TWI529352B - Incineration of waste residue sorting process - Google Patents

Description

Incineration bottom slag washing and sorting process

The invention relates to a sorting process, in particular to an incineration bottom slag washing and sorting process.

Waste disposal is a major environmental issue facing humans after their high industrialization and urbanization. Among the many waste treatment methods, it is widely used as a garbage disposal method to burn and incinerate waste after incineration. The use of incinerators to treat waste has at least the following advantages: (1) the volume of waste can be greatly reduced after burning incineration; (2) the environmentally hazardous substances contained in the waste can be used by Incineration and combustion are removed; (3) The combustion of the incinerator is carried out under controlled conditions, and the exhaust gas is also properly monitored and treated to reduce the harm to the human body; and (4) the bottom slag after combustion can be recycled. Use to improve the economic benefits of waste disposal.

After incineration, the residue left on the incinerator bed is Bottom Ash. At present, the bottom slag treatment procedure is to store the bottom slag, and then perform the steps of sieving, magnetic separation, eddy current selection, and crushing to obtain the desired product. However, the bottom slag which has undergone the above steps has the odor and the lack of re-dissolution of the harmful substances cannot be overcome, and also causes doubts about reuse.

At present, the bottom slag has been washed with water to overcome the odor of the bottom slag and the re-dissolution of the harmful substances. However, the above-mentioned washing method only treats the bottom slag simply by immersion, and the effect is limited.

Accordingly, it is an object of the present invention to provide an incineration bottoms water washing and sorting process which can improve the quality and appearance of the bottom slag.

Therefore, the incineration bottom slag washing and sorting process of the present invention comprises the following steps: collecting the bottom slag of the incinerator and performing dry screening, and the bottom slag having a particle size larger than 50 mm is sent to the crusher for crushing, and then subjected to dry screening again after the crushing, the bottom slag. The particle size is less than 50 mm and the next step is carried out. If the bottom slag particle size is less than 50 mm, wet screening is performed, and the bottom slag particle size is less than 5.5 mm by flushing. The iron-containing metal is selected by magnetic separation, and the non-ferrous metal is selected by eddy current sorting, and the remaining bottom slag is carried to the next step. The secondary crushing was carried out to control the particle size of the bottom slag to be 19.5 mm or less. The mixture was washed with water, and the bottom slag was subjected to rolling and stirring water washing, and the bottom slag particle size was less than 5.5 mm. The bottom slag which was stirred and washed was subjected to pressure filtration treatment to remove water, and a finished pellet product was obtained.

The effect of the invention is that the wet slag has two chances of reacting with water by wet screening and stirring water washing, and then the bottom slag is washed by rolling and stirring, and the bottom slag is rubbed against each other to be washed, not only the slag is rubbed, but also the slag is washed. It can improve the washing efficiency and make the bottom slag look closer to natural sand.

Other features and effects of the present invention will be apparent from the embodiments of the drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart showing an embodiment of the incineration bottoms water washing and sorting process of the present invention.

Referring to FIG. 1 , an embodiment of the incineration bottom slag water washing and separating process of the present invention comprises the following steps: First, the incinerator bottom slag is collected and subjected to dry screening, wherein the dry screening can be performed by a vibrating coarse screening machine or a drum screening machine, or It is used together. After the dry screening, if the bottom slag particle size is larger than 50 mm, it is sent to the crusher for crushing, and then broken and then subjected to dry screening again. The bottom slag particle size is less than 50 mm and the next step is carried out.

Wet screening is carried out for the bottom slag particle size less than 50 mm. The wet screening is carried out by placing a water supply unit in a drum screen, rolling the screen in the drum screen, and flushing the bottom slag with a high pressure water column. The slag particle size is less than 5.5 mm. Through the flushing of the high-pressure water column, the organic matter and the chloride ions in the bottom slag can be taken away by the water, and the high-pressure water injection can also wash the sieve hole of the drum screen to prevent the screen hole from being blocked by the bottom slag and reduce the screening efficiency. Since the structure of the water supply unit and the drum screen is not the focus of this case, the detailed structure is not shown.

After the wet screening, the iron-containing metal is screened from the bottom slag by magnetic separation and sent to the ferrous metal recovery tank for recycling, and the non-ferrous metal is selected by eddy current sorting. The eddy current sorting system uses the change of the magnetic field to separate the non-ferrous metal from other components. The flow path of the eddy current must be a closed curve, and the flow direction is parallel to the winding direction of the coil, and the magnetic flux perpendicular to the direction of the alternating magnetic field and with the alternating current. It changes and flows in the opposite direction, so its frequency is the same as the frequency of the alternating current. a substance that can induce an eddy current The piece must be a conductive conductor. Using this principle, metals including aluminum and copper can be sorted from the bottom slag to increase the recovery value and reduce secondary pollution, and the remaining bottom slag is carried to the next step.

After magnetic separation and eddy current sorting, manual sorting can also be carried out according to the situation, and the plastic materials and other impurities in the bottom slag can be manually picked out. In addition, the bottom slag is subjected to secondary crushing, and the bottom slag particle size is controlled to be less than 19.5 mm, and then the bottom slag is stirred and washed by a rolling type water washing device by rolling and stirring, and the bottom slag particle size is less than 5.5. Mm. In the present embodiment, the weight ratio of the amount of water used for the agitating water washing to the bottom slag to be washed is 2:1 to 5:1, and the time for performing the agitating water washing is 2 to 5 minutes. During the agitated water washing process, the bottom slag is rubbed against each other for rinsing, which not only improves the washing efficiency, but also removes impurities attached to the bottom slag during the rinsing process, so that the bottom slag looks closer to the natural sand. Further, the organic matter and the chloride ions in the bottom slag can be taken away again in the process of stirring and washing. Finally, the bottom slag after the water washing is stirred and subjected to pressure filtration to remove water, thereby obtaining a finished pellet.

In addition, the bottom slag having a particle diameter of less than 5.5 mm which was removed by wet screening and stirring water washing was collected, and then separated by mud sand, and the recovered slag having a particle diameter of 1 to 4.75 mm was collected to prepare reclaimed sand.

In summary, the present invention has two steps of wet screening and stirring water washing, so that the bottom slag has two chances of reacting with water, which can greatly reduce the organic matter and chloride ions contained in the bottom slag, and reduce the organic matter to reduce the bottom. The odor of the slag, while reducing the chloride ion can reduce the corrosive effect on the steel bar, and then the bottom slag is washed by rolling, instead of simply immersing, so that the bottom slag can mutually Rubbing and washing can not only improve the washing efficiency, but also remove the impurities adhering to the bottom slag during the washing process, and make the bottom slag look closer to the natural sand, so the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and patent specification content of the present invention, All remain within the scope of the invention patent.

Claims (6)

An incineration bottom slag washing and sorting process comprises the following steps: collecting the bottom slag of the incinerator and performing dry screening, and the bottom slag having a particle size larger than 50 mm is sent to a crusher for crushing, and then subjected to dry screening again after crushing, and the bottom slag particle size is smaller than 50mm for the next step; the bottom slag particle size less than 50mm for wet screening, flushing to remove the bottom slag particle size less than 5.5mm, the remaining bottom slag to the next step; magnetically selected iron-containing metal, and The non-ferrous metal is selected by eddy current sorting, and the remaining bottom slag is subjected to the next step; the secondary crushing is performed to control the bottom slag particle size to be less than 19.5 mm; the stirring is washed, the bottom slag is washed by rolling, and the bottom slag is washed and removed. The bottom slag particle size is less than 5.5 mm; and the bottom slag after stirring and washing is subjected to pressure filtration to remove water, and the finished product of the granules is obtained. After the bottom slag particle size is less than 5.5 mm, the sediment is collected and separated, and the bottom slag particle size is collected. Reclaimed sand is made from 1 to 4.75 mm. The incineration bottom slag washing and sorting process according to claim 1, wherein the rolling water washing device is used for the agitating water washing. The incineration bottom slag washing and sorting process according to claim 1, wherein the weight ratio of the amount of water used for the agitated water washing to the bottom slag to be washed is from 2:1 to 5:1. The incineration bottom slag washing and sorting process according to claim 1, wherein the agitating water washing time is 2 to 5 minutes. The incineration bottom slag washing and sorting process according to claim 1, wherein the non-metallic impurities are removed by manual sorting before the secondary crushing. The incineration bottom slag water washing and sorting process according to claim 1, wherein the wet screening is performed by disposing a water supply unit in a drum screen, and performing the rolling screening in the drum screen while flushing the bottom slag with a high pressure water column.