was set at any of the following positions on the top, side, bottom, range from the top to the side, range from the side to the bottom, and range including the top and side of the loaded steel slag for each example. The distance between the pair of current electrodes and the pair of potential electrodes set on the surface of the steel slag was set to 1 to 4 m, and the resistivity was calculated. The distance between the pair of current electrodes and the pair of potential electrodes set on the surface of the steel slag was set to the same as the distance between the pair of current electrodes and the pair of potential electrodes. The current information and voltage information for calculating the resistivity were measured at time intervals of 5 to 120 min.

[0053] In the examples, the moisture supply rate supplied to the steelmaking slag at the start of the aging treatment ("moisture supply rate" in Table 1) was confirmed. In addition, the "minimum resistivity value reached Ω·m", which is the minimum resistivity value calculated during the aging treatment, the total processing time required for the aging treatment, and the moisture supply rate changed after calculation of the resistivity value (minimum resistivity value reached) ("changed moisture supply rate" in Table 1) were confirmed. The "total processing time" was the processing time predetermined in each example, or, when an additional processing time was calculated, the total time of the predetermined processing time and the additional processing time.

[0054] Furthermore, after the aging treatment, the "resistivity measurement value after treatment Ω·m" was measured on the slag material after the aging treatment, and the "quality of the slag material after treatment" was also confirmed as the quality of the slag material. The "quality of the slag material after treatment" was confirmed based on the water immersion expansion test in "JIS A 5015:2018 Steel slag for road use." The "quality of the slag material after treatment" was evaluated as "Good" when the expansion rate was 1% or less, and as "Poor" when the expansion rate exceeded 1%. The results of the examples are shown in Table 1.

[0055] [Table 1]

[0056] In Comparative Example 1, a pair of current electrodes and a pair of potential electrodes were installed on the upper surface of the steelmaking slag, and the distance between the electrodes ("electrode arrangement distance" in Table 1) was set to 4 m. As a result, the position of the electric field formed in the depth direction of the inner layer of the steelmaking slag was deeper than the thickness of the steelmaking slag, and an accurate resistivity value could not be calculated.

[0057] In Comparative Example 2, the water supplied to the steelmaking slag was set to a water flow, but water was not actually supplied, so the aging treatment of the steelmaking slag did not progress. In other words, the minimum resistivity reached was the same as the resistivity value of the steelmaking slag at the start of the aging treatment (2000 Ω m), confirming that the penetration of water into the inner layer of the steelmaking slag did not progress.

[0058] In Examples 1 to 18, calculation of the resistivity value of the steelmaking slag was started when the supply of moisture to the steelmaking slag began, and the resistivity value was continued to be calculated periodically, making it possible to easily grasp the progress of the aging treatment in the inner layer of the steelmaking slag.

[0059] In addition, in Examples 1 to 10 and 14 to 18, the "minimum resistivity achieved value Ω·m" during the aging treatment was less than 700 Ω·m, and the "measured resistivity value after treatment Ω·m" was also less than 700 Ω·m after the aging treatment, so the "slag material quality after treatment" was evaluated as "Good."

[0060] From the above, it has been confirmed that the slag aging treatment method of the present invention makes it possible to easily grasp the progress of the aging treatment in the inner layer of the stacked steelmaking slag without the need to install and recover measuring equipment in the inner layer. [Explanation of symbols]

[0061] 11 Aging treatment plant 12 Moisture supply device 13 Control device 14 Storage device 20 Progress Judgment Device A current electrode V potential electrode S Steel slag C midpoint D Distance N measurement points ST upper layer SM middle class SB lower layer

Claims

1. A method for aging steelmaking slag, comprising: a moisture supply starting step of starting to supply moisture from a moisture supplying device to the steelmaking slag; a resistivity calculation step of calculating a resistivity value of the steelmaking slag using a current electrode and a potential electrode installed on a surface of the steelmaking slag; a progress status determination step of determining a progress status of the aging treatment based on the resistivity value calculated in the resistivity value calculation step; A method for aging steelmaking slag, comprising the steps of:

2. The steelmaking slag aging treatment method according to claim 1 , wherein the progress determination process determines the end of the aging treatment based on the resistivity value calculated in the resistivity value calculation process becoming less than a threshold value.

3. The method for aging steelmaking slag according to claim 2, wherein the threshold value is 700 Ω·m.

4. The steelmaking slag aging treatment method according to claim 1, further comprising, after the progress status determination process, an additional treatment time calculation process for calculating additional treatment time required for the aging treatment or a control process for controlling the moisture supply device.

5. A method for producing a slag material, comprising producing a slag material by the steelmaking slag aging treatment method according to any one of claims 1 to 4.

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