CN101037633A - Natural mineral powder coal desulfurize agent - Google Patents

Abstract

The invention relates to a natural mineral flour coal desulfurizer, which pertain to one kind of desulfurizer, composed by material with weight percent as following: 20-50% of calcite, 51-54% of CaO content, 10-20% of zeolite with 0.034 mm-0.074 mm granul diametre, 30-70% of gellib ckite with 0.074-0.15 mm granul diametre and exchange capacity of NH4 >=1mmol/g, 35-48% of SiO2 content, 30-45% of CaO content with 0.074-0.15 mm granul diametre. Advantages of the invention: all material is inorganic mineral, wide resource, hazardless. The invention adopts dry desulfidation with wide range of application suit for any steam power plant, heating power company.

Description

Natural mineral powder coal desulfurizer

Technical Field

The invention relates to application of natural minerals in the field of environmental protection, in particular to a coal desulfurizer.

Background

SO of China₂The emission is high, and the people are in the front of all countries in the world. According to data statistics, from 1990 to 2005, the SO of China₂The discharge amount is about 2200 to 2500 million tons, wherein the discharge amount of a power plant accounts for 67 percent of the total amount. If emission reduction is not controlled, the emission amount reaches 3500 million tons by 2020. Estimating SO in atmosphere of China according to environmental protection department₂The capacity of the concentration quality secondary standard is 1200 ten thousand tons. While the actual displacement is more than doubled. The environmental crisis has been a reality. At present, more technologies for desulfurization and emission reduction are available worldwide. There are three main approaches: wet desulfurization, semi-dry desulfurization and dry desulfurization. The wet desulfurization and the semi-dry desulfurization require complicated equipment and a large amount of capital, thereby causing the production cost of the thermal power plant to be increased. The dry desulfurization effect is not very ideal. The average desulfurization amount is about 40-50%. The main raw material of the desulfurizer is only limestone. A large amount of CO is generated in the desulfurization process₂The discharge amount causes a new pollution source. The latest emerging chemical raw material mixing method. But also can generate a large amount of nitrogen oxide and chlorine emission.

Disclosure of Invention

The invention provides a natural mineral powder coal desulfurizer, which solves the problems of poor effect and new pollution source generation in the existing desulfurization and emission reduction process. The technical scheme adopted bythe invention is as follows: the material is composed of the following raw materials by mass ratio:

20 to 50 percent of calcite, 51 to 54 percent of CaO, 0.034 to 0.074mm of grain diameter,

zeolite: 10% -20%, NH₄ ⁺The exchange capacity is more than or equal to 1mmol/g, and the grain diameter is 0.074 mm-0.15 mm

Wollastonite: 30% -70% of SiO₂35-48% of CaO, 30-45% of CaO, and particle size0.074mm～0.15mm。

The technical basis of the invention is that

Wollastonite and CaSi₃Calcium metasilicate mineral, the crystal is needle-shaped. The density is 2.78-2.91g/cm³Melting point: wollastonite decomposing at 1540 deg.C into CaO and free SiO₂。SiO₂With SO under acidic conditions₂The colloidal silica sol generated by the reaction is precipitated, and a large amount of CaO is generated to supplement Ca to the desulfurizer²⁺The concentration of (c). Meanwhile, the needle-shaped bodies have higher density and play a role in pressing and filtering smoke dustThe application is as follows. Can increase Ca content²⁺And smoke suppressant effect.

Calcite (crystalline limestone) CaCO₃. The crystal is triangular and rhombohedral, the density is 2.60-2.72, and the melting point is 2850 ℃. Calcite can be decomposed into CaO and CO at 1000-1200 DEG C₂The mineral disintegrates. When SO is in the furnace body₂With increasing concentration, spread along the mineral surface, and then when calcite decomposes, SO₂And then diffuses along the inner part and is simultaneously solidified by chemical reaction with CaO.

The reaction formula is as follows:

calcite desulfurization is a series of reactions in which physical adsorption and chemical reactions are synchronized. The calcite is disintegrated during the reaction, so that the formation of the coke slag is effectively inhibited.

Zeolite: (Na, K, Ca)_2-3[Ai₃(AiSi)₃Si₁₃O₁₆]·12H₂O three-dimensional silicon-aluminum-oxygen framework structure: the crystal is in a nanometer level lattice shape. Melting point: 1500 ℃ in the presence of a catalyst. The reaction temperature is below 900 ℃ to normal temperature. The zeolite framework has large cavities which allow gas and other ions and molecules to enter and be adsorbed in the cavities. When coal is burnt, the temperature rises, and H is in the cavity₂And removing the O. To become the cavity zeolite. SO that SO₂、CO₂、Cl^-、NO、NO₂Etc. can enter the lumen and be retained therein. Measurement of zeolite to SO₂Saturated adsorption capacity of 200mg/g, CO₂The saturated adsorption amount was 81mg/g, and the adsorption amount by other gases or liquids was also excellent.

In conclusion, the desulfurizing agent of our invention is practical and feasible. The generated physical and chemical reactions can achieve the purposes of coal desulfurization, decoking, smoke suppression and stable combustion.

The invention selects the desulfurizer used in the dry desulfurization process. Ca²⁺Ion is atPlays a leading role in the desulfurizing agent. Therefore we have designed the Ca/S molar ratio to be in the range of 2-3. The reaction process of the desulfurizer and the combustion of the coal is very complicated. In general, Ca is present at 750 ℃ to 850 DEG C²⁺While zeolites below 900 c are the optimal reaction zones. Ca at 900-1150 ℃²⁺An optimal reaction zone. 1150-1300 ℃ is the optimal activation zone of wollastonite, Ca²⁺Ions are generated in large quantities. 1300 ℃ to 1500 ℃ is a dead burning zone. All ores terminated the reaction. In addition, the particle size of the mineral is also an important factor for the desulfurization of the desulfurizing agent, the particle is too large, the specific surface area of the mineral is small, and the mineral is mixed with SO₂The contact probability is small, and the desulfurization effect is influenced. CaSO generated early when desulfurizer is too fine₄Clogging of the leading holes also affects the desulfurization effect.

According to the mineral combination proportion, the invention designs 3 experimental schemes, all achieve the expected effect, and the actual measurement result is as follows:

analysis of calorific value (J/g) of sample cylinder Total Sulfur (%) Coke breeze characteristics

H₁Raw coal 245912.807

H₂EXAMPLE 1 formulation 245811.405

H₃Example 2 formulation 246141.004

H₄Example 3 formulation 246361.004

From the results, the present invention has reached moderate desulfurization agent levels. The sulfur fixation rate is 65-71%, the heat release rate is improved by 10%, the generation of coke slag is inhibited, nitrogen oxides, chlorine and the like are few, the content of fly ash is low, and the aim of the invention is comprehensively achieved.

The invention has the advantages that the adopted raw materials are all inorganic minerals, the source is wide,and no public nuisance is caused. The invention adopts dry desulphurization, and all thermal power plants and heating power companiesCan be adopted, and has wide application range. The invention utilizes the uniqueness of minerals and the coking property and SO of the coal according to different reaction mechanisms of different stages of the coal₂The content is large, the mineral combination proportion is carried out, and the design is novel and unique. The invention is not only a complex of various minerals, but also an environment-friendly green product, accords with the national policy and policy, and ensures that the product is a natural productHowever, minerals are widely developed and applied. Once the social benefit and the economic benefit are realized, the win-win effect is achieved. Also one blue sky in China. A social harmony is created.

Detailed Description

Example 1

The material is composed of the following raw materials by mass ratio:

20 percent of calcite, 51 to 54 percent of CaO content, 0.034mm to 0.074mm of grain diameter,

zeolite: 10% of NH₄ ⁺The exchange capacity is more than or equal to 1mmol/g, and the grain diameter is 0.074 mm-0.15 mm

Wollastonite: 70% of SiO₂35-48% of CaO, 30-45% of CaO and 0.074-0.15 mm of grain size.

Example 2

The material is composed of the following raw materials by mass ratio:

40 percent of calcite, 51 to 54 percent of CaO content, 0.034mm to 0.074mm of grain diameter,

zeolite: 15% of NH₄ ⁺The exchange capacity is more than or equal to 1mmol/g, and the grain diameter is 0.074mm-0.15 mm

Wollastonite: 45% of SiO₂35-48% of CaO, 30-45% of CaO and 0.074-0.15 mm of grain size.

Example 3

The material is composed of the following raw materials by mass ratio:

50 percent of calcite, 51 to 54 percent of CaO content, 0.034mm to 0.074mm of grain diameter,

zeolite: 20% of NH₄ ⁺The exchange capacity is more than or equal to 1mmol/g, and the grain diameter is 0.074 mm-0.15 mm

Wollastonite: 30% of SiO₂35-48% of CaO, 30-45% of CaO and 0.074-0.15 mm of grain size.

Claims (1)

1. The natural mineral powder coal desulfurizer is characterized by comprising the following raw materials by mass:

20 to 50 percent of calcite, 51 to 54 percent of CaO, 0.034 to 0.074mm of grain diameter,

zeolite: 10% -20%, NH₄ ⁺The exchange capacity is more than or equal to 1mmol/g, and the grain diameter is 0.074 mm-0.15 mm

Wollastonite: 30% -70% of SiO₂35-48% of CaO, 30-45% of CaO and 0.074-0.15 mm of grain size.