Method for producing water-granulated nonferrous metal slag

Abstract

To provide a technology capable of realizing, by a simple method, a reduction in work load such as cleaning of a flow path, in a method for producing a water-granulated nonferrous metal slag including a cooling step in which cold water heated by water granulation is treated with a heat exchanger to circulate and reuse the water.SOLUTION: A method for producing a water-granulated nonferrous metal slag includes: a rapid cooling and crushing step of water-granulating a molten nonferrous metal slag; a removal step of removing the slag from a water granulation tank in a state where the slag water-granulated in the rapid cooling and crushing step is contained in the tank; and a step of cooling water in the water granulation tank, the temperature of which has risen due to the water granulation in the rapid cooling and crushing step. The cooling water in water storage equipment obtained in the cooling step is supplied as cold water used in the rapid cooling and crushing step to be used as granulation water for water-granulating the molten nonferrous metal slag. Furthermore, in at least one of the rapid cooling and crushing step, the removal step of the slag, and the cooling treatment step, a polymer coagulant is added so that the agent, the nonferrous metal slag, and the cold water are mixed and coexist in a turbulent state with a flow velocity of 0.5 m / s or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for producing non-ferrous metal slag obtained secondarily when dry-smelting non-ferrous metals, and particularly to a method for producing non-ferrous metal granulated slag in which molten non-ferrous metal slag from a heating furnace is granulated with cold water and the cold water is circulated (reused) for granulation. More specifically, when producing granulated slag by rapidly cooling (granulating) molten non-ferrous metal slag with cold water (granulation water), by effectively using a polymer coagulant, it is extremely convenient to convert the water that has been heated for use in granulation and was conventionally frequently generated into cold water (cooling water) that can be reused for granulation, and it becomes possible to reduce the frequency of blockage of the flow path of a cooling treatment device (heat exchanger), and the present invention relates to a technique for a method for producing industrially useful non-ferrous metal granulated slag that realizes smooth circulation and reuse of cooling water.

Background Art

[0002] Non-ferrous metal slag (hereinafter also referred to as non-ferrous slag) is obtained secondarily in the dry-smelting process of non-ferrous metals such as copper, lead, and zinc, and is used, for example, as an iron source for cement raw materials, sand blasting, fine aggregate, caisson (filling material), etc. Among them, copper slag and ferronickel slag have been standardized by JIS as slag aggregates for concrete and are being used. Non-ferrous metal slag, which can become a useful resource as described above and is expected to have various uses, is generally produced by rapidly cooling or slowly cooling molten slag and then subjecting it to crushing and particle size adjustment. The non-ferrous metal slag thus obtained usually has the shape of sand or gravel.

[0003] Copper slag is known to have the characteristic of high density and angular particle shape. For example, the main components of copper slag are 50% or more of iron (FeO) and 30% or more of silica (SiO2), and it also contains lime (CaO), alumina (Al2O3), etc. Granulated slag of ferronickel is sand-like with a diameter of 5 mm or less and hard. Its main components are 50% or more of silica (SiO2) and 30% or more of magnesia (MgO), and it also contains about 5% to 10% of iron (FeO). Since both copper slag and ferronickel have a unit volume weight greater than that of sand, they are generally more advantageous than sand as backfill materials and are also being utilized. In addition, there are reports that using ferronickel slag as an aggregate contributes to the long life of asphalt pavement. Also, non-ferrous metal slag, unlike blast furnace slag for steel, has almost no hydraulicity.

[0004] As slag, granulated slag obtained by rapidly cooling blast furnace slag, which is obtained when extracting iron from iron ore, with high-pressure water is well-known and widely used because of its large production volume. The manufacturing method of blast furnace slag, as a by-product of steel production, has been established and generalized. On the other hand, for non-ferrous metal slag, the smelting furnace differs depending on the target metal, and the scale is also different for each. Methods for granulating non-ferrous metal slag include, in addition to the method of rapidly cooling with water and granulating, methods such as air granulation by rapid cooling with air and slow granulation by cooling in the atmosphere. In the present invention, among these methods, the improvement of the manufacturing method of granulated slag of non-ferrous metals that performs granulation by circulating and using cold water is particularly targeted.

[0005] As a method of granulating non-ferrous metal slag by granulation through granulation, the following methods are known. For example, the slag discharged in the dry smelting process of copper is generally made into granulated slag with a particle size of about 2 mm by performing so-called "granulation" in which the molten slag is dropped into the granulation water flow of the slag to cause rapid solidification (see Patent Document 1). In the methods described in FIGS. 1 and 5 attached to Patent Document 1, high-temperature molten slag is charged into a tank containing granulation water for the slag, granulation is performed with the granulation water for the slag in the tank, and after the granulated slag is taken out of the granulation water for the slag, the granulation water for the slag heated by granulation is cooled by a heat exchanger and recycled.

[0006] In Patent Document 2, a method for treating granulation water for slag is proposed to prevent the adhesion of scale to the flow path for transporting granulation water for slag when recycling the granulation water used for granulating the slag generated in non-ferrous metal smelting without discharging it outside the system. And the copper slag separated and discharged from the smelting furnace in the copper smelting process is supposed to be pulverized by high-pressure water in the granulation pit. In Patent Document 3, a circulation method of granulation water for slag is proposed in which the granulation water containing heavy metals is bled off from the granulation water obtained by granulating the slag generated in the smelting furnace, and the treated water after removing the heavy metals is recycled as granulation water again without discharging it. Also in the case of Patent Document 3, the granulation water obtained by granulating the slag generated in the smelting furnace with the granulation water stored in the cold water tank is recycled. In all of the above-mentioned prior arts, granulated slag is produced from molten slag generated in a copper smelting furnace or the like using granulation water in a granulation tank (granulation pit), and all of them relate to technologies that have considered the granulation water to be recycled.

[0007] In Patent Document 4, in the wastewater treatment method of a copper smelting plant having a granulation process for producing granulated slag from molten slag generated in a copper smelting furnace, the usefulness of adjusting the pH value of the granulation water to be recycled within the range of 7.0 to 8.5 at a specific point in time is disclosed. Further, in Patent Document 5, as a method for obtaining copper smelting granulated slag (karami) particles with a low arsenic elution amount, an inorganic flocculant and an organic flocculant are added to the circulating granulation water, the pH is adjusted to 5 to 10, and after removing suspended matter in a sedimentation tank, it is proposed to reuse it as granulation water. Regarding the granulation method, the karami discharged from the furnace flows into the granulation trough through the karami trough, and is granulated by the granulation water flowing down the granulation trough and falls into the granulation pit as granulated karami. Further, in Patent Document 6, it is proposed that by controlling the pH of the circulating granulation water, the obtained slag has a reduced elution of arsenic and cadmium. The above-mentioned prior arts also relate to technologies that have examined the granulation water to be recycled, and in particular, the effect of reducing the elution amount of arsenic and the like from the granulated non-ferrous metal slag by making the granulation water have a specific configuration is described.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0009] In view of the above-described current situation, the present inventors have found that there are the following problems in the cooling water that is circulated and used as granulation water, particularly in the method of rapidly cooling with water and granulating, which is a general method for granulating non-ferrous metal slag. As exemplified above, when producing non-ferrous metal granulated slag, after the step of spraying pressurized water (cooling water) into the slag trough in the transfer path of the molten non-ferrous metal slag (high-temperature molten slag) to rapidly cool and granulate it, or after the step of rapidly solidifying and granulating the high-temperature molten slag by dropping or flowing it into the slag granulation water flow in the granulation tank (granulation pit) or in the granulation trough where granulation water flows into the granulation tank, the granulated non-ferrous metal slag that has settled in the granulation tank (granulation pit) is taken out from the granulation tank to the outside. As a result of examining the granulated non-ferrous metal slag that has settled in the granulation tank, the present inventors have recognized that if the granulated non-ferrous metal slag that has settled in the granulation tank (granulation pit) can be made into a form that is more abundant and easier to take out, the recovery rate of the granulated non-ferrous metal slag can be improved. In addition, since the amount of fine particles of non-ferrous metal slag remaining in the water in the granulation tank after taking it out can be reduced, it is extremely useful for the cooling treatment performed to recycle the granulation water whose temperature has risen due to granulation.

[0010] In the process of examining the method of granulating non-ferrous metal slag by granulation, the present inventors have recognized that there are specific problems with non-ferrous metal slag, particularly in the cooling treatment step of the granulation water that has been used and heated. As described above, in the prior art, the granulated non-ferrous metal slag in the granulation tank (granulation pit) is taken out to the outside as a sediment. The heated water after taking out the sediment is introduced into a sedimentation tank (sedimentation pit) to precipitate fine particles, and the supernatant water from which the fine particles have been separated is introduced into a cooler and cooled to a temperature at which it can function as granulation water in the cooler, and then used again as granulation water (cold water) for non-ferrous metal slag. When cooling the heated water, a cooling treatment device (heat exchanger) such as a plate heat exchanger or a tubular heat exchanger is used.

[0011] In contrast, the inventors of the present invention have recognized that a large amount of non-ferrous metal slag with a small particle size (fine particles) remains in the heated water supplied to the above-described cooling treatment apparatus (heat exchanger), and that specific technical problems to be solved have arisen due to this. Specifically, the fine particles that are not taken out to the outside among the water-granulated non-ferrous metal slag are difficult to settle in the water-granulation tank (water-granulation pit) or the sedimentation tank (sedimentation pit), and thus circulate through the narrow flow path of the cooling treatment apparatus (heat exchanger) together with the water to be cooled. As a result, the flow path is easily blocked, which causes a decrease in the heat exchange efficiency of the cooling treatment apparatus (heat exchanger), and it is necessary to frequently clean the flow path and perform equipment maintenance, resulting in an increased work load.

[0012] In addition, the inventors of the present invention have recognized that the fine particles remaining in the water introduced from the water-granulation tank (water-granulation pit) into the sedimentation tank (sedimentation pit) or in the water to be cooled, which is introduced from the sedimentation tank (sedimentation pit) into the cooling treatment facility, are angular or hard, and in addition to the above problems, they are also the cause of the following other problems. That is, when continuously producing non-ferrous metal water-granulated slag by using a water-granulation method and circulating and using cold water (water-granulation water), the angular or hard fine particles remaining in the heated water to be treated cause wear on the flow path in the above-described cooling treatment apparatus, the flow path for transferring the heated water to be treated, and peripheral equipment, etc., and are a factor that impairs the durability of the apparatus and the like.

[0013] In view of the above technical problems, the inventors of the present invention believe that if the amount of sediment taken out from a granulation tank or the like to the outside can be increased, and the amount of fine particles remaining in the water to be cooled can be reduced by a simple means, the frequency of blockage of the flow path of a cooling treatment device (heat exchanger) can be reduced, the problem of wear of the flow path, peripheral equipment, etc. can be suppressed, and as a result, in addition to improving the production efficiency in the method for producing non-ferrous metal slag by granulation performed continuously, it becomes possible to enhance the durability of the cooling treatment device and related treatment facilities, etc., and above all, it becomes possible to reduce the workload in cleaning the flow path, etc. which had to be performed frequently, and it becomes possible to provide an industrially useful production method capable of continuously and economically producing non-ferrous metal granulated slag.

[0014] Therefore, an object of the present invention is to develop a technology that can improve production efficiency by a simple method and enhance the durability of treatment facilities, etc. in a method for producing non-ferrous metal slag by granulation including a cooling treatment step of cooling the heated cold water used for granulation with a cooling treatment device (heat exchanger) so that it can be recycled as granulation water. More specifically, an object of the present invention is to reduce the frequency of blockage of the flow path of a cooling treatment device (heat exchanger) that has increased the workload, and to suppress the problem of wear occurring in the flow path, peripheral equipment, etc. Therefore, it is to develop a useful technology that can effectively reduce the amount of fine particles contained in the heated water used for granulation after taking out the granulated non-ferrous metal slag, which is the object of the cooling treatment performed by the cooling treatment device (heat exchanger), by a simple means.

Means for Solving the Problems

[0015] The above object is achieved by the following present invention. That is, the present invention provides the following method for producing non-ferrous metal granulated slag. [1] A method for producing non-ferrous metal granulated slag by granulation using recycled cold water in non-ferrous metal smelting, comprising: A step of rapidly cooling and pulverizing the molten non-ferrous metal slag by granulating the molten non-ferrous metal slag from the heating furnace with cold water; A step of taking out the comminuted non-ferrous metal slag contained in a granulation tank in a state where the non-ferrous metal slag granulated in the quenching and comminution step is accommodated, to the outside of the tank, In the quenching and comminution step, in order to recycle the water in the granulation tank whose temperature has risen due to granulating the molten non-ferrous metal slag, as cooling water to be used again for granulation, there is a cooling treatment step of cooling the water whose temperature has risen, In the cooling treatment step, cooling treatment of the water whose temperature has risen is performed using a plate heat exchanger or a tube heat exchanger, and the cooling water in the water storage facility obtained by the cooling treatment is used as the cooling water for granulating the molten non-ferrous metal slag with cold water in the quenching and comminution step of the non-ferrous slag, and the cooling water for granulation is recycled, and In at least any one of the quenching and comminution step, the step of taking out the non-ferrous metal slag, and the cooling treatment step, a polymer flocculant is added so that the polymer flocculant, the comminuted non-ferrous metal slag or the non-ferrous metal slag before being in a comminuted state, and the cold water are mixed and coexist in a turbulent flow state with a flow velocity of 0.5 m / second or more. A method for producing non-ferrous metal granulated slag, characterized in that.

[0016] Preferred forms of the method for producing non-ferrous metal granulated slag of the present invention having the above configuration include the following two forms. [2] In the quenching and comminution step, pressurized water (cooling water) is sprayed into a slag trough in the transfer path of the molten non-ferrous metal slag from the heating furnace to quench the transferred molten non-ferrous metal slag to perform granulation, and the addition of the polymer flocculant is performed at any position while the non-ferrous metal slag is being transferred in the slag trough, and / or the addition of the polymer flocculant is performed at any position from the outlet of the slag trough before the non-ferrous metal slag is accommodated in the granulation tank, and / or the addition of the polymer flocculant is performed in the water storage facility. The method for producing non-ferrous metal granulated slag according to [1] above. [3] In the rapid cooling and pulverization step, the molten non-ferrous metal slag from the heating furnace is transferred into the cold water in the turbulent water granulation tank and granulated with the cold water, and / or the molten non-ferrous metal slag from the heating furnace is charged into the water granulation trough through which cold water (water granulation water) flows into the water granulation tank to perform granulation, and the addition of the polymer coagulant is carried out in the turbulent water granulation tank, and / or the addition of the polymer coagulant is carried out in the water granulation water flow in the water granulation trough into which the molten non-ferrous metal from the heating furnace is charged, and / or the addition of the polymer coagulant is carried out in the water storage facility. The method for producing non-ferrous metal granulated slag according to [1] above.

[0017] Preferred embodiments of the method for producing non-ferrous metal granulated slag of the present invention having the above-described configuration include the following. [4] The method for producing non-ferrous metal granulated slag according to any one of [1] to [3] above, wherein the polymer coagulant is a cationic or amphoteric copolymer derived from a raw material monomer containing 5 mol% or more of any one or both of the monomers represented by the following general formula (1) and the following general formula (2) as essential components, and having the copolymer as the main component. TIFF2025111918000002.tif62170 [In the above general formulas (1) and (2), R1 and R2 each independently represent CH3 or C2H5, R3 represents H, CH3 or C2H5, and X - represents an anionic counter ion. ] [5] The method for producing non-ferrous metal granulated slag according to any one of [1] to [4] above, wherein the water in the water granulation tank whose temperature has risen due to granulating the molten non-ferrous metal slag is directly cooled in the cooling treatment step. [6] The water in the water granulation tank whose temperature has risen due to granulating the molten non-ferrous metal slag is introduced into a sedimentation pit, and the granulated non-ferrous metal slag particles remaining in the introduced water in the sedimentation pit are sedimented, and the supernatant water of the sedimentation pit is cooled in the cooling treatment step. The method for producing non-ferrous metal granulated slag according to any one of [1] to [4] above.

[0018] Preferred embodiments of the method for producing a non-ferrous metal granulated slag of the present invention having the above-described configuration include the following. [7] The method for producing a non-ferrous metal granulated slag according to any one of [1] to [6] above, wherein the components of the non-ferrous metal slag contain 35% or less of CaO, or 5% or more of FeO, or contain 35% or less of CaO and 5% or more of FeO, based on the mass standard of oxide notation. [8] The method for producing a non-ferrous metal granulated slag according to any one of [1] to [7] above, wherein the non-ferrous metal slag is a slag obtained secondarily when smelting at least any non-ferrous metal selected from the group consisting of copper, lead, and zinc.

Advantages of the Invention

[0019] According to the present invention, in a method for producing a granulated non-ferrous metal slag including a cooling treatment step in which heated cold water used for granulation is cooled by a cooling treatment device (heat exchanger) and recycled as granulation water, it is possible to improve the production efficiency and enhance the durability of processing equipment and the like in a simple manner. In particular, it is possible to provide a technology capable of reducing the work load such as cleaning of the flow path that has been frequently required. More specifically, according to the present invention, by effectively reducing the amount of fine particles remaining in the heated water used for granulation after taking out the granulated non-ferrous metal slag, which is the object of the cooling treatment performed by the cooling treatment device (heat exchanger), by a simple means, it is possible to reduce the frequency of blockage of the flow path and the like of the cooling treatment device (heat exchanger) caused by the fine particles. As a result, it is possible to reduce the frequency of cleaning of the flow path and the number of equipment maintenance that have been frequently required, thereby realizing a reduction in the work load. In addition, according to the present invention, it is possible to suppress the problem of wear occurring in the flow path and peripheral instruments and the like caused by the fine particles remaining in the water, and it is possible to provide a method for producing a non-ferrous metal granulated slag excellent in economy that can obtain practically useful effects.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0021] The present invention will be described in detail below by way of preferred embodiments. As described above, the inventors of the present invention have found that in the method for producing non-ferrous metal granulated slag in which granulation is carried out by circulating cold water, there is a need to frequently clean the flow path and maintain the devices and equipment, which increases the work load. In some cases, it may cause damage to the durability of the device. As a result of intensive studies on the fact that a large amount of small-sized non-ferrous metal slag (fine particles) remains in the heated water after granulation supplied to the cooling treatment device (heat exchanger), the present invention has been achieved. The inventors of the present invention have found an extremely simple method capable of reducing the large amount of fine particles remaining in the heated water after granulation (after use) to be treated in the cooling treatment step without changing the granulation flow and the water cooling treatment flow of the conventional method for producing non-ferrous metal granulated slag. Specifically, the present invention has been achieved by finding that the technical problem of frequently cleaning the flow path and maintaining the devices and equipment in the prior art, which increases the work load, can be effectively reduced by a simple means of using a polymer coagulant at the point defined in the present invention in the granulation flow and the water cooling treatment flow of the conventional method for producing non-ferrous metal granulated slag.

[0022] The method for producing non-ferrous metal granulated slag of the present invention can basically be applied to any method that has been conventionally used, such as a granulation method in which cooling water (pressurized water) is sprayed onto molten slag for granulation (hereinafter also referred to as "the first granulation form"), and a method in which molten slag is poured into the cooled flowing water of a granulation trough or a granulation tank (hereinafter also referred to as "the second granulation form"). Hereinafter, the flows of these granulation methods will be described using representative examples.

[0023] The method for producing non-ferrous metal granulated slag of the present invention performs granulation of molten slag by circulating and using cold water, and includes a rapid cooling and pulverizing step of granulating the molten non-ferrous metal slag from the heating furnace with cold water, and a step of taking out the granulated non-ferrous metal slag from the granulation tank in a state where the granulated non-ferrous metal slag granulated in the rapid cooling and pulverizing step is accommodated, to the outside. And a cooling treatment step of cooling the water in the granulation tank whose temperature has risen due to granulating the molten non-ferrous metal slag in the rapid cooling and pulverizing step, for recycling it again as the cold water used for granulation. In the cooling treatment step, the water whose temperature has risen is cooled using a plate heat exchanger or a tubular heat exchanger, and the cooling water in the water storage facility obtained by the cooling treatment is used as the cold water used in the rapid cooling and pulverizing step of the non-ferrous slag to granulate the molten non-ferrous metal slag with cold water. It is recycled as granulation water, and the cold water for granulation is circulated and used. And a polymer coagulant is added in at least one of the rapid cooling and pulverizing step, the non-ferrous metal slag taking-out step, and the cooling treatment step, so that the polymer coagulant, the non-ferrous metal slag before becoming the granulated non-ferrous metal slag, and the cold water are mixed in a turbulent flow state with a flow velocity of 0.5 m / second or more and coexist.

[0024] Hereinafter, the method for manufacturing non-ferrous metal granulated slag of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an outline of a manufacturing flow of an example of the "first granulation form", and FIG. 2 is a schematic diagram showing an outline of a manufacturing flow of an example of the "second granulation form". Although a sedimentation pit is provided in both schematic diagrams, it is not necessarily required in the present invention. The reason is that in the manufacturing method of the present invention, by effectively using a polymer coagulant, the granulated non-ferrous metal slag quickly coagulates and quickly settles in the granulation tank, so that the non-ferrous metal granulated slag can be taken out from the granulation tank to the outside in a good state. This point will be described later. However, in the present invention, in the cooling treatment step performed after the step of taking out the non-ferrous metal slag, it is desired that the water in the granulation tank whose temperature has risen due to granulation and is supplied to a plate heat exchanger or a tubular heat exchanger has as little remaining fine particles as possible. Therefore, as shown in FIGS. 1 and 2, providing a sedimentation pit is a preferred form. That is, by providing a sedimentation pit, the fine particles in the water whose temperature has risen and is supplied to the heat exchanger can be reduced, so the frequency of blockage of the flow path is reduced, and a more stable operation with a reduced work load becomes possible.

[0025] The differences between the first granulation form shown in FIG. 1 and the second granulation form shown in FIG. 2 are as follows. First, in the first granulation form, granulation is performed by spraying pressurized water (cooling water) into the slag trough in the transfer path of the molten non-ferrous metal slag from the heating furnace. On the other hand, in the second granulation form, in the example shown in FIG. 2, the molten slag is put into the granulation trough through which cold water for introducing cold water into the granulation tank flows, and granulation is performed in the granulation tank. As the second granulation form, for example, the molten slag may be directly put into the granulation trough containing cold water without passing through the granulation trough (not shown). The first granulation form of the present invention and the second granulation form of the present invention are the same in both the step of taking out the granulated non-ferrous metal slag and the cooling treatment step of the water whose temperature has risen used for granulation, except that the configuration of the rapid cooling and pulverization step of the molten slag is different as described above. The important point in the method for manufacturing non-ferrous metal granulated slag of the present invention lies in the method of using the polymer coagulant applied to the above-described conventional manufacturing flow, and such a configuration realizes obtaining a remarkable effect of the present invention.

[0026] The method for producing non-ferrous metal granulated slag of the present invention is characterized in that a polymer coagulant is added in at least one of the steps of the rapid cooling and pulverization step of molten slag, the step of taking out the granulated non-ferrous metal slag, and the cooling treatment step of the water whose temperature has risen used for granulation, and the polymer coagulant, the non-ferrous metal slag before it becomes the granulated non-ferrous metal slag, and the cold water for granulation are configured to be mixed and coexist in a turbulent flow state with a flow velocity of 0.5 m / second or more. According to the study by the present inventors, due to the above configuration, the molten slag is granulated in a good state, and the non-ferrous metal slag accommodated in the granulation tank is in a state where fine particles quickly coagulate with coarse particles and settle. As a result, the amount of fine particles remaining in the water after taking out the granulated non-ferrous metal slag in a coagulated state from the granulation tank is less in each stage compared to the case where the polymer coagulant is not added with the above-described specific configuration. For this reason, the water whose temperature has risen by being used for granulation of the molten slag to be cooled using a plate heat exchanger or a tubular heat exchanger has a significantly smaller amount of fine particles remaining in the water compared to the water that was the object of cooling treatment in the prior art. This means that the problem of frequent blockage of the flow path caused by the fine particles remaining in the water circulating in the narrow flow path of the cooling treatment device (heat exchanger) can be reduced, the number of times of cleaning the flow path can be reduced, and the frequency of equipment maintenance can be suppressed, so that it becomes possible to reduce the work load in the method for producing non-ferrous metal granulated slag.

[0027] Regarding the timing of adding a polymer coagulant that characterizes the method for producing non-ferrous metal granulated slag of the present invention, an explanation will be given with reference to the drawings. In the first granulation form in which pressurized water (cooling water) is sprayed into a slag trough located in the transfer path of the molten non-ferrous metal slag from the heating furnace to perform granulation, the addition of the polymer coagulant (hereinafter also referred to as the chemical) is carried out at any position while the non-ferrous metal slag is being transferred in the slag trough, as shown in Example 1-1 of the chemical addition location in FIG. 1, or at any position before the non-ferrous metal slag is accommodated in the granulation tank, as shown in Example 1-2 of the chemical addition location in FIG. 1, or in a water storage facility that stores the cooling water obtained by cooling treatment in a cooling treatment device (heat exchanger), as shown in Example 1-3 of the chemical addition location in FIG. 1. When the addition of the polymer coagulant is carried out at the chemical addition location example 1-3, the cold water in the water storage facility becomes pressurized water (cooling water) that is sprayed into the slag trough to perform granulation. Therefore, in terms of the relationship with the non-ferrous metal slag, it is equivalent to adding the polymer coagulant at the chemical addition location example 1-1.

[0028] In the second granulation form, in which the molten non-ferrous metal slag from the heating furnace is transferred into the cold water in a turbulent granulation tank and granulated with the cold water, or the molten non-ferrous metal slag is introduced into a granulation trough through which cold water for introducing cold water into the granulation tank flows and granulated in the granulation tank, the addition of the polymer coagulant is carried out at at least any one of the following three locations. That is, as shown in Example 2-1 of the chemical addition location in FIG. 2, it is added into the granulation water flow in the granulation trough into which the molten non-ferrous metal from the heating furnace is introduced, or as shown in Example 2-2 of the chemical addition location in FIG. 2, it is added into the turbulent granulation tank, or as shown in Example 2-3 of the chemical addition location in FIG. 2, it is added into a water storage facility that stores the cooling water obtained by cooling treatment in a cooling treatment device (heat exchanger). The addition of the polymer coagulant is carried out at at least any one of the three locations selected.

[0029] According to the study by the present inventors, in the first granulation form and the second granulation form, by adding a polymer coagulant at at least any of the above-described locations, the polymer coagulant, the non-ferrous metal slag before becoming the granulated non-ferrous metal slag, and the cold water used for granulation can be mixed and coexist in a turbulent flow state with a flow velocity of 0.5 m / second or more. According to the study by the present inventors, by configuring as described above, the fine particles of the granulated non-ferrous metal slag quickly coagulate with the coarse particles and quickly settle. As a result, according to the present invention, it is possible to significantly reduce the amount of fine particles remaining in the water after the granulated non-ferrous metal slag is taken out to the outside, so that good granulation with reduced work load is possible in the method for producing granulated non-ferrous metal slag that performs granulation using recycled cold water.

[0030] The polymer coagulant used in the present invention is not particularly limited, and for example, drugs such as organic flocculants selected from acrylic-based, polyamine-based, and diallylammonium-based compounds can be used. According to the study by the present inventors, for example, cationic or amphoteric copolymers described in Japanese Patent No. 6068112, Japanese Patent No. 6374157, Japanese Patent No. 6374351, and Japanese Patent No. 6374352, and drugs such as cationic or amphoteric crosslinked water-soluble polymers having a crosslinked structure described in Japanese Patent No. 6387337 can be used.

[0031] Particularly preferred as the polymer coagulant characterizing the method for producing granulated non-ferrous metal slag of the present invention is a polymer coagulant mainly composed of a cationic or amphoteric copolymer derived from a raw material monomer containing 5 mol% or more of either one or both of the monomers represented by the following general formula (1) and the following general formula (2) as essential components. As commercially available products, for example, liquid ion-bonded water treatment agent Kayee Relief NCS-8104 (trade name, manufactured by Nippon Steel & Sumikin Environment Co., Ltd.) can be preferably used. Among them, cationic drugs are particularly preferred.

[0032] TIFF2025111918000003.tif62170In the above general formulas (1) and (2), R1 and R2 each independently represent CH3 or C2H5, R3 represents H, CH3 or C2H5, and X - represents an anionic counter ion.]

[0033] According to the studies of the present inventors, what is important in the present invention is that the non-ferrous metal slag that is water-granulated and has various sizes is configured to be violently mixed and coexist with the above-described chemicals. Specifically, the water-granulated non-ferrous metal water-granulated slag and the non-ferrous metal slag before water granulation, the cold water for water granulation, and the above-described chemicals are mixed in a turbulent flow state with a flow velocity of 0.5 m / second or more, and a remarkable effect of the present invention can be obtained by configuring them to coexist. The addition amount of the chemical added to characterize the present invention is not particularly limited. Although it depends on the abundance of SS, for example, it is preferable to add it so that the concentration of the polymer flocculant becomes about 0.1 to 5.0 mg / L in the above-described coexisting state. More preferably, it is about 0.3 mg / L to 3.0 mg / L.

[0034] The plate-type heat exchanger or the tube-type heat exchanger used when cooling the water with an increased temperature, which constitutes the method for producing the non-ferrous metal water-granulated slag of the present invention, may be any of those conventionally used. In these heat exchangers, the heat of the water with an increased temperature moves through heat transfer plates or tubes with holes made of metal or resin, and cooling water is obtained by heat exchange. In these heat exchangers, the water with an increased temperature to be cooled flows through a narrow gap, and heat exchange is carried out quickly and efficiently. The heat transfer coefficient improves as the flow velocity increases. On the other hand, if the water with an increased temperature that is the object of heat exchange contains fine particles, the fine particles accumulate in the narrow gap and cause blockage. And when blockage occurs, it leads to a decrease in heat exchange efficiency, so it is necessary to clean the flow path and maintain the equipment. This means that if the water with an increased temperature contains a large amount of fine particles, it is necessary to frequently clean the flow path and maintain the equipment, increasing the work load in the method for producing non-ferrous metal water-granulated slag.

[0035] As described above, according to the method for producing non-ferrous metal granulated slag of the present invention, the amount of fine particles remaining in the water with an increased temperature used for water cooling of the non-ferrous metal granulated slag can be effectively reduced, thereby reducing blockages in the flow paths that frequently occurred in plate heat exchangers and tubular heat exchangers. Therefore, it becomes possible to significantly reduce the frequency of cleaning the flow paths and equipment maintenance in the heat exchanger.

Examples

[0036] Next, the present invention will be described in more detail by giving consideration examples and comparative examples. The present invention is not limited to the following test examples.

[0037] [Test method] In order to recycle the cooling water used in the method for producing non-ferrous metal granulated slag, which is carried out in non-ferrous metal smelting, the residual state of fine particles in the water supplied to a plate heat exchanger or a tubular heat exchanger in the cooling treatment step constituting the present invention, which targets the water with an increased temperature in the granulation treatment in the rapid cooling and pulverization step constituting the present invention, was confirmed as follows.

[0038] First, for the confirmation test, various simulated wastewaters in which coarse-grained SS and fine-grained SS are mixed in their respective abundances were prepared as follows. After pulverizing commercially available copper slag, it was classified using a sieve with a mesh size of 1 mm and a sieve with a mesh size of 100 μm, respectively. The particles with a particle size of 100 μm or less were adjusted as fine-grained SS, and the particles with a particle size of 1 mm or more and 3 mm or less were adjusted as coarse-grained SS. The fine-grained SS obtained as described above was contained in tap water at about 410 mg / L, and coarse-grained SS was added so that the abundance of coarse-grained SS was 0 mg / L, 10,000 mg / L, 50,000 mg / L, and 100,000 mg / L, respectively, to prepare each simulated wastewater.

[0039] Using a jar test apparatus, while stirring each of the previously prepared simulated wastewaters so that they are mixed in a turbulent state with a flow velocity of 0.5 m / s or more, a polymer coagulant was added to each so that the concentration became 0.1 - 3.0 mg / L, and the stirring in the above state was continued for a predetermined time, and then left to stand. In the above, Kayee Relief NCS-8104 (trade name, manufactured by Nippon Steel & Sumikin Environment Co., Ltd.) was used as the polymer coagulant. Also, the stirring time in the above test was set to 20 seconds, and the standing time after the end of stirring was calculated from the water surface height assuming an OFR (water surface area load) of 50 m / hr. After taking out the condensate after standing, the SS concentration in the remaining treated water was measured to confirm the residual state of the fine particles in each simulated wastewater. The obtained results are shown in Table 1.

[0040] [Test Results] As a result of the above-mentioned test, under the condition where coarse-grained SS and fine-grained SS were mixed, in the case of Examination Examples 1 to 12 of the system in which the polymer coagulant (chemical agent) was added stepwise so as to be 0.1 - 3.0 mg / L, and in the case of Comparative Examples 1 to 3 of the system in which the same test as above was conducted under the condition of no addition of the chemical agent, it was confirmed that the SS value of the treated water after treatment was significantly reduced in any of Examination Examples 1 to 12. Also, in the tests under the condition where only fine-grained SS was present without coarse-grained SS in Comparative Examples 4 to 8, the remarkable reduction effect of the fine-grained SS value of the treated water obtained by the addition of the polymer coagulant in Examination Examples 1 to 12 could not be confirmed. From the above, it was confirmed that in order to reduce the SS concentration in the treated water, it is necessary that the coarse-grained SS and fine-grained SS of the copper slag are in a condition of being mixed in a turbulent state with a flow velocity of 0.5 m / s or more. In the rapid cooling and pulverization process of the molten non-ferrous metal slag from the heating furnace with cold water, which constitutes the manufacturing method of the present invention, the non-ferrous metal granulated slag obtained by granulation naturally has a state in which fine-grained SS and coarse-grained SS of the size as confirmed in the above test are mixed. Therefore, similar to the result of the above confirmation test, it can be expected that by performing granulation provided to the heat exchanger in the cooling treatment process, the amount of fine-grained SS in the water whose temperature has risen can be significantly reduced.

[0041] TIFF2025111918000004.tif170170

[0042] [Simulation test results] In copper smelting, a test was conducted to confirm the effect of the method for producing the non-ferrous metal granulated slag of the present invention. Specifically, regarding the molten slag in copper smelting, a simulation tester with the configuration shown in FIG. 1 was fabricated, and the frequency of blockage occurring in the flow path of the plate heat exchanger when using cold water circulated was examined with and without using a polymer coagulant. As a result, when the polymer coagulant was not used, the flow path was blocked in 20 days, whereas when the polymer coagulant was added when spraying pressurized water (cooling water) onto the molten copper slag in the slag trough, no blockage of the flow path occurred even after 60 days. This indicates that the working load can be reduced by effectively using the polymer coagulant.

Claims

1. A method for manufacturing non-ferrous metal granulated slag that is granulated using circulated cold water in non-ferrous metal smelting, comprising: A rapid cooling and pulverizing step of granulating molten non-ferrous metal slag from a heating furnace with cold water; A step of taking out the granulated non-ferrous metal slag from the granulation tank in a state where the granulated non-ferrous metal slag granulated in the rapid cooling and pulverizing step is accommodated, to the outside of the tank; In the rapid cooling and pulverizing step, in order to recycle the water in the granulation tank whose temperature has risen due to granulating the molten non-ferrous metal slag as cold water to be used again for granulation, a cooling treatment step of cooling the water whose temperature has risen; In the cooling treatment step, cooling treatment of the water whose temperature has risen is performed using a plate heat exchanger or a tube heat exchanger, and the cooling water in the water storage facility obtained by the cooling treatment is used as the granulation water when granulating the molten non-ferrous metal slag with cold water in the rapid cooling and pulverizing step of the non-ferrous slag, and the cold water for granulation is recycled, and In at least any one of the rapid cooling and pulverizing step, the step of taking out the non-ferrous metal slag, and the cooling treatment step, a polymer coagulant is added so that the polymer coagulant, the granulated non-ferrous metal slag or the non-ferrous metal slag before being granulated, and the cold water are mixed and coexist in a turbulent flow state with a flow velocity of 0.5 m / sec or more. A method for manufacturing non-ferrous metal granulated slag, characterized in that.

2. In the rapid cooling and pulverizing step, pressurized water (cooling water) is sprayed into a slag trough in the transfer path of the molten non-ferrous metal slag from the heating furnace to rapidly cool the transferred molten non-ferrous metal slag to perform granulation, and the addition of the polymer coagulant is performed at any position while the non-ferrous metal slag is being transferred in the slag trough, and / or the addition of the polymer coagulant is performed from the outlet of the slag trough, at any position before the non-ferrous metal slag is accommodated in the granulation tank, and / or the addition of the polymer coagulant is performed in the water storage facility. The method for manufacturing non-ferrous metal granulated slag according to claim 1.

3. In the rapid cooling and pulverization step, the molten non-ferrous metal slag from the heating furnace is transferred into the cold water in the water granulation tank in a turbulent state and granulated with the cold water, and / or the molten non-ferrous metal slag from the heating furnace is introduced into a water granulation trough through which cold water (water for granulation) flows into the water granulation tank to perform granulation, and the addition of the polymer coagulant is carried out in the water granulation tank in a turbulent state, and / or the addition of the polymer coagulant is carried out in the water flow of the water granulation trough into which the molten non-ferrous metal from the heating furnace is introduced, and / or the addition of the polymer coagulant is carried out in the water storage facility. The method for producing non-ferrous metal granulated slag according to claim 1.

4. The method for producing non-ferrous metal granulated slag according to claim 1, wherein the polymer coagulant is a cationic or amphoteric copolymer derived from a raw material monomer containing 5 mol% or more of either one or both of the monomers represented by the following general formula (1) and the following general formula (2) as essential components, and having the copolymer as the main component. [In the above general formulas (1) and (2), R １ , R ２ each independently represents CH ３ or C ２ H ５ , R ３ represents H, CH ３ or C ２ H ５ , and X － represents an anionic counter ion.]

5. The method for producing non-ferrous metal granulated slag according to claim 2 or 3, wherein the water in the water granulation tank whose temperature has risen due to granulating the molten non-ferrous metal slag is directly cooled in the cooling treatment step.

6. The method for producing non-ferrous metal granulated slag according to claim 2 or 3, wherein the water in the water granulation tank whose temperature has risen due to granulating the molten non-ferrous metal slag is introduced into a sedimentation pit, the granulated non-ferrous metal slag particles remaining in the introduced water are sedimented in the sedimentation pit, and the supernatant water of the sedimentation pit is cooled in the cooling treatment step.

7. The method for producing non-ferrous metal granulated slag according to claim 1, wherein the components of the non-ferrous metal slag contain 35% or less of CaO, or 5% or more of FeO, or contain 35% or less of CaO and 5% or more of FeO, on a mass basis in oxide notation.

8. The method for producing non-ferrous metal granulated slag according to claim 1, wherein the non-ferrous metal slag is a slag obtained as a by-product when smelting at least any one non-ferrous metal selected from the group consisting of copper, lead, and zinc.

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