Dry desulfurization agent and its preparation method and application

Abstract

The present invention provides a dry desulfurization agent for comprehensive utilization of solid waste materials, and a preparation method and application thereof. The dry desulfurization agent composition of the present invention comprises, by weight: 30 to 60 parts of white mud; 10 to 40 parts of manganese slag; and 5 to 20 parts of a binder. In some embodiments of the present invention, the manganese slag is electrolytic manganese slag. The present invention provides a new way to comprehensively utilize manganese slag, reduces environmental pollution and safety risks caused by the stacking of manganese slag, and improves the economic benefits of the smelting plant.

Description

Technical Field

[0001] The present invention relates to the fields of solid waste pollution disposal and resource recycling in energy-saving and environmental protection industries; atmospheric pollution prevention and control materials, and in particular to a dry desulfurization agent for comprehensive utilization of solid waste materials and a preparation method and application thereof. Background Art

[0002] Electrolytic manganese slag is waste generated during the production of pure manganese, and is transported to the stockpile and stored in a dammed wet method. The large amount of electrolytic manganese slag not only occupies a large amount of land, but also the harmful substances in the electrolytic manganese slag penetrate into the soil, surface water and groundwater, causing serious environmental pollution and major safety hazards.

[0003] SO2 produced by coal combustion in thermal power plants has become one of the main sources of global environmental pollution. At the same time, there are also problems with SO2 emissions in the production processes of some non-power industries. Dry desulfurization technology has unique advantages such as no scaling, condensation, clogging, less secondary pollution, easy maintenance, and low operating costs. However, the current dry desulfurization efficiency is low, the calcium utilization rate is low, and it is limited by flue gas conditions (flue gas temperature, flue gas water content, flue gas components). The application field is relatively narrow, especially in the field of low-temperature and low-nitrogen oxide flue gas, where it is less used and most of the desulfurization efficiency is very low. Low-temperature and low-nitrogen oxide flue gas desulfurization: electrolytic aluminum flue gas, dry coke quenching tail gas, steel rolling low-temperature heating furnace flue gas, etc. have a large market demand for high-efficiency dry desulfurizers, so the development of a dry desulfurizer with high desulfurization efficiency suitable for low-temperature and low-nitrogen oxide flue gas will have broad application prospects.

[0004] For the current dry calcium-based desulfurizer, the flue gas temperature and flue gas composition have a great influence on the desulfurization efficiency of the desulfurizer. Too low flue gas temperature leads to a decrease in the diffusion rate of SO2, and a decrease in the mass transfer rate of calcium ions in the calcium-based desulfurizer, which in turn affects the desulfurization efficiency of the desulfurizer. x On the one hand, the presence of can oxidize SO2 to SO3, which is more soluble in water and reacts with calcium hydroxide in the calcium-based desulfurizer, thereby greatly improving the desulfurization efficiency. On the other hand, NOx reacts with calcium hydroxide in the calcium-based desulfurizer to generate Ca(NO3)2. The generation of Ca(NO3)2 changes the surface structure of the desulfurizer, making the surface of the desulfurizer rough and no longer dense, making it easier for SO2 to diffuse into the desulfurizer and react with the internal calcium hydroxide, thereby improving the desulfurization efficiency of the desulfurizer. Therefore, when the NOx content in the flue gas is low, the desulfurization rate of the desulfurizer will be greatly reduced.

[0005] For low-temperature and low-nitrogen oxide flue gas, the currently reported technology oxidizes SO2 to SO3 by adding metal oxides and strong oxidizing substances, thereby increasing the desulfurization rate of calcium-based desulfurizers. However, the metal oxides CuO, Fe2O3, MnO2, etc. currently used have low activity, poor oxidation effect, and are added in large quantities, and cannot be recycled for secondary use; general strong oxidizing additives such as calcium hypochlorite, sodium chlorate, and sodium dichloroisocyanurate have the following disadvantages: ① unstable and easy to decompose, resulting in unstable performance of the prepared desulfurizer and difficulty in long-term storage; ② Most strong oxidizing substances are flammable and explosive, and are highly dangerous to use; ③ Containing highly penetrating chloride ions, which are highly corrosive to desulfurization equipment and harmful to the environment. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] The present invention is expected to at least partially solve one of the above technical problems.

[0008] (II) Technical solution

[0009] According to the first aspect of the present invention, a dry desulfurization agent composition is provided, which comprises, by weight: 30 to 60 parts of white mud; 10 to 40 parts of manganese slag; and 5 to 20 parts of a binder. In some embodiments of the present invention, the manganese slag is electrolytic manganese slag.

[0010] In some embodiments of the present invention, the lime mud is a by-product of the papermaking industry.

[0011] In some embodiments of the present invention, the present invention further comprises, by weight: 5 to 10 parts of auxiliary agent, which is a sodium salt and / or a potassium salt.

[0012] In some embodiments of the present invention, the present invention further comprises, by weight, 5 to 15 parts of water.

[0013] In some embodiments of the present invention, the binder is selected from one or more of the following materials: cement, desulfurized ash, gypsum, kaolin, bentonite, and diatomaceous earth.

[0014] In some embodiments of the present invention, the auxiliary agent is selected from one or more of the following materials: potassium hydroxide, potassium sulfate, potassium carbonate, potassium aluminum sulfate, potassium silicate, potassium phosphate, potassium dihydrogen phosphate, sodium hydroxide, sodium sulfate, sodium carbonate, sodium bicarbonate, potassium silicate, sodium phosphate, and sodium dihydrogen phosphate.

[0015] According to a second aspect of the present invention, there is provided a method for preparing a dry desulfurization agent, comprising:

[0016] Step A, roasting the white mud at a temperature between 850 and 1000° C.;

[0017] Step B, mixing and grinding the calcined white mud and manganese slag to obtain a first semi-finished product material;

[0018] Step C, roasting the first semi-finished product material at a temperature between 200 and 400° C. to obtain a second semi-finished product material;

[0019] Step D, mixing and grinding the second semi-finished product material and the binder to obtain a dry desulfurization agent powder;

[0020] Among them, by weight, white mud, 30 to 60 parts; manganese slag, 10 to 40 parts; binder, 5 to 20 parts.

[0021] In some embodiments of the present invention, step B comprises:

[0022] Sub-step B1, obtaining an additive solution;

[0023] Sub-step B2, wet grinding the calcined white mud, auxiliary agent solution and manganese slag;

[0024] Sub-step B3, drying the wet-milled material to obtain a first semi-finished product material;

[0025] Wherein, the auxiliary agent is potassium salt and / or sodium salt, and the auxiliary agent is 5 to 10 parts by weight.

[0026] In some embodiments of the invention, step D comprises:

[0027] Sub-step D1, grinding the second semi-finished product material;

[0028] Sub-step D2, mixing the ground material with a binder and continuing to grind to obtain a dry desulfurization agent powder.

[0029] In some embodiments of the present invention, the manganese slag is electrolytic manganese slag.

[0030] In some embodiments of the present invention, the lime mud is a by-product of the papermaking industry.

[0031] In some embodiments of the present invention, the auxiliary agent is selected from one or more of the following materials: potassium hydroxide, potassium sulfate, potassium carbonate, potassium aluminum sulfate, potassium silicate, potassium phosphate, potassium dihydrogen phosphate, sodium hydroxide, sodium sulfate, sodium carbonate, sodium bicarbonate, potassium silicate, sodium phosphate, and sodium dihydrogen phosphate.

[0032] In some embodiments of the present invention, the binder is selected from one or more of the following materials: cement, desulfurized ash, gypsum, kaolin, bentonite, and diatomaceous earth.

[0033] In some embodiments of the present invention, step A includes: sub-step A1, drying the white mud until the moisture content is less than 3%; sub-step A2, placing the dried white mud in a muffle furnace for calcining for 3 to 5 hours.

[0034] In some embodiments of the present invention, in step C, the second calcination process takes longer than 1 hour; and / or

[0035] In some embodiments of the present invention, after step D, the following further comprises: step E, adding water to the dry desulfurization agent powder, extruding and molding; and obtaining a dry desulfurization agent block after drying.

[0036] According to a third aspect of the present invention, a dry desulfurization agent is provided, which is prepared by the above dry desulfurization agent preparation method.

[0037] According to a fourth aspect of the present invention, a dry desulfurization agent composition as above is provided, or a dry desulfurization agent as above is used in a low-temperature low-nitrogen oxide flue gas desulfurization scenario; wherein the low-temperature low-nitrogen oxide flue gas is: a flue gas temperature of 20°C to 320°C, SO2 <1000ppm, NO x <25ppm, H2O<0.5%, electrolytic aluminum flue gas, dry coke quenching tail gas, and environmental dust removal gas.

[0038] (III) Beneficial effects

[0039] It can be seen from the above technical solution that the present invention has at least one of the following beneficial effects compared with the prior art:

[0040] (1) It provides a new way for the comprehensive utilization of manganese slag, reduces the environmental pollution and safety risks caused by manganese slag stacking, and improves the economic benefits of the smelting plant.

[0041] (2) Manganese slag is electrolytic manganese slag, and white mud is a by-product of the papermaking industry, and the two account for 50% to 90% of the weight of the dry desulfurizer of the present invention. It can be seen that the main raw materials used in the present invention are all industrial by-products. After the industrial by-products are processed through a certain preparation process, a desulfurizer with excellent desulfurization performance is obtained, which truly turns industrial by-products into treasures and recycles them.

[0042] Furthermore, the waste agent of the dry desulfurizer after desulfurization can be recovered and ground into powder and used as a binder for re-preparing the desulfurizer, thus truly achieving recycling.

[0043] (3) The calcium-based substance in white mud is mainly calcium carbonate, which is decomposed into calcium oxide after high-temperature roasting. Calcium oxide reacts with water to form calcium hydroxide. Calcium hydroxide has strong alkalinity. During the wet mixing process with electrolytic manganese slag, it can react with silicon dioxide and aluminum oxide in the electrolytic manganese slag to produce volcanic ash, calcium silicate, calcium aluminosilicate and other substances with large specific surface area, high water retention and certain strength, creating excellent reaction conditions for desulfurization. At the same time, the prepared desulfurizer also has a certain dust removal effect.

[0044] In order to solve the problem that the current desulfurizer has low desulfurization efficiency under this flue gas condition, the dry desulfurizer of the present invention is added with electrolytic manganese slag, which contains a large amount of Fe3+, Mn2+, NH+4-N, Ca2+, Al3+, Si4+, Mg2+, Zn2+, Ni2+, and Cu2+. During the process of calcium oxide in the white mud reacting with water to generate calcium hydroxide after roasting, these ions are uniformly embedded in the generated calcium hydroxide or dispersed on its surface. On the one hand, the ions embedded in the calcium hydroxide change the crystal form of the calcium hydroxide, forming multiple oxygen vacancies. The formation of oxygen vacancies increases the amount of oxygen adsorbed on its surface, making it oxidatively active. On the other hand, the metal ions dispersed on the surface of calcium hydroxide make the surface of the generated calcium hydroxide rich in multiple reactive sites, making it catalytically oxidatively active. Among them, Fe 3+ , Mn 2+ It can also react with calcium hydroxide to produce iron hydroxide and manganese hydroxide. After roasting at 200-400℃, iron hydroxide and manganese hydroxide are transformed into highly active iron oxide and manganese oxide. Compared with directly adding metal oxides to the desulfurizer, the oxides generated by this method are highly active. Highly active iron oxide and manganese oxide can oxidize SO2 to SO3, and iron oxide and manganese oxide are transformed into iron sulfate and manganese sulfate. Among them, iron and manganese are transition metals with multiple variable valence states. Fe3+ / Mn2+ has the function of synergistic catalytic oxidation of SO2, and then continues to catalytically oxidize SO2, thus solving the problem of low SO2 oxidation efficiency and low desulfurization efficiency under low nitrogen oxide flue gas.

[0045] (4) In view of the problem that the initial desulfurization product calcium sulfate of ordinary calcium-based desulfurizers tends to form a dense product on the surface of the desulfurizer under low nitrogen oxide flue gas, making it difficult for SO2 to diffuse into the interior of the desulfurizer in the later stage, resulting in reduced desulfurization efficiency, the sodium ions and potassium ions introduced into the dry desulfurizer provided by the present invention can be embedded in the desulfurization product calcium sulfate crystals during the desulfurization process, thereby forming crystal defects. In the subsequent desulfurization process, the internal calcium ions can jump to the surface of the desulfurizer to react with sulfur dioxide, thereby improving the desulfurization rate of the desulfurizer.

[0046] At the same time, the auxiliary agents added to the dry desulfurizer provided by the present invention are all soluble salts. The soluble salts are soluble in water and are mixed with other materials in the form of an aqueous solution. Compared with the method of mixing metal oxides with other materials in the form of powder, they can be dispersed more evenly in the desulfurizer, thereby providing more uniform active sites and higher desulfurization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 The present invention is a flowchart of a method for preparing a dry desulfurizing agent for comprehensive utilization of solid waste materials according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The flue gas dry desulfurizer provided by the present invention uses calcium-based substances in white mud as the main active absorption component, uses electrolytic manganese slag as a carrier and an active substance for catalytic oxidation, adds an appropriate amount of binder and a small amount of auxiliary agent, and is obtained by extrusion molding. The feature of the present invention is that it truly realizes the comprehensive utilization of solid waste materials.

[0049] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific implementation methods and with reference to the accompanying drawings.

[0050] According to a first aspect of the present invention, a desulfurization agent composition suitable for low-temperature and low-nitrogen oxide flue gas desulfurization scenarios is provided, comprising: 30 to 60 parts of white mud, 10 to 40 parts of electrolytic manganese slag, 5 to 10 parts of additives, 5 to 20 parts of binders, and 5 to 15 parts of water.

[0051] Preferably, the white mud is a byproduct of the papermaking industry, and the manganese slag is electrolytic manganese slag, both of which are industrial solid waste materials. The two are used to produce desulfurization agents, thereby realizing the comprehensive utilization of solid waste materials. At the same time, a new way for the comprehensive utilization of manganese slag is provided, which reduces the environmental pollution and safety risks caused by the stacking of manganese slag and improves the economic benefits of the smelting plant.

[0052] Furthermore, the auxiliary agent is a sodium salt and / or a potassium salt, specifically including: one or more of potassium hydroxide, potassium sulfate, potassium carbonate, potassium aluminum sulfate, potassium silicate, potassium phosphate, potassium dihydrogen phosphate, sodium hydroxide, sodium sulfate, sodium carbonate, sodium bicarbonate, potassium silicate, sodium phosphate, and sodium dihydrogen phosphate.

[0053] Furthermore, the binder is a viscous material, including at least one of cement, desulfurized ash, gypsum, kaolin, bentonite, diatomaceous earth, etc.

[0054] According to a first aspect of the present invention, a method for preparing a dry desulfurization agent for comprehensive utilization of solid waste materials is provided. Figure 1 The flowchart of the method for preparing a dry desulfurizing agent for comprehensive utilization of solid waste materials according to an embodiment of the present invention is shown in FIG. Figure 1 As shown,

[0055] Step A, roasting the white mud at a temperature between 850 and 1000° C.;

[0056] Step B, mixing and grinding the calcined white mud and electrolytic manganese slag to obtain a first semi-finished product material;

[0057] Step C, roasting the first semi-finished product material at a temperature between 200 and 400° C. to obtain a second semi-finished product material;

[0058] Step D, mixing and grinding the second semi-finished product material and the binder to obtain a dry desulfurization agent powder;

[0059] Step E, adding water to the dry desulfurization agent powder, extruding and molding; and obtaining a dry desulfurization agent block after drying.

[0060] Among them, by weight, white mud is 30 to 60 parts; electrolytic manganese slag is 10 to 40 parts; and binder is 5 to 20 parts.

[0061] Each step is described in detail below.

[0062] Step A specifically includes: sub-step A1, drying 30-60 parts of white mud in an oven until the moisture content is less than 3%; sub-step A2, placing the dried white mud in a muffle furnace and roasting at 850-1000° C. for 3-5 hours. The white mud is a by-product of the papermaking industry.

[0063] Those skilled in the art should understand that if the white mud raw material itself is relatively dry, sub-step A1 can be omitted, or the drying in sub-step A1 can be incorporated into the roasting step in sub-step A2. At the same time, the degree of drying, the type of roasting furnace, the roasting temperature, the roasting time, etc. can also be adjusted according to actual needs.

[0064] Step B specifically includes: sub-step B1, dissolving the auxiliary agent in an appropriate amount of water to prepare an auxiliary agent solution; sub-step B2, placing the calcined white mud and the auxiliary agent solution obtained in step A and 10 to 40 parts of electrolytic manganese slag in a ball mill, and fully wet-grinding for 3 hours to 5 hours; sub-step B3, drying the wet-grinded material until the moisture content is less than 3%, to obtain a first semi-finished product material.

[0065] In this step, the auxiliary agent is 5 to 10 parts by weight. The auxiliary agent is a potassium salt and / or a sodium salt, which can be selected from one or more of the following materials: potassium hydroxide, potassium sulfate, potassium carbonate, potassium aluminum sulfate, potassium silicate, potassium phosphate, potassium dihydrogen phosphate, sodium hydroxide, sodium sulfate, sodium carbonate, sodium bicarbonate, sodium silicate, sodium phosphate, sodium dihydrogen phosphate.

[0066] In view of the problem that the initial desulfurization product calcium sulfate of ordinary calcium-based dry desulfurizers tends to form a dense product on the surface of the desulfurizer under low nitrogen oxide flue gas, making it difficult for SO2 to diffuse into the interior of the desulfurizer in the later stage, resulting in reduced desulfurization efficiency, the sodium ions and potassium ions introduced into the desulfurizer provided by the present invention can be embedded in the desulfurization product calcium sulfate crystals during the desulfurization process, thereby forming crystal defects. In the subsequent desulfurization process, the internal calcium ions can jump to the surface of the desulfurizer to react with sulfur dioxide, thereby improving the desulfurization rate of the desulfurizer.

[0067] At the same time, the additives added to the desulfurizer provided by the present invention are all soluble salts. The soluble salts are soluble in water and are mixed with other materials in the form of an aqueous solution. Compared with the method of mixing metal oxides with other materials in the form of powder, they can be dispersed more evenly in the desulfurizer, thereby providing more uniform active sites and higher desulfurization efficiency.

[0068] Step C specifically includes: placing the first semi-finished product material in a muffle furnace and roasting it at 200-400° C. for 5 hours to allow various materials to fully react.

[0069] Among them, the calcium-based substance in white mud is mainly calcium carbonate, which is decomposed into calcium oxide after high-temperature roasting. Calcium oxide reacts with water to form calcium hydroxide. Calcium hydroxide has strong alkalinity. During the ball milling wet mixing process with electrolytic manganese slag, it can react with silicon dioxide and aluminum oxide in the electrolytic manganese slag to produce volcanic ash, calcium silicate, calcium aluminosilicate and other substances with large specific surface area, high water retention and certain strength, creating excellent reaction conditions for desulfurization. At the same time, the desulfurizer also has a certain dust removal effect.

[0070] In view of the low desulfurization efficiency of the current desulfurizer under this flue gas condition, the desulfurizer of the present invention is added with electrolytic manganese slag, which contains a large amount of Fe 3+ , Mn 2+ NH +4 -N, Ca 2+ 、Al 3+ 、Si 4+ Mg 2+ 、Zn 2+ 、Ni 2+ , Cu 2+ In the process of calcium oxide in the white mud reacting with water to generate calcium hydroxide after roasting, these ions are uniformly embedded in the generated calcium hydroxide or dispersed on its surface. On the one hand, the ions embedded in the calcium hydroxide change the crystal form of the calcium hydroxide, forming multiple oxygen vacancies. The formation of oxygen vacancies increases the oxygen adsorption on its surface, making it oxidatively active. On the other hand, the metal ions dispersed on the surface of calcium hydroxide make the surface of the generated calcium hydroxide rich in multiple reactive sites, making it catalytically oxidatively active. Among them, Fe 3+ , Mn 2+ It can also react with calcium hydroxide to produce iron hydroxide and manganese hydroxide. After roasting at 200-400℃, iron hydroxide and manganese hydroxide are converted into highly active iron oxide and manganese oxide. Compared with directly adding metal oxides to the desulfurizer, the oxides generated by this method are highly active. Highly active iron oxide and manganese oxide can oxidize SO2 to SO3, and iron oxide and manganese oxide are converted into iron sulfate and manganese sulfate. Iron and manganese are transition metals with multiple variable valence states. Fe 3+ / Mn 2+It has the function of synergistically catalyzing the oxidation of SO2, and then continues to catalyze the oxidation of SO2, thus solving the problem of low SO2 oxidation efficiency and low desulfurization efficiency under low nitrogen oxide flue gas.

[0071] The reaction process of SO2 oxidation by iron salt and manganese salt:

[0072] Fe 3+ +Ca(OH)2→Fe(OH)3↓+Ca 2+

[0073] Mn 2+ +Ca(OH)2→Mn(OH)2↓+Ca 2+

[0074]

[0075] Fe2O3(active)+SO2+Ca(OH)2→Fe 2+ +CaSO4+H2O

[0076] MnO2(active)+SO2+Ca(OH)2→Mn 2+ +CaSO4+H2O

[0077] Fe 2+ / Mn 2+ The reaction process of synergistic catalytic oxidation of SO2:

[0078] Fe 2+ +O2→Fe 3+

[0079] Fe 3+ +Mn 2+ →Mn 3+ +Fe 2+

[0080] Mn 3+ +SO2+Ca(OH)2→Mn 2+ +CaSO4+H2O

[0081] The step D comprises: sub-step D1, ball-milling the calcined product obtained in step C again in a ball mill for 3 hours to 4 hours; sub-step D2, fully mixing and stirring one or more of the binders with the ball-milled material in a stirring tank according to the above-mentioned proportion to obtain a dry desulfurization agent powder.

[0082] The binder is selected from one or more of the following materials: cement, desulfurized ash, gypsum, kaolin, bentonite, and diatomaceous earth.

[0083] It should be noted that the present invention can provide dry desulfurization agent powder or block material. If powder material is needed, the process can be ended at step D. If block material is needed, the process proceeds to step E as follows.

[0084] Step E comprises: slowly adding an appropriate amount of water during the ball milling process, fully stirring and mixing, and then extruding a columnar or four-leaf clover-shaped sample; and drying the extruded sample at 50-100° C. for 2-6 hours to obtain a finished desulfurizer. The dry desulfurizer block can be columnar or four-leaf clover-shaped.

[0085] According to the third aspect of the present invention, a dry desulfurization agent is also provided, which is prepared by the above dry desulfurization agent preparation method.

[0086] It should be particularly noted that the waste desulfurizer provided by the present invention after desulfurization can be recycled and ground into powder and used as a binder for the desulfurizer, thus truly achieving recycling.

[0087] According to the third aspect of the present invention, there is also provided a dry desulfurization agent composition and desulfurization agent as described above, which are used in low-temperature and low-nitrogen oxide flue gas desulfurization scenarios. Specifically, the desulfurization agent composition and desulfurization agent of the present invention can be used in flue gas temperatures of 20°C to 320°C, SO2 <1000ppm, NO x <25ppm, H2O<0.5%, in the dry flue gas desulfurization technology of electrolytic aluminum flue gas, dry quenching tail gas, environmental dust removal and other industrial flue gases, the SO2 removal rate can reach more than 95%.

[0088] The present invention is described in more detail below with reference to specific examples.

[0089] Example 1

[0090] By weight, 50 parts of white mud, 30 parts of electrolytic manganese slag, 5 parts of potassium hydroxide, 15 parts of cement and 15 parts of water are used as raw materials for preparing the desulfurizer.

[0091] The preparation method of the desulfurizer in Example 1 is as follows: dry and calcine the white mud at 900°C for 4 hours; dissolve potassium hydroxide in water to prepare an auxiliary agent solution; place the calcined white mud and electrolytic manganese slag in a ball mill according to a ratio, add the auxiliary agent solution at the same time, and fully wet grind them in the ball mill for 4 hours; dry and calcine the wet-milled material in a muffle furnace at 300°C for 5 hours; place the dried and calcined material and cement in a ball mill for fully grinding for 2 hours to mix evenly to obtain a powdery mixed material; add water to the powdery mixed material, knead it, and extrude it into strips; dry the extruded material at 250°C for 3 hours to obtain a finished desulfurizer.

[0092] The desulfurization test results of the desulfurizer in Example 1 are as follows: the experiment lasted about 136 hours, the desulfurization rate was 100% for about 33.8 hours, and then the desulfurization rate slowly decreased, and the desulfurization rate dropped to 20% after about 112.9 hours of reaction. The calculated sulfur capacity was 23.25%.

[0093] Example 2

[0094] The raw materials and preparation method of the composition of this embodiment are similar to those of Embodiment 1, except that 5 parts by weight of potassium hydroxide are replaced by potassium sulfate.

[0095] The desulfurization test results of the desulfurizer of this embodiment are as follows: the experiment lasted about 136.2 hours, the desulfurization rate was 100% for about 34 hours, and then the desulfurization rate slowly decreased, and the desulfurization rate dropped to 20% after about 113.2 hours of reaction. The calculated sulfur capacity was 23.35%.

[0096] As can be seen from Examples 1 and 2, substantially similar effects can be achieved by changing the type of potassium salt.

[0097] Example 3

[0098] The raw materials and preparation method of the composition of this embodiment are similar to those of Embodiment 1, except that 5 parts by weight of potassium hydroxide are replaced by potassium aluminum sulfate.

[0099] The desulfurization test results of the desulfurizer of this embodiment are as follows: the experiment lasted about 136.1 hours, the desulfurization rate was 100% for about 33.9 hours, and then the desulfurization rate slowly decreased, and the desulfurization rate dropped to 20% after about 113 hours of reaction. The calculated sulfur capacity was 23.30%.

[0100] It can be seen from Examples 1 and 3 that substantially similar effects can be achieved by changing the type of potassium salt.

[0101] Example 4

[0102] The raw materials and preparation method of the composition of this embodiment are similar to those of Embodiment 1, except that 5 parts by weight of potassium hydroxide are replaced by potassium carbonate.

[0103] The desulfurization test results of the desulfurizer of this embodiment are as follows: the experiment lasted about 136.25 hours, the desulfurization rate was 100% for about 34.5 hours, and then the desulfurization rate slowly decreased, and the desulfurization rate dropped to 20% after about 113.4 hours of reaction. The calculated sulfur capacity was 23.40%.

[0104] It can be seen from Examples 1 and 4 that substantially similar effects can be achieved by changing the type of potassium salt.

[0105] Example 5

[0106] The raw materials and preparation method of the composition of this embodiment are similar to those of Embodiment 1, except that 5 parts by weight of potassium hydroxide are replaced by sodium hydroxide.

[0107] The desulfurization test results of the desulfurizer of this embodiment are as follows: the experiment lasted about 136.28 hours, the desulfurization rate was 100% for about 34.6 hours, and then the desulfurization rate slowly decreased, and the desulfurization rate dropped to 20% after about 113.6 hours of reaction. The calculated sulfur capacity was 23.43%.

[0108] In combination with Examples 1 and 5, it can be seen that similar effects can be achieved by replacing potassium salt with sodium salt of the same type.

[0109] Example 6

[0110] The raw materials and preparation method of the composition of this embodiment are similar to those of Embodiment 1, except that 5 parts by weight of potassium hydroxide are replaced by sodium carbonate.

[0111] The desulfurization test results of the desulfurizer of this embodiment are as follows: the experiment lasted about 136.15 hours, the desulfurization rate was 100% for about 34.05 hours, and then the desulfurization rate slowly decreased, and the desulfurization rate dropped to 20% after about 113.4 hours of reaction. The calculated sulfur capacity was 23.38%.

[0112] In combination with Examples 1 and 6, it can be seen that similar effects can be achieved by replacing potassium salt with sodium salt.

[0113] Example 7

[0114] The raw materials and preparation method of the composition of this embodiment are similar to those of Example 1, except that 15 parts by weight of cement are replaced by desulfurized ash.

[0115] The desulfurization test results of the desulfurizer of this embodiment are as follows: the experiment lasted about 136.3 hours, the desulfurization rate was 100% for about 34.2 hours, and then the desulfurization rate slowly decreased, and the desulfurization rate dropped to 20% after about 113.5 hours of reaction. The calculated sulfur capacity was 23.45%.

[0116] Combining Examples 1 and 7, it can be seen that similar effects can be achieved by replacing the binder with desulfurized ash.

[0117] Example 8

[0118] The raw materials and preparation method of the composition of this embodiment are similar to those of Embodiment 1, except that 15 parts by weight of cement is replaced by diatomaceous earth.

[0119] The desulfurization test results of the desulfurizer of this embodiment are as follows: the experiment lasted about 136.43 hours, the desulfurization rate was 100% for about 34.3 hours, and then the desulfurization rate slowly decreased, and the desulfurization rate dropped to 20% after about 113.65 hours of reaction. The calculated sulfur capacity was 23.54%.

[0120] It can be seen from Examples 1 and 8 that similar effects can be achieved by replacing the binder with diatomaceous earth.

[0121] At this point, the various embodiments of the present invention have been introduced. According to the above description, those skilled in the art should have a clear understanding of the present invention.

[0122] It should be noted that, unless explicitly indicated to the contrary, the numerical parameters in the specification and claims of the present invention may be approximate values ​​and may be changed according to the content of the present invention. Specifically, all the numbers indicating the content of the composition, reaction conditions, etc. recorded in the specification and claims should be understood to be modified by the term "about" in all cases, and the meaning of the expression is to include a change of ±10% from a specific number in some embodiments.

[0123] Those skilled in the art should understand that in the claims and description of the present invention, the word "comprising" does not exclude the presence of materials (or steps) not listed in the claims. The word "a" or "an" before a material or step does not exclude the presence of multiple such materials (or steps).

[0124] For certain implementations, if they are not the key content of the present invention and are well known to ordinary technicians in the relevant technical field, they are not described in detail in the drawings or text of the specification due to space limitations. At this time, they can be understood by referring to the relevant prior art. In addition, the purpose of providing the above embodiments is only to make the present invention meet legal requirements, and the present invention can be implemented in many different forms and should not be interpreted as limited to the embodiments described herein. In addition, the above definitions of each element and method are not limited to the various specific structures, shapes or methods mentioned in the embodiments, and ordinary technicians in this field can simply change or replace them.

[0125] Similarly, it should be understood that in order to simplify the present invention, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the invention should not be interpreted as reflecting the following intention: the claimed invention requires more features than the features explicitly stated in each claim. More specifically, as reflected in the claims, each inventive aspect lies in less than all the features of the previous single embodiment. Moreover, the embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, the technical features in different embodiments can be freely combined to form more embodiments. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present invention.

[0126] The above specific embodiments provide a detailed description of the objectives, technical means and beneficial effects of the present invention. It should be understood that the purpose of the detailed description is to enable those skilled in the art to understand the present invention more clearly, and it is not used to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a dry desulfurizing agent, characterized in that: include: Step A, roasting the white mud at a temperature between 850 and 1000° C.; Step B, mixing and grinding the roasted white mud and manganese slag to obtain a first semi-finished product material, comprising: Sub-step B1, obtaining an auxiliary agent solution, wherein the auxiliary agent is a sodium salt and / or a potassium salt, and the auxiliary agent is 5 to 10 parts by weight; Sub-step B2, wet grinding the calcined white mud, auxiliary agent solution and manganese slag; Sub-step B3, drying the wet-milled material to obtain a first semi-finished product material; Step C, roasting the first semi-finished product material at a temperature between 200 and 400° C. to obtain a second semi-finished product material; Step D, mixing and grinding the second semi-finished product material and the binder to obtain a dry desulfurization agent powder; Among them, by weight, white mud, 30 to 60 parts; manganese slag, 10 to 40 parts; binder, 5 to 20 parts.

2. The method for preparing a dry desulfurization agent according to claim 1, characterized in that: In step B, the auxiliary agent is selected from one or more of the following materials: potassium hydroxide, potassium sulfate, potassium carbonate, potassium aluminum sulfate, potassium silicate, potassium phosphate, potassium dihydrogen phosphate, sodium hydroxide, sodium sulfate, sodium carbonate, sodium bicarbonate, potassium silicate, sodium phosphate, and sodium dihydrogen phosphate.

3. The method for preparing a dry desulfurization agent according to claim 2, characterized in that: The step D comprises: Sub-step D1, grinding the second semi-finished product material; Sub-step D2, mixing the ground material with a binder and continuing to grind to obtain a dry desulfurization agent powder.

4. The method for preparing a dry desulfurization agent according to claim 3, characterized in that: The manganese slag is electrolytic manganese slag; and / or The white mud is a by-product of papermaking industry; and / or The binder is selected from one or more of the following materials: cement, desulfurized ash, gypsum, kaolin, bentonite, and diatomaceous earth.

5. The method for preparing a dry desulfurization agent according to claim 2, characterized in that: The step A comprises: sub-step A1, drying the white mud until the moisture content is less than 3%; sub-step A2, calcining the dried white mud in a muffle furnace for 3 to 5 hours; and / or In the step C, the second roasting process takes longer than 1 hour; and / or After step D, the method further includes: step E, adding water to the dry desulfurization agent powder, extruding and forming; and obtaining a dry desulfurization agent block after drying.

6. A dry desulfurization agent, characterized in that: The dry desulfurization agent is prepared by the preparation method of any one of claims 1 to 5.

7. Application of the dry desulfurizer as claimed in claim 6 in low-temperature and low-nitrogen oxide flue gas desulfurization scenarios; in, Low-temperature and low-nitrogen oxide flue gas refers to: flue gas temperature 20℃~320℃, SO2<1000ppm, NOx<25ppm, H2O<0.5%, electrolytic aluminum flue gas, dry coke quenching tail gas, and environmental dust removal gas.

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