Desulfurized ash reduction-oxidation two-stage treatment method

A technology for desulfurization ash and carbon monoxide, applied in chemical instruments and methods, sulfur compounds, calcium/strontium/barium oxide/hydroxide, etc., can solve the problems of difficult comprehensive treatment of desulfurization ash, and achieve significant economic and environmental benefits Effect

Pending Publication Date: 2020-02-28
SHAGANG GROUP +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] Technical problem to be solved: Aiming at the technical problem that the comprehensive treatment of desulfurization ash is difficult, the present invention provides a two-stage reduction-oxidation treatment method for desulfurization ash, which solves the problem of comprehensive treatment of desulfurization ash

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  • Desulfurized ash reduction-oxidation two-stage treatment method

Examples

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Embodiment 1

[0016] The present invention will be further explained below in conjunction with the accompanying drawings.

[0017] The desulfurization ash used in this example is a dry desulfurization ash with a moisture content of less than 10%. The main components of the dry desulfurization ash are shown in Table 1.

[0018] Table 1. Main components of dry desulfurization ash (%)

[0019] SiO 2

[0020] Such as figure 1 As shown, the dry desulfurization ash is sent to a high-temperature reactor after grinding, and a reducing atmosphere is introduced. The carbon monoxide content (volume fraction) in the reducing atmosphere is controlled at 15%, and the oxygen content (volume fraction) is 1.5%. , and the rest are inert gases. The inert gas is preferably nitrogen or carbon dioxide or a mixed gas of nitrogen and carbon dioxide. The furnace temperature is controlled at 800-900°C, so that the calcium sulfite and calcium sulfate in the desulfurization ash are reduced to calcium su...

Embodiment 2

[0022] The desulfurization ash used in this example is the wet desulfurization ash after the dry desulfurization ash used in Example 1 has been dampened, and the moisture content of the wet desulfurization ash is 30%.

[0023] The wet desulfurization ash is sent to a high-temperature reactor after pretreatment such as drying, crushing, and grinding, and a reducing atmosphere is introduced. The carbon monoxide content (volume fraction) in the reducing atmosphere is controlled at 10%, and the oxygen content (volume fraction ) 1%, and the rest is inert gas. The inert gas is preferably nitrogen or carbon dioxide or a mixture of nitrogen and carbon dioxide. The furnace temperature is controlled at 900-1000°C, so that the calcium sulfite and calcium sulfate in the desulfurization ash are reduced to calcium sulfide; reduction The final desulfurized ash enters the second-stage high-temperature reactor, and the oxidizing atmosphere is introduced. The oxygen content (volume fraction) in ...

Embodiment 3

[0025] The wet desulfurization ash (the composition is the same as in Example 2) is pretreated by drying, crushing, and grinding, and then sent to a high-temperature reactor, and a reducing atmosphere is introduced. The carbon monoxide content (volume fraction) in the reducing atmosphere is controlled at 5%, oxygen content (volume fraction) 0.5%, and the rest is inert gas. The inert gas is preferably nitrogen or carbon dioxide or a mixture of nitrogen and carbon dioxide. Calcium is reduced to calcium sulfide; the reduced desulfurized ash enters the second-stage high-temperature reactor and is introduced into an oxidative atmosphere. The oxygen content (volume fraction) in the oxidative atmosphere is controlled at 5%, and the carbon monoxide (volume fraction) is 0.2%. The rest is inert gas. The inert gas is preferably nitrogen or carbon dioxide or a mixed gas of nitrogen and carbon dioxide. The furnace temperature is controlled at 1050-1150°C to convert the desulfurized ash calc...

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Abstract

The invention provides a desulfurized ash reduction-oxidation two-stage treatment method. The desulfurized ash reduction-oxidation two-stage treatment method comprises the following steps: feeding desulfurized ash into a first-stage high-temperature reactor, controlling proper temperature and atmosphere, reducing calcium sulfite and calcium sulfate in the desulfurized ash into calcium sulfide, feeding the calcium sulfide into a second-stage high-temperature reactor, controlling proper temperature and atmosphere, converting the calcium sulfide into sulfur dioxide and calcium oxide, and generating sulfur-containing flue gas and residues. According to the method, the desulfurized ash is converted into SO2-rich flue gas and calcium and iron-containing residues; sulfuric acid can be prepared from the SO2-rich flue gas through dust removal, purification, catalytic oxidation and absorption processes, the residues can be added into iron ore according to a certain proportion to be sintered to replace part of iron-containing raw materials and flux or be used for steelmaking desulfurization, the desulfurized ash is fully recycled, and economic benefits and environmental benefits are remarkable.

Description

technical field [0001] The invention belongs to the field of comprehensive utilization of metallurgical solid waste resources, and relates to a two-stage reduction-oxidation treatment method for desulfurization ash. Background technique [0002] Due to the advantages of high desulfurization efficiency, short process flow, small footprint, and low investment, the semi-dry desulfurization process is widely used in the flue gas desulfurization projects of small and medium-sized generating units in my country and sintering plants of some iron and steel enterprises. The raw material of the semi-dry desulfurization process is quicklime, which is made into a slurry, and fully contacts and reacts with the sulfur-containing flue gas in the absorption tower to achieve the purpose of removing SO2 in the flue gas. The biggest disadvantage of the semi-dry desulfurization process is that a large number of by-products will be produced after the flue gas is desulfurized, which is called d...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B17/52C01B17/74C01F11/10C01B17/42C01B17/44C22B7/02C22B1/16C21C7/064
CPCC01B17/52C01B17/74C01F11/10C01B17/42C01B17/44C22B7/02C22B7/001C22B1/16C21C7/0645Y02P10/20
Inventor 毛瑞茅沈栋王飞苏航
Owner SHAGANG GROUP
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