JP4500255B2 - Mud material for waste melting furnace and refractory raw material composition used for it - Google Patents

Description

  The present invention relates to a waste melting furnace mud material for closing a tap in a waste melting furnace for melting waste such as municipal waste, industrial waste, or incinerated ash, and a raw material for the mud material for the waste melting furnace It relates to a refractory raw material composition used as a base material.

  At present, most of the waste is processed by the incineration method. However, the incineration method has a drawback in that it requires a landfill site for incineration ash. Therefore, a technology has been developed in which waste is reduced by melting the waste using a waste melting furnace and reused as a stable substance.

  FIG. 1 is a schematic view illustrating a conventionally known waste melting furnace. This waste melting furnace 1 is of a type referred to as a direct melting furnace (shaft furnace), and has a loading port 2 and an exhaust port 3 at the top of a vertical type furnace 1 and a tuyere 4 at the bottom. And a tap 5. A water tank 6 is disposed below the hot water outlet 5.

  The hot water outlet 5 is closed with a mud material 7 injected by a mud gun (press-fit machine) (not shown). Waste, coke, limestone and the like are charged into the furnace 1 from the charging port 2. Part of the charged waste is burned by the oxygen-enriched air supplied from the tuyere 4, and water vapor, pyrolysis gas, fine dust, etc. generated in the combustion process are discharged from the exhaust port 3. Is done. On the other hand, waste ash, non-combustibles, coke, coal, and the like are lowered to the bottom of the furnace 1 while being heated to a high temperature, and are accumulated at the bottom of the furnace 1 in a molten state of 1300 ° C to 1650 ° C.

  The mud material 7 filled in the hot water outlet 5 is fired by the heat of the waste melting furnace 1. The sintered mud material 7 is excavated by an opening machine 8 equipped with a rod having a bit formed at the tip, and the tap 5 is opened. Then, the waste molten slag accumulated at the bottom of the furnace 1 is discharged out of the furnace 1 through the tap 5. The discharged waste molten slag flows into the water tank 6 through the basket 9 and is rapidly cooled to become sandy grains. The waste slag that has become sandy grains is separated into metal and ash by a magnetic separator, and the metal is reused as heavy equipment counterweight, and the ash is reused as aggregate for roadbeds and other concrete products. The

  By the way, conventionally, the mud material 7 that closes the tap 5 of the waste melting furnace 1 is used as it is. The blast furnace mud material is a kneaded clay-like material in which a binder is added to a powdery refractory raw material composition with adjusted particle size, and the binder is a type using coal or petroleum fraction such as tar or pitch. Of a type using a synthetic resin such as a phenol resin (see Patent Document 2, etc.) and a type using both a coal or petroleum fraction and a synthetic resin ( (See Patent Document 3 etc.).

In this specification, a binder is a kneading liquid added to a refractory raw material composition in order to make a powdery refractory raw material composition into a kneaded clay, and refers to coal or petroleum fractions and / or synthetic resins. Shall. In the present specification, the symbol “to” is used to include both end points. Also, in this specification, those expressed by chemical formulas such as Al ₂ O ₃ , SiO ₂ , C, etc. mean chemical components, and are expressed in katakana such as alumina raw materials, siliceous raw materials, and carbonaceous raw materials. The thing shall mean the actual refractory raw material which may contain inevitable impurities.
JP 11-278949 A Japanese Patent Laid-Open No. 10-036178 JP 11-349383 A

  In the process in which the waste molten slag is discharged, a part of the mud material 7 may be eluted into the waste molten slag, or excavation debris of the mud material 7 may be mixed into the waste molten slag. In the blast furnace, even if part of the mud material is eluted or mixed in the slag, since it is excluded in the subsequent steelmaking process, there is no problem without affecting the quality of the steel product. However, in the melting treatment of waste, the elution components and the like of the mud material are not removed from the waste melt slag, and the waste molten slag flows into the water tank 6 while containing the elution components and the like of the mud material. As a result, the waste slag and the stored water in the water tank 6 contain harmful substances such as benzpyrene, although it is very little.

  In the past, the amount of hazardous substances contained in waste slag and water stored in the aquarium 6 has sufficiently cleared safety standards. For example, waste slag (the above ash) is as harmless and safe as natural sand. is there. However, if the amount of hazardous substances contained in the waste slag and the stored water in the water tank 6 can be further reduced, the process for draining the stored water can be simplified, and the waste slag can be reused. The potential for use will expand and the benefits to the industry will be significant.

  The inventors arrived at the idea that the leaching of harmful substances into the waste slag and the stored water in the water tank 6 may be caused by the binder constituting the mud material. As a result of investigation, the elution of harmful substances to waste slag, etc. becomes particularly noticeable when mud type using coal or petroleum fraction is used as binder, and mud type using synthetic resin as binder. Even when using materials, it has been found that there is a considerable amount of elution of harmful substances caused by the binder. One of the objects of the present invention is to provide a mud material for a waste melting furnace that can reduce the mixing of harmful substances into waste slag, stored water in a water tank, or the like.

  Moreover, in the blast furnace, for example, in the case of a waste melting furnace, the opening of the hot water outlet is performed about once every 30 minutes to 1 hour. For this reason, from the viewpoint of reducing the work load in front of the furnace and improving the work environment, in the melting process of waste, for example, the ease of opening the mud material (free cutting) and the mud material excavation, compared with the case of the blast furnace In particular, suppression of dust generation is strongly desired. In this regard, the conventional types of blast furnace mud materials described above are excellent in hot strength and sintering strength, but excessive strength is considered to be a cause of dust generation and ease of opening. It is done. Another object of the present invention is to provide a waste melting furnace mud material capable of reducing the work load in front of the furnace and improving the work environment.

Moreover, the waste slag produced in the waste melting furnace has a lower mass ratio of CaO / SiO ₂ (hereinafter referred to as C / S) than the slag produced in the blast furnace, for example, 0.5 to 1 .2 or so. For this reason, in the waste melting furnace, there is a problem that the mud material is more easily eroded than in the blast furnace. Still another object of the present invention is to provide a mud material for a waste melting furnace that can exhibit sufficient corrosion resistance even with respect to a waste melting slag.

  If the inventors use water without using a binder as a liquid material for kneading the powdery refractory raw material composition, it is possible to avoid mixing harmful substances into waste slag, stored water in the water tank, etc. I got the idea. However, simply using water in place of the binder cannot provide the characteristics necessary for functioning as a waste melting furnace mud material, particularly the strength during sintering. If the strength during sintering of the mud material is too small, hot water leaks out of the mud material during operation of the furnace.

The strength of the mud material for the waste melting furnace is normal temperature when the mud material is pressure-molded into a shape of 40 mm × 40 mm × 160 mm at a molding pressure of 10.2 MPa (100 kg / cm ² ) and fired at 1500 ° C. for 1 hour. The value of the bending strength measured according to JIS-R2575 needs to be 1 MPa or more.

  As a result of diligent research, the inventors have selected the composition of the chemical composition of the refractory raw material composition and optimized the particle size composition so that the mud material can be used without blending a hardening accelerator such as a binder or cement. The knowledge that the above-described necessary strength can be imparted has been obtained, and the following invention has been completed.

According to the first aspect of the present invention, Al ₂ O ₃ and SiO ₂ are preferably added under the condition that the mass ratio of SiO ₂ / Al ₂ O ₃ is preferably 0.2 to 5, more preferably 1 to 4. 80% by mass or more, having a chemical composition comprising 0.3 to 3% by mass of Na ₂ O and K ₂ O in total, and having a particle size of 0.045 mm or less, 30 to 70% by mass, particle size It had a particle size composition consisting of 5 to 30% by mass of more than 0.045 mm and 0.21 mm or less, 50% by mass or less of particles having a particle size of more than 0.21 mm and 3 mm or less, and 10% by mass or less of particles having a particle size of more than 3 mm There is provided a waste melting furnace mud material in which 100% by mass of a powdery refractory raw material composition is kneaded with 13 to 25% by mass of water based on this.

  According to the second aspect of the present invention, there is also provided a waste melting furnace mud material in which the refractory raw material composition further contains 1 to 15% by mass of C.

According to another aspect of the present invention, Al ₂ O ₃ and SiO ₂ total 80% by mass or more, Na ₂ O and K ₂ O total 0.3 to 3% by mass, preferably C 1 to 15%. It is obtained by kneading a powdery refractory raw material composition containing mass% with water, and pressure-molded into a shape of 40 mm × 40 mm × 160 mm at a molding pressure of 10.2 MPa (100 kg / cm ² ), and at 1500 ° C. The value measured in accordance with JISR2575 for the bending strength at normal temperature when fired for 1 hour is 1 MPa or more, preferably 1.5 MPa or more, more preferably 2 MPa or more, 30 MPa or less, preferably 25 MPa or less, more preferably 10 MPa or less. A waste melting furnace mud material is also provided.

  According to still another aspect of the present invention, there is also provided the powdery refractory raw material mixture used as a raw material for each of the waste melting furnace mud materials.

  According to the 1st aspect of this invention, in addition to selection of the chemical component structure of a refractory raw material mixture, there exist the following effects by optimizing a particle size structure. That is, despite the fact that water is used as the kneading liquid, it is possible to impart the necessary strength to the mud material, so there is no need to use a binder, waste slag resulting from the use of the binder, stored water in the water tank, etc. Elution of harmful substances into the can be avoided. On the other hand, since excessive strength expression due to the binder can be prevented, the ease of opening is better than the conventional mud material using the binder. Moreover, since generation | occurrence | production of the dust at the time of opening can be suppressed, the improvement of the working environment in front of a furnace is achieved. Furthermore, sufficient erosion resistance can be exhibited even for waste molten slag having a low C / S.

  According to the second aspect of the present invention, in addition to the above effects, the inclusion of C makes it difficult for the mud material to get wet with the waste molten slag, so that the erosion resistance can be further improved. Moreover, when the specific amount of C moderately suppresses the sintering of the mud material, the ease of opening can be further improved while maintaining the strength necessary for the mud material.

Embodiments of the present invention will be described below. First, the chemical component configuration will be described. Mud material according to the embodiment, the material serving as a refractory raw material formulation _thereof, containing at least 80 wt% Al 2 _{O 3} and SiO ₂ in total. Thereby, sufficient erosion resistance can be exhibited even for waste molten slag having C / S of about 1.5 or less, for example. From the standpoint of further improving erosion resistance, the total content of Al ₂ O ₃ and SiO _{2 in} the refractory raw material composition is preferably 85% by mass or more, and 90% by mass or more. More preferred.

The proportion of Al ₂ O _{3 in} the refractory raw material composition is preferably 20 to 50% by mass. By setting the upper limit of the content of Al ₂ O ₃ to 50% by mass, it is possible to prevent a delay in sintering and set the hot strength to a more appropriate value. Further, by setting the lower limit of the content of Al ₂ O ₃ and 20 wt%, can prevent a decrease in melting point of the mud material, the durability and erosion resistance can be further improved. Considering these effects, the content of Al ₂ O ₃ is preferably 30 to 40% by mass, and more preferably 35 to 40% by mass.

The proportion of SiO _{2 in} the refractory raw material composition is preferably 30 to 60% by mass. By setting the upper limit of the content ratio of SiO ₂ to 60% by mass, it is possible to further suppress the deterioration of the erosion resistance and wear resistance of the mud material, and it is possible to perform stable hot water for a long time. Further, by setting the lower limit of the content of SiO ₂ to 30% by mass, it is possible to suppress excessive hot strength of the mud material and further improve the ease of opening. Considering these effects, the content of SiO ₂ is preferably 40 to 50% by mass, and more preferably 40 to 45% by mass.

Further, refractory raw material formulation, containing 0.3 to 3 wt% in total of Na ₂ O and _{K 2} O. By setting the lower limit of the content ratio of Na ₂ O and K ₂ O to 0.3% by mass, it is possible to suppress the occurrence of cracks, hole breakage, etc. in the mud material and to set the strength of the mud material to an appropriate value. it can. In the present invention in which no binder is used, it is particularly important to contain Na ₂ O and K ₂ O. Also, by a 3 wt% upper limit for the content of Na 2 _O and K _{2 O,} it can prevent a decrease in erosion resistance of the mud material. Considering these effects, the total content of Na ₂ O and K ₂ O is preferably 0.4 to 1% by mass.

  Moreover, a refractory raw material compound contains 1-15 mass% of C. By containing at least 1% by mass of C, the mud material becomes difficult to get wet with the waste molten slag, so that the erosion resistance can be further improved. Further, when C moderately suppresses the mud material from being sintered, the ease of opening can be further improved while at least maintaining the strength necessary for the mud material. As a result, it is possible to suppress bit wear in the hole opening machine, reduce the time required for opening the mud material, and improve the operating rate of the waste melting furnace. However, if the C content exceeds 15% by mass, sintering of the mud material is suppressed too much, and it becomes difficult to express the strength necessary for the mud material. From such a viewpoint, the C content is preferably 5 to 13% by mass, and more preferably 5 to 10% by mass.

The chemical composition of the remainder of the refractory raw material formulation, for example MgO, _CaO, may be constituted by unavoidable components such _{Fe 2} O 3, TiO 2.

  Next, the particle size configuration will be described. The refractory raw material composition is 30 to 70% by mass with a particle size of 0.045 mm or less and 5 to 30 with a particle size of more than 0.045 mm and 0.21 mm or less as measured using a standard sieve specified in JIS-Z8801. The particle size is adjusted so as to be 50% by mass or less, and 10% by mass or less of the particles having a particle diameter of more than 3 mm.

  When the blending ratio of the particles having a particle diameter exceeding 3 mm exceeds 10% by mass, the press-fit resistance when the mud material is filled into the tap is excessively increased. The blending ratio of those having a particle diameter exceeding 3 mm is preferably 7% by mass or less. Here, what exceeds the particle size of 3 mm is an optional component, and this particle size range may not be included.

  When the blending ratio of the particles having a particle size of 0.045 mm or less is less than 30% by mass, the mud material cannot be provided with sufficient plasticity, and troubles such as hole breakage are caused. On the other hand, if the blending ratio of particles having a particle size of 0.045 mm or less exceeds 70% by mass, a problem arises that a lot of dust is generated during mud material excavation. From such a viewpoint, it is preferable that the blending ratio of the particles having a particle size of 0.045 mm or less is 35 to 65% by mass.

  The reason why the blending ratio of the particles having a particle size of more than 0.045 mm and 0.21 mm or less was set to 5 to 30% by mass and the reason why the blending ratio of the particles having a particle diameter of more than 0.21 mm and 3 mm or less was set to 50% by mass or less were In order to obtain the effects of improving the workability by adding the necessary strength to the mud material in combination with the blending ratio and chemical composition of other particle size ranges and giving the mud material an appropriate shape retention. The mixing ratio was found as a result of trial and error by the inventors. Here, the particle size of more than 0.21 mm and 3 mm or less is an optional component, and this particle size range may not be included. In addition, it is preferable that the compounding rate of a thing with a particle size over 0.045mm and 0.21mm or less is 10-21 mass%, and a compounding rate with a particle size over 0.21mm and 3 mm or less is 45 mass% or less. It is preferable.

  The refractory raw material composition has the above-mentioned chemical composition and particle size constitution, for example, alumina such as bauxite, diaspore, van earth shale, fused alumina, sintered alumina, calcined alumina, sintered spinel, and fused spinel. Raw materials, siliceous raw materials such as silica, silica flour, fused silica, alumina siliceous raw materials such as rholite, chamotte, synthetic mullite, electrofused mullite, kaolin, clay, sericite, silimanite (silicalite) and andalusite Carbonaceous raw materials such as natural or artificial graphite (including surface-treated graphite) such as scaly graphite and earthy graphite, and amorphous carbon such as carbon black (however, coal such as tar and pitch or petroleum fractions and other benzpyrenes) Except those containing.

  In addition, you may further mix | blend another additive with a refractory raw material compound. Examples of the additive include salts such as NaCl and KCl. By adding salts, it is possible to impart a strain to the mud material and to improve the shape retention.

  The mud material is obtained by kneading the refractory raw material composition with water. Since the chemical component structure and the particle size structure of the refractory raw material composition are defined as described above, the necessary strength can be imparted to the mud material without using a binder. Since it is not necessary to use a binder, it is possible to avoid elution of harmful substances in waste slag and stored water in the water tank due to the use of the binder. Further, it is possible to suppress smoke generation immediately after the start of the hot water due to the binder, and to improve the working environment in front of the furnace. Moreover, since the excessive strength expression resulting from a binder can be avoided, the time required for opening can be shortened and the operating rate of a waste melting furnace can be raised.

  If the amount of water added to the refractory raw material composition is too large, bubbling occurs in the mud material due to the heat of the waste melting furnace, causing waste melting slag to leak out of the furnace. On the other hand, if the amount of water to be added is too small, sufficient plasticity is not imparted to the mud material, making it difficult to fill the mud gun. From such a viewpoint, the amount of water added to the refractory raw material composition is preferably 13 to 25% by mass, and 17 to 22% by mass, as an outer shell with respect to 100% by mass of the refractory raw material composition. More preferred.

  The water for kneading the refractory raw material composition may contain starch or other thickener (workability improving agent) that does not contain substances harmful to the human body. Even if a thickener that does not contain harmful substances is used, the effect of avoiding the elution of harmful substances to waste slag, stored water in the water tank, etc. is not impaired. Furthermore, a very small amount of binder may be added to the mud material within a range not impairing the effects of the present invention.

  If the mud material of the present invention is not used immediately, it is molded into an appropriate shape such as a block shape if necessary, and then wrapped with a water-resistant sheet such as vinyl, polyethylene, rubber, etc. It is preferable to stock the product in a state where moisture evaporation prevention measures are taken. By providing the mud material as a preform type in which the mud material is kneaded and formed in advance, it is possible to prevent the variation in the quality of the mud material and to further stabilize the hot water discharge time. However, the refractory raw material composition that is the raw material for the mud material can also be provided in the form of powder. In this case, kneading work is required on site such as before the furnace, but it can be set in the mud gun immediately after kneading. There is no need to consider hardening due to evaporation of moisture in the material.

  Table 1 shows the composition and evaluation results of the mud materials according to the examples and comparative examples. The chemical component was measured by fluorescent X-ray analysis specified in JIS-R2216. The measurement of particle size constitution was performed using a standard sieve specified in JIS-Z8801. The blank in Table 1 indicates that the material is not included.

In addition, except for the mud materials of Comparative Examples 1 and 3, 100% by mass of the refractory raw material composition was kneaded with only 17% by mass of water with respect to this. The mud material of Comparative Example 1 is obtained by kneading the refractory raw material composition with a binder instead of water, and the mud material of Comparative Example 3 is obtained by adding 100% by weight of the refractory raw material composition with water of 28% by weight on the outer surface. Obtained by kneading.

  Each evaluation item in Table 1 will be described.

  Ease of opening: Evaluated based on the number of usable bits of the opening machine. The number of times the bit can be used is a value representing how many times the outlet hole can be formed before the bit becomes worn and becomes unusable. For simplicity, Table 1 shows the usable index, which is a relative value of the number of usable bits for each mud material, where the usable number of bits for the mud material of Example 1 is 100. The larger the usable index, the easier the opening, and the smaller the usable index, the faster the wear of the bid, indicating that the opening is difficult.

  Dust generation amount: The actual machine test was conducted in the waste melting furnace shown in FIG. The temperature of the waste molten slag accumulated at the bottom of the furnace during the operation of the furnace is about 1300 ° C to 1650 ° C, and the mud material fired by this heat is excavated by an opening machine having a bit. The amount generated was evaluated by visual observation with the naked eye. In Table 1, o indicates that the amount of dust generated is relatively small. Δ indicates that much dust was observed. X indicates that a large amount of dust was observed.

  Corrosion resistance: Evaluated by a erosion index. The erosion index refers to the amount of erosion by the rotating drum erosion test conducted at 1500 ° C. to 1550 ° C. for 3 hours using waste molten slag as the erodant, and the amount of erosion of the mud material of Example 2 as 100. This is expressed as a relative value. The erosion index indicates that the smaller the value, the better the erosion resistance.

Bending strength: At a normal temperature (about 20-25 ° C.) when the mud material is pressure-formed into a shape of 40 mm × 40 mm × 160 mm at a forming pressure of 10.2 MPa (100 kg / cm ² ) and fired at 1500 ° C. for 1 hour. It is the value which measured bending strength according to JIS-R2575.

  Workability: From the viewpoint of the size of the press-fit resistance when the mud material is press-fitted into the tapping hole, the evaluation was made in three stages:.

  As shown in Table 1, since the mud materials of Examples 1 to 3 do not contain any binder, they do not contain harmful substances. For this reason, the elution of a hazardous | toxic substance to waste slag and the stored water in a water tank can be avoided. Moreover, as shown in Table 1, the mud materials according to Examples 1 to 3 are all excellent in the ease of opening and corrosion resistance, and can suppress the generation of dust. The bending strength is also in the range of 19 to 25 MPa and has the necessary strength. Furthermore, workability is also good.

  The mud materials according to Examples 4 to 6 have a bending strength of 2.7 to 18 MPa, which is lower than the mud materials of Examples 1 to 3 due to the inclusion of C. However, this level of bending strength (for example, about 1 to 20 MPa from a broader viewpoint) is sufficient for use in a waste melting furnace. Further improvement in the ease of opening is achieved. It can be seen that the higher the C content, the easier the opening is, and this is because C exhibits the function of suppressing the sintering of the mud material. Moreover, corrosion resistance is also improving from the thing of Examples 4-6. Although it turns out that corrosion resistance improves, so that the content rate of C is high, this is because C improves the wettability with respect to the waste molten slag of a mud material. As a raw material for C, carbon black in which C accounts for 99% by mass or more was used.

On the other hand, the mud material of Comparative Example 1 contains 0.6% by mass of harmful substances due to the use of liquid tar and a phenol resin solution as the binder. This harmful substance is benzpyrene mainly contained in liquid tar, but may also contain phenol, formaldehyde, ammonia or the like resulting from the phenol resin. In addition, due to the formation of carbon bonds due to the binder, excessive strength was developed, and the ease of opening was deteriorated. Furthermore, since the total amount of Al ₂ O ₃ and SiO ₂ was too small, the corrosion resistance deteriorated.

  Since the mud material of Comparative Example 2 contained too much coarse particles having a particle diameter of more than 3 mm, the generation of dust could be suppressed, but the filling press-fit resistance increased and the filling workability deteriorated. Further, the bending strength was an insufficient value of 18 MPa.

  Since the mud material of Comparative Example 3 is composed of fine powder of 0.045 mm or less, it is dense and excellent in corrosion resistance, but the ease of opening is remarkably reduced, and the amount of time required for the opening work is much longer. Occupancy rate decreased. In addition, a great deal of dust was generated during excavation, and the working environment in front of the furnace deteriorated. Further, since it is composed only of fine powder, a large amount of kneading water is required to obtain plasticity, and there is a concern that bubbling may occur in the filling state of the tapping hole.

The mud material of Comparative Example 4 has a particle size of 0.21 mm or less and more than 0.045 mm, so that the ease of opening is reduced, the amount of dust generated is slightly higher, and the workability is slightly poor. Met. Furthermore, the bending strength was an insufficient value of 15 MPa. In addition, although it is thought that the decrease in the ease of opening and the bending strength is caused by the fact that the content of Al ₂ O ₃ is too large, a combination of particles having a particle size of 0.21 mm or less and more than 0.045 mm is assumed. If the ratio is within the range specified in the present invention, it is considered that the drawback of having too much Al ₂ O ₃ content can be alleviated.

The mud material of Comparative Example 5 has a particle size of 3 mm or less and a mixing ratio of more than 0.021 mm, so that generation of dust can be suppressed, but corrosion resistance and bending strength are insufficient, and filling press-fit resistance As a result, the filling workability deteriorated. In addition, although it is thought that the fall of corrosion resistance is also caused by too much content of SiO ₂ , if the blending ratio of particles having a particle size of 3 mm or less and more than 0.021 mm is within the range specified in the present invention, SiO 2 _It is thought that the fault of having too much content of ₂ can be relieved.

  Although the mud material of Comparative Example 6 contained C, the ease of opening was very good, but the C content was too high, so the bending strength was as extremely low as 0.6 MPa. This value is insufficient for use as a mud material for a waste melting furnace, and there is a concern of hot water leakage.

  Examples of the waste melting furnace include an ash melting furnace and a gasification melting furnace. An ash melting furnace is a plant that melts incineration ash once incinerated in an incinerator or the like as a processing target, and an ash melting furnace includes, for example, an electric furnace type. The gasification melting furnace is a plant that generates pyrolysis gas from waste and melts residues such as incineration ash with heat from the pyrolysis gas. There is. FIG. 1 shows this shaft type gasification melting furnace. However, the mud material of the present invention is not limited to this, but is used for the electric furnace type ash melting furnace and other intermittent hot water type waste melting furnaces. Can be used widely.

The conceptual diagram which shows an example of a waste melting furnace.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Waste melting furnace 2 Charging inlet 3 Exhaust outlet 4 Tuyere 5 Outlet 6 Water tank 7 Mud material 8 Opening machine 9 樋

Claims (3)

It has a chemical composition comprising Al ₂ O ₃ and SiO ₂ in total of 80% by mass or more and Na ₂ O and K ₂ O in total of 0.3 to 3% by mass, and a particle size of 0.045 mm or less. 30 to 70% by mass, 5 to 30% by mass with a particle size of more than 0.045 mm and 0.21 mm or less, 0 to 50% by mass with a particle size of more than 0.21 mm and 3 mm or less, and a particle size of more than 3 mm A waste melting furnace mud material in which 100% by mass of a powdery refractory raw material composition having a particle size composition of 0 to 10% by mass is kneaded with an outer coating of 13 to 25% by mass of water.   The waste material melting furnace mud material according to claim 1, wherein the refractory raw material composition further contains 1 to 15 mass% of C.   The said powdery refractory raw material mixture used as a raw material of the mud material for waste melting furnaces of Claim 1 or 2.

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