JP2018099676A - Separation method and device of mixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device capable of separating a mixture comprising a plurality of objects each having different apparent density, efficiently into each object.SOLUTION: In a method for supplying a mixture comprising a plurality of objects each having different apparent density into a solid-gas fluid bed formed by supplying gas for fluidizing powder into powder, and separating the mixture into each object by utilizing a sink-and-float phenomenon of the plurality of objects in the solid-gas fluid bed, supply of gas into powder is performed in the state where a temperature of gas is set higher than an environmental temperature, and/or in the state where a relative humidity of gas is set lower than an environmental relative humidity.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a mixture separation method and apparatus, and more particularly to a method and apparatus capable of efficiently separating a mixture of a plurality of objects having different apparent densities for each object.

  Continuous casting of steel is performed by pouring molten steel in a ladle into a tundish, and pouring molten steel into a mold in a state where a predetermined amount of molten steel stays in the tundish. FIG. 1 shows a side sectional view of a typical tundish. The tundish 1 shown in this figure has a structure in which an outer shell is an iron skin 2 and a refractory made up of a permanent brick 3 and a work brick 4 is installed inside the iron skin 2. Here, a magnesium oxide (MgO) coating layer 5 is formed on the surface of the work brick 4 by spraying or the like. A nozzle 6 for injecting molten steel in the tundish 1 into a mold is attached to the bottom of the tundish 1 via a nozzle receiving brick 7. The nozzle 6 includes an upper nozzle 6a and an immersion nozzle 6b.

  As described above, the refractory includes the permanent brick 3 and the work brick 4, and the permanent brick 3 has silica as a main component, while the work brick 4 has alumina as a main component. Since the work brick 4 is in direct contact with the molten steel, heat resistance and corrosion resistance are required. In continuous casting of steel, when molten steel is repeatedly poured into the tundish 1, the work brick 4 deteriorates from the surface layer. Therefore, when the thickness of the work brick 4 is equal to or less than the specified dimension, the refractory is dismantled. The surface layer of several tens of millimeters of the deteriorated work brick 4 is infiltrated with iron (Fe), manganese (Mn), or the like, and is in a state of blackish discoloration.

  The dismantled scrap contains a mixture of bullion iron, infiltrated work brick 4, healthy work brick 4, and permanent brick 3. Treating the used refractory contained in such demolition waste as industrial waste is not only expensive, but also undesirable from the viewpoint of resource saving. Therefore, many methods for reusing used refractories generated at steelworks have been proposed.

For example, Patent Document 1 describes a technique of reusing a used refractory as a ironmaking material for hot metal pretreatment using the relationship between the crushed particle size and the components.
Patent Document 2 discloses a technology for reusing a part of a used refractory as a refractory and utilizing the remainder as a steel refining auxiliary material or a material for civil engineering, utilizing the relationship between the crushing particle size and the components. Is described.
Furthermore, Patent Document 3 describes a technique of reusing a used refractory material that has been crushed and adjusted in particle size as a decarburizing material.

  The techniques described in Patent Documents 1 to 3 are reused as a refining auxiliary material or a material for civil engineering work. However, since the used refractory is a material rich in components inherently having the ability as a refractory, it is a method with low economic value to be used as an inexpensive auxiliary material or civil engineering material. Therefore, it is desirable to separate used refractories for each component, collect valuable materials with high economic value, and reuse them as refractories.

  However, it is difficult to separate used refractories for each component due to the problem of dismantling construction of the tundish 1 shown below. Specifically, the tundish 1 is disassembled as follows. That is, first, only the work brick 4 is peeled off or scraped by a heavy machine or a dedicated machine. At that time, the scraps of the peeled work brick 4 accumulate on the bottom surface of the tundish 1. In general, the entire tundish 1 is rolled in order to discharge the accumulated brick waste. Then, since the permanent brick 3 is usually only stacked along the iron skin 2 of the tundish 1 and is fixed so as to be pressed against the iron skin 2 by the work brick 4, the work brick 4 is shaved. Later, when the tundish 1 is rolled, not only the work brick 4 scrap but also the permanent brick 3 collapses and is discharged. For the above reasons, it is difficult to collect the work brick 4 and the permanent brick 3 separately, and these bricks are discharged as waste.

  Under such a background, a method for separating and recovering the work brick 4 which is a valuable material from the used refractory has been proposed. For example, Patent Documents 4 and 5 describe techniques for selecting work bricks 4 and permanent bricks 3 by combining crushing, magnetic selection, and color selection. However, since the infiltrating layer has changed to dark gray, there is a possibility that it can be sorted. However, since the healthy work brick 4 and the permanent brick 3 both have white colors, the color sorting alone is not possible. Sorting is difficult.

Here, looking at the components of the work brick 4 and the permanent brick 3, the work brick 4 contains 60% by mass of alumina (Al ₂ O ₃ ) and 35% by mass of silica (SiO ₂ ). 15% by weight of Al ₂ O ₃ and 80% by weight of SiO ₂ . Thus, both are mainly composed of Al ₂ O ₃ and SiO ₂ . Of these components, Al ₂ O ₃ has a high value, the work brick 4 is rich in Al ₂ O ₃ , and the permanent brick 3 is rich in SiO ₂ . Therefore, if only the work brick 4 can be separated and recovered with high purity, it can be reused as a raw material rich in Al ₂ O ₃ .

By the way, the density of Al ₂ O ₃ is 3.95 to 4.1 (g / cm ³ ), and the density of SiO ₂ is 2.2 (g / cm ³ ). That is, when the work brick 4 and the permanent brick 3 are compared, the work brick 4 whose main component is Al ₂ O ₃ has a higher density than the permanent brick 3. That is, by utilizing the difference in density, it is expected that the work brick 4 can be separated and recovered from the demolition waste of the used refractory.

  Sorting methods using the difference in specific gravity or density have been proposed in various fields. For example, there is a method of dividing water into lighter and heavier ones using water, and a method of further developing it and dividing it into suspended matter and sediment by a liquid called heavy liquid with a specific gravity adjusted to 1 to 3. It is considered. A specific gravity of 1 to 3 can be used for a wide range of applications such as waste plastics, minerals, and light metal parts, and is often used in the field of waste recycling. The wet cyclone method is often used for applications in which separation is performed at high speed and in large quantities. This wet cyclone is used on a large scale in the field of beneficiation.

  Furthermore, an air table method is also well known in which vibration and air flow are simultaneously applied to separate the specific gravity. This method was originally developed as a technique for separating grain grains and rice husks in the agricultural field, but in recent years it has also been introduced in the waste recycling field. Since this method is performed in a dry manner, there is an advantage that waste liquid treatment is unnecessary and a small-scale facility is sufficient.

JP 2009-263742 A JP 2005-58835 A JP 2006-241478 A Japanese Patent No. 3645843 Japanese Patent No. 3704301

However, a technique for separating the used refractory into the valuable work brick 4 and the permanent brick 3 by using the difference in the apparent density has not been proposed so far. In addition to bricks used for tundish 1, ironworks also include bricks used for blast furnace pots and blast furnace pits, magnesia carbon bricks used for converters, etc., because these are generated in large quantities at steelworks. Therefore, there has been a demand for development of a technique for efficiently separating a mixture of a plurality of objects having different apparent densities for each object.
Therefore, an object of the present invention is to propose a method and apparatus for efficiently separating a mixture of a plurality of objects having different apparent densities for each object.

  In the previous applications (Japanese Patent Application Nos. 2014-210492, 2014-210596, and Japanese Patent Application No. 2015-048466), the present inventors have used a mixture of used refractories having different apparent densities (hereinafter referred to as “unknown density”). , Referred to as “mixed refractory”), a gas is supplied to the powder as a fluidized medium to form a solid-gas fluidized bed, and a mixture is supplied to the solid-gas fluidized bed. A method and apparatus for separating mixed refractories into refractories using density is proposed.

  FIG. 2 shows a general flow for separating the mixed refractories into refractories using a solid-gas fluidized bed. In order to satisfactorily separate the mixed refractory using a solid-gas fluidized bed, the particle size of the refractory is preferably about 10 to 50 mm. On the other hand, the particle size of the used refractories generated at the steelworks is usually about several hundred mm. Therefore, as shown in the flow of FIG. 2, after crushing the refractory in advance, the particle size range is adjusted to, for example, 10 mm or more and 50 mm or less using a sieve or the like.

  A large amount of dust is generated and scattered during the refractory crushing process. Therefore, the crushing process is performed while sprinkling water over the refractory. In addition, since the refractory whose particle size has been adjusted as described above is rarely subjected to separation treatment immediately, it is once piled up and stored in a yard without a roof, but the refractory is in a state covered with dust. Therefore, water is sprayed onto the refractory as necessary to prevent dust scattering.

  In density separation using a solid-gas fluidized bed, the fluidity of the fluidized bed affects the separation performance. As the powder as a fluid medium, sand or iron powder having a diameter of 100 to 300 μm is usually used. When moisture is mixed in these powders, the powder as the fluidized medium is hardened in a dumpling form, and when a large amount of moisture is mixed, the fluidized bed does not flow and the density separation performance of the solid-gas fluidized bed is remarkably increased. It will decline.

  Therefore, it is necessary that the separation object such as the refractory is dried before being supplied to the solid-gas fluidized bed. The wet refractory that had been piled up and stored in the tank was subjected to a drying process using, for example, a rotary kiln.

  However, since the drying process consumes a lot of energy, it is essential to reduce energy consumption. Here, with respect to the dust generated in the crushing process, a method of collecting dust and using a dust collector can be considered. However, during storage in the yard, the refractory is wet by rain, and as a result, the refractory often contains moisture. For such refractory, the amount of refractory and slag generated at the steelworks is enormous, so it is not economical to prepare a storage space with a roof.

  Therefore, the inventors of the present invention formed a solid-gas fluidized bed as a result of earnestly examining the method of separating each refractory using a solid-gas fluidized bed even when the mixed refractory as a separation target is wet. It is extremely effective to supply the gas to the powder in a state where the temperature of the gas is higher than the ambient temperature, or a state where the relative humidity of the gas is lower than the relative humidity of the environment, or both. As a result, the present invention has been completed.

That is, the gist of the present invention is as follows.
(1) A mixture composed of a plurality of objects having different apparent densities is supplied to a solid-gas fluidized bed formed by supplying a gas for fluidizing the powder to the powder, and the plurality of the plurality of objects in the solid-gas fluidized bed In a method of separating the mixture into objects using the object's ups and downs,
Supplying the gas to the powder is performed in a state where the temperature of the gas is higher than an environmental temperature, and / or in a state where the relative humidity of the gas is lower than the relative humidity of the environment. To separate the mixture.

(2) The method for separating a mixture according to (1), wherein the supply of the gas to the powder is performed in a state where the temperature of the gas is higher by 5 ° C. or more than the environmental temperature.

(3) The method for separating a mixture according to (1), wherein the supply of the gas to the powder is performed in a state where the relative humidity of the gas is 5% or more lower than the relative humidity of the environment.

(4) The supply of the gas to the powder is performed in a state in which the wind speed of the gas is 1.05 times or more and 2 times or less the minimum fluidization speed of the solid-gas fluidized bed. The method for separating a mixture according to any one of 3).

(5) The method for separating a mixture according to any one of (1) to (4), wherein the mixture supplied to the solid-gas fluidized bed is wet.

(6) The method for separating a mixture according to any one of (1) to (5), wherein the object is a used refractory material generated at a steelworks.

(7) The method for separating a mixture according to any one of (1) to (6), wherein the gas is air.

(8) The mixture according to any one of (1) to (7), wherein after separating the mixture for each object, the powder adhered and fixed to the surface of the object is removed and collected. Separation method.

(9) A gas supply means for supplying a gas for fluidizing the powder to the powder, a separation tank for storing a solid-gas fluidized bed formed by fluidizing the powder, and a plurality of different apparent densities Mixture supply means for supplying a mixture of objects to the solid-gas fluidized bed, suspended matter recovery means for recovering objects floating in the solid-gas fluidized bed of the mixture, and sedimentation in the solid-gas fluidized bed of the mixture A sediment collection means for collecting the collected object, and a thermometer for measuring the temperature of the gas supplied from the gas supply means and / or a hygrometer for measuring the relative humidity of the gas, from the gas supply means Separation device for a mixture, characterized in that the temperature of the gas supplied is higher than the ambient temperature or / and the relative humidity of the gas is lower than the relative humidity of the environment.

(10) The apparatus for separating a mixture according to (9), further including a powder removing unit that removes the powder adhered and fixed to the surface of the separated object.

(11) The apparatus for separating a mixture according to (9) or (10), wherein the temperature of the gas supplied from the gas supply means is 5 ° C. or more higher than the environmental temperature.

(12) The apparatus for separating a mixture according to (9) or (10), wherein the relative humidity of the gas supplied from the gas supply means is 5% or more lower than the relative humidity of the environment.

(13) The above-mentioned (9) to (9), wherein the wind speed of the gas supplied from the gas supply means is 1.05 to 2 times the minimum fluidization speed of the solid-gas fluidized bed. The apparatus for separating a mixture according to any one of 12).

(14) The mixture separation apparatus according to any one of (9) to (13), wherein the mixture supplied to the solid-gas fluidized bed is wet.

(15) The apparatus for separating a mixture according to any one of (9) to (14), wherein the object is a used refractory material generated in an ironworks.

(16) The mixture separation device according to any one of (9) to (15), wherein the gas is air.

  According to the present invention, a mixture composed of a plurality of objects having different apparent densities can be efficiently separated for each object.

It is side sectional drawing of a general tundish. It is a figure which shows the general flow which isolate | separates a mixed refractory for every refractory using a solid-gas fluidized bed. (A) is a figure explaining the measurement principle of the apparent density by the conventional Archimedes method, (b) is a figure explaining the measurement principle of the apparent density by the improved Archimedes method in this invention. It is a figure which shows typically the movement of the water | moisture content from the refractory to the powder which is a fluid medium. It is a figure which shows an example of the method of making temperature of the gas supplied to powder higher than environmental temperature. It is a figure which shows another example of the method of making temperature of the gas supplied to powder higher than environmental temperature. It is a figure explaining suitable embodiment of the present invention. It is a figure which shows an example of the method of making relative humidity of the gas supplied to powder lower than the relative humidity of an environment. It is a figure explaining another suitable embodiment of the present invention. It is a figure which shows the relationship between the wind speed of the gas supplied to powder, and the pressure loss of a solid-gas fluidized bed. It is a figure which shows an example of the separation apparatus of the mixture by this invention.

(Method of separating the mixture)
Embodiments of the present invention will be described below with reference to the drawings. In the method for separating a mixture according to the present invention, a mixture comprising a plurality of objects having different apparent densities is supplied to a solid-gas fluidized bed formed by supplying a gas for fluidizing the powder to a solid-gas fluidized bed. This is a method of separating a mixture for each object by utilizing a floating phenomenon of a plurality of objects in a fluidized bed. Here, it is important to supply the gas to the powder in a state where the temperature of the gas is higher than the environmental temperature or / and in a state where the relative humidity of the gas is lower than the relative humidity of the environment. is there.

  Here, “environment temperature” refers to the gas temperature around the solid-gas fluidized bed apparatus being used, and gas supply means (blower, air) for supplying a gas for fluidizing the powder to the powder. It is equal to the inlet side gas temperature of a compressor.

  In the present invention, an object (mixture) that is an object to be separated is not particularly limited, and may be used refractories generated at a steelworks such as refractory waste metal debris and mixed concrete debris. In particular, the present invention is suitable for efficiently separating mixed refractories composed of used refractories having different apparent densities for each refractory.

  In addition, the present invention is suitable when the object (mixture) is wet. As mentioned above, used refractories generated in steelworks are usually stored in a yard without a roof before being subjected to separation treatment, and in order to prevent rain and dust scattering during storage. It gets wet with water spray and contains moisture. The present invention is suitable for separating mixed refractories made of such wet refractories into refractories. Hereinafter, the present invention will be described in detail by taking as an example a case where the object is a used refractory material generated in a steelworks, but the present invention is not limited thereto.

  As described above, when the mixed refractory is separated for each refractory using the solid-gas fluidized bed, the particle size of the refractory is preferably about 10 to 50 mm. Before subjecting to the separation treatment, the particle size of the refractory is preferably adjusted to a particle size range of 10 mm to 50 mm, more preferably 10 mm to 30 mm. For this purpose, first, the refractory (mixed refractory) is crushed. This crushing process is performed while sprinkling water in order to prevent dust generated by crushing from scattering.

  The refractory (mixed refractory) to be subjected to the crushing treatment is not particularly limited, and is, for example, a brick used for the tundish 1, a brick used for a blast furnace pan or a blast furnace bowl, or a magnesia carbon brick used for a converter. .

  A blast furnace pan is composed of an iron skin and bricks arranged inside thereof, and this brick generally contains alumina and SiC as main components. In addition, bricks deteriorate with the transport of hot metal and subsequent pretreatment, and slag and bullion solidify and adhere due to a decrease in temperature, so only healthy bricks are separated and recovered efficiently. It is desirable.

  Moreover, the blast furnace iron has a good iron oxide resistance (FeO) resistance, that is, a metal line portion made of a brick mainly composed of alumina to which iron oxide hardly adheres, and a brick composed mainly of SiC having a good slag resistance. It consists of the slag line part. Among these, since the brick which has SiC as a main component is useful, it is desirable to isolate | separate and collect only this brick efficiently.

  Furthermore, magnesia carbon bricks are bricks used as refractories for converters. Metals infiltrate and increase in impurity concentration as the number of uses increases, so magnesia carbon bricks with less impurities from used refractories. It is desirable to efficiently separate and recover only.

  The mixed refractory composed of a plurality of refractories having different apparent densities is a refractory composed of refractories having different compositions, such as a mixed refractory composed of permanent bricks 3 and work bricks 4 in the tundish 1. In addition to the refractory material, the refractory material includes a refractory material including a portion in which the molten steel has infiltrated as impurities and the apparent density is changed, and a healthy portion in which the molten steel is not infiltrated.

  The crushing of the mixed refractories composed of a plurality of refractories having different apparent densities can be performed using, for example, a jaw crusher or a bucket crusher.

  Next, the crushed mixed refractory is adjusted to a particle size range of, for example, 10 mm or more and 50 mm or less, which is preferable for density separation by a solid gas fluidized bed. Specifically, the particle size adjustment processing of the mixed refractory can be performed using a sieve. When adjusting the particle size range of the mixed refractory to 10 mm or more and 50 mm or less, first, the crushed mixed refractory is sieved using a sieve having an opening size of 50 mm.

  Next, the mixed refractory material having passed through a sieve having an opening size of 50 mm is sieved with a sieve having an opening size of 10 mm. The mixed refractory remaining on the 10 mm sieve is a mixed refractory having a particle size range of 10 mm to 50 mm. As is clear from the above description, a mixed refractory having a desired particle size range does not mean that the maximum particle size of the mixed refractory is within the above particle size range, but simply the upper limit of the particle size range. This means the mixed refractory remaining on the sieve after passing through the sieve and then passing the sieve through the sieve on the lower limit of the particle size range.

  When adjusting the particle size of the mixed refractory, the mixed refractory left on the sieve by the first sieving process and the mixed refractory passed through the sieve by the second sieving process are too large in particle size, Or since it is too small and is not suitable for density separation by a solid-gas fluidized bed, it is not reused as a refractory and is used for civil engineering work. However, in the first sieving treatment, the mixed refractory having a large particle size remaining on the sieving is subjected to crushing treatment again to reduce the particle size, and then the particle size is adjusted again and used for density separation by the solid-gas fluidized bed. be able to.

  In addition, as described above, the mixed refractory whose particle size has been adjusted is often stored once in a yard before being subjected to a separation process using a solid-gas fluidized bed. In this case, in order to prevent dust from scattering. Watered as needed.

  Subsequently, according to the method for separating a mixture according to the present invention, the mixed refractory having the particle size adjusted as described above is supplied to a solid-gas fluidized bed formed by supplying a gas for fluidizing the powder to the powder. The mixed refractories are separated for each refractory using the floating phenomenon of a plurality of objects in the solid-gas fluidized bed. In the present invention, the “solid-gas fluidized bed” means a fluid having a property similar to that of a liquid by supplying a fluid to powder as a fluid medium and fluidizing it.

Here, the principle of density separation of the refractory by the solid-gas fluidized bed will be described. When a gas is supplied to the powder and suspended and fluidized, the solid-gas fluidized bed containing the powder exhibits the same behavior as the liquid. Accordingly, the bulk density ρfb of the solid-gas fluidized bed is expressed by the following equation.
ρfb = Wp / Vf = (1−εf) ρp (1)
Here, Wp is the weight of the powder as the fluid medium, Vf is the volume during fluidization, εf is the porosity during fluidization, and ρp is the density of the powder as the fluid medium.

  When a refractory having a density ρs is mixed in a solid-gas fluidized bed having such a bulk density ρfb, if ρs <ρfb, it floats above the fluidized bed, and if ρs> ρfb, the fluidized bed. It settles in the lower part of 12. When ρs = ρfb, the middle part of the fluidized bed floats. Using this principle, the mixed refractories are separated into refractories.

The density ρs of the refractory is generally determined by the Archimedes method. That is, as shown in FIG. 3A, first, the weight ma of the refractory in a dry state is measured in the air. The refractory is then immersed in water and the weight in water is measured. Since the refractory immersed in water has buoyancy corresponding to the volume of the refractory, the difference between the dry weight ma and the weight in water ml corresponds to the volume v of the refractory. Therefore, the apparent density ρ of the refractory is given by the following equation.
ρ = ma / (ma-ml) (2)

  However, when the refractory is made of a porous material and has a high water absorption, when the apparent density is measured by the above-mentioned normal Archimedes method, the refractory absorbs water and its weight in water Is measured larger by the weight Δm of the absorbed water. Therefore, if the apparent density of the refractory is obtained using the measured weight in water ml as it is, it becomes larger than the true value. Therefore, when the refractory has high water absorption, it is preferable to obtain the apparent density using the Archimedes method improved as follows.

That is, as shown in FIG. 3B, first, the weight ma of the refractory in a dry state is measured in the air. The refractory is then immersed in water for a sufficient time and the weight in water is measured. Subsequently, the refractory is taken out of the water, and water droplets adhering to the surface of the refractory are sufficiently wiped off, and then the wet weight mw is measured. The difference mw−ma between the wet weight mw and the dry weight ma is the weight Δm of water absorbed by the refractory. And the true apparent density ρr of the refractory is given by the following equation.
ρr = ma / (mw-ml) = ma / (ma + Δm-ml) (3)
By using this formula (3), the apparent density of the refractory can be accurately obtained even when the refractory has porosity and high hygroscopicity.

  The immersion time of the refractory in water depends on the particle size of the refractory, but according to the study by the inventors, the particle size is about 10 to 50 mm, which is a preferable particle size in a mixture separator using a solid-gas fluidized bed described later. In about 3 to 5 minutes, the water is sufficiently absorbed to the inside, and the water is saturated inside.

  In the present invention, when the mixed refractory is separated for each refractory by density separation processing using such a solid-gas fluidized bed, the gas to form the solid-gas fluidized bed is supplied to the powder at the temperature of the gas. It is important to carry out in a state where the temperature is higher than the environmental temperature or / and in a state where the relative humidity of the gas is lower than the relative humidity of the environment.

  As mentioned above, used refractories generated in steelworks are porous, so they are wet by watering during crushing and storage in the yard or by rainfall during storage, and the surface and interior are moisture. Is included. For this reason, when the refractory is put into the solid-gas fluidized bed as it is, the water contained in the refractory permeates into the powder that is the fluidized medium and seems to inhibit the fluidization of the powder.

  However, as a result of detailed investigation on the movement of moisture when the present inventors put a refractory containing moisture into the solid-gas fluidized bed, the movement of moisture from the refractory to the powder as the fluid medium is It turned out to be not as big as expected. Hereinafter, the experiment that has led to this finding will be described.

  First, air as a gas for fluidization was supplied to 50 kg of a fluid medium made of zircon sand at a wind speed 1.3 times the minimum fluidization speed to form a solid-gas fluidized bed. Next, a mixed refractory material (blast furnace refractory material) wet and containing moisture was supplied to the formed solid-gas fluidized bed at a treatment rate of 1 t / h, and density separation was performed for each refractory material.

  FIG. 4 schematically shows the movement of moisture from the refractory to the powder as the fluid medium in this experiment. From the measured value of moisture contained in the refractory before being supplied to the solid-gas fluidized bed, it was found that the amount of moisture supplied into the solid-gas fluidized bed was 49.0 kg / h. It was also found from the measured value of the moisture of the refractory discharged from the solid-gas fluidized bed that the amount of water discharged from the solid-gas fluidized bed was 45.1 kg / h.

  In other words, a net moisture of 3.9 kg / h was supplied into the solid-gas fluidized bed, and 7.9% of the moisture contained in the refractory put into the solid-gas fluidized bed penetrated into the powder as the fluidized medium. It turned out. This amount of water is slightly below the initial expectation. With this amount of water, the moisture that has permeated the powder is dried while the normal temperature gas continues to be supplied to the powder. The fluidized state of the body can be made healthy.

  However, from an industrial point of view, it is necessary to treat the refractory continuously and promptly, so that it cannot take a long time for drying. Therefore, the present inventors have intensively studied how to dry the powder in which moisture contained in the refractory has permeated more quickly and make the fluidization of the powder sounder. The idea was to raise the temperature of the gas to be supplied above the ambient temperature, that is, to increase the saturation vapor pressure by supplying warm air to the fluid medium, thereby increasing the drying rate of the powder.

  For example, when the gas is air, as shown in FIG. 5, the hot air generated by the hot air generator is combined with the normal temperature air blown from the blower, and the anemometer and the thermometer are passed. The air velocity and temperature of the air supplied to the solid-gas fluidized bed are monitored and generated from a hot air generator so that the temperature of the air supplied to the powder constituting the solid-gas fluidized bed is higher than the environmental temperature. This can be done by adjusting the temperature and air volume of the hot air and the air volume of the room temperature air from the blower.

  Alternatively, as shown in FIG. 6, the hot air generated by the hot air generator is configured to be blown by the blower, and the air velocity and temperature of the air supplied to the solid-gas fluidized bed are monitored to configure the solid-gas fluidized bed. It can also be performed by adjusting the temperature and air volume of hot air generated from the hot air generator and the air volume of the blower so that the temperature of the air supplied to the powder to be heated is higher than the environmental temperature.

  If the temperature of the gas supplied to the powder is higher than the environmental temperature, the drying speed can be increased. In particular, as schematically shown in FIG. 7, the temperature of the gas is 5 ° C. or more higher than the environmental temperature. In this case, the mixed refractory can be separated continuously from object to body while drying the moisture that has penetrated the powder from the wet refractory, against a large amount of used mixed refractory generated at steelworks. it can. Moreover, it is more preferable that the temperature of gas is 10 degreeC or more higher than environmental temperature at the point of processing speed.

  Since the temperature of the gas supplied to the solid-gas fluidized bed may be about ambient temperature + 10 ° C., the temperature may be raised to about 50 to 60 ° C. even in the harshest summer season. Heat can be recovered even from hot water at about 60 ° C. discharged after recovering thermal energy from steam at about ° C.

  This makes it possible to separate moist refractories as they are without using high-value steam, electricity, fuel, etc., which have high utility value, in addition to the minimum energy required for air blowing, and refractory recycling with low environmental impact. A flow can be achieved.

  The effect of drying such wet powder can be achieved by lowering the relative humidity of the gas below the relative humidity of the environment instead of increasing the temperature of the gas supplied to the powder above the ambient temperature. it can. That is, the drying rate of the wet powder can be increased by supplying a gas that is dried from the environment to the fluid medium.

  For example, as shown in FIG. 8, the gas generated by a dry gas generator capable of generating a low humidity gas is supplied to the inlet side of the blower so as to pass through the flow meter and the hygrometer. The humidity and air volume of the gas generated by the dry gas generator and the air volume of the blower are adjusted so that the relative humidity of the gas supplied to the powder constituting the solid-gas fluidized bed is lower than the relative humidity of the environment. This can be done.

  The drying rate can be increased if the relative humidity of the gas supplied to the powder is lower than the relative humidity of the environment. In particular, as shown schematically in FIG. 9, the relative humidity of the gas is the relative humidity of the environment. If it is lower than 5%, the mixed refractory is continuously applied to each object while drying the moisture that has penetrated the powder from the wet refractory to the large amount of used mixed refractory generated at the steelworks. Can be separated. Further, in terms of processing speed, it is more preferable that the relative humidity of the gas is 10% or more lower than the relative humidity of the environment.

  Needless to say, the effect of drying the wet powder can also be achieved by raising the temperature of the gas above the ambient temperature and lowering the relative humidity of the gas below that of the environment.

  The gas wind speed is preferably high in terms of drying the moisture absorbed by the fluid medium. However, since the present invention is a method of separating a mixture using the floating phenomenon of the solid-gas fluidized bed, if the gas wind speed is increased too much, the bubble size in the fluidized bed increases and the solid-gas fluidized bed is vigorously stirred. There is a possibility that separation of the mixed refractories cannot be performed efficiently.

  FIG. 10 shows the relationship between the wind speed of the gas supplied to the powder and the pressure loss of the solid-gas fluidized bed. As shown in this figure, when the gas wind speed reaches the minimum fluidization speed, the pressure loss of the solid-gas fluidized bed is saturated and becomes constant. Therefore, the supply of the gas to the powder is preferably performed in a state where the gas wind speed is 1.05 to 2 times the minimum fluidization speed of the solid-gas fluidized bed. Thereby, it is possible to efficiently separate the mixed refractories while quickly drying the moisture absorbed by the powder.

  The powder constituting the solid-gas fluidized bed is not particularly limited, and is appropriately selected according to the density of the objects constituting the mixture. For example, when the mixture is a used refractory discharged at an ironworks, silica sand, chromite sand, zircon sand or iron powder can be used.

  The particle size of the powder is not particularly limited, but it is preferably 100 μm or more and 500 μm or less from the viewpoint that if the particle size is large, more air blowing capacity is required.

  Further, the gas supplied to the powder is not particularly limited as long as it is stable when performing the density separation, but is preferably air. The bulk density of the solid-gas fluidized bed can be adjusted by changing the mixing ratio and the wind speed of the gas supplied to the powder.

  Furthermore, when the wet mixed refractory is supplied to the solid-gas fluidized bed and separated for each refractory, the powder constituting the solid-gas fluidized bed adheres to the surface of the wet refractory and remains as it is. It may be dried in a state and fixed to the surface of the refractory. Then, when the refractory separation process is continued, the powder fixed to the surface of the refractory is discharged from the solid-gas fluidized bed together with the refractory, and the volume of the solid-gas fluidized bed decreases.

  Therefore, after separating the mixed refractories for each refractory, it is preferable to remove and collect the powder fixed on the surface of the object. Thereby, even when the powder adhering to the surface of the wet refractory is fixed, the separation of the mixed refractory can be performed continuously.

(Mixture separator)
Next, the apparatus for separating a mixture according to the present invention will be described. The mixture separation apparatus according to the present invention includes a gas supply means for supplying a gas for fluidizing the powder to the powder, a separation tank for containing a solid-gas fluidized bed formed by fluidizing the powder, Mixture supply means for supplying a mixture of a plurality of objects having different apparent densities to a solid-gas fluidized bed, suspended matter recovery means for recovering an object floating in the solid-gas fluidized bed of the mixture, and a solid-gas fluidized bed of the mixture A sediment collecting means for collecting the object that has settled in the above, and a thermometer for measuring the temperature of the gas supplied from the gas supply means and / or a hygrometer for measuring the relative humidity of the gas. Here, it is important that the temperature of the gas supplied from the gas supply means is higher than the environmental temperature, and / or the relative humidity of the gas is lower than the relative humidity of the environment.

  FIG. 11 shows an example of a separation device for a mixture according to the invention. The separation device 10 shown in this figure includes a separation tank 11, and the separation tank 11 is filled with powder constituting the solid-gas fluidized bed 12. Further, in the vicinity of the central portion in the separation tank 11, the suspended matter collection having a scraper 13 a for collecting the suspended matter S floating in the solid-gas fluidized bed 12 and having a density lower than the bulk density of the solid-gas fluidized bed 12. Means 13 are provided, and the collected suspended matter S is discharged out of the apparatus by the discharge unit 14. Furthermore, a sediment recovery means 15 having a scraper 15 a for recovering sediment P having a density higher than the bulk density of the solid-gas fluidized bed 12, which has settled in the solid-gas fluidized bed 12 along the inner wall of the separation tank 11. The collected sediment P is discharged out of the apparatus by the discharge unit 16.

  Further, a hot air generator and a blower are provided as the gas supply means, and hot air and normal temperature gas respectively generated by them are merged and passed through a pipe surrounded by a heat insulating material, and the lower part of the separation tank 11 The solid-gas fluidized bed 12 is formed by supplying gas to the powder to fluidize the powder. The pipe is provided with an anemometer that measures the wind velocity of the gas and a thermometer that measures the temperature.

  Here, it is important that the temperature of the gas supplied from the gas supply means is higher than the environmental temperature, and / or the relative humidity of the gas is lower than the relative humidity of the environment. Thereby, even when a wet mixture is introduced into the solid-gas fluidized bed 12, the drying rate of the powder that is the fluid medium is increased to fluidize the mixture, and the mixture is continuously separated for each object. Can do.

  Here, when making the temperature of gas higher than environmental temperature, it is preferable that the temperature of gas is 5 degreeC or more higher than environmental temperature, and with this, with respect to a lot of used mixed refractory materials generated at a steelworks The mixed refractory can be continuously separated for each object while drying the moisture permeating into the powder from the wet refractory. In terms of processing speed, it is more preferable to increase the temperature by 10 ° C. or more.

  In addition, when the relative humidity of the gas is made lower than the relative humidity of the environment, the relative humidity of the gas supplied to the powder is preferably 5% or more lower than the relative humidity of the environment. With respect to a large amount of used mixed refractory, the mixed refractory can be continuously separated for each object while drying the moisture permeating into the powder from the wet refractory. From the viewpoint of processing speed, it is more preferable to lower by 10% or more.

  The effect of drying the wet powder can also be achieved by making the temperature of the gas higher than the ambient temperature and lowering the relative humidity of the gas lower than the relative humidity of the environment.

  The powder constituting the gas-solid fluidized bed 12 is not particularly limited, and is appropriately selected according to the density of the objects constituting the mixture. For example, when the mixture is a used refractory discharged at an ironworks, silica sand, chromite sand, zircon sand or iron powder can be used.

  The particle size of the powder is not particularly limited, but it is preferably 100 μm or more and 500 μm or less from the viewpoint that if the particle size is large, more air blowing capacity is required.

  Furthermore, the mixture (object) provided to the separation apparatus of the present invention is not particularly limited, and is a used refractory material generated at an ironworks, such as refractory metal clasp scraps or mixed concrete scraps. Suitable for separating mixed refractories composed of different used refractories into refractories. In addition, the present invention is suitable for separating the mixture for each object when the object is wet.

  Furthermore, the gas supplied to the powder constituting the solid-gas fluidized bed 12 is not particularly limited as long as it is stable when performing the density separation, but is preferably air. The gas wind speed is preferably 1.05 to 2 times the minimum fluidization speed of the solid-gas fluidized bed 12. Thereby, it is possible to efficiently separate the mixed refractories while quickly drying the moisture absorbed by the powder.

  In addition, when the wet mixed refractory is supplied to the solid-gas fluidized bed 12 and is separated for each refractory, the powder constituting the solid-gas fluidized bed 12 adheres to the surface of the wet refractory and remains as it is. The powder removal means that removes the powder fixed on the surface of the object and collects it after separating the mixed refractory into each refractory, since it may be dried and fixed on the surface of the refractory. It is preferable to further comprise. Thereby, even when the powder adhering to the surface of the wet refractory is fixed, the separation of the mixed refractory can be performed continuously.

  Separation for each refractory using the separation device 10 can be performed as follows. That is, first, zircon sand or iron powder, which is powder as a fluid medium, is introduced into the separation tank 11, and a gas having a temperature higher than the environmental temperature is introduced into the separation tank 11 from the lower surface of the separation tank 11. A gas having a humidity lower than the relative humidity is blown to fluidize the powder to form the solid-gas fluidized bed 12. Next, the mixed refractory is introduced from the upper surface opening (not shown) of the separation tank 11. Then, the refractory P having a density higher than the bulk density of the solid-gas fluidized bed 12 settles, while the refractory S having a density lower than the bulk density of the solid-gas fluidized bed 12 floats.

  The scraper 13a attached to the floating substance collecting means 13 moves in the direction of the arrow in FIG. 11, collects the floating substance S floating in the solid-gas fluidized bed 12, and the discharge unit 14 collects the floating substance S collected. Is discharged out of the separation tank 11. On the other hand, the scraper 15a attached to the sediment recovery means 15 moves in the direction of the arrow in FIG. 11 and sediments the sediment P having a density higher than that of the solid-gas fluidized bed 12 settled in the solid-gas fluidized bed 12. The scraping and discharging unit 16 discharges the collected sediment P to the outside of the separation tank 11. In this way, the mixture can be separated into objects using the bulk density of the solid-gas fluidized bed 12.

  In this way, a mixture of a plurality of objects having different apparent densities can be efficiently separated for each object.

  Examples of the present invention will be described below, but the present invention is not limited thereto.

(Invention Example 1)
The used blast furnace refractory was separated into a silica-rich layer and an alumina-rich layer using the apparatus shown in FIG. That is, first, a blast furnace refractory material in which the ratio of silica-rich layer (density: 2.3 g / cm ³ ) to alumina-rich layer (density: 3.0 g / cm ³ ) is approximately 1: 1 is compressed. Crushing was performed using a jaw crusher with a blade clearance of 30 mm. Next, the crushed refractory is passed through a sieve having an opening size of 30 mm, the brick that has passed through the sieve is passed through a sieve having an opening size of 10 mm, and the refractory remaining on the sieve is collected to be 10 mm or more and 30 mm or less. A refractory having a particle size was recovered. Thereafter, the recovered refractory is introduced into a separation device (length: 2500 mm, width: 1000 mm, depth: 250 mm) using a solid-gas fluidized bed, and the suspended refractory and the settled refractory are recovered. It separated into a rich layer and an alumina rich layer. Here, as a powder for constituting the gas-solid fluidized layer, chromite sand (particle size: 300 [mu] m, density: 2.55g / cm ³⁾ to iron powder (particle size: 150 [mu] m, density: 4.31g / cm ³⁾ the What mixed and adjusted the apparent density to 2.7 g / cm < ³ > was used. A gas-air fluidized bed was formed by blowing gas to such powder at a wind speed 1.3 times the minimized fluidization speed. At that time, as the gas supplied to the powder, warm air (air) of 20 ° C. with respect to the environmental temperature of 12 ° C. was used. The solid gas fluidized bed thus formed was supplied with a blast furnace refractory and subjected to separation treatment at a treatment rate of 1.0 t / h. In addition, the moisture content contained in the blast furnace refractory before being charged into the solid-gas fluidized bed was 10%.
As a result of separation under the above conditions, the concentration of the settled refractory was 90%, and the recovery rate was 90%.

(Invention Example 2)
As in Invention Example 1, the blast furnace refractory was separated into a silica-rich layer and an alumina-rich layer. At that time, the gas supplied to the powder to form the solid-gas fluidized bed was warm air (air) at 37 ° C. with respect to the environmental temperature of 21 ° C. Other conditions are the same as those of Invention Example 1.
As a result of separation under the above conditions, the concentration of the settled refractory was 90%, and the recovery rate was 90%.

  In addition, although this invention was demonstrated to the case where the mixed refractory material which generate | occur | produces in a steelworks is isolate | separated for every refractory material, it is not limited to this, Since various deformation | transformation is possible and it can collect | recover floating and sediment. If it exists, various forms can be adopted. Further, the powder constituting the solid-gas fluidized bed is not limited to the embodiment as long as the objects constituting the mixture can be separated.

  According to the present invention, since a mixture composed of a plurality of objects having different apparent densities can be efficiently separated for each object, it is particularly useful in the steel industry.

DESCRIPTION OF SYMBOLS 1 Tundish 2 Iron skin 3 Perm brick 4 Work brick 5 Cover layer 6 Nozzle 6a Upper nozzle 6b Immersion nozzle 7 Nozzle receiving brick 10 Separator 11 Separation tank 12 Solid-gas fluidized bed 13 Floating substance collection means 13a, 15a Scrapers 14, 16 Discharge unit 15 Sediment collection means S Suspended matter P Sediment

Claims (16)

A mixture of a plurality of objects having different apparent densities is supplied to a solid-gas fluidized bed formed by supplying a gas for fluidizing the powder to the powder, and the floating and sinking of the plurality of objects in the solid-gas fluidized bed In a method of separating the mixture into objects using a phenomenon,
Supplying the gas to the powder is performed in a state where the temperature of the gas is higher than an environmental temperature, and / or in a state where the relative humidity of the gas is lower than the relative humidity of the environment. To separate the mixture.   The method for separating a mixture according to claim 1, wherein the supply of the gas to the powder is performed in a state where the temperature of the gas is higher by 5 ° C or more than the environmental temperature.   The method for separating a mixture according to claim 1, wherein the supply of the gas to the powder is performed in a state where the relative humidity of the gas is 5% or more lower than the relative humidity of the environment.   The supply of the gas to the powder is performed in a state where the wind speed of the gas is 1.05 times to 2 times the minimum fluidization speed of the solid-gas fluidized bed. A method for separating the mixture according to item.   The method for separating a mixture according to any one of claims 1 to 4, wherein the mixture supplied to the solid-gas fluidized bed is wet.   The method for separating a mixture according to any one of claims 1 to 5, wherein the object is a used refractory material generated in a steelworks.   The method for separating a mixture according to any one of claims 1 to 6, wherein the gas is air.   The method for separating a mixture according to any one of claims 1 to 7, wherein after separating the mixture for each object, the powder adhered to and fixed to the surface of the object is removed and collected. A gas supply means for supplying a gas for fluidizing the powder to the powder, a separation tank for storing a solid-gas fluidized bed formed by fluidizing the powder, and a plurality of objects having different apparent densities A mixture supplying means for supplying the mixture to the solid-gas fluidized bed; a suspended matter collecting means for collecting an object floating in the solid-gas fluidized bed of the mixture; and an object settling in the solid-gas fluidized bed of the mixture. A sediment collecting means for collecting; a thermometer for measuring a temperature of the gas supplied from the gas supplying means; and / or a hygrometer for measuring a relative humidity of the gas;
The apparatus for separating a mixture, wherein the temperature of the gas supplied from the gas supply means is higher than an environmental temperature, and / or the relative humidity of the gas is lower than the relative humidity of the environment.   The apparatus for separating a mixture according to claim 9, further comprising powder removing means for removing the powder adhered and fixed to the surface of the separated object.   The temperature of the said gas supplied from the said gas supply means is a separation apparatus of the mixture of Claim 9 or 10 which is 5 degreeC or more higher than environmental temperature.   The apparatus for separating a mixture according to claim 9 or 10, wherein the relative humidity of the gas supplied from the gas supply means is 5% or more lower than the relative humidity of the environment.   The wind speed of the gas supplied from the gas supply unit is any one of claims 9 to 12, wherein the wind speed of the gas is 1.05 to 2 times the minimum fluidization speed of the solid-gas fluidized bed. Separating device for the mixture according to item.   The apparatus for separating a mixture according to any one of claims 9 to 13, wherein the mixture supplied to the solid-gas fluidized bed is wet.   The apparatus for separating a mixture according to any one of claims 9 to 14, wherein the object is a used refractory material generated in a steel mill.   The apparatus for separating a mixture according to any one of claims 9 to 15, wherein the gas is air.

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