Fly ash sulfur fixation melting harmless treatment method

A harmless treatment, fly ash technology, applied in the direction of chemical instruments and methods, combustion methods, incinerators, etc., can solve the problem of poor harmless treatment effect

Active Publication Date: 2021-06-25
CHINA ENFI ENGINEERING CORPORATION
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The main purpose of the present invention is to provide a harmless treatment method for solid sulfur melting of fly ash, so as to solve the problem in the prior art that the harmless treatment effect is poor when dealing with waste incineration fly ash

Method used

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  • Fly ash sulfur fixation melting harmless treatment method
  • Fly ash sulfur fixation melting harmless treatment method
  • Fly ash sulfur fixation melting harmless treatment method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0069] The composition of fly ash is shown in Table 1 (%):

[0070]

[0071] use figure 1 The process shown is to process the above-mentioned fly ash, and the processing capacity is 50t / d, the details are as follows:

[0072]Mix fly ash, reducing agent carbon powder (particle size2 =1.4) The mixing amount accounts for 15% of the fly ash amount, and the mixing amount of quartz sand accounts for 20% of the fly ash amount to obtain a mixed raw material. The molar ratio of C and S in the mixed raw material is 2.5, using SiO 2 -CaO-FeO slag type, SiO in mixed raw materials 2 and Al 2 o 3 The total weight of CaO and MgO is recorded as m, the total weight of CaO and MgO is recorded as n, FeO, MnO, Na 2 O and K 2 The total weight of O is recorded as l, m / n is 1.15, and l / m is 0.25.

[0073] The mixed raw materials are pressed into balls with a particle size of 2~4cm, and then sent to an electric furnace for sulfur fixation and melting. The electric furnace adopts a graphite ...

Embodiment 2

[0081] The difference from Example 1 is that the S / C of the mixed material is 3.5.

[0082] Other parameters are the same as in the embodiment. The flue gas outlet temperature is 1662°C, and the flue gas volume is 979Nm 3 / h (the air leakage is about 500Nm 3 / h). Outer exhaust gas volume 13848Nm 3 / h. The secondary combustion temperature is controlled at 900°C, and the fuel consumption is 79.46Nm 3 / h (natural gas). The composition of slag is shown in Table 5, the composition of molten salt is shown in Table 6, and the composition of secondary fly ash is shown in Table 7.

[0083]

[0084]

[0085]

[0086] Calculated: the direct sulfur fixation rate of this embodiment is 83.70% (relative to the original fly ash), and the remaining S is expressed as SO 2 into the flue gas in the form of deacidification into gypsum sludge. As the ingredients are C / S increased to 3.5 (compared to Example 1), the sulfur fixation effect becomes better, but the CO content in the fl...

Embodiment 3

[0088] Adopt electric furnace melting to handle fly ash, and embodiment 1 difference is as follows:

[0089] Fly ash, reducing agent carbon powder (particle size 2 -Al 2 o 3 -CaO slag type, SiO in mixed raw materials 2 and Al 2 o 3 The total weight of CaO and MgO is recorded as m, the total weight of CaO and MgO is recorded as n, and m / n is 1.20.

[0090] The electric furnace is used for melting and solidifying sulfur, the temperature of the slag is 1350°C, and the temperature of the molten salt layer is 1280°C. The depth of the slag is 500mm, the depth of the molten salt layer is 200mm, and the depth of the material layer is 100mm. The flue gas of the electric furnace is cooled by secondary combustion and sprayed with wind and water. The temperature of secondary combustion flue gas is 1200℃, and natural gas is blown into 00Nm 3 / h. The temperature is lowered to 200°C by wind cooling, the amount of water sprayed is 0.97t / h, and the compressed air is 2174Nm 3 / h, outlet...

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Abstract

The invention provides a fly ash sulfur fixation melting harmless treatment method. The method comprises the following steps that fly ash, a reducing agent and flux are mixed to obtain a mixed raw material, wherein the molar ratio of C to S in the mixed raw material is 2.5 to 3.5; the slag type is controlled to be an SiO2-Al2O3-CaO slag type, and m / n is 0.8 to 1.5; or the slag type is controlled to be an SiO2-CaO-FeO slag type, m / n is 1.0 to 1.6, and l / m is 0.15 to 0.30; the mixed raw material is fed into an electric furnace in a blowing mode or a pressed material ball mode to be subjected to sulfur fixation melting, the temperature of a slag layer is controlled to range from 1250 DEG C to 1350 DEG C in the period, the temperature of a molten salt layer on the top of the slag layer is controlled to be smaller than 1200 DEG C, and molten salt, slag and exhaust gas are obtained; the molten salt is cooled, and the slag is subjected to water cooling or air cooling; and the exhaust gas is treated through one of three modes. According to the method, a systematic solution is provided for fly ash treatment in the aspects of material blending, sulfur fixation melting, exhaust gas treatment and the like, and the maximum harmless treatment is achieved.

Description

technical field [0001] The invention relates to the technical field of harmless treatment of waste incineration fly ash, in particular to a method for harmless treatment of fly ash solid sulfur melting. Background technique [0002] A large amount of fly ash is produced during the purification process of domestic waste / hazardous incineration flue gas. Fly ash contains harmful components such as Cl, S, and heavy metal elements. If it is not treated and stored randomly, it will cause irreversible pollution to the soil and water environment. The fly ash is melted at high temperature so that the heavy metals in it are solidified in the high temperature slag, and the glass slag is obtained after water crushing, which can better realize the harmless disposal of the fly ash. Currently reported fly ash melting technologies include plasma melting and submerged electric furnace melting, both of which can achieve fly ash melting, as listed below: [0003] Patent CN207709525 U disclose...

Claims

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Application Information

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IPC IPC(8): B09B3/00B09B5/00F23G7/06
CPCB09B5/00F23G7/06B09B2101/30B09B3/40
Inventor 唐续龙胡立琼高术杰
Owner CHINA ENFI ENGINEERING CORPORATION
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