阅读说明：本技术 一种沸腾炉处理脱硫灰的方法 (Method for treating desulfurized ash by fluidized bed furnace ) 是由 毛瑞 茅沈栋 王飞 苏航 于 2019-10-23 设计创作，主要内容包括：本发明提供一种沸腾炉处理脱硫灰的方法,该方法通过将脱硫灰送入沸腾炉,在反应气氛保护下,在沸腾炉炉内对脱硫灰进行流态化氧化焙烧反应,然后将氧化焙烧后的脱硫灰经过降温冷却后,通过旋风除尘器进行物料回收。还可以将回收的脱硫灰掺入高炉水渣制备得到矿渣微粉。本发明通过合理控制沸腾炉的反应温度和反应气氛,将脱硫灰中的不稳定的亚硫酸钙氧化成稳定的硫酸钙,沸腾炉处理后的脱硫灰可掺入高炉水渣制备矿渣微粉,用于水泥混凝土行业,不仅解决了脱硫灰处理难题,还能创造显著的经济效益。(The invention provides a method for treating desulfurization ash in a fluidized bed furnace, which comprises the steps of feeding desulfurization ash into the fluidized bed furnace, carrying out fluidized oxidation roasting reaction on the desulfurization ash in the fluidized bed furnace under the protection of reaction atmosphere, cooling the desulfurization ash after oxidation roasting, and recovering materials through a cyclone dust collector. The recycled desulfurized ash can also be mixed with blast furnace granulated slag to prepare slag micro powder. The invention reasonably controls the reaction temperature and reaction atmosphere of the fluidized bed furnace, so that unstable calcium sulfite in the desulfurized fly ash is oxidized into stable calcium sulfate, and the desulfurized fly ash treated by the fluidized bed furnace can be mixed with blast furnace granulated slag to prepare slag micropowder.)

1. A method for treating desulfurized ash by a fluidized bed furnace is characterized by comprising the following steps:

(1) conveying the desulfurized ash into a fluidized bed furnace through pneumatic conveying;

(2) introducing reaction gas, and carrying out fluidized oxidizing roasting reaction on the desulfurized ash in a fluidized bed furnace, wherein the oxidizing roasting temperature is 600-1000 ℃, the reaction gas is mixed gas obtained by mixing and burning coal gas and air, and the oxygen content of the mixed gas after burning is 5-15%;

(3) and (3) cooling the oxidized and roasted desulfurized ash, and then recovering the materials by using a cyclone dust collector.

2. The method for treating desulfurized ash in a fluidized bed furnace according to claim 1, characterized in that: the desulfurization ash is dry desulfurization ash.

3. The method for treating desulfurized ash in a fluidized bed furnace according to claim 1, characterized in that: the desulfurization ash is obtained by drying, crushing and grinding wet desulfurization ash.

4. The method for treating desulfurized ash in a fluidized bed furnace according to claim 3, wherein: the drying temperature is 200-300 ℃.

5. The method for treating desulfurized ash in a fluidized bed furnace according to claim 3, wherein: the granularity of the grinded desulfurized ash is 80-400 meshes.

6. Desulphurised ash obtainable by the process of any one of claims 1 to 5.

7. The slag micro powder is characterized in that: the fine slag powder is prepared by mixing the desulfurized fly ash of claim 6 into blast furnace granulated slag.

8. Slag micropowder according to claim 7, characterized in that: the doping amount of the desulfurization ash is not higher than 3%.

Technical Field

The invention belongs to the field of comprehensive utilization of metallurgical solid waste resources, and relates to a method for treating desulfurized fly ash by a fluidized bed combustion boiler.

Background

The semi-dry desulfurization process has the advantages of high desulfurization efficiency, short process flow, small occupied area, investment saving and the like, and is widely applied to flue gas desulfurization engineering of small and medium-sized generating sets and sintering plants of part of steel enterprises in China. The raw material of the semi-dry desulfurization process adopts quicklime to prepare slurry, and the slurry is fully contacted and reacted with sulfur-containing flue gas in an absorption tower to remove SO in the flue gas ₂The purpose of (1). The major disadvantage of the semi-dry desulfurization process is that a large amount of byproducts, called desulfurization ash, are generated after the flue gas is desulfurized, and belong to metallurgical solid wastes. The main components of the desulfurized fly ash are as follows: free calcium oxide, calcium sulfite, calcium carbonate, calcium sulfate, calcium hydroxide, ferric trioxide, and the like. Because the desulfurized fly ash has the characteristics of unstable components, alkalinity, easy decomposition, easy water absorption, easy expansion and the like, the comprehensive utilization of the desulfurized fly ash is very difficult, and the common treatment mode of the desulfurized fly ash at present is stacking and landfill, thereby not only polluting the environment and occupying the land, but also having great potential safety hazard.

In recent years, many researches on the utilization of desulfurized fly ash resources are carried out, but the desulfurized fly ash resources are not mature in practical application and have many problems, such as the use of desulfurized fly ash in sintering ore blending affects the operation stability rate of a sintering machine and deteriorates the quality of sintered ore; the desulfurized ash is used for preparing various brick products and concrete, and can generate volume expansion to cause cracking; the desulfurized fly ash is used for soil remediation, and causes the problems of secondary pollution and the like, so that the development of a high-efficiency, harmless, stable and feasible resource utilization technology of the desulfurized fly ash has great significance.

Disclosure of Invention

The technical problem to be solved is as follows: aiming at the technical problem that the desulfurization ash is difficult to comprehensively treat, the invention provides a method for treating the desulfurization ash by using a fluidized bed furnace, unstable calcium sulfite in the desulfurization ash is oxidized into stable calcium sulfate by reasonably controlling the reaction temperature and the reaction atmosphere of the fluidized bed furnace, and the desulfurization ash treated by the fluidized bed furnace can be mixed with blast furnace water slag to prepare slag micropowder for the cement concrete industry.

The technical scheme is as follows: the invention provides a method for treating desulfurized fly ash by a fluidized bed furnace, which comprises the following steps:

(1) conveying the desulfurized ash into a fluidized bed furnace through pneumatic conveying;

(2) introducing reaction gas, and carrying out fluidized oxidizing roasting reaction on the desulfurized ash in a fluidized bed furnace, wherein the oxidizing roasting temperature is 600-1000 ℃, the reaction gas is mixed gas obtained by mixing and burning coal gas and air, and the oxygen content of the mixed gas after burning is 5-15%;

(3) and (3) cooling the oxidized and roasted desulfurized ash, and then recovering the materials by using a cyclone dust collector.

Further, the desulfurized fly ash is dry desulfurized fly ash.

Further, the desulfurized fly ash is obtained by drying, crushing and grinding wet desulfurized fly ash.

Further, the drying temperature is 200-300 ℃.

Further, the granularity of the grinded desulfurized ash is 80-400 meshes.

The invention provides desulfurized fly ash prepared by the method.

The invention also provides slag micro powder prepared by mixing the desulfurized fly ash into blast furnace granulated slag.

Further, the doping amount of the desulfurized fly ash is not more than 3%.

Has the advantages that: the method is characterized in that after the desulfurized fly ash is oxidized and roasted by a fluidized bed roaster, calcium sulfite unstable substances in the desulfurized fly ash are changed into stable calcium sulfate, and the detection shows that CaSO is contained in the desulfurized fly ash ₄The content is more than 90 percent, and the content of CaO is less than 10 percent, so the composite material has the characteristics of stable components, difficult decomposition, difficult water absorption expansion and the like, and reduces the pollution to the environment. And the granulated slag can be mixed to prepare slag micro powder, so that the problem of treatment of the desulfurized fly ash is solved, and remarkable economic benefit can be created, thereby realizing high-efficiency, harmless, stable and feasible resource utilization of the desulfurized fly ash and having great significance.

Drawings

FIG. 1 is a process flow diagram of a method for treating desulfurized fly ash in a fluidized bed furnace according to the present invention.

Detailed Description