KR101497892B1 - Abrasive material for shot blasting, and method for producing same - Google Patents

Abstract

An object of the present invention is to provide an abrasive which has a large crushing strength and a small variation in its Fe concentration in a range as high as 6.0 to 35.0 mass% in terms of FeO. The present abrasive has a continuous phase containing Fe, Si, Ca, Al, Mg and Mn and having an amorphous phase, and has a total content of Fe, Si and Ca in terms of FeO, SiO ₂ or CaO, And Fe in an amount of not less than 6.0 mass% and not more than 35.0 mass% in terms of FeO, 15.0 mass% or more and 35.0 mass% or less in terms of SiO ₂ , and Ca in an amount of 10.0 mass% or more and 35.0 mass% or less in terms of CaO . The present method comprises the steps of crushing molten slag to form slag particles, a step of dropping the slag particles downward or falling downward, spraying water to cool the slag particles, and a step of dewatering while conveying the slag particles Respectively.

Description

TECHNICAL FIELD [0001] The present invention relates to abrasive materials for shot blasting,

The present invention relates to an abrasive for shot blasting and a method for producing the same. More particularly, the present invention relates to an abrasive for a shot blast mainly composed of an Fe component, a Si component, and a Ca component, and a method for producing the same.

The steelmaking slag may be produced in an amount of 10 to 30 mass% of the raw materials at the time of melting and refining various metal materials. As a result, various methods for effectively utilizing steelmaking slag have been studied. Among them, it is thought that steel making slag is used in the form of particles, and it is used as an increasing material and an abrasive. Particularly, as the abrasive, particles having high crushing strength can be obtained, and as the abrasive using the granulated steel making slag, the techniques disclosed in the following patent documents 1 and 2 are known.

Japanese Patent Laid-Open No. 2001-47365 Japanese Patent Application Laid-Open No. 2008-45002

In an abrasive using steelmaking slag, if steel making slag having a high Fe content is used and an abrasive with a high Fe concentration is to be produced, there is a problem that the crush strength is not sufficiently obtained or the crush strength varies. For this reason, in order to obtain an abrasive, a steelmaking slag having a low Fe concentration is used, or a controlled slag having a Fe concentration lowered by component adjustment is used.

Patent Document 1 discloses a solid for shot blast obtained by crushing a cured product obtained by cooling molten slag obtained by reacting a melt of reduced slag discharged from an electric steelmaking furnace with an anti-different agent containing various components. However, the Fe concentration of the abrasive disclosed in Patent Document 1 is as low as 2.46 to 3.01 mass% even when iron oxide such as scale is added, and the grinding material having a high Fe concentration has not been studied.

Further, the above Patent Document 2 discloses an abrasive for blasting of amorphous state. However, the grinding material disclosed in Patent Document 2 has an Fe concentration of 5% by mass, and the grinding material having a high Fe concentration has not been studied.

The object of the present invention is to provide an abrasive for shot blasting which has a high crushing strength even when Fe concentration is as high as 6 to 35 mass% in terms of FeO.

The present invention is as follows.

(1) The shot blast for abrasive according to claim 1, which contains Fe, Si, Ca, Al, Mg and Mn,

Having a continuous phase that is amorphous,

The total content of Fe, Si and Ca in terms of FeO-converted, SiO ₂ -converted or CaO-converted is 50.0% by mass or more with respect to the entire 100% by mass,

Fe in an amount of not less than 6.0 mass% and not more than 35.0 mass% in terms of FeO, 15.0 mass% or more and 35.0 mass% or less of Si in terms of SiO ₂ , and Ca in an amount of 10.0 mass% or more and 35.0 mass% or less in terms of CaO.

(2) The abrasive for shot blasting according to claim 2, wherein the abrasive for shot blasting according to claim 1 contains not less than 3.0 mass% and not more than 25.0 mass% of Al in terms of Al ₂ O _{3 based} on 100 mass% It is essential.

(3) The abrasive for shot blasting according to claim 3, wherein the abrasive for shot blasting according to claim 1 or 2 contains Mn in an amount of 2.0 to 20.0 mass% in terms of MnO based on 100 mass% .

(4) The abrasive for shot blast according to claim 4 is the abrasive for shot blast according to any one of claims 1 to 3, which comprises Ti,

And Ti is contained in an amount of not less than 0.01% by mass and not more than 10.0% by mass in terms of TiO ₂ with respect to the total 100% by mass.

(5) The short-blast abrasive according to claim 5 is the abrasive for shot blasting according to any one of claims 1 to 4,

And 0.5% by mass or more and 5.0% by mass or less in terms of Cr ₂ O _{3 based} on 100% by mass of the whole.

(6) The shot blast abrasive according to claim 6 is the shot blast abrasive according to any one of claims 1 to 5, which is a slag particle obtained by shrinking molten slag.

(7) The abrasive article for shot blast according to claim 7 is the abrasive article for shot blasting according to claim 6, wherein the molten slag is an electric furnace slag.

(8) The abrasive for short blast according to (8) is characterized in that, in the abrasive for shot blasting according to the sixth or seventh aspect, the molten slag contains waste glass and / or silica sand as a component adjusting material.

(9) The abrasive article for shot blasting according to claim 9 is the abrasive article for shot blasting according to claim 8, wherein the waste glass is glass for automobiles.

(10) The method for producing an abrasive for shot blast according to claim 10 is the method for manufacturing an abrasive for shot blast according to claim 6 or 7,

A blowing step of blowing the melted slag to form slag particles,

A cooling step of cooling the slag particles by dropping the slag particles downward or downward and spraying water,

And a dewatering and conveying step of dewatering the slag particles while conveying the slag particles.

(11) The method for producing an abrasive for shot blast according to claim 11 is the method for manufacturing an abrasive for shot blast according to claim 8 or 9,

A component adjusting step of adding waste glass and / or silica sand to the electric furnace slag as a component adjusting material;

A weaving step of weaving the molten slag obtained through the component adjusting step to form slag particles,

A cooling step of cooling the slag particles by dropping the slag particles downward or downward and spraying water,

And a dewatering and conveying step of dewatering the slag particles while conveying the slag particles.

According to the shot blast abrasive of the present invention, it is possible to obtain a shot blast abrasive having a high crushing strength even when the FeO concentration is as high as 6.0 to 35.0 mass%. Therefore, it is possible to obtain an abrasive for short blast which is excellent in grindability, inhibits particle fracture at the time of grinding, has a small amount of dust, and is excellent in reusability.

When the shot blast grinding material of the present invention is a slag particle obtained by shrinking molten slag, since the particle shape is directly obtained from the slag in the molten state, the mass of the steelmaking slag is crushed to form a granulated grinding material It is easy to obtain an excellent crush strength in comparison with the original. Further, the steelmaking slag can be converted into the shot blasting abrasive material without loss by crushing, and the production efficiency is excellent.

When the molten slag contains waste glass as a component regulating material, the waste glass can be effectively utilized. In addition, when the waste glass is automotive glass, waste glass for automobile use can be effectively utilized. In particular, automotive glass generated by scrap processing of automobiles often involves resin parts and metal parts that are difficult to remove, so that it is difficult to utilize recycling, and the glass is buried. However, in the present invention, even when accompanied by a resin component, it can be utilized without any problem as an effective component regulating material, contributing to the reduction of garbage.

According to the method for producing an abrasive for shot blasting of the present invention, a shot blasting abrasive material having a high crushing strength even in a high FeO concentration range of 6.0 to 35.0 mass% can be produced. Thus, it is possible to produce a shot blast abrasive having excellent grinding performance, suppressing particle breakage at the time of polishing, and having a small dust amount and excellent reusability.

Further, such a shot blast abrasive can be continuously produced, and further, it can be produced in a small space. By providing a cooling step for cooling the slag particles by spraying water after dropping the cobbled slag downward or downward, it is not necessary to use a large space in the planar direction, The abrasive can be stably manufactured.

Fig. 1 is an explanatory view for explaining a phase shape in a short blast abrasive according to the present invention, wherein (a) and (b) are of the upper form included in the present invention, and (c) It is not included.
Fig. 2 is an explanatory view schematically showing an apparatus for manufacturing a shot blast grinding material used in the embodiment. Fig.
Fig. 3 is an explanatory view schematically showing the vicinity of the crimping means in the apparatus for producing a shot blast for abrasive blast in Fig. 2;

Hereinafter, the present invention will be described in detail.

[1] abrasives for shot blasting

The shot blast abrasive according to the present invention contains Fe, Si, Ca, Al, Mg and Mn,

Having a continuous phase that is amorphous,

The total content of Fe, Si and Ca in terms of FeO-converted, SiO ₂ -converted or CaO-converted is 50.0% by mass or more with respect to the entire 100% by mass,

Fe in an amount of not less than 6.0 mass% and not more than 35.0 mass% in terms of FeO, 15.0 mass% or more and 35.0 mass% or less of Si in terms of SiO ₂ , and Ca in an amount of 10.0 mass% or more and 35.0 mass% or less in terms of CaO.

The term "amorphous continuous phase" means that the main portion is amorphous. Specifically, only one phase of an amorphous phase (amorphous continuous phase (1)) is recognized (see Fig. 1 (a)) or a crystalline phase (2) (Regardless of the size of the crystal grains) is recognized, it indicates that the crystalline phase 2 is surrounded by the continuous amorphous phase 1 (see Fig. 1 (b)). That is, when the crystalline phase (2) is recognized, it indicates that the crystalline phase (2) is dispersed in the amorphous phase (1). Whether the observed phase is amorphous or not is determined by X-ray diffraction measurement. That is, if the chart obtained by X-ray diffraction measurement is amorphous, it is amorphous, and if attributable peak is recognized, it is crystal. In the abrasive for shot blasting of the present invention, crystals that are surrounded and surrounded by the amorphous continuous phase (1) include, for example, spinel crystals.

On the other hand, Fig. 1 (c) is an example of a form having no continuous phase which is amorphous. That is, there can be mentioned a form having a continuous phase 3 (a polycrystalline phase in which microcrystals are gathered) which is crystalline. In this embodiment, the coarse crystals 4 which are coarser than other crystals and are precipitated are often found in a part of the continuous phase 3 as a crystal phase. Also in this embodiment, a crystal phase 2 such as a spinel crystal may be precipitated.

The shot blasting abrasive according to the present invention contains at least Fe, Si, Ca, Al, Mg and Mn.

When the total amount of the abrasive for shot blasting is 100% by mass, Fe, Si and Ca are contained in an amount of 50.0% by mass or more in terms of FeO-converted, SiO ₂ -converted or CaO-converted, respectively.

The " Fe " is contained in an amount of not less than 6.0 mass% and not more than 35.0 mass% in terms of FeO, where the total amount of the abrasive for shot blasting is 100 mass%. Conventionally, it has been difficult to obtain a shot blasting abrasive having a high crushing strength from steel making slag having a FeO content of at least 6.0 mass%. However, if the grinding material composition range of the present invention is used, a shot blasting abrasive material having a large crushing strength can be obtained. Specifically, the crushing strength at a particle diameter of 2.0 mm can be set to 20 kgf or more.

On the other hand, if the content of Fe in terms of FeO is more than 35.0% by mass, it tends to be difficult to reduce the variation of the crushing strength, and it tends to be difficult to sufficiently maintain the high crushing strength. Specifically, there is a tendency that it becomes difficult to maintain the crushing strength at 20 kgf or more at a particle diameter of 2.0 mm.

The content of Fe in terms of FeO is preferably from 7.0 mass% to 32.0 mass%, more preferably from 8.0 mass% to 30.0 mass%, still more preferably from 9.0 mass% to 28.0 mass%, still more preferably from 10.0 mass% And particularly preferably 26.0 mass% or less.

The " Si " is contained in an amount of 15.0 mass% or more and 35.0 mass% or less in terms of SiO ₂ when the entirety of the abrasive for shot blast is made 100 mass%. In this range, particularly in a composition having Fe content of not less than 6.0 mass% and not more than 35.0 mass% as calculated as FeO, the variation of the crushing strength can be suppressed to be small and a high crushing strength can be obtained. When the content of Si in terms of SiO ₂ is less than 15.0% by mass, it tends to be difficult to sufficiently maintain the composition of Fe in terms of FeO as 6.0% by mass or more and 35.0% by mass or less, sufficiently amorphous. On the other hand, when the content of Si in terms of SiO ₂ is more than 35.0% by mass, the viscosity of the slag in the molten state tends to be high, making it difficult to granulate the slag.

The content of Si in terms of SiO ₂ is preferably from 15.0 mass% to 34.0 mass%, more preferably from 16.0 mass% to 33.0 mass%, still more preferably from 16.0 mass% to 32.0 mass%, further preferably from 17.0 mass% , More preferably not less than 30.0 mass%, particularly preferably not less than 18.0 mass% but not more than 30.0 mass%, more preferably not less than 20.0 mass% but not more than 30.0 mass%, more preferably not less than 21.0 mass% nor more than 29.0 mass% .

Ca "is contained in an amount of 10.0 mass% or more and 35.0 mass% or less in terms of CaO when the total amount of the abrasive for shot blasting is 100 mass%. In this range, particularly in a composition having Fe content of not less than 6.0 mass% and not more than 35.0 mass% as calculated as FeO, the variation of the crushing strength can be suppressed to be small and a high crushing strength can be obtained. Although the content of Ca in terms of CaO is less than 10.0% by mass, it is considered that there is no problem as a shot blasting abrasive. In fact, most of the slag having a CaO content of less than 10.0% by mass is not obtained. On the other hand, when the content of Ca in terms of CaO is more than 35.0% by mass, the viscosity of the slag in the molten state tends to be high, making it difficult to granulate the slag with the trowel. Further, the melting point of the slag tends to be increased, which is not preferable.

The content of Ca in terms of CaO is preferably from 11.0 mass% to 34.0 mass%, more preferably from 12.0 mass% to 33.0 mass%, still more preferably from 13.0 mass% to 32.0 mass%, still more preferably from 15.0 mass% And particularly preferably not more than 31.0 mass%.

These three components of Fe, Si and Ca, when the entirety of the abrasive for shot blasting is made up to 100 mass%, can be obtained by adjusting the content of Fe in terms of FeO, the content of Si in terms of SiO ₂ and the content of Ca in terms of CaO And the total content is 50.0 mass% or more. In this range, particularly in a composition having Fe content of not less than 6.0 mass% and not more than 35.0 mass% as calculated as FeO, the variation of the crushing strength can be suppressed to be small and a high crushing strength can be obtained. The upper limit of the total content is not particularly limited, but is usually 95.0 mass% or less.

The total content of each of these Fe, Si and Ca in terms of the oxide conversion is preferably 50.0 mass% or more and 95.0 mass% or less, more preferably 53.0 mass% or more and 90.0 mass% or less, still more preferably 54.0 mass% or more and 85.0 mass% By mass, and particularly preferably from 55.0% by mass to 80.0% by mass.

The respective contents and total contents of Al, Mg and Mn contained in the above three components other than Fe, Si and Ca are not particularly limited.

The Al content is preferably 3% by mass or more and 25% by mass or less in terms of Al ₂ O ₃ . Even if the Al content in terms of Al ₂ O ₃ is less than 3.0% by mass, it is considered that there is no problem as a shot blasting abrasive. In fact, most of the slag in which the content in terms of Al ₂ O ₃ is less than 3.0% by mass is not obtained. On the other hand, when the content of Al in terms of Al ₂ O ₃ exceeds 25.0% by mass, the viscosity of the slag in the molten state tends to be high, making it difficult to granulate the slag with the trowel. Further, the melting point of the slag tends to be increased, which is not preferable.

The content of Al in terms of Al ₂ O ₃ is preferably 3.0 mass% or more and 25.0 mass% or less, more preferably 4.0 mass% or more and 23.0 mass% or less, still more preferably 5.0 mass% or more and 20.0 mass% More preferably not less than 18.0 mass%, particularly preferably not less than 5.5 mass% nor more than 18.0 mass%, even more preferably not less than 6.0 mass% nor more than 17.0 mass%, and particularly preferably not less than 6.0 mass% nor more than 16.5 mass% And more preferably 6.5% by mass or more and 16.5% by mass or less.

The Mg is preferably 1% by mass or more and 20.0% by mass or less in terms of MgO. Even if the content of Mg in terms of MgO is less than 1.0% by mass, it is considered that there is no problem as a shot blasting abrasive. In fact, most of the slag in which the MgO content is less than 1.0% by mass is not obtained. On the other hand, when the content of Mg in terms of MgO is more than 20.0% by mass, the viscosity of the slag in the molten state tends to be high, making it difficult to granulate the slag with the trowel.

The content of Mg in terms of MgO is preferably at least 1.0 mass% and at most 20.0 mass%, more preferably at least 2.0 mass% and at most 17.0 mass%, still more preferably at least 3.0 mass% and at most 13.0 mass% And particularly preferably 10.0 mass% or less.

The Mn is preferably 2.0% by mass or more and 20.0% by mass or less in terms of MnO. Although the content of Mn in terms of MnO is less than 1.0% by mass, it is considered that there is no problem as an abrasive for shot blasting. In practice, however, most of the slag having a MnO content of less than 1.0% by mass is not obtained. On the other hand, when the content of Mn in terms of MnO is more than 20.0% by mass, the viscosity of the slag in the molten state tends to be high, making it difficult to granulate the slag with the trowel.

The content of Mn in terms of MnO is preferably 2.0 mass% or more and 20.0 mass% or less, more preferably 3.0 mass% or more and 18.0 mass% or less, still more preferably 4.0 mass% or more and 15.0 mass% And particularly preferably 13.0 mass% or less.

Further, it is preferable that the ratio of the content of Mn to the content of MnO in terms of FeO-converted content (content in terms of MnO / content in terms of FeO) is 0.26 or more and 1.50 or less. In this range, the crushed slag particles are obtained as a shape that is more spherical. The ratio is more preferably 0.28 or more and 1.00 or less, and particularly preferably 0.30 or more and 0.90 or less.

The shot blast abrasive according to the present invention may contain another component (usually containing O), which contains Fe, Si, Ca, Al, Mg, and Mn. Examples of other components include Ti, Cr, P, and S. These other components may be contained only in one kind, or two or more kinds may be contained at the same time.

Among these other components, Ti is preferably contained. It is considered that the grinding material is densified by the inclusion of Ti, so that it functions advantageously in terms of the characteristics as an abrasive. Ti is preferably 0.01 mass% or more and 10.0 mass% or less in terms of TiO ₂ . In this range, the effect of containing Ti can be obtained more effectively.

The content of Ti in terms of TiO ₂ is preferably from 0.1 mass% to 10.0 mass%, more preferably from 0.1 mass% to 8.0 mass%, still more preferably from 0.3 mass% to 4.0 mass%, even more preferably from 0.4 mass% Or more and 1.0 mass% or less.

Further, the Ti to the content of FeO in terms of Fe content in terms of TiO ₂ ratio (TiO ₂ in terms of the content / content in terms of FeO) is preferably not more than 0.10 over 0.02. In this range, the crushed slag particles are obtained as a shape that is more spherical. The ratio is more preferably 0.02 or more and 0.09 or less, and particularly preferably 0.02 or more and 0.08 or less.

Further, the Ti content of Ca in terms of CaO for the TiO ₂ in terms of the content ratio (in terms of TiO ₂ content / CaO in terms of the content) is preferably not more than 0.04 over 0.13. In this range, the crushed slag particles are obtained as a shape that is more spherical. The ratio is more preferably 0.04 or more and 0.10 or less, and particularly preferably 0.04 or more and 0.09 or less.

Among the other components, Cr is preferably contained together with Mn. It is considered that the grinding material is densified by containing Cr, and thus it is advantageous in terms of the characteristics as an abrasive. Cr is preferably 0.5% by mass or more and 5.0% by mass or less in terms of Cr ₂ O ₃ . In this range, the effect of containing Cr can be obtained more effectively.

The content of Cr in terms of Cr ₂ O ₃ is preferably 1.0 mass% or more and 4.0 mass% or less, more preferably 1.2 mass% or more and 3.7 mass% or less, still more preferably 1.3 mass% or more and 3.5 mass% or less.

Further, the shot blast abrasive of the present invention is preferably slag particles obtained by shrinking molten slag. In the case of the slag particles (shot blast abrasive) obtained by shrinking the molten slag, the particle shape is obtained directly from the slag in the molten state. Therefore, compared with the abrasive material obtained by crushing the slag mass, Can be obtained. That is, in the abrasive material obtained by crushing the slag mass, the slag mass itself is large, so that the time required for cooling is prolonged, and the possibility of generating a crystal phase in the slag mass becomes higher. Also, since it is crushed after being cooled, the stress balance in the slag mass produced by cooling tends to be broken. In addition, a potential flaw (fracture origin) may be formed during fracturing. In this respect, the grinding material particles are likely to be broken by an impact at the time of polishing. On the other hand, the shot blast abrasive composed of the slag particles obtained by shrinking the molten slag can be used as it is for the abrasive material particles while maintaining the shape of the particles obtained at the time of cooling with high probability. As a result, the stress balance in the slag grains obtained at the time of cooling can be maintained, so that a higher crushing strength can be maintained, and variation in crushing strength can be suppressed to a small degree. In addition, the steelmaking slag can be converted into the shot blasting abrasive without loss by crushing, and the production efficiency is excellent.

The molten slag is preferably an electric furnace slag. That is, usually, the steelmaking slag includes blast furnace slag, converter slag, and electric furnace slag, but it is preferable that the slag is furnace slag. The electric furnace slag includes oxidized slag and reduced slag, but it is preferable that the slag is an oxidized slag. That is, it is preferably an electric furnace oxide slag. The electric furnace slag, particularly the electric furnace slag, is characterized by having a large content of iron components, and is therefore particularly suitable as the molten slag for use in the abrasive for shot blasting of the present invention.

Further, the molten slag may contain waste glass and / or silica sand as a component regulating material. Among them, the waste glass containing typically, SiO _2, CaO, Al ₂ O ₃ and Na ₂ O or the like. Among these, the ratio of SiO ₂ and Na ₂ O is particularly large. Waste glass is an amorphous material, and since it has a low melting point, it can be easily dissolved in molten slag, and therefore, it is suitable as a component regulating material for easily adjusting components of molten slag.

It is preferable that the waste glass is automotive glass. Glass for automobiles (waste glass for automobiles) is glass used for automobiles generated by scrap processing of automobiles. That is, for example, a front glass, a rear glass, a side glass, a lamp glass and the like are included. These may include only one kind, or two or more kinds may be included. In general, glass for automobiles often contains parts other than glass. Parts other than glass are parts used for assembly in automobiles, and include resin parts, metal parts, and the like. BACKGROUND ART [0002] Conventionally, waste glass for automobiles for automobiles generated by scrap processing of automobiles involves components other than glass, so that reuse is difficult, and landfills are generally disposable. On the other hand, in the case of mixing with molten slag, the presence of the parts does not affect the abrasive. That is, by injecting waste glass for automobiles into a slag in a molten state at a high temperature of 1500 DEG C or higher, the resin parts and the like are lost, and the metal parts and the like are melted and introduced into the slag. In addition, since the glass is an amorphous component having a low melting point, it can be dissolved in the molten slag smoothly, so that it can be dissolved in an energy efficient manner and the proportion of the SiO ₂ component in the molten slag can be increased. Further, automotive glass is highly preferable as a form to be added to melted slag since a heat-treated glass in which debris forms a granular state is usually employed in the case of being broken.

The Vickers hardness of the abrasive particles constituting the abrasive for shot blasting of the present invention can be 650 Hv or more (particularly 660 to 900 Hv, or 670 to 800 Hv, particularly 680 to 750 Hv).

The crushing strength of one grain of the abrasive grains is 18 kgf (176.4 N) or more, more preferably 20 kgf (196 N) or more (particularly 30 to 70 kgf (294 to 686) N) and further 45 to 60 kgf (441 to 588) N)}. For example, in the case of particles having a diameter of 1 mm or more, it may be 7 kgf (68.6 N) or more (especially 7 to 15 kgf (68.6 to 147) N) and further 8 to 13 kgf (78.4 to 127.4 N). Further, the crushing strength is converted into 1 kgf to 9.8N.

The above values are values measured using abrasive particles classified as " shots " defined in 3. (b) of JIS Z0312. The Vickers hardness is an average value of Vickers hardness obtained by measuring ten randomly selected abrasive particles in accordance with JIS Z2244. On the other hand, the crushing strength is an average value of the load values when 10 grinding particles selected at random are provided to the universal testing machine and the load is applied to each grinding particle of one egg to cause a collapse.

The average particle diameter of the abrasive particles constituting the abrasive for shot blast is not particularly limited and may be set to a particle diameter suitable for use, but is usually 5 mm or less in average particle diameter. In this range, the shot blast abrasive material maintains a high crushing strength and tends to be low-dispersed. The average particle diameter is preferably 0.05 to 4.0 mm, more preferably 0.1 to 3.0 mm, and particularly preferably 0.2 to 2.0 mm. The mean particle size means a 50% particle size in the integrated body percentage measured by JIS Z8815, which is applied to the particle size in JIS Z0312 (non-metallic abrasive for blast treatment).

[2] Manufacturing method of abrasive for shot blast

The present method (1) is a method for manufacturing an abrasive for shot blasting,

A weaving step of weaving molten slag to form slag particles,

A cooling step of cooling the slag particles by dropping the slag particles downward or downward and spraying water,

And a dewatering and conveying step of dewatering while conveying the slag particles.

The present method (2) is a method for manufacturing the abrasive for shot blasting,

A component adjusting step of adding waste glass and / or silica sand to the electric furnace slag as a component adjusting material;

A weaving step of weaving the molten slag obtained through the component adjusting step to form slag particles,

A cooling step of cooling the slag particles by dropping the slag particles downward or downward and spraying water,

And a dewatering and conveying step of dewatering while conveying the slag particles.

The "component adjusting step" is a step of adding waste glass and / or silica sand to the electric furnace slag as a component adjusting material. Among these, the waste glass usually contains SiO ₂ , CaO, Al ₂ O ₃ , Na ₂ O, and the like. Among these, the ratio of SiO ₂ and Na ₂ O is particularly large. The waste glass is an amorphous material and is low in melting point and can be easily dissolved in the molten slag. Therefore, the waste glass is suitable as a component adjusting material for easily adjusting the components of the molten slag.

The composition of the waste glass is not particularly limited, but the total amount of Si in terms of SiO ₂ , Ca in terms of CaO, Al in terms of Al ₂ O ₃ , and Na in terms of Na ₂ O is More preferably 70.0 mass% or more (usually 99.9 mass% or less), more preferably 80.0 to 98.0 mass%, still more preferably 85.0 to 95.0 mass%.

The content of Si in terms of SiO ₂ and the content of Na in terms of Na ₂ O is preferably 50.0 mass% or more (usually 90.0 mass% or less), more preferably 60.0 to 90.0 mass% And still more preferably 70.0 to 85.0% by mass. Among them, the content of Si in terms of SiO ₂ is preferably 50.0% by mass or more (usually 80.0% by mass or less), more preferably 55.0 to 80.0% by mass, and more preferably 60.0 to 75.0% by mass with respect to 100% %.

The amount of waste glass and / or silica sand added in this step is not particularly limited, and consequently, it can be added so as to have the composition range shown in the abrasive for short blast of the present invention described above. In other words, it is preferable that Fe, Si, Ca, Al, Mg and Mn are contained, and Fe, Si and Ca are added in an amount of 50.0 mass% or more in terms of FeO conversion, SiO ₂ conversion or CaO conversion And Fe in terms of FeO is not less than 6.0 mass% and not more than 35.0 mass%, the content of Si in terms of SiO ₂ is not less than 15.0 mass% and not more than 35.0 mass%, and the content of Ca in terms of CaO is not less than 10.0 mass% and not more than 35.0 mass% .

The waste glass is preferably glass for automobiles. Glass for automobiles (waste glass for automobiles) is glass used for automobiles generated by scrap processing of automobiles. That is, for example, a front glass, a rear glass, a side glass, a lamp glass and the like are included. These may include only one kind, or two or more kinds may be included. In general, glass for automobiles often contains parts other than glass. Parts other than glass are parts used for assembling in automobiles, and include resin parts and metal parts. BACKGROUND ART [0002] Conventionally, waste glass used for automobiles generated by car scrap processing involves components other than glass, and therefore, reuse is difficult, and landfills are generally disposed. On the other hand, in the case of mixing with molten slag, the presence of the parts does not affect the abrasive. That is, by injecting waste glass for automobile use into a slag in a molten state at a high temperature of 1500 ° C or higher, the resin parts and the like are lost, and the metal parts and the like are melted and introduced into the slag. Further, since the glass is an amorphous component having a low melting point, it can be dissolved smoothly in the molten slag, dissolving it in an energy-efficient manner, and increasing the proportion of the SiO ₂ component in the molten slag. Further, automotive glass is highly preferable as a form to be added to molten slag since a heat-treated glass in which debris forms a granular state is usually employed in case of breakage.

The " stranding step " is a step of stranding molten slag to form slag particles. The shroud indicates grinding using a gas, and is usually performed by supplying molten slag to the substrate before being discharged from the nozzle. The shape and the number of the nozzles used at this time are not particularly limited. That is, for example, there can be mentioned a ring nozzle having a plurality of nozzles radially arranged so as to discharge gas toward the center portion, and a parallel nozzle having a plurality of nozzles arranged so as to face each other so that gas is emitted toward the center portion. Among these, the ring nozzle (see Figs. 2 and 3) is preferable. The ring nozzle can be provided with uniformly arranged nozzles over the entire circumference of the ring, and the molten slag can be more uniformly atomized, which is effective for obtaining slag particles having homogeneous and excellent mechanical strength.

The number of nozzles (gas discharge ports) provided in the ring nozzle is not particularly limited, but is usually 20 to 100, preferably 20 to 70, and more preferably 30 to 60. In this range, a stable crimping can be performed.

The angle? (See FIG. 3) with respect to the central portion of each nozzle is not particularly limited, but is usually in the range of 5 to 45 degrees with respect to the falling direction of the molten slag (usually, More preferably 20 to 30 degrees. Within this range, the molten slag is easily crushed. In addition, it is possible to prevent the splashed slag particles from splashing upward, and to prevent the slag particles still at high temperature from sticking to each other.

The gas discharge pressure from the nozzle is not particularly limited, but is usually 3 to 25 kgf / cm 2 per nozzle, preferably 5 to 23 kgf / cm 2, and more preferably 7 to 20 kgf / cm 2. In this range, it is particularly easy to form small-diameter slag particles, and it is possible to suppress the collapse of the shape of the slag particles obtained by colliding the cobbled slag with the inner wall of the chamber or the like.

Although the amount of the gas to be discharged is not particularly limited, it is preferable that the amount of the gas is appropriately determined depending on the amount and the particle diameter of the slag particles to be dropped. For example, when the amount of molten slag is 2000 to 4000 kg (more preferably 2500 to 3000 kg) The gas release amount is preferably 600 to 6000 mPa (more preferably 800 to 4000 mPa, more preferably 1250 to 3500 mPa) per 60 minutes. There is no particular limitation on the type of the gas used for the trowel, and various gases can be used, but it is preferable to use air in order to make the apparatus simple structure.

The temperature of the molten slag to be used is not particularly limited, but the molten slag used in the present invention is preferably 1150 to 1600 占 폚 (more preferably 1200 to 1550 占 폚, and more preferably 1250 to 1500 占 폚) Do. The steelmaking slag to be used may be any slag, but as described above, the molten slag is preferably an electric furnace slag. That is, usually, the steelmaking slag includes blast furnace slag, converter slag, and electric furnace slag, but it is preferable that the slag is furnace slag. The electric furnace slag includes oxidizing slag and reducing slag, but it is preferable that the slag is an oxidizing slag. That is, it is preferably an electric furnace oxide slag. The electric furnace slag, particularly the electric furnace slag, is characterized by a large content of iron components, and thus is particularly suitable in the present invention.

The " cooling step " is a step of cooling the slag particles by dropping downwardly or downwardly the corrugated slag particles, and then spraying water. Naturally, it is also possible to cool the slag particles by spraying water while dropping the sprouted slag particles downward, and spraying water again after cooling down the slag particles. By performing this cooling step, the slag particles can be properly cooled.

According to this cooling step, even when the outer surface portion of the slag particles is cooled, the slag particles can be sent to the dehydrating and transporting process in a state where the core portion is not cooled. That is, the thermal conductivity of the slag used in the present invention is usually about 0.3 to 2.0 W / (m · K). Therefore, the slag particles do not collapse due to excessive cooling, and an excessively long cooling process is required, or a complicated manufacturing method such as requiring a reheating process and the like do not cause enlargement of the apparatus.

Generally, cooling methods to be performed in the cooling step include water cooling and air cooling. In this method, water cooling is used. In the production of an abrasive, cooling efficiency is not sufficiently obtained only by air cooling (natural heat radiation, gas injection, etc.), and a large space (particularly a large area or a long cooling distance) is required for heat removal. However, in the present method, a sufficient cooling effect can be obtained in a small space.

In addition to the cooling method described above, a method of dropping slag particles into water stored in the chamber may be considered as a method of achieving space saving when water cooling is performed. However, in this method, excessively rapid cooling is performed, so that the slag particles are collapsed (deformation and cracking are likely to occur). On the other hand, in the present method, adequate cooling can be performed, and the slag particles are not collapsed. In addition, since the slurry particles fall through the gas without passing through water and vertically downward, the shape of the slag particles can be easily formed into a shape closer to a sphere. Therefore, it is easy to hold a shape capable of exhibiting high mechanical strength (see Fig. 2).

In addition, in the method of dropping slag particles in water, it is necessary to close the lower part of the chamber because water is stored in the chamber, and the production is performed in a batch manner. On the other hand, in the present method, the chamber can be used in an open state, and an abrasive can be continuously produced, thereby achieving high manufacturing efficiency (see FIG. 2). In particular, steelmaking facilities and the like, which are continuously operated, have an advantage that the cost of storing slag can be reduced.

The falling distance at the time of performing the cooling step is not particularly limited, but is usually 3 m or more (preferably 4 to 10 m, more preferably 4.5 to 8 m, particularly preferably 5 to 7 m, usually 40 m or less). When the falling distance is within this range, cooling can be performed in a small space while preventing the cooling shortage. Therefore, it is possible to manufacture the shot blasting abrasive with high mechanical strength with high efficiency while keeping the apparatus compact.

Particularly, when the slag particles are cooled by spraying water after falling down, it is possible to prevent fusion of particles having a large grain size, which is an unfixed grain, even after falling, and the yield of the recovered product can be improved. As a method for cooling the slag particles by spraying water after dropping the sprouted slag particles downward, there is a method of dropping the slag particles passing through the chamber onto a steel conveyor and spraying water on the slag particles on the conveyor while conveying the slag particles onto a steel conveyor Method. At this time, it is preferable to spray water toward the same direction as the proceeding direction of the steel conveyor (that is, the traveling direction of the slag particles). The spray amount of water is not particularly limited, but it is preferable to use 0.08 liters or more (preferably 0.03 to 0.30 liters, and more preferably 0.05 to 0.20 liters) of water per 1 kilogram of crushed slag particles.

The " dewatering and conveying step " is a step of removing the adhered water from the slag particles in the cooling step while conveying the slag particles subjected to the cooling step. By this dewatering and conveying step, water is removed (not necessarily completely removed) from the slag particles, and heat is dissipated. In this dewatering and conveying step, the slag particles sent from the cooling step usually have sufficient heat to vaporize the water, so that part of the dewatered water is removed by vaporization. Therefore, it is considered that a part of the heat of the slag particles in the dewatering and conveying step is also removed by the heat of vaporization of water. In other words, the temperature of the slag particles transferred from the cooling step to the dehydrating and conveying step is not particularly limited, but is preferably 500 ° C or higher (preferably 500 to 1200 ° C).

In addition, the temperature of the slag particles recovered after the dewatering and conveying step is preferably 70 占 폚 or higher (more preferably 80 to 800 占 폚, still more preferably 85 to 500 占 폚, particularly preferably 90 to 200 占 폚, To 150 < 0 > C). In this range, the obtained slag particles can be maintained in an amorphous state, and particularly excellent mechanical strength can be obtained. The transportation time in this dewatering and transportation step, that is, the heat radiation time is not particularly limited, but is usually 0.5 to 10 minutes (preferably 0.5 to 3 minutes, more preferably 1 to 2 minutes). In this range, slag particles having particularly excellent mechanical strength can be obtained.

In the present method, other processes besides the above-described spunbonding step, cooling step and dewatering / conveying step may be provided. Other processes include a grinding process and a fractionation process.

The grinding step (sizing step) is a step of rubbing the slag particles obtained through the dewatering and conveying step. By carrying out this polish-grinding process, it is possible to form the deformed slag particles into a more spherical shape such that a plurality of slag particles are connected to each other before being sufficiently cooled. That is, the particles can be divided into particles from the connecting portion of the releasing slag particles and molded into a normal particle shape. For example, by crushing the needle-like, whisker-shaped and tear-shaped slag particles, the shape of the slag particles of the finished product can be made closer to a sphere shape.

The fractionation step is a step that can be carried out after the grinding step when the grinding step is performed after the dehydrating and conveying step and is a step of separating the slag particles having a desired shape and / or particle diameter from the obtained slag particles. In this step, usually, sieving is performed.

In this method, an abrasive for shot blasting may be produced by using any apparatus. However, in order to reliably perform each of the above-described steps, the molten slag (melted slag) A cooling means 120 for cooling the slag particles 201 by spraying water after dropping the slag particles 201 downward or downward and a cooling means 120 for cooling the slag particles 201, It is preferable to use a manufacturing apparatus 100 for a shot blast grinding material having a dehydrating and conveying means 130 for dehydrating water used for cooling from the slag particles 201 while conveying the water 201 3).

The crushing means 110 is means for crushing molten slag 200 to form slag particles 201. This spoil is carried out by using the gas released from the nozzle 111. The shape and the number of the nozzles 111 used for shoveling are not particularly limited, but the ring nozzle 110 is preferable as described above. The location of the ring nozzle 110 is not particularly limited, but is preferably disposed at the upper end of the chamber 121 to save space.

The cooling means 120 is means for cooling the slag particles 201 by dropping the slag particles 201 downward or downward, and then spraying water. Therefore, usually, a chamber 121 for dropping the slag particles 201 and waterproof means 124 for spraying water to the slag particles 201 are provided. By providing the chamber 121, the slag particles 201 can be dropped without being influenced by the surrounding environment (even when they are dropped). Further, the cooling effect by the waterproofing means 124 is also improved.

The shape of the chamber 121 is not particularly limited, but it is generally longitudinally long (see Fig. 2). By having a vertically long shape, it is possible to save space while securing a falling distance. As described above, the falling distance is usually 3 m or more (preferably 4 to 10 m, more preferably 4.5 to 8 m, particularly preferably 5 to 7 m, usually 40 m or less). Therefore, the space in the chamber 121 also normally has this distance in the longitudinal direction. The shape in the transverse direction (sectional shape in the falling direction of the slag particles) is not particularly limited and may be circular, rectangular, or other shape, but is preferably circular (i.e., cylindrical portion 122 )]. This is because the recovery efficiency of the slag particles is excellent. For example, in the case of a circular shape (the maximum length of the inside when it is not a circular shape), the inner diameter at the main portion is preferably 1 to 10 m (more preferably 2 to 8 m, and more preferably 3 to 6 m) . It is preferable that the lower end of the chamber 121 has a narrowed portion 123 toward the steel conveyor 126 or the dewatering and conveying means 130. It is preferable that the lower end of the chamber 121 is open to the steel conveyor 126 or the dewatering and conveying means 130 as described above. Thereby, the slag particles can be produced continuously and the mechanical strength of the obtained slag particles can be kept high.

The shape and size of the waterproofing means 124 are not particularly limited as long as they can be waterproofed to the slag particles 201. The waterproofing by the waterproofing means 124, It is preferable to perform it on the steel conveyor 126 provided below the chamber 121. [ In other words, it is preferable to cool the slag particles 201 falling from the chamber 121 onto the steel conveyor 126 by pouring the water-protected water from the water-proof nozzle 125.

The dewatering and conveying means 130 is means for dewatering the water used for cooling from the slag particles while conveying the slag particles 201. Since the dewatering and conveying means 130 has both the dewatering function and the conveying function, the slag particles 201 can be continuously produced. That is, the water is sprayed and cooled after dropping the spunlaid slag particles 201, and thereafter, the slag particles do not stay in a wet state, and dehydration is carried out continuously and further transported. As a result, the slag particles 201 are not excessively rapidly cooled, and the slag particles 201 having excellent mechanical strength are obtained. Further, such slag particles can be continuously and efficiently produced stably and efficiently.

The dewatering and transporting functions of the dewatering and conveying means 130 may be provided over the entire dewatering and conveying means 130 (that is, when the entire dewatering and conveying means 130 are made up of the wedge wire screen 132 (For example, the front portion is made up of a wedge wire screen, and the rear portion is made up of a heat-resistant conveyor such as a steel conveyor). This is because, even in the case of the dewatering and conveying means 130 having only the conveying function in the rear portion as in the latter case, the water can be evaporated by the heat of the slag particles 201 in this stage while being radiated. In general, in this dewatering and conveying means 130, as compared with the case where the slag particles 201 are already cooled to such an extent that water can not be vaporized by the heat in this stage (for example, less than 70 ° C) (For example, 80 DEG C or higher, preferably 100 DEG C or higher) at a stage where water can be evaporated in the step (1), slag particles having higher mechanical strength tend to be obtained.

In this dewatering and conveying means 130, it is preferable that the temperature of 800 ° C or more is maintained in the slag particles 201 immediately after the transition from the cooling means 120. In this dewatering and conveying means 130, a temperature of 130 to 600 ° C / min (more preferably 150 to 400 ° C / min, more preferably 180 to 300 ° C / min, particularly preferably 180 to 250 ° C / (Usually, cooled) at a rate of 10 < -6 > In this range, it is possible to achieve a shorter conveying distance while satisfactorily dewatering and cooling, so that product quality and space saving can be effectively achieved at the same time.

When the dewatering and conveying means 130 does not have a dewatering function and has a conveying portion having a conveying function as described above, the conveying portion may convey the slag particles in the planar direction. However, It can be conveyed in the vertical direction. That is, for example, a bucket conveyor 134 and the like can be mentioned. Thereby, further space saving can be achieved.

The shape of the dewatering and conveying means 130 is not particularly limited but the dewatering and conveying means 130 may be at least a part of the dewatering and conveying means 130 and may include wedge wires 131 arranged at intervals such that the slag particles 201 do not pass therethrough And a wedge wire screen 132 having a wedge wire screen 132. When the wedge wire screen 132 is provided only in a part, it is preferable that the wedge wire screen 132 is provided on the leading end side (the side closer to the cooling means) of the dewatering and conveying means 130. This is because the wedge wire screen 132 can perform dehydration and transportation with a simple facility.

The shape of the wedge wire 131 used in the wedge wire screen 132 is not particularly limited. When the average particle size of the objective slag particles 201 is 5 mm or less, the wedge wire 131 is 0.1 to 4.0 mm (preferably 0.1 To 1.0 mm, more preferably 0.2 to 0.5 mm) of the wedge wire 131 is used. The slag particles 201 closer to the spherical shape are easily obtained without performing the grinding step (sizing step) in the next step.

When the wedge wire screen 132 is used, it is preferable that the wedge wire screen 132 can perform dehydration by vibration. It is also preferable that the slag particles 201 can be simultaneously conveyed by this vibration. Therefore, it is preferable that the dewatering and conveying means 130 is provided with the vibration generating means 133 and can transmit the generated vibration to the wedge screen 132.

The apparatus 100 used in the present method may have other means besides the crawling means 110, the cooling means 120 and the dewatering means 130. As another means, the molten slag storing means 150 for feeding molten slag 200 to the crushing means 110 in an appropriate amount may be mentioned. The molten slag storage means 150 may also include a heating means 152 such as a burner and / or a heater to prevent the molten slag 200 from being frozen. As the molten slag storing means 150, a tundish 150 is usually used. The capacity and shape of the tundish 150 are not particularly limited, but it is preferable that the tundish 150 is provided with an opening through which molten slag can flow downward. It is also preferable that the opening is circular and has an inner diameter of 10 to 50 mm (more preferably 12 to 35 mm, and more preferably 16 to 28 mm). The depth of the tundish 150 is preferably 50 to 200 cm (more preferably 70 to 150 cm, and further preferably 80 to 120 cm). The flow rate of molten slag from the tundish 150 is preferably 5 to 40 liters / min (more preferably 7 to 30 liters / min, and more preferably 8 to 15 liters / min) Do.

In addition, as another means, it is possible to provide a conveying-time waterproofing means for waterproofing the slag particles 201 conveyed by the dewatering and conveying means 130 to cool again. The shape of the waterproofing means during transportation is not limited, but a waterproof pipe can be arranged in parallel to the dewatering and conveying means 130 (for example, the wedge wire screen 132).

As other means, heat exchange means may be provided. The heat exchanging means is means for recovering the heat radiated from the apparatus (the manufacturing apparatus 100 for the shot blast) in the process of the molten slag 200 becoming the slag particles 201. The shape of the heat recovery means is not limited, but heat recovery means can be provided by installing various known heat recovery apparatuses at various positions of the apparatus (for example, the chamber 121, the tundish 150, etc.) . By providing the heat recovery means, the arrangement can be efficiently used and the cooling efficiency can be improved.

In addition, as other means, a crushing means for performing the crushing process in the above-described method can be provided. As the crushing means, an apparatus such as an Irish mixer and a mortar mixer can be used. Further, after this crushing means, it is possible to provide a sorting means for carrying out the present method. As the separation means, a body device such as a vibrating body and a mono layer can be used.

<Examples>

Hereinafter, the present invention will be described in detail with reference to examples.

[1] Manufacture of abrasive for shot blast

The shot blast abrasive material manufacturing apparatus 100 shown in Fig. 2 and the apparatus having the structure near the shovel means 120 shown in Fig. 3 were used to manufacture the shot blast abrasive material 201. [

2 is provided with a crawling unit 110, a cooling unit 120, a dewatering and conveying unit 130, and a collection container 141. The crawler unit 100 includes a crawler unit 110, a cooling unit 120, a dewatering unit 130, In addition, molten slag storage means (tundish) 150 is provided as a pre-means of the shovel means 110. Further, almost all of the manufacturing apparatus 100 is disposed in the underground pit (the underground arrangement can suppress the external leak of the operation sound).

The molten slag storage means 150 is a so-called tundish. The tundish 150 has a rectangular parallelepiped shape with a size of 200 cm x 100 cm x depth 100 cm and has openings 151 with a diameter of about 24 mm provided with a nozzle formed from refractory at the bottom, To the crushing means (110). In addition, the burner 152 is provided with a temperature controllable melted slag 200 stored in the tundish 150. In addition, a dam and a damper (not shown) are also provided to prevent the ingress of massive foreign matter.

The crushing means (ring nozzle) 110 is composed of a ring nozzle (typical diameter 30 cm) in which 45 nozzles 111 are radially arranged in the direction of the center. The angle? (See FIG. 3) of each nozzle is set to 26 to 27 degrees.

The cooling means 120 includes a chamber 121, a waterproofing means 124 and a steel conveyor 126. The chamber 121 has a cylindrical portion 122 having a diameter of 400 cm and a length of 4.3 m and a portion 123 having a lower end diameter of 150 cm and a length of 1.4 m and extending from the cylindrical portion 122 (The dropping distance of the triturated slag from immediately after the shovel means is 5.7 m). The waterproofing means (124) has a waterproof nozzle (125). The waterproof nozzle 125 is installed on the upper part of the steel conveyor 126 and is waterproofed to the slag particles 201 falling from the chamber 121 onto the steel conveyor 126. The steel conveyor 126 is provided below the chamber 121 and the slag particles 201 falling from the chamber 121 are conveyed to the wedge wire screen 132 via the steel conveyor 126.

The dewatering and conveying means 130 includes a wedge wire screen 132 having a length of 3 m and a wedge wire 131 having an inverted triangular shape arranged with a gap of 0.2 mm and a bucket conveyor 134 having a length of 12.5 m in the longitudinal direction . Among them, the wedge wire screen 132 is connected to the vibration generating device 133 so as to be vibrated at a vibration width (45 ° C upward in the advancing direction) of 6 mm width and 60 Hz. On the wedge wire screen 132, the cobbled slag 201 dropped by the cooling means is dehydrated and conveyed at a conveying speed of about 12 m / min. On the other hand, the bucket conveyor 140 is a conveyor for conveying the cobbled slag 201 conveyed from the wedge wire screen 132 to the collection container 141 disposed on the ground in the underground pit, Lt; / RTI &gt;

[2] Manufacturing of abrasive for shot blast

(1) Experimental Examples 1-6 and Experimental Examples 12-16

A shot blasting abrasive was produced as follows using steel blasting slag obtained in an electric furnace by using the apparatus 100 for producing a shot blast for abrasive as described in [1] above.

That is, about 3 tons of the molten slag 200 obtained in the electric furnace was charged into the tundish 150 of the manufacturing apparatus 100 of the above-mentioned [1].

The molten slag 200 flows down from the bottom opening of the tundish 150 into the chamber 121 and thereafter passes through the center of the ring nozzle 110. From the ring nozzle 110, air was released at a gas discharge pressure of 16 kgf / cm 2. As a result, the molten slag 200 passing through the ring nozzle 110 becomes a particle shape due to the sprocket and falls down in the chamber 121. In the chamber 121, the cobbled slag 201 was cooled by air cooling.

The air-cooled cobbled slag 201 is discharged from the narrowed portion 123 and dropped onto the steel conveyor 126. The cooling water discharged from the waterproof means 125 is discharged at a rate of 3 liters / And drops onto the wedge wire screen 132 of the dewatering and conveying means 130. [

On the wedge wire screen 132, the cobbled slag 201 is dropped and dehydrated, and the cobbled slag 201 is sent in turn to the bucket conveyor 140 by vibration. It was observed that the state of the black color of the traction slag 201 immediately after it fell onto the steel conveyor 126 was visually observed and was around 1000 캜. The transport time on a 3 m long wedge wire screen was 0.25 minutes. Further, it was conveyed at a speed of 8 m / min by the bucket conveyor 140 and recovered to the recovery container 141. The temperature of the tumbled slag immediately after being housed in the recovery container was 99.5 ° C.

Thereafter, the slag particles 201 were recovered from the recovery container 141, charged into a separately provided crushing apparatus, and polished for 2 minutes under the conditions of agitator rotation speed of 800 rpm and fan rotation speed of 85 rpm. Subsequently, the slag particles obtained by passing through a sieve having an eye of 0.2 mm were collected as an abrasive for shot blasting.

(2) Example 7 (Component adjustment by silica sand)

(100% by mass of Si, 93.1% by mass in terms of SiO ₂ , and Al in terms of SiO ₂₎ were added to the steelmaking slag in a melted state obtained in an electric furnace by using the apparatus 100 for producing a shot blast of [1] (Containing 1.8% by mass in terms of Al ₂ O ₃ ) was added at a ratio of 0.845 ton per 10 tons of steelmaking slag to obtain molten slag 200 (composition adjustment was performed using silica sand).

A shot blasting abrasive was produced in the same manner as in the other experimental examples except that the molten slag used for the component adjustment was made of this silica sand.

(3) Examples 8-11 (Component adjustment by waste glass for automobile)

Using the apparatus 100 for producing a shot blast for abrasive as described in [1], waste glass discharged in scrap of an automobile was added to steel slag in a molten state obtained in an electric furnace at a ratio of 1 ton per 10 tons of steelmaking slag So that molten slag 200 was obtained (component adjustment was carried out using waste glass for automobiles). As a result of the component analysis of the added waste glass for automobiles, only the glass portion was found to contain 67.7% by mass of Si in terms of SiO ₂ , 12.6% by mass in terms of Na ₂ O based on 100% by mass of all the waste glass for automobiles , 2.0% by mass of Al in terms of Al ₂ O ₃ , and 9.5% by mass of Ca in terms of CaO.

A shot blasting abrasive was produced in the same manner as in the other experimental examples except that molten slag obtained by adjusting the components using the waste glass for automobile was used.

&Quot; Fe + Si + Ca &quot; in Table 1 represents the total of FeO-converted content, SiO ₂ -constituted content, and CaO-converted content.

"Mn / Fe" in Table 1 indicates the content in terms of MnO / FeO.

&Quot; Ti / Fe &quot; in Table 1 indicates the content in terms of TiO ₂ / the content in terms of FeO.

&Quot; Ti / Ca &quot; in Table 1 indicates the content in terms of TiO ₂ / CaO.

[3] Evaluation of abrasive for shot blast

(1) Component analysis

In Experimental Example 1-16, the obtained shot blast abrasive was pulverized by a vibrating mill, and a sample obtained by subjecting the obtained powder to powder compacting was subjected to a multi-element simultaneous X-ray fluorescence spectrometer (manufactured by Kabushiki Kaisha, MULTIX 10 type &quot;). The results are shown in Table 1.

(2) Crush strength

In Experimental Example 1-16, it was found from the obtained abrasive for shot blast that the grinding material particles classified as &quot; shots &quot; defined in 3. (b) of JIS Z0312 were spherical in shape, A grinding material particle having a measurement of 2 mm (2.0 mm 占 0.1 mm in particle diameter measurement using digital nog- ness) was selected. Further, the crushing strength (the load value when the load was applied to each grinding material particle by each load) of ten grinding material particles randomly selected from the grinding material particles was measured by a crushing strength meter (manufactured by Tokyo Koki Seisakusho Co., , Type "Amsler type universal material testing machine AU-30"), and the average value of data of each of the obtained 10 points was calculated and shown in Table 1.

(3) Vickers hardness

In Experimental Example 1-16, it was found from the obtained abrasive for shot blast that the grinding material particles classified as &quot; shots &quot; defined in 3. (b) of JIS Z0312 were spherical in shape, A grinding material particle having a measurement of 2 mm (2.0 mm 占 0.1 mm in particle diameter measurement using digital nog- ness) was selected. Further, the Vickers hardnesses of 10 grinding particles randomly selected from the grinding particles were measured (according to JIS Z2244) using a Vickers hardness tester (type "MVK" manufactured by Akashi Seisakusho Co., Ltd.) , And the data average value of each of the obtained 10 points was calculated and shown in Table 1.

(4) Confirmation of existence of amorphous continuous layer

From the thus obtained shot blast abrasive, abrasive particles classified as "short" as defined in 3. (b) of JIS Z0312 and having a spherical shape were picked up, 2.0 mm 占 0.1 mm in the measurement of particle diameter using digital nog- ness) was selected. Further, ten randomly selected abrasive particles among the abrasive particles were cut, and the surface thereof was polished. The obtained polished surface was magnified and observed 500 times by an optical microscope, and the presence or absence of an amorphous continuous phase was observed. As a result, in the experimental example in which amorphous continuous phase was observed in all of the 10 samples, "O" was shown in the column of "amorphous continuous layer" in Table 1. On the other hand, in an experimental example in which no amorphous continuous phase was observed in any of the ten samples, "x" was shown in the column of "amorphous continuous layer" in Table 1.

1: amorphous continuous phase
2: Crystalline phase
3: a continuous phase (crystalline phase)
4: crystal phase (coarse crystal)
100: Equipment for manufacturing abrasive material for shot blast
110: crimping means (ring nozzle)
111: Nozzle
120: cooling means
121: chamber
122: cylindrical portion
123: The narrowed part
124: Waterproofing means
125: Waterproof nozzle
126: Steel conveyor
130: Dewatering and conveying means
131: Wedge wire
132: Wedge wire screen
133: Vibration generating means (vibration generating apparatus)
140: Bucket conveyor
141: Collection container
150: Melting slag storage means (tundish)
151: opening of molten slag storage means
152: Heating means (burner)
200: Melted slag
201: Slag particles (abrasive for shot blasting)

Claims (11)

Fe, Si, Ca, Al, Mg and Mn,
Having a continuous phase that is amorphous,
The total content of Fe, Si and Ca in terms of FeO-converted, SiO ₂ -converted or CaO-converted is 50.0% by mass or more with respect to the entire 100% by mass,
Fe in an amount of not less than 6.0 mass% and not more than 35.0 mass% in terms of FeO, 15.0 mass% or more and 35.0 mass% or less of Si in terms of SiO ₂ , and Ca in an amount of 10.0 mass% or more and 35.0 mass% or less in terms of CaO. Grinding abrasive for blast. The short-blast abrasive according to any one of claims 1 to 3, wherein Al is contained in an amount of not less than 3.0% by mass and not more than 25.0% by mass in terms of Al ₂ O _{3 based} on 100% by mass of the total. The short-blast abrasive according to any one of claims 1 to 3, which contains 2.0 to 20.0 mass% of Mn in terms of MnO, based on 100 mass% of the total. 3. The steel sheet according to claim 1 or 2,
Wherein the Ti content is 0.01% by mass or more and 10.0% by mass or less in terms of TiO ₂ with respect to the entire 100% by mass of the abrasive. 3. The steel sheet according to claim 1 or 2,
Wherein the Cr content is 0.5% by mass or more and 5.0% by mass or less in terms of Cr ₂ O _{3 based} on 100% by mass of the whole. The abrasive for shot blasting according to claim 1 or 2, wherein the slag particles are obtained by shrinking molten slag. 7. The abrasive according to claim 6, wherein the molten slag is an electric furnace slag. 8. The shot blast for abrasive according to claim 7, wherein the molten slag contains at least one of waste glass and silica sand as a component adjusting material. 9. The abrasive according to claim 8, wherein the waste glass is glass for automobiles. 8. A method of manufacturing an abrasive for shot blast according to claim 7,
A blowing step of blowing the molten slag or the electric furnace slag to form slag particles,
A cooling step of cooling the slag particles by dropping the slag particles downward or downward and spraying water,
And a dewatering and conveying step of dewatering the slag particles while conveying the slag particles. 9. A method of manufacturing an abrasive for shot blasting according to claim 8,
A component adjusting step of adding at least one of waste glass and silica sand to the molten slag or the electric furnace slag as a component adjusting material;
A crushing step of crushing molten slag or electric furnace slag obtained through the component adjusting step to form slag particles,
A cooling step of cooling the slag particles by dropping the slag particles downward or downward and spraying water,
And a dewatering and conveying step of dewatering the slag particles while conveying the slag particles.

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