TWI723352B - Method of incineration ash reused for synthesis of porous materials - Google Patents

Abstract

This invention discloses a method of incineration ash reused for synthesis of porous materials, comprising: (a) providing an incineration ash; (b) adjusting silica to aluminum ratio of silica and aluminide which are collected from the incineration ash; (c) dissolving the incineration ash by an alkali fusion reaction; (d) obtaining a solid product and a hydrolysis solution by a hydrolysis reaction; (e) obtaining a precursor by mixing the hydrolysis solution with an adjustment solution; (f) obtaining a precipitate by a hydrothermal synthesis reaction of the precursor; and (g) obtaining a porous material by washing ,drying and calcining the precipitate.

Description

Method for synthesizing porous material by incinerating ash

The invention provides a method for synthesizing porous materials by incinerating ash and slag, in particular to a method for synthesizing porous materials through alkali fusion hydrothermal method.

Generally speaking, Incineration ash includes incineration bottom ash (Bottom ash) and fly ash (Fly ash), which is defined as the residue produced by burning waste in an incinerator. At present, most of the bottom slag is crushed and sorted and then reused in various engineering fillers or engineering materials, or directly collected and buried; while most of the fly ash is currently solidified/stabilized and stacked in a landfill, or After washing with water, it can be used as cement additives.

However, when the bottom slag and fly ash are collected and buryed, they often face the dilemma of insufficient landfill capacity, so that burial cannot be a long-term feasible treatment method. What's more, heavy metals or dioxin and other harmful substances are still eluted in the reuse of ash and slag, causing doubts and potential risks of secondary environmental pollution. In addition, fly ash is cured and stabilized by adding cement and chelating agents, which will not only increase the volume and further accelerate the consumption of landfill space, but the inorganic components such as chloride salts and calcium oxide are more likely to cause the curing required. The reaction time is prolonged, and even it is easy to absorb moisture and cause the cured product to swell and disintegrate.

In summary, the current treatment methods of incineration bottom slag and fly ash have problems such as environmental pollution concerns and poor social perception, which further affect the stable development of waste incineration. Because of this, the proper treatment and reuse of incineration ash has become an urgent problem faced by waste incineration plants.

In recent years, the incineration fly ash has the potential to synthesize porous materials and environmentally-friendly moisture-absorbing or adsorbent materials due to the fact that the incineration fly ash is rich in specific components such as silicon and aluminum compounds. According to the existing technical theory, for synthetic porous materials and environmentally friendly hygroscopic or absorbent materials, most of them use natural clay minerals, water purification sludge or waste glass and other wastes as raw materials.

In view of the shortcomings mentioned in the prior art, the present invention provides a method for incineration of ash to synthesize porous materials. The method for synthesizing porous materials from incineration ash disclosed in the present invention mainly includes seven major steps.

First, perform step (a) to provide an incineration ash, and then perform step (b) to adjust the silicon-to-aluminum ratio of the silicon compound and aluminum compound in the incineration ash, then proceed to step (c), add An alkali activator is mixed and stirred, and an alkali fusion reaction is carried out.

Step (d) is performed to separate a solid and a hydrolyzed solution after a hydrolysis reaction is performed, and then step (e) is performed to add the hydrolyzed solution to a conditioning solution and stir to form a precursor solution. Then the obtained precursor liquid is subjected to step (f), the precursor liquid is subjected to a hydrothermal synthesis reaction to obtain a precipitate, and finally through step (g), the precipitate is taken out, washed, dried and calcined to form a poly Porous materials. Wherein, the adjustment solution of step (e) contains a sulfuric acid, and the pH value of the precursor solution is adjusted to 8-12.

Thereby, the present invention can successfully recover and reuse the incineration ash, and appropriately adjust the control conditions to synthesize porous materials. In addition to allowing the incineration ash to be recycled and reused by itself, it can also be used for air pollution and water pollution control in incineration plants, creating another treatment method and reuse pipeline for incineration ash, reducing the amount of incineration ash treatment and reducing the possibility The resulting environmental pollution improves the value and application benefits of incineration ash recovery and resource recycling products.

The above brief description of the present invention aims to provide a basic description of several aspects and technical features of the present invention. The brief description of the invention is not a detailed description of the invention. Therefore, its purpose is not to specifically enumerate the key or important elements of the invention, nor to define the scope of the invention. It merely presents several concepts of the invention in a concise manner.

In order to understand the technical features and practical effects of the present invention, and implement it in accordance with the content of the specification, the preferred embodiment shown in the figure is further described in detail as follows:

Please refer to FIG. 1, which is a flow chart of a method for incineration of ash and slag to synthesize a porous material according to an embodiment of the present invention. As shown in Fig. 1, the method for synthesizing porous materials from incineration ash and slag in the embodiment of the present invention mainly includes seven major steps.

First, perform step (a) to provide an incineration ash. In this embodiment, the incineration ash is Bottom ash, Fly ash, or a combination thereof, depending on the incineration ash provided by the incineration plant or related industry, and the present invention is not limited . Then, step (b) is performed to adjust the ratio of silicon to aluminum of the silicon compound and aluminum compound in the incineration ash, and then step (c) is performed to add an alkali activator to mix and stir, and perform an alkali melting reaction.

In steps (b)-(c) of this embodiment, the ratio of silicon to aluminum is between 10-40, preferably 10, 20 or 40; the adjustment method is to recover silicon compounds from incineration ash It is compounded with aluminum, and the ratio of silicon to aluminum molar is adjusted appropriately. The alkali activator can be an alkali substance, such as sodium hydroxide (NaOH), potassium hydroxide (KOH), sodium carbonate (Na ₂ CO ₃ ), or a combination thereof, which is added in a fixed alkali-to-ash ratio of 1.5 and mixed uniformly.

As for the alkali fusion reaction, the appropriate liquid-to-solid ratio will be adjusted to facilitate the use in the next step; in this step, the recommended liquid-to-solid ratio can be adjusted between 100-200, and 100, 150 or 200 is better. . The reaction hardware used in the alkali fusion reaction in this step is a high-temperature furnace, the reaction time can be between 20-80 minutes, and the reaction temperature can be between 200-800 degrees Celsius. In this step, the optimal alkali fusion reaction temperature and time are 400-600 degrees Celsius for 40-60 minutes in order.

Then, step (d) is performed, a hydrolysis reaction is performed and then separated into a solid and a hydrolysis solution. In this embodiment, the parameter used in the hydrolysis reaction is a reaction at 105 degrees Celsius for 24 hours. After the reaction is completed, the temperature is cooled down and the remaining insoluble substances are removed.

Then perform step (e), add the hydrolysis solution to an adjustment solution and stir to form a precursor solution. In step (e) of this embodiment, the adjustment solution contains a sulfuric acid, and the volumetric molar concentration of the sulfuric acid is 1 M. The adjustment solution further includes a Cetyltrimethylammonium bromide (CTAB) solution with a concentration of 1.2% by weight of the total solution (that is, the sum of the adjustment solution and the hydrolysis solution). Finally, in step (d) of this embodiment, the pH value of the precursor solution is adjusted to 8-12 through sulfuric acid.

Then, the obtained precursor liquid is continued to step (f), and the precursor liquid is subjected to a hydrothermal synthesis reaction to obtain a precipitate. In step (f) of this embodiment, the method used for the hydrothermal synthesis reaction is a hot water reactor with a cover and a seal. The reaction time is between 12-48 hours; and the reaction temperature is between 80-180 degrees Celsius. The optimal parameter used in step (f) of this embodiment is that the reaction temperature and time are 105 degrees Celsius for 24 or 48 hours in sequence.

Finally, through step (g), the precipitate is taken out for cleaning, dried and calcined to form a porous material. In step (g) of this embodiment, the precipitate obtained in step (f) will be filtered after being taken out and cleaned, and then the calcination parameter adopts 450-650 degrees Celsius for 3-6 hours.

The porous material finally produced in this example is Zeolite. Please refer to FIG. 2, which is a final product diagram of the method for incineration of ash and slag to synthesize porous materials according to an embodiment of the present invention. As shown in Figure 2, under the premise that Figure 2 is a scanning electron microscope image, it can be seen that the zeolite synthesized in the embodiment of the present invention has high-quality characteristics, and zeolites with different properties can be synthesized according to different conditions and parameters. It can also be used as an adsorbent, a catalyst support, a temperature-resistant material or a surface modification material, etc. It can only be adjusted according to the requirements of the implementation, and the present invention is not limited.

However, the above are only the preferred embodiments of the present invention, and should not be used to limit the scope of implementation of the present invention, that is, simple changes and modifications made in accordance with the scope of the patent application and the description of the present invention still belong to the present invention. Covered.

(a)-(g): steps

Fig. 1 is a flow chart of steps of a method for incineration of ash to synthesize porous materials according to an embodiment of the present invention. Fig. 2 is a final product diagram of the method for incineration of ash and slag to synthesize porous materials according to an embodiment of the present invention.

(a)-(g): steps

Claims (5)

A method for synthesizing porous materials from incineration ash, comprising: (a) providing an incineration ash; (b) adjusting the silicon-to-aluminum molar ratio of the silicon compound and the aluminum compound in the incineration ash, and the silicon The aluminum mole ratio is between 10-40; (c) Add an alkali activator, mix and stir, and perform an alkali melting reaction, the alkali activator is sodium hydroxide (NaOH), potassium hydroxide (KOH), carbonic acid Sodium (Na ₂ CO ₃ ) or a combination thereof, the reaction time of the alkali fusion reaction is between 40-60 minutes; the reaction temperature of the alkali fusion reaction is between 400-600 degrees Celsius, and the alkali activator The weight ratio of alkali ash to the incineration ash is fixed at 1.5; (d) After undergoing a hydrolysis reaction, it is separated into a solid and a hydrolyzed solution, and the liquid-to-solid weight ratio of the solid to the hydrolyzed solution is between 100-200 (E) The hydrolysis solution is added to an adjustment solution and then stirred to form a precursor; (f) the precursor is subjected to a hydrothermal synthesis reaction to obtain a precipitate, and the reaction time of the hydrothermal synthesis reaction is between 12- 48 hours; the reaction temperature of the hydrothermal synthesis reaction is between 80-180 degrees Celsius; and (g) the precipitate is taken out, washed, dried and calcined to form a porous material, the calcining parameters Use a temperature of 450-650 degrees Celsius for 3-6 hours; wherein the adjustment solution of step (e) contains sulfuric acid and Cetyltrimethylammonium bromide (CTAB), and the volume of sulfuric acid is molar The concentration is 1M, and the adjustment solution adjusts the pH value of the precursor solution to 8-12. The method for synthesizing porous materials from incineration ash as described in claim 1, wherein the incineration ash in step (a) is bottom ash, fly ash, or a combination thereof. The method for synthesizing porous materials from incineration ash as described in claim 1, wherein the weight percent concentration of the cetyltrimethylammonium bromide (CTAB) is the total solution of the hydrolyzed solution plus the adjustment solution 1.2%. The method for synthesizing porous materials from incineration ash as described in claim 1, wherein the optimal reaction time of the hydrothermal synthesis reaction in step (f) is 24 or 48 hours; the reaction temperature of the hydrothermal synthesis reaction is optimal The temperature is 105 degrees Celsius. The method for synthesizing porous materials from incineration ash as described in claim 1, wherein the porous material in step (g) is Zeolite.

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