KR20100092773A - A fly ash purify and product collection method - Google Patents

Abstract

PURPOSE: Method for refining fly ashes and for collecting a refined product are provided to maximize the recycling efficiency of resources by simultaneously performing distributing and sorting processes in a refining process. CONSTITUTION: Collected fly ashes are mixed with water in order to form a mixture. A reagent including wasted oil and wasted cooling oil is added to the mixture. The mixture with the reagent is induced into a floatation machine. A floatation-sorting process is performed. A precipitation process, a concentration process, a dehydration process, and a dry process are performed. Refined products are collected.

Description

Fly Ash Purification and Product Recovery Method {A FLY ASH PURIFY AND PRODUCT COLLECTION METHOD}

The present invention relates to a method for refining coal ash and recovering products, and more particularly, to a recovery method for effectively separating and recovering various products including unburned carbon powder as impurities so that waste coal ash can be recycled to an industry.

In general, it is known that about 10% of unburned carbon powder (unburned coal powder) is contained in coal ash (fly ash) that is generated and discarded after burning coal in a coal-fired power plant.

As such, various methods have been conventionally used to completely remove unburned carbon powder contained in 10% of coal ash, and thus, up to 5% of the coal is removed. Due to the difficulty, developed countries are already making efforts to reduce unburned carbon by 1%.

That is, in order to use the discarded coal ash for the purpose of concrete admixtures, lightweight building materials, agricultural fillers, etc., the content of unburned carbon powder, which is an impurity, should be about 3% or less so that it can be sufficiently used for building and industrial purposes.

However, it is not possible for dry treatment facilities that are already in operation in Korea to reduce the unburned carbon fraction of coal ash to less than 3%. Therefore, the domestic dry treatment process removes unburned carbon powder from coal ash by wet treatment method like other developed countries. There is a need to be done.

Accordingly, the present invention has been proposed to improve the above problems in the prior art, by using a complex method applied to the wet treatment method in place of the existing dry treatment method to effectively remove the unburned carbon powder coal ash The purpose is to minimize the unburned carbon content.

The present invention for achieving the above object, the water mixing step of mixing the collected coal ash with water; A reagent addition step of adding a reagent including waste oil and cooking oil to the mixed coal ash; Stirring the coal ash to which the reagent is added; A flotation screening step of sorting the stirred matter into a flocculant and sorting the unburned carbon fractions discharged from the flotation and the coal ash products precipitated in the lower portion; A precipitation step of transferring the coal ash product precipitated in the lower portion to a sedimentation tank through the outlet of the lower portion of the flotation separator for precipitation for 10 to 20 minutes; A concentration step of discharging the coal ash precipitate which is precipitated in the precipitation tank and concentrating in the concentration tank; A dehydration step of dewatering the coal ash in the slurry state in which the concentration is made; A drying step of drying the dehydrated coal ash in a solid state; Characterized in that it comprises a; purified product recovery step of recovering the dried unburned carbon powder.

The present invention shows the effect of maximizing the resource recycling efficiency by being able to be purified with high purity so that the discarded coal ash can be recycled for construction and industrial use.

In particular, the unburned carbon content can be lowered to 0.1%, and the products containing unburned carbon powder can be individually recovered and reused for optimum use.

In addition, since the classification and specific gravity screening of coal ash is made in the refining process, it shows the advantage that can be utilized according to the intended use without the need for a separate classification operation during recycling.

Hereinafter, specific embodiments of the present invention will be described in detail.

On the other hand, the chemical component content of the two sample samples 1.2 used in the experiment of the present invention was analyzed, respectively, which is shown in the following [Table 1].

Sample
Chemical Analysis (% by weight) Sio ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO K ₂ O Na ₂ O Tio ₂ MnO P ₂ O ₅ F.C One 63.0 21.7 5.0 2.8 1.8 1.1 0.9 1.0 0.1 0.5 7.9 2 65.5 23.8 5.3 2.5 1.4 1.8 0.6 1.2 0.1 0.6 6.5

[F.C: Fixed Carbon]

Coal ash shown in the table can be confirmed that the residual amount of unburned carbon is contained in about 6 to 8% by weight, the coal ash in this state is unsuitable for industrial use.

In other words, the limit value is less than 5% by weight, and when it is higher than that, the cement strength does not come out, so it is inevitable that the entire amount is buried.

Thus, by reducing the residual amount of unburned carbon by the process of the present invention, the purified coal ash is made available for industrial use.

Hereinafter, a process of recovering unburned carbon powder from a coal circuit according to an embodiment of the present invention will be described with reference to the flowchart of FIG. 1.

First, 70 to 80% by weight of water is mixed with 20 to 30% by weight of the coal ash sample in which the two sample samples are mixed. In this case, the coal ash that is supplied to the vibrating feeder in the condition tank is water (including mineral grains). The mixing with the water is made in the tank, and the mixing shaft is provided in the mineral liquid tank to smoothly mix the mixture.

Subsequently, the reagent for sorting is mixed in an amount of 0.1 to 1% by weight to 99 to 99.9% by weight of the mixture.

At this time, the reagent used in the present invention is to use a mixture of waste oil and waste oil to be discarded, that is, to recycle the waste oil used in the edible oil and waste engine oil plant used for edible so as to ensure economic efficiency It is preferable to.

In addition, as a result of the experiment, waste oil or cooking oil alone was used as a reagent, resulting in deterioration of the quality of unburned carbon products. Most preferably, the intrinsic reaction of oil when the mixture was mixed in half at a ratio of 50 wt%: 50 wt%. It was confirmed that the combination of these exhibits the maximum characteristics.

In particular, the reagent is added to the waste oil and edible oil, as well as oleic acid ethanol solution and polyphenol in a certain ratio, it is possible to recover the more effective unburned carbon powder in the flotation process, such as waste oil 40 Reagents contained in weight percent, waste oil 40 weight percent, oleic ethanol 6 weight percent, and polyphenol 4 weight percent can be used.

That is, by adding oleic acid ethanol and polyphenol having excellent adhesion to unburned carbon powder particles, the recovery efficiency of unburned carbon powder can be increased.

On the other hand, after mixing the reagents, the unsorted carbon powder contained in the coal ash is suspended by the flotation separator, and the flotation separator is a container for coal ash and water, that is, a cell and a mineral liquid contained in the cell (coal ash + water). A conventional flotation sorter capable of injecting outside air with stirring) was enabled.

This flotation screening process is carried out for about 2 minutes, and the suspended product is discharged in the form of bubbles of mineral liquid as unburned carbon powder, so that it can be concentrated and dehydrated and used for other purposes.

On the other hand, after flowing into the sedimentation tank through the outlet installed in the bottom of the flotation separator, precipitation is performed for about 10 to 20 minutes so that the solid concentration of the refined coal ash, which is a precipitate, is about 20 to 30%.

At this time, it is preferable to achieve a high temperature state by passing a heating furnace for instantaneous heating of the mineral ash coal ash precipitate to 150 ~ 250 ℃ to make the concentration in the next concentration tank more effectively.

Subsequently, the high temperature precipitate in the mineral liquid state is again deposited by using a concentration tank to induce discharge of a slurry product having a concentration of about 50% solids through a lower spigot. Drain the water and reuse it as water.

On the other hand, the refined coal ash in the slurry state recovered through the lower spigot of the concentrating tank can be dehydrated in a dehydrator so that a cake product of about 70% solids can be recovered.

Then, when the drying process in the dryer, it is possible to recover the coal ash refined product in the solid form.

As a result of analyzing the recovered ash ash component, it was confirmed that the content of unburned carbon powder was detected as 0.1% by weight. Accordingly, high-quality coal can be recovered and used again as a fuel for power generation.

On the other hand, Figure 2 shows the refining process of coal ash according to another embodiment of the present invention, to further maximize the purification efficiency by combining the magnetic screening and gravity screening method with the wet screening method.

That is, as shown in the flotation screening step, the same operation as in the above embodiment is carried out, and after the flotation screening step, a magnetic screening step for separately recovering the magnetic products contained in the coal ash sediment is performed.

Magnetic screening is to separate the magnetic particles and non-magnetic particles among the coal ash precipitate components by using the magnet attracting iron. In this embodiment, by applying a magnetic force of 10,000 gauss, about 8% of 100% by weight of the coal ash precipitate is applied. It was confirmed that the magnetic product of ~ 10% by weight was recovered.

Subsequently, the non-magnetic product passing through the magnetic screening step is subjected to the wet classification step of separating the particle size into about 0.3 mm or more and 0.3 mm or less through the wet classification of the cyclone method.

In the wet classification process in this example, the recovered non-magnetic product was subjected to the general wet spiral method, and the experimental procedure was carried out by injecting a sample suspended with water at a solid concentration of 30% by weight to about 3 tons per hour directly on top of the spiral. As a result of the natural gravity of the screw-like device, the water flows downward, and the product with the coarse particles flows down into the spiral, and the relatively thin particles flow outward with the water flow. Then, as a result of separating and recovering each of the products flowing in the center and the products flowing outwards at the bottom discharge inlet, the particles were separated based on the diameter of 0.3 mm.

At this time, by changing the position of the recovery membrane installed on the bottom discharge side little by little for recovery, the reference particle diameter can be adjusted as necessary within the range of 0.3mm ~ 0.7mm.

In addition, the wet fractionation of the product is separated by less than 0.3mm in particle size to separate the sedimentation-concentration-dehydration-drying process A, proceeds to the process, the particles of 0.3mm or more through heavy gravity screening again with heavy minerals and hard minerals The specific gravity sorting step of separating once is performed.

At this time, the gravity screening process uses a swinging table device that continuously shakes from side to side, before and after, and separates heavy and light products by putting 1 ton per hour of particles in a suspension of about 50% by weight solids. It can be recovered.

At this time, the recovered heavy minerals, that is, heavy minerals, can easily separate and recover valuable valuable metals such as alumina, magnesium and manganese as materials of nonferrous metals, and the products recovered as relatively light minerals, ie, hard minerals, are quartz, feldspar, kaolin, etc. Recovery of non-metallic products.

The heavy mineral coal ash product and the hard coal coal ash product thus separated are each recovered and recovered by performing A process in which sedimentation-concentration-dehydration-drying is performed.

Coal ash recovered through this method is recovered by dividing by classification and specific gravity, and the products recovered in the process (unburned carbon powder, magnetic products, less than 0.3mm coal ash, heavy mineral coal ash more than 0.3mm, light minerals more than 0.3mm) Coal ash) shows the advantage that can be recycled for each purpose.

In addition, although specific embodiments of the present invention have been described and illustrated above, it will be apparent that the purification process for regeneration of coal ash of the present invention may be variously modified and implemented by those skilled in the art.

It should be understood, however, that such modified embodiments are not to be understood individually from the spirit and scope of the invention, and such modified embodiments are intended to be included within the scope of the appended claims.

1 is a flow chart of coal ash refining process according to an embodiment of the present invention.

Figure 2 is a flow chart of coal ash refining process according to another embodiment of the present invention.

Claims (6)

A water mixing step of mixing the collected coal ash with water; A reagent addition step of adding a reagent including waste oil and waste cooking oil to the mixture; A flotation screening step of sorting the stirred solution to which the reagent is added and then placing it in a flotation sorter to sort the unburned carbon powder discharged from the flotation and the coal ash precipitate deposited at the bottom; A precipitation step of depositing the coal ash precipitated in the lower portion to a sedimentation tank through the outlet of the lower portion of the flotation separator for 10 to 20 minutes; Concentrating step of discharging the coal ash precipitate in the 20 ~ 30% mineral state in which the precipitation was made in the precipitation tank to concentrate in the concentration tank; A dehydration step of dewatering the slurry of coal ash in the 40 to 60% mineral liquid state in which the concentration is performed; A drying step of drying the dehydrated coal ash in a high purity slurry state in a solid state; Refining product recovery step for recovering the dried coal ash powder; Coal ash purification and product recovery method comprising a. A water mixing step of mixing the collected coal ash with water; A reagent addition step of adding a reagent including waste oil and waste cooking oil to the mixture; A flotation screening step of evenly mixing the stirred solution to which the reagent is added and then sorting it into a flotation sorter to discharge and discharge unburned carbonaceous product suspended in the flocculant and the sediment deposited on the bottom; After the flotation screening step of applying a magnetic force of 5,000 ~ 25,000 Gauss to the coal ash sediment discharged in the lower portion of the magnetic separation step of recovering the magnetic product contained in the sediment separately; The non-magnetic product is not recovered separately in the magnetic separation step of the wet classification step of separating based on a predetermined particle size through the wet classification of the cyclone method; A specific gravity separation step of separating products having a small particle size from among the products in which the wet classification is performed, and separating the product having a large particle diameter into heavy minerals and hard minerals through a specific gravity selection operation using a rocking table; A precipitation step of moving the heavy minerals and the hard minerals made by the specific gravity selection to the sedimentation tanks separately for 10 to 20 minutes; Concentrating step of discharging the coal ash precipitate in the 20 ~ 30% mineral state in which the precipitation was made in the precipitation tank to concentrate in the concentration tank; A dehydration step of dewatering the slurry of coal ash in the 40 to 60% mineral liquid state in which the concentration is performed; A drying step of drying the dehydrated coal ash in a high purity slurry state in a solid state; Refining product recovery step of recovering the dried coal powder is made; Coal ash purification and product recovery method comprising a. The method according to claim 2, In the specific gravity screening step, heavy minerals, which are heavy minerals, are recovered from alumina magnesium and manganese as materials of nonferrous metals. The hard mineral is a coal ash refining and product recovery method, characterized in that the non-metal products including quartz, feldspar, kaolin are recovered. The method according to claim 1 or 2, The water mixing step, the coal ash purification, characterized in that the operation is carried out in a condition tank equipped with a mineral liquid tank for mixing the coal ash supplied to the vibrating feeder with the water and a stirring shaft for evenly stirring the mixture mixed in the mineral liquid tank And product recovery methods. The method according to claim 1 or 2, The reagent is a method for purification and product recovery of coal ash, characterized in that the oleic acid ethanol solution and polyphenol is further added. The method according to claim 1 or 2, In the condensing step, the method of refining and recovering the product of lime ash, characterized in that the coal ash precipitate is introduced into the concentrating tank at a high temperature after passing the heating furnace for instantaneous heating at 150 to 250 ° C.

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