JP4998694B2 - Ceramic fired body and method for producing the same - Google Patents

Description

  The present invention relates to a ceramic fired body such as roof tile and wall material using coal ash, aluminum dross, and clay as starting materials, and a method for producing the same.

  From the long-term perspective of global oil supply and demand, the importance of coal-fired power generation is inevitable. Currently, about 10 million tons / year of coal ash is discharged from coal-fired power plants, and this amount is expected to increase in the future. Although about 40% of this coal ash (mainly fly ash) is used as a raw material for cement, most of it is landfilled, and the importance of using coal ash as a resource is also seen from the situation where landfill sites are tight. It is increasing.

  On the other hand, slag-like aluminum dross (aluminum residue ash) generated in the process of melting aluminum or aluminum alloy contains aluminum nitride, metal oxide, flux component, sulfide, etc. in addition to metal aluminum and aluminum oxide. Yes. Thus, when aluminum dross is treated as industrial waste, it is dangerous to generate hydrogen when it reacts with rainwater to form hydroxide, and there is also a problem of generating off-flavor by generating ammonia gas. is there. Therefore, it is also desired to utilize aluminum dross as a resource.

  On the other hand, in the tile manufacturing industry, the clay for tiles has been depleted, and securing it is becoming a problem.

By the way, a method for producing synthetic zeolite using coal ash and aluminum dross as raw materials is known (see, for example, Patent Document 1).
JP 2004-300005 A

  Synthetic zeolite obtained using coal ash and aluminum dross as raw materials is used as land improvement material or roadbed improvement material. However, in view of the composition of coal ash, there is a possibility of further added value from the viewpoint of resource recycling. However, no technical means to make it possible have been proposed.

  An object of the present invention is to provide a ceramic fired body that uses coal ash and aluminum dross as a part of raw materials and can be used as a tile, a wall material, a roadbed material, and the like, and a method for manufacturing the ceramic fired body.

  In order to solve the above problems, the invention according to claim 1 is to obtain a porous body containing synthetic zeolite by adding coal ash to an alkali treatment liquid obtained by reacting aluminum dross in an alkaline aqueous solution and heating and reacting. This is a ceramic fired body obtained by adding the porous granular powder containing the synthetic zeolite to clay, kneading, drying, and firing.

  The invention according to claim 2 is to obtain a porous body containing synthetic zeolite by adding coal ash to an alkali treatment liquid obtained by reacting aluminum dross in an alkaline aqueous solution, and heating and reacting the resulting mixture. It is a ceramic fired body for roof tiles obtained by adding the body to the clay for tiles in a proportion of 40% by weight or less, kneading and drying, and firing.

  The invention according to claim 3 adds a caustic soda solution to aluminum dross to obtain a soluble sodium aluminate, and adds coal ash to the solution containing the soluble sodium aluminate, and a temperature range of 80 ° C. to 120 ° C. for 5 hours or more. A porous body containing synthetic zeolite is made to react, and the porous granular powder containing the synthetic zeolite and clay are kneaded, molded, dried, and then fired at a temperature range of 1100 ° C. to 1400 ° C. for 20 hours or more. This is a method for producing a ceramic fired body.

  In the invention according to claim 4, a caustic soda solution is added to aluminum dross to obtain soluble sodium aluminate, coal ash is added to the solution containing the soluble sodium aluminate, and a temperature range of 80 ° C. to 120 ° C. for 5 hours or more. A porous body containing synthetic zeolite is allowed to react, and the porous granular powder containing the synthetic zeolite is added to the clay for clay within a range of 40% by weight or less, kneaded, molded, dried, and then 1100 ° C. to 1400 ° C. It is the manufacturing method of the ceramic sintered body used as a roof tile characterized by performing baking for 20 hours or more in the temperature range.

  According to the present invention, an inexpensive ceramic fired body that can be used as a roofing material for roofing, roofing materials, etc., which is lightweight as a part of raw materials such as coal ash and aluminum dross, which are industrial wastes, and a method for producing the same Can be provided. Thus, in terms of resource recycling, the replacement of clay is also effective in protecting resources of clay for tiles.

  When the ceramic fired body of the present invention is used as a roof tile, the roof tile can be reduced in weight by having strength equal to or higher than that of a clay roof tile, and an effect of facilitating roof tile construction can be achieved. In addition, since the ceramic fired body of the present invention is rich in water retention, it has an effect of being excellent in moldability when kneaded and molded with clay.

  When obtaining synthetic zeolite from coal ash, it is necessary to add a soluble alumina component because the alumina component in the coal ash is insufficient. Table 1 shows an example of the composition of coal ash. In the present invention, a porous body containing synthetic zeolite is obtained using aluminum dross generated in the process of melting coal ash and aluminum or an aluminum alloy as a raw material.

On the other hand, for example, aluminum dross generated from an aluminum recycling manufacturer includes, as an example, metal aluminum: 35.7 wt% and alumina (Al ₂ O ₃ ): 27.8 wt%. Thus, the aluminum dross is added to the sodium hydroxide (NaOH) solution to change to sodium aluminate (NaAlO ₂ ). Next, coal ash is added to an alkali treatment solution of aluminum dross containing sodium aluminate and reacted at a temperature of 80 ° C. to 120 ° C., preferably 90 ° C. to 100 ° C. for 5 hours or more, preferably 6 hours to 8 hours. A synthetic zeolite is obtained. The blending ratio of the aluminum dross alkali treatment solution and coal ash at this time is preferably in the range of 2.3 to 2.4 by weight. If it is less than 2.3, unreacted SiO ₂ remains due to lack of Al, and if it exceeds 2.4, a large amount of unreacted Al ₂ O ₃ remains due to excess Al.

  The obtained synthetic zeolite granular powder is added to clay within a range of 40% or less by weight, kneaded and molded, and then fired at a temperature range of 1100 ° C. to 1400 ° C. for 20 hours or more, thereby firing the ceramic. Get the body.

Fly ash having the composition shown in Table 1 discharged from a coal-fired power plant (F city B city) and aluminum dross generated from an aluminum recycling manufacturer (Y city S city) (metal aluminum: 35.7% by weight, Alumina (Al ₂ O ₃ ): 27.8% by weight was used as a starting material. The aluminum dross was added at room temperature to 1 mol to 3 mol of caustic soda (NaOH) solution. As a result of X-ray analysis of aluminum dross treated with an alkaline aqueous solution, it was found that metal Al disappeared, and Al and caustic soda (NaOH) reacted to change to sodium aluminate (NaAlO ₂ ).

Next, the coal ash is added to the alkali treatment solution of aluminum dross in an amount sufficient to change the silica (SiO ₂ ) in the coal ash to zeolite, and reacted in a temperature range of 90 ° C. to 100 ° C. for 7 hours. To obtain X-type zeolite.

  Thereafter, the X-type zeolite granular powder obtained above is added to the clay (Ishizu clay for clay) produced from the Iwami district of Shimane Prefecture, and added at a blending ratio of 0% to 70% by weight, and kneaded. Molded (thickness: 15 mm, diameter: 30 mm disk shape) and dried in the sun for one week. This sun-dried molded body was heated and fired at 1200 ° C. for 24 hours.

  For the obtained ceramic fired bodies with a X-type zeolite blending ratio of 0%, 10%, 20%, 30%, 50%, 60%, and 70%, the weight reduction rate before and after firing, the volume before and after firing. The reduction rate, bulk density, and strength were measured. The average value of the results is shown in Table 2, the measurement results of strength are shown in Table 3, the measurement results of weight reduction rate and volume reduction rate before and after firing are shown in Tables 4 and 5, and the measurement of bulk density is shown in Table 6.

  As is clear from Table 1, the strength is almost the same as that of the clay for clay: 100% when the blending ratio (% by weight) of the synthetic zeolite is up to 30%. Further, the blending ratio (wt%) of the synthetic zeolite: 70% strength does not extremely decrease. Further, by blending synthetic zeolite, the weight can be reduced by 7% to 9% compared to the case of clay for tiles: 100%.

INDUSTRIAL APPLICABILITY The present invention can be used as a roof tile, a wall material, a roadbed material for greening a building roof, etc., and has a wide range of uses as a drainage layer forming material, a material for earthen pipe, etc. utilizing the porosity.

Claims (4)

  Coal ash is added to an alkali treatment solution obtained by reacting alumidos in an alkaline aqueous solution, heated and reacted to obtain a porous body containing synthetic zeolite, and the porous granular powder containing synthetic zeolite is added to clay and kneaded and dried. A fired ceramic body obtained by firing.   A porous material containing synthetic zeolite is obtained by adding coal ash to an alkali treatment liquid obtained by reacting alumidos in an alkaline aqueous solution, followed by heating and reaction, and a porous granular powder containing the synthetic zeolite is contained in a proportion of 40% by weight or less. A ceramic fired body for roof tiles obtained by kneading and drying in addition to clay for roof tiles and then firing.   Porous containing synthetic zeolite by adding caustic soda solution to Almidros to obtain soluble sodium aluminate, adding coal ash to the solution containing soluble sodium aluminate and reacting at 80 ° C to 120 ° C for 5 hours or more A method for producing a ceramic fired body, comprising kneading, molding and drying a porous granule powder containing the synthetic zeolite and clay, followed by firing in a temperature range of 1100 ° C. to 1400 ° C. for 20 hours or more. Porous containing synthetic zeolite by adding caustic soda solution to Almidros to obtain soluble sodium aluminate, adding coal ash to the solution containing soluble sodium aluminate and reacting at 80 ° C to 120 ° C for 5 hours or more And then the porous granule powder containing the synthetic zeolite is added to the clay for clay within a range of 40% by weight or less, kneaded, molded and dried, and then fired at a temperature range of 1100 ° C. to 1400 ° C. for 20 hours or more. A method for producing a ceramic fired body used as a roof tile.