JP3507157B2 - Incineration ash solidification equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to general waste, sewage sludge,
Cementation of incineration ash containing cement, which contains harmful heavy metals etc. remaining after incineration of industrial waste
About the method . 2. Description of the Related Art In a conventional refuse treatment plant, the volume of refuse that cannot be reused is reduced by incineration, and the remaining incinerated ash is discarded as it is in a controlled disposal site or mixed with cement. It is processed by solidification. A method of preventing the release of harmful substances into the environment by mixing incinerated ash with cement and solidifying it has a prima facie effect, but since excess water is used in the cement, a capillary is formed after solidification due to the evaporation of the water. , The solidified material has water permeability, and harmful substances may elute, and over a long period of time,
Elution may not be negligible. The problem with the ash after incineration is that the ash contains a lot of harmful components, heavy metals and organic matter. These substances were not decomposed due to the high heat of incineration, and were often difficult to chemically treat. Dechlorination shows strong alkalinity due to lime, so metals and heavy metals present as oxides become insoluble salts of hydroxides when dissolved in water,
When the dissolution test is carried out, even a small amount of the metal is eluted, so that the elution of heavy metals continues even in a very small amount. If incinerated ash containing such harmful components is used as such in landfills, the harmful components elute and adversely affect the environment. Must. Accordingly, the present invention is intended not only to solidify incinerated ash with Portland cement but also to solidify the incinerated ash in a stable state with cement, and to use the solidified molded product thus obtained in various ways. SUMMARY OF THE INVENTION The present invention relates to a concrete container comprising a hazardous heavy metal or an organic salt, and an incineration ash added with an organic substance stabilizing agent mainly containing a glass-forming component such as anhydrous sodium carbonate. The solidification in the medium prevents harmful substances from being eluted into the environment. The harmful substance stabilizing agent used in the present invention is based on the reaction between carbon dioxide and sodium silicate. Carbon dioxide generated from sodium carbonate or the like assists the decomposition of sodium silicate to reduce the system. It is believed that colloidal silica is formed within the colloidal silica, which forms a carbon-silicon bond. The stabilizer of the present invention is Si
It contains a carbon dioxide gas supply component in addition to glass solidification components such as O ₂ , Na ₂ SiO ₃ , NaCO ₃ , and CaCO _{3. As} the carbon dioxide gas supply component, urethane formation reactions such as polyisocyanates and polyols are also conveniently used. can do. Further, by adding boric anhydride H ₃ BO ₃ , a hard glass-based material can be obtained, and CaCO ₃ , Si
Cement components such as O ₂ , SO ₂ Al ₂ O ₃ , Fe ₂ O ₃ , and MgO are also mixed. The component of this cement is 1
By adding about 20 g to 00 g, the work of the rock formation work is further strengthened, and H ₂ SiO ₃ + which is a main component of the rock is added.
It is intended to develop a SiO ₂ over the years. In the chemical treatment method for harmful substances contained in the incinerated ash, the efficiency of mixing and stirring the incinerated ash and the chemical is the most important issue in any treatment method. The test of the mixing method and the treatment time was repeated, and as a result, the inorganic components of the incinerated ash particles required for solidification were lime (CaO), silicic acid (SiO ₂ ), and alumina (Al
Compounds such as ₂ O ₃ ), iron (Fe ₂ O ₃ ), and sulfate (—SO ₄ ) are reacted with water to form hydrates, and the ionic charge is corrected according to the change in the liquid ion concentration. , Deposition begins. [0008] The greatest impediment to the hardening of liquid layers, gas layers and organic matter in incinerated ash is that the hydraulic mineral of cement reacts quickly with calcium ions generated by hydrolysis to form insoluble or soluble compounds. Is to do. For example, when an insoluble salt is formed, the formed product covers the surface of the cement particles so that the subsequent reaction does not proceed.In the case of a soluble salt, it reacts one after another to form a solution outside the hydration reaction system. This is the effect of taking away. In any case, the chemical balance of the hydration reaction is disrupted if calcium ions, which should be the main component of the hydration reaction, are carried away to another reaction system. Therefore, by mixing the stable calcium treating agent of the present invention, the liquid phase increases the lime content and becomes an alkaline composition, and further solidifies before the hydration inhibiting effect is exerted by the rapid hydration reaction. Hydration reaction of lime aluminate hydrate is promoted, and ettringite (3CaO.Al ₂ O ₃ .3
CaSO ₄ .32H ₂ O) is produced more, and these double salts fix harmful substances including heavy metals and keep them from being eluted. Examples of the present invention will be described below, but these examples are merely means for assisting the understanding of the present invention.
It should be understood that these examples do not limit the invention in any way. In the following examples, Osaka City, Tokyo, Tsunomiya City,
The test was conducted in 20 towns and villages such as Tochigi regional administrative district and Tomisato town, and was based on test data from a Ministry of Health and Welfare-certified inspection organization. In addition,
In the example, "Incineration ash from a waste incineration plant in Tokyo"
Etc., but cement is added to the incinerated ash
It means incinerated ash that has been heat-treated in a tally kiln. Example 1 Silicon dioxide SiO ₂ 10 as a main raw material of a stabilizing agent
g, calcium oxide CaO 3 g, anhydrous sodium carbonate Na ₂ CO ₃ 10 g, aluminum oxide Al ₂ O ₃
2 g, boric anhydride B ₂ O ₃ 10 g, anhydrous potassium carbonate K ₂ CO _{3 3} g, sodium acetate CH ₃ COONa ·
5 g of 3H ₂ O, potassium silicate SiO ₂ · K ₂ O 5
g, water H ₂ O 5000 ml, organic ammonium salt 50 ml as auxiliary material, salt NaCl 2 g, cobalt oxide CoO 2 g, methyl ethyl ketone C ₂ H ₅ as catalyst
COCH ₃ 5 g, ethylenediamine NH ₂ CH ₂ CH
5 g of ₂ NH ₂ were used. The temperature of water H ₂ O was set to 60 ° C., and the chemicals were stirred for 30 minutes before the catalyst was added, and the catalyst was further added and stirring was continued for 30 minutes. Portland cement 2 is added to 1000 g of incinerated ash from Osaka city garbage incineration plant.
00 g and 4 l of the stabilizing agent of the present invention are kneaded, and slump 8
The solidification was carried out with a water content of 1 cm, and a curing period of one month was allowed, followed by a dissolution test. The dissolution test is cadmium, cyanide, organic phosphorus, lead, hexavalent chromium, arsenic, alkylmercury, PCB
I went about. As a result of this test, cyanide, organic phosphorus,
Hexavalent chromium, alkylmercury, PCB not detected, lead less than 0.5 mg / l, cadmium and arsenic less than 0.05 mg / l, total mercury 0.0005 mg / l.
Both values were less than the harmful substance criteria. EXAMPLE 2 200 g of Portland cement and 4 l of the stabilizing agent of the present invention were added to 1000 g of incineration ash discharged from a waste incineration plant in Tokyo.
Was kneaded, and one month after solidification, a dissolution test was conducted.
Among mercury, cadmium, lead, arsenic, cyan and chromium, lead was less than 0.34 mg / l and chromium was less than 0.06 mg / l, and no mercury, cadmium, arsenic and cyan were detected. Example 3 A mixture of 1000 g of incineration ash from a Utsunomiya incineration plant, 200 g of Portland cement and 4 l of the treating agent of the present invention was kneaded and subjected to a dissolution test one month after solidification. The dissolution test was performed on lead, cadmium, arsenic, hexavalent chromium, total mercury, organic phosphorus, and total cyan. The results of this dissolution test were as follows: lead less than 0.17 mg / l, cadmium 0.005 m
g / l, arsenic 0.02 mg / l, hexavalent chromium 0.1
Less than 4 mg / l, less than 0.0005 mg / l of total mercury, non-detection of organophosphorus and total cyan were all values that did not reach the criteria for harmful substances. Example 4 200 g of Portland cement and 4 liters of the treating agent of the present invention were kneaded with 1000 g of incineration ash from the incineration plant of the Tochigi district wide area administrative office, and the dissolution test was carried out one month later. The dissolution test results of lead, cadmium, arsenic, hexavalent chromium, total mercury, organic phosphorus, and total cyan were 1.00 for lead, 0.0005 for cadmium, 0.02 for arsenic, 0.0 for hexavalent chromium.
6. Total 0.0005 of mercury, organic phosphorus and total cyan were not detected, and all had a value not meeting the criteria. Example 5 1000 kg of incinerated ash was put into a concrete kneader, and 200 kg of cement was put therein while rotating, followed by stirring for 10 minutes. Then, 18 l of the stabilizing agent of the present invention was diluted with 10 times water and added. After kneading for 15 minutes, slump 15cm
The inside was poured into a concrete disposal place formed into a hollow block by a pressure pump and sealed. [0015] By solidifying and shaping the incinerated ash into a block using the stabilizing agent of the present invention, not only the transportation is simplified, but also the incinerated ash included in the incinerated ash, which has been considered difficult so far, is included. Since a solidified molded product from which no harmful substance leaks out can be obtained, the solidified molded product can be used as it is as a civil engineering or construction material for concrete blocks and the like. The compressive strength of the product of the present invention as a cement material can be arbitrarily changed by adjusting the ratio of Portland cement and stabilizing agent. As a result, the incinerated ash is not waste but a by-product that can be sufficiently used as a cement material.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view showing an example of an incineration ash solidification device of the present invention. [Explanation of reference numerals] 1. Chopper receiving hopper Belt feeder 3.6.7. Belt conveyor4. Excellent feed5. Vibrating screen 8. Magnetic separator 1. ^{8KW 5KW} 9. Rotary kiln 10.11.12.13.17.21.22.25.2
8.33.38. Screw conveyor 14. Bucket elevator 15. Raw material tank 16. Insert slide gate 18. Roller mill 19. Cyclone 20. Dust collector 23. Tray 24. Bucket elevator 26. Raw material tank 27. Roller valve 29. Weighing hopper 30. Kneading mixer 31. Charge hopper 32. Rotary valve 35. Hoist 36. Cement silo 39. Dust collector 40. Stabilizer dosing device

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-15248 (JP, A) JP-A-5-317830 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B09B 3/00

Claims (1)

(57) [Claims] [Claim 1] After incineration of sewage sludge, industrial waste, etc.
Cement is added to the remaining incinerated ash containing harmful heavy metals and organic matter , heat-treated in a rotary kiln, and the subsequent processes
A method for solidifying incinerated ash comprising cement as a main component, characterized by adding a harmful substance stabilizing agent in the above, and then adding Portland cement to solidify the harmful substance.
The stabilizing agent is SiO ₂ , CaO, Na ₂ C as a main raw material.
O ₃ , Al ₂ O ₃ , B ₂ O ₃ , K ₂ CO ₃ , CH ₃ COONa
3H ₂ O , SiO ₂ · K ₂ O, water, and organic
Monium salt, NaCl, CoO, C ₂ H ₅ CO as catalyst
This is obtained by using a _{CH 3, NH 2 CH 2 CH} 2 NH 2
And a method characterized by the following.