CN106377993B - A method and device for removing SO2 from flue gas with pyrolusite slurry and its resource utilization - Google Patents

Abstract

The invention discloses a method for removing SO in flue gas by pyrolusite ₂ And its resource utilization method and device, wet grinding pyrolusite with ball mill, adding water, regulating pH value to obtain pyrolusite pulp, mixing with SO-containing material ₂ The flue gas is subjected to reverse contact reaction desulfurization in a desulfurizing tower, the flue gas is defogged and then enters the next working procedure, the circulating ore pulp flow is subjected to vacuum filtration, pH adjustment by lime and then filtration, filtrate pH adjustment sedimentation tank sedimentation, vacuum evaporation crystallization solid-liquid separation and filtrate carbonization solid-liquid separation; the invention uses manganese ore pulp to remove SO in the flue gas ₂ At the same time SO ₂ The manganese sulfate and manganese carbonate react with manganese dioxide in manganese ore to generate manganese sulfate, and the manganese sulfate monohydrate and the manganese carbonate with high added value are obtained through the processes of purification, evaporative crystallization, mother liquor carbonization and the like, SO that SO in flue gas is treated ₂ Treating, preventing secondary pollution of flue gas, generating high added value product, and solving SO ₂ And obtains economic benefit.

Description

A method and device for removing SO2 from flue gas with pyrolusite slurry and its resource utilization

technical field

The invention relates to a method and device for removing _SO2 in flue gas from pyrolusite and its resource utilization, which can achieve the purpose of pollution control with raw ore and obtain high value-added products at the same time, belonging to the technical field of environmental protection.

Background technique

Flue gas desulfurization methods can be roughly divided into dry desulfurization and wet desulfurization according to the phase of desulfurization agent. At present, there are more than 200 kinds of flue gas desulfurization technology processes at home and abroad, and there are only more than ten kinds of processes and supporting equipment with industrial application value. Wet desulfurization is the most commonly used because of its simple operation and low cost. In the wet desulfurization technology, although the lime-limestone method is the most mature technology at present, the desulfurization efficiency of this process is high (the desulfurization rate is above 90%), the absorbent is cheap and the source is wide, but its system is complicated, the investment and energy consumption are large, and the production The application value of the waste residue is not great, and it is easy to cause secondary pollution; although the by-products of the ammonia water absorption method (amic acid method) can be used as fertilizer, it is accompanied by ammonia volatilization loss during desulfurization, and is limited by the ammonia source; other sodium methods or double The cost of the alkaline method is also high, and the value of the by-products is not very valuable. The enterprise is under great economic pressure. With the improvement of environmental protection regulations, it is imperative to find new desulfurization processes and equipment.

China is rich in manganese resources, widely distributed, and low in price. Using manganese ore slurry to remove sulfur dioxide in flue gas can not only eliminate environmental pollution, but also can recycle SO ₂ . At the same time, it can increase the added value of pyrolusite, and enterprises can obtain additional economic benefits.

The invention utilizes manganese ore slurry to remove _SO2 in flue gas, and simultaneously proposes methods, approaches and equipment for purifying and separating products after the reaction of _SO2 and pyrolusite, and further producing high value-added manganese sulfate and manganese carbonate.

The characteristics of the _present invention are: (1) use manganese ore pulp as desulfurizer to treat SO in the flue gas , prevent the secondary pollution of flue gas, and realize the purpose of waste pollution control; (2) in the desulfurization process, The desulfurized slurry is filtered through a slurry pump to a vacuum filter, then heated in a purification tank, added lime to adjust pH, filtered to remove manganese dithionite, then added ammonia water in a neutralization tank, clarified and precipitated, and filtered to remove other metal impurities to obtain Manganese sulfate clear liquid, the clear liquid is vacuum evaporated and crystallized, separated with a centrifuge while it is hot, and dried with microwaves to obtain manganese sulfate monohydrate; after evaporation, the mother liquor is added to the carbonization tank to produce manganese carbonate precipitation, separated with a centrifuge, and the filter cake Manganese carbonate is obtained by microwave drying; (3) Manganese ore pulp is used as a desulfurization agent, which has low operating costs and can be used for resource utilization while removing SO ₂ .

Contents of the invention

The object of the present invention is to provide a kind of manganese ore pulp to remove _SO in flue gas and its resource utilization method, concrete steps are as follows:

(1) Utilize the ball mill to wet-grind the pyrolusite, pass through a 200-mesh sieve, add water to make pyrolusite slurry, the solid content of the pyrolusite slurry is 18-22%, and adjust the pH value of the pyrolusite slurry to 3.5-4.5;

(2) The flue gas with a higher temperature first enters the waste heat exchanger to generate low-pressure steam for use in the evaporation process. After cooling down, the flue gas enters from the lower part of the desulfurization tower, and the pyrolusite slurry prepared in step (1) is pumped to the desulfurization tower for spraying. The flue gas and the sprayed manganese ore slurry react in reverse contact. After the flue gas is desulfurized, it comes out from the flue gas outlet. After passing through the demister, the flue gas enters the next process or is directly emptied. The slurry is circulated and sprayed, while spraying The slurry is replaced and supplemented, and the process is carried out continuously. The circulating slurry mainly contains manganese sulfate, followed by iron sulfate, and also contains a small amount of calcium, magnesium, iron, aluminum and a small amount of heavy metal ions, as well as distillate generated during the desulfurization process. Manganese sulfate, the slurry is vacuum filtered;

(3) Add lime to the filtrate obtained by filtering in step (2) to adjust the pH value to 4.5-5, and then heat it to 70-80°C with steam to decompose manganese dithionate, let it stand for precipitation, and filter the precipitate to obtain a purified filtrate ;

(4) Pour the purified filtrate of step (3) into the neutralization tank, add ammoniacal liquor, adjust the pH value to 5-5.5, make calcium, magnesium, iron, aluminum and a small amount of heavy metal ions generate hydroxide precipitates, and neutralize Put the liquid into the clarification sedimentation tank, the sediment is clarified, and further filtered with an evaporating filter to obtain the clear liquid;

(5) the clear liquid of step (4) is carried out vacuum evaporation crystallization with vacuum evaporator, and vacuum tightness is 0.07～0.08MPa, and temperature is 70～80 ℃, and manganese sulfate monohydrate mass percent concentration is concentrated to 38～40%, while heat for centrifugation, and the filter residue is dried to obtain manganese sulfate monohydrate;

(6) After the filtrate obtained in step (5) is to be cooled, add soda ash to produce manganese carbonate precipitation, carry out solid-liquid separation, and dry the filter residue to obtain manganese carbonate. The separated filtrate is heated with direct steam in the ammonia distillation tower, and the mixture of ammonia and steam Through the shrinker, the outlet temperature of the shrinker is controlled, and the ammonia returns to the neutralization tank for recycling.

In step (6), the outlet temperature of the shrinker is controlled to be 80-95°C.

Another object of the present invention is to provide the described manganese ore slurry to remove SO in the flue gas ₂ and resource utilization device, comprising pressurized blower 1, desulfurization tower 2, mist eliminator 3, slurry pump 14, circulating pump 5, adjusting Slurry tank 6, desulfurization slurry storage tank 7, slurry pump II8, vacuum filter I9, receiving tank I10, vacuum pump I11, purification tank 12, screw pump 13, filter press 14, neutralization tank 15, clarification sedimentation tank 16, slurry Pump III17, vacuum filter II18, receiving tank II19, vacuum pump II20, vacuum evaporator 21, centrifuge I22, clear liquid pump 23, carbonization tank 24, centrifuge II25, mother liquor tank 26, ammonia pump 27, ammonia distillation tower 28, Shrinker 29, dryer I30, dryer II31;

The pressurized blower 1 is connected to the lower part of the desulfurization tower 2, the bottom of the desulfurization tower 2 is provided with a storage box, and the upper part is provided with a spray device, the storage tank is connected to the circulation pump 5, the circulation pump 5 is connected to the spray device, and the top of the desulfurization tower 2 There is a flue gas outlet, the flue gas outlet is connected to the demister 3, the bottom storage box of the desulfurization tower 2 is also connected to the slurry pump I 4, and the slurry pump I 4 is connected to the slurry mixing tank 6, and the bottom storage box of the desulfurization tower 2 is also connected to the desulfurization tower Slurry storage tank 7 is connected, desulfurization slurry storage tank 7 is connected with vacuum filter Ⅰ 9 through slurry pump Ⅱ 8, vacuum filter Ⅰ 9 is connected with receiving tank Ⅰ 10, the top of receiving tank Ⅰ 10 is connected with vacuum pump Ⅰ 11, and the bottom of receiving tank Ⅰ 10 Connect the purification tank 12, the bottom of the purification tank 12 is connected to the filter press 14 through the screw pump 13, the filter press 14 is connected to the neutralization tank 15, the bottom of the neutralization tank 15 is connected to the clarification sedimentation tank 16, and the clarification sedimentation tank 16 is connected to the vacuum through the slurry pump III17 Filter II 18, vacuum filter II 18 are connected to receiving tank II 19, the top of receiving tank II 19 is connected to vacuum pump II 20, the bottom of receiving tank II 19 is connected to vacuum evaporator 21, centrifuge I 22 in turn, and centrifuge I 22 is respectively connected Dryer II 31 and clear liquid pump 23 are arranged, clear liquid pump 23 connects carbonization tank 24, centrifuge II 25 successively, centrifuge II 25 connects drier I 30 and mother liquor tank 26 respectively, and mother liquor tank 26 connects ammonia gas pump 27, Ammonia distillation tower 28, shrinker 29, and shrinker 29 are connected with neutralization tank 15.

The clarification and sedimentation tank 16 is provided with a honeycomb sloping plate filler.

The mixing tank 6, the desulfurization pulp storage tank 7, the purification tank 12, the neutralization tank 15, and the carbonization tank 24 are all equipped with stirring paddles.

The ammonia-containing steam whose ammonia concentration is increased to about 10% through the shrinker 29 is returned to the neutralization tank 15 for recycling.

Advantages of the present invention:

1. Use pyrolusite as a desulfurizer to treat SO ₂ in flue gas, prevent secondary pollution of flue gas, achieve the purpose of pollution control with waste, and realize the purpose of environmental protection.

2. In the process of desulfurization, the manganese dioxide in the pyrolusite is utilized as a resource at the same time to generate manganese sulfate monohydrate and manganese carbonate with higher added value. While removing _SO2 , the pyrolusite resource is fully utilized to make the best use of it. The purpose of resource utilization has been realized.

3. The present invention uses manganese ore as a desulfurizer, and the operation cost is low; at the same time, resource utilization is carried out, and high value-added manganese sulfate monohydrate and manganese carbonate are produced through desulfurization products, which improves the enterprise and has obvious economic benefits, and recovers 1 ton of SO ₂ , which can The profit is 3,000 to 3,500 yuan, and the environmental pollution control does not cost money, but has good economic benefits.

Description of drawings

Fig. 1 is the structural representation of device described in the present invention;

In the figure, 1-pressurized blower; 2-desulfurization tower; 3-demister; 4-slurry pump I; 5-circulation pump; 6-slurry mixing tank; 9-vacuum filter I; 10-receiving tank I; 11-vacuum pump I; 12-cleaning tank; 13-screw pump; 14-filter press; 15-neutralization tank; III; 18-vacuum filter II; 19-receiving tank II; 20-vacuum pump II; 21-vacuum evaporator; 22-centrifuge I; 23-clear liquid pump; 24-carbonization tank; 25-centrifuge II; -Mother liquor tank; 27-Ammonia pump; 28-Ammonia distillation tower; 29-Splitter; 30-Dryer I; 31-Dryer II.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1

As shown in Figure 1, a device for manganese ore slurry to remove _SO2 in flue gas and its resource utilization, including pressurized blower 1, desulfurization tower 2, demister 3, slurry pump 14, circulation pump 5, slurry mixing Tank 6, desulfurization slurry storage tank 7, slurry pump II8, vacuum filter I9, receiving tank I10, vacuum pump I11, purification tank 12, screw pump 13, filter press 14, neutralization tank 15, clarification sedimentation tank 16, slurry pump III17, vacuum filter II18, receiving tank II19, vacuum pump II20, vacuum evaporator 21, centrifuge I22, clear liquid pump 23, carbonization tank 24, centrifuge II25, mother liquor tank 26, ammonia pump 27, ammonia distillation tower 28, separation Compressor 29, dryer I30, dryer II31; pressurized blower 1 is connected to the lower part of desulfurization tower 2, the bottom of desulfurization tower 2 is provided with a storage box, the upper part is provided with a spray device, the storage box is connected with circulation pump 5, and the circulation The pump 5 is connected to the spraying device, and the spraying device is provided with three rows at different heights, and each row has 5 nozzles. The top of the desulfurization tower 2 is provided with a flue gas outlet, and the flue gas outlet is connected to the demister 3. The bottom of the desulfurization tower 2 is filled with material The box is also connected to the pulp pump I 4, the pulp pump I 4 is connected to the pulp mixing tank 6, the bottom storage tank of the desulfurization tower 2 is also connected to the desulfurization pulp storage tank 7, and the desulfurization pulp storage tank 7 is connected to the vacuum filter I 9 through the pulp pump II 8 Connection, vacuum filter I 9 is connected to receiving tank I 10, the top of receiving tank I 10 is connected to vacuum pump 11, the bottom is connected to purge tank 12, the bottom of purge tank 12 is connected to filter press 14 through screw pump 13, and filter press 14 is connected to neutralization The tank 15, the bottom of the neutralization tank 15 is connected to the clarification sedimentation tank 16, and the clarification sedimentation tank 16 is equipped with a honeycomb sloping plate filler, the clarification sedimentation tank 16 is connected to the vacuum filter II 18 through the slurry pump III 17, and the vacuum filter II 18 is connected to the receiving tank II 19. The top of the receiving tank II 19 is connected to the vacuum pump II20, and the bottom of the receiving tank II 19 is connected to the vacuum evaporator 21 and the centrifuge I22 in turn, and the centrifuge I22 is respectively connected to the dryer II31 and the clear liquid pump 23, and the clear liquid pump 23 is connected to carbonization in turn Tank 24, centrifuge II 25, centrifuge II 25 are respectively connected to dryer II 30 and mother liquor tank 26, and mother liquor tank 26 is connected to ammonia pump 27, ammonia distillation tower 28, shrinker 29 in turn, splitter 29 and neutralization tank 15 Connecting, pulp mixing tank 6, desulfurization pulp storage tank 7, purification tank 12, neutralization tank 15, carbonization tank 24 are all equipped with stirring paddles.

Utilize above-mentioned device to carry out manganese ore pulp to remove _SO in the flue gas and the method for resource utilization thereof, concrete steps are as follows:

(1) Utilize the ball mill to wet-grind the pyrolusite, pass through a 200-mesh sieve, add water to make pyrolusite slurry in the slurry mixing tank 6, the solid content of the pyrolusite slurry is 20%, and the pH value of the pyrolusite slurry is adjusted to 3.5;

(2) _The flue gas is anode calcined flue gas, the flue gas volume is 60000Nm ³ /h, the SO ₂ content in ^{the flue gas is 3000mg/Nm 3 ,} and the average temperature is 220°C. High flue gas first enters the waste heat exchanger to generate low-pressure steam for use in the evaporation process. After cooling, the flue gas enters from the lower part of the desulfurization tower 2 through the pressurized blower 1, and pumps the pyrolusite slurry prepared in step (1) with the circulation pump 5 The desulfurization tower 2 is sprayed with a spraying device. The spraying device is equipped with three rows at different heights, and each row has 5 nozzles. The flue gas and the sprayed manganese ore slurry are reversely contacted and reacted. After the flue gas is desulfurized, it comes out of the flue gas outlet. After passing through the demister 5, the SO ₂ content of the flue gas is 90mg/Nm ³ , discharged up to the standard, directly emptied, the slurry is circulated and sprayed, and the slurry is discharged and replenished while spraying. The process is carried out continuously, and the main It is manganese sulfate, followed by ferric sulfate, which also contains a small amount of calcium, magnesium, iron, aluminum and a small amount of heavy metal ions, and also contains manganese dithionate generated in the desulfurization process. The slurry is stored in the desulfurization slurry storage tank 7. The pump II8 is pumped to the vacuum filter I9 for vacuum filtration, and the filtrate obtained by filtration enters the receiving tank I10;

(3) The filtrate obtained by step (2) filtration enters the purification tank 12 from the receiving tank I10, the purification tank 12 is provided with a stirring paddle, and lime is added while stirring to adjust the pH value of the slurry to 5, and then heated with the steam generated by the waste heat of the flue gas To 80 ℃, manganese dithionate is decomposed, the slurry is pumped to the filter press 14 through the screw pump 13, and the sediment is filtered, and the purified filtrate enters the neutralization tank 15;

(4) adding ammoniacal liquor to the purified filtrate in step (3) and tank 15, adjusting the pH value to 5, making calcium, magnesium, iron, aluminum and a small amount of heavy metal ions generate hydroxide precipitates, and putting the neutralizing solution into In the clarification settling tank 16, the honeycomb inclined plate packing is used for sedimentation and clarification, and the slurry pump III17 is used to pump the liquid to the vacuum filter II18 for further filtration, and the obtained clear liquid enters the receiving tank II19;

(5) Carry out vacuum evaporation and crystallization of the clear liquid in the receiving tank II19 of step (4) through the vacuum evaporator 21, the vacuum degree of the vacuum evaporator 21 is 0.08MPa, the temperature is 80°C, and the mass percentage concentration of manganese sulfate monohydrate is concentrated to 38%, centrifuge through centrifuge I22 while it is hot, and obtain manganese sulfate monohydrate after the filter residue is dried by dryer II31, and produce about 2000 tons of manganese sulfate monohydrate every year;

(6) After the filtrate gained by centrifugation in step (5) is to be cooled, it enters the carbonization tank 24 through the clear liquid pump 23 and then adds soda ash to produce manganese carbonate precipitation. Manganese, the filtrate enters the mother liquor tank 26, is pumped into the ammonia distillation tower 28 through the ammonia pump 27, and is heated by the steam generated by the waste heat of the direct flue gas. 80°C, the ammonia concentration reaches about 10%, returns to the neutralization tank for 15 cycles, and produces about 2100 tons of manganese carbonate per year.

Example 2

The manganese ore slurry described in this embodiment removes SO in the flue gas ₂ and the method for resource utilization thereof, adopts device and embodiment 1 except that two rows of spraying devices are arranged, and each row is provided with 7 nozzles, the others are the same, and the specific steps as follows:

(1) Utilize the ball mill to wet-grind the pyrolus ore, pass through a 200-mesh sieve, add water to make pyrolusite slurry in the pulp mixing tank 6, the solid content of the pyrolusite slurry is 22%, and the pH value of the adjusted pyrolusite slurry is 4;

(2) The flue gas is boiler flue gas in a power plant, the flue gas volume is 100,000Nm ³ / _h , the SO ₂ content in the flue ^{gas is 2000mg/Nm 3 ,} and the average temperature is 120°C. High flue gas first enters the waste heat exchanger to generate low-pressure steam for use in the evaporation process. After cooling, the flue gas enters from the lower part of the desulfurization tower 2 through the pressurized blower 1, and pumps the pyrolusite slurry prepared in step (1) with the circulation pump 5 To the desulfurization tower 2, the spraying device is used for spraying, and the flue gas and the sprayed manganese ore slurry are reversely contacted and reacted. After the flue gas is desulfurized, _it comes out from the flue gas outlet. The SO ₂ content of the flue gas after SO ₂ removal is 300mg/Nm ³ , the flue gas is discharged up to the standard, and is directly emptied. The slurry is sprayed in a circular manner, and the slurry is discharged and replenished while spraying. It is mainly manganese sulfate, followed by iron sulfate, and also contains a small amount of calcium, magnesium, iron, aluminum and a small amount of heavy metal ions, and also contains manganese dithionate generated during the desulfurization process. The slurry is stored in the desulfurization slurry storage tank 7. The pulp pump II8 is pumped to the vacuum filter I9 for vacuum filtration, and the filtrate obtained by filtration enters the receiving tank I10;

(3) The filtrate that step (2) filters to obtain enters in the purification tank 12 from receiving tank I10, and the purification tank 12 is provided with a stirring paddle, adds lime while stirring and regulates the slurry pH value to 4.5, then heats to 70 ℃ with steam, makes Manganese dithionate is decomposed, the slurry is pumped to the filter press 14 through the screw pump 13, the sediment is filtered, and the purified filtrate enters the neutralization tank 15;

(4) add ammoniacal liquor to the purified filtrate in neutralizing tank 15 in step (3), adjust the pH value to 5.5, make calcium, magnesium, iron, aluminum and a small amount of heavy metal ions generate hydroxide precipitates, put the neutralizing solution into In the clarification settling tank 16, the honeycomb sloping plate filler is used for long-term precipitation clarification, and the liquid is pumped to the vacuum filter II18 by the slurry pump III17 for further filtration, and the clear liquid is obtained and enters the receiving tank II19;

(5) carry out vacuum evaporation and crystallization through vacuum evaporator 21 with the clear liquid in step (4) receiving tank II19, the vacuum degree of vacuum evaporator 21 is 0.07MPa, and temperature is 70 ℃, and manganese sulfate monohydrate concentration is concentrated to 39% , Centrifuge through the centrifuge I22 while it is hot, and obtain manganese sulfate monohydrate after the filter residue is dried by the dryer II31, and produce about 180 tons of manganese sulfate monohydrate every year;

(6) After the filtrate gained by centrifugation in step (5) is to be cooled, it enters the carbonization tank 24 through the clear liquid pump 23 and then adds soda ash to produce manganese carbonate precipitation. Manganese, the filtrate enters the mother liquor tank 26, is pumped into the ammonia distillation tower 28 through the ammonia pump 27, and is heated by the steam generated by the waste heat of the direct flue gas. 90 ℃, the ammonia concentration reaches about 10%, returns to the neutralization tank for recycling, and produces about 1900 tons of manganese carbonate per year.

Example 3

The manganese ore slurry described in this embodiment removes _SO in the flue gas and its resource utilization method adopts the same device as that in Example 1, and the specific steps are as follows:

(1) Utilize the ball mill to wet-grind the pyrolusite, pass through a 200-mesh sieve, add water in the slurry mixing tank 6 to make pyrolusite slurry, the solid content of the pyrolusite slurry is 18%, and the pH value of the pyrolusite slurry is adjusted to 4.5;

(2) The flue gas is flue gas from a sulfuric acid production plant, the sulfuric acid tail gas treatment capacity is 200,000Nm ³ /h, the SO ₂ content in the tail gas of the two-turn and two-suction sulfuric acid unit is 650mg/Nm ³ , and the tail gas outlet requires that the SO ₂ content is below 100mg/Nm ³ , The desulfurization efficiency is above 85%. The flue gas with higher temperature first enters the waste heat exchanger to generate low-pressure steam for use in the evaporation process. After cooling down, the flue gas enters from the lower part of the desulfurization tower 2 through the pressurized blower 1, and the obtained in step (1) The pyrolusite slurry is pumped to the desulfurization tower for spraying, and the flue gas reacts with the sprayed manganese ore slurry in reverse contact. After the flue gas is desulfurized, it comes out from the flue gas outlet. After passing through the demister 5, the _SO2 in the flue gas is absorbed and removed. The SO ₂ content of the flue gas after SO ₂ is 300mg/Nm ³ , and the flue gas reaches the standard and is discharged into the next process. The slurry is circulated and sprayed, and the slurry is discharged and replenished while spraying. It is mainly manganese sulfate, followed by iron sulfate, and also contains a small amount of calcium, magnesium, iron, aluminum and a small amount of heavy metal ions, and also contains manganese dithionate generated during the desulfurization process. The slurry is stored in the desulfurization slurry storage tank 7. The pulp pump II8 is pumped to the vacuum filter I9 for vacuum filtration, and the filtrate obtained by filtration enters the receiving tank I10;

(3) The filtrate obtained by step (2) filtration enters the purification tank 12 from the receiving tank 110, the purification tank 12 is provided with a stirring paddle, adds lime to adjust the pH value of the slurry to 4.5 while stirring, and then heats to 75 DEG C with steam to make Manganese dithionate is decomposed, the slurry is pumped to the filter press 14 through the screw pump 13, the sediment is filtered, and the purified filtrate enters the neutralization tank 15;

(4) adding ammoniacal liquor to the purified filtrate in step (3) and tank 15, adjusting the pH value to 5, making calcium, magnesium, iron, aluminum and a small amount of heavy metal ions generate hydroxide precipitates, and putting the neutralizing solution into In the clarification settling tank 16, the honeycomb inclined plate packing is used for sedimentation and clarification, and the slurry pump III17 is used to pump the liquid to the vacuum filter II18 for further filtration, and the obtained clear liquid enters the receiving tank II19;

(5) carry out vacuum evaporation and crystallization through vacuum evaporator 21 with the clear liquid in step (4) receiving tank II19, the vacuum degree of vacuum evaporator 21 is 0.08Mpa, and temperature is 75 ℃, manganese sulfate monohydrate mass percent concentration concentration to 40%, centrifuge through the centrifuge I22 while it is hot, and obtain manganese sulfate monohydrate after the filter residue is dried by the dryer II31, and produce about 1,800 tons of manganese sulfate monohydrate every year;

(6) After the filtrate gained by centrifugation in step (5) is to be cooled, it enters the carbonization tank 24 through the clear liquid pump 23 and then adds soda ash to produce manganese carbonate precipitation. Manganese, the filtrate enters the mother liquor tank 26, is pumped into the ammonia distillation tower 28 through the ammonia pump 27, and is heated by the steam generated by the waste heat of the direct flue gas. 95 ℃, the ammonia concentration reaches about 10%, returns to the neutralization tank for recycling, and produces about 1,500 tons of manganese carbonate per year.

It should be understood that those skilled in the art can make improvements or transformations based on the above description, and all of them belong to the protection scope of the appended claims of the present invention.

Claims (4)

1. Removal of SO in flue gas from manganese ore pulp ₂ The method for recycling the same is characterized by comprising the following specific steps:

(1) Wet grinding pyrolusite, sieving with a 200-mesh sieve, adding water to prepare pyrolusite pulp, wherein the solid content of the pyrolusite pulp is 18-22%, and regulating the pH value of the pyrolusite pulp to be 3.5-4.5;

(2) Cooling the flue gas with higher temperature by a waste heat exchanger, then allowing the flue gas to enter from the lower part of a desulfurizing tower, pumping the soft manganese ore pulp prepared in the step (1) to the desulfurizing tower for spraying, allowing the flue gas to reversely contact and react with the sprayed manganese ore pulp, allowing the flue gas to exit from a flue gas outlet after desulfurization, allowing the flue gas to enter into the next working procedure or be directly emptied after demisting, allowing slurry to circularly spray, performing slurry replacement and supplement while spraying, allowing the process to continuously perform, and performing vacuum filtration on the recycled slurry;

(3) Adding lime into the filtrate obtained by filtering in the step (2) to adjust the pH value to 4.5-5, heating to 70-80 ℃, and filtering the precipitate to obtain purified filtrate;

(4) Adding ammonia water into the purified filtrate obtained in the step (3), adjusting the pH value to be 5-5.5, settling and clarifying, and carrying out vacuum filtration to obtain clear liquid;

(5) Carrying out vacuum evaporation crystallization on the clear liquid obtained in the step (4), wherein the vacuum degree is 0.07-0.08 MPa, the temperature is 70-80 ℃, the mass percent concentration of the manganese sulfate monohydrate is concentrated to 38-40%, and the manganese sulfate monohydrate is obtained after centrifugal separation while the manganese sulfate monohydrate is hot and filter residues are dried;

(6) Adding sodium carbonate into the filtrate obtained by the separation in the step (5) after cooling, generating precipitate, performing solid-liquid separation, drying filter residues to obtain manganese carbonate, controlling the outlet temperature of a separator by the separation of the filtrate, and returning the obtained ammonia gas to the step (4) for recycling;

the manganese ore pulp removes SO in the flue gas ₂ And the device of the recycling method comprises a pressurizing blower, a desulfurizing tower, a demister, a slurry pump I, a circulating pump, a slurry mixing tank, a desulfurizing slurry storage tank, a slurry pump II, a vacuum filter I, a receiving tank I, a vacuum pump I, a purifying tank, a screw pump, a filter press, a neutralizing tank, a clarifying sedimentation tank, a slurry pump III, a vacuum filter II, a receiving tank II, a vacuum pump II, a vacuum evaporator, a centrifuge I, a clear liquid pump, a carbonization tank, a centrifuge II, a mother liquid tank, an ammonia pump, an ammonia distillation tower, a separator, a dryer I and a dryer II;

the pressurized blower is connected with the lower part of the desulfurizing tower, the bottom of the desulfurizing tower is provided with a material containing tank, the upper part of the desulfurizing tower is provided with a spraying device, the material containing tank is connected with a circulating pump, the circulating pump is connected with a spraying device, a flue gas outlet at the top of the desulfurizing tower is connected with a demister, the material containing tank at the bottom of the desulfurizing tower is also connected with a slurry pump I, the slurry pump I is connected with a slurry pump I through the slurry pump II, the vacuum filter I is connected with a receiving tank I, the receiving tank I is connected with a vacuum pump I, the bottom of the receiving tank I is connected with a purifying tank, the bottom of the purifying tank is connected with a filter press through a screw pump, the filter press is connected with a neutralization tank, the neutralization tank is connected with a clarification sedimentation tank, the clarification sedimentation tank is connected with a vacuum filter II through the slurry pump III, the vacuum filter II is connected with a vacuum evaporator and a centrifuge I sequentially, the centrifuge I is connected with a dryer II and a cleaning pump sequentially, the carbonization tank and the centrifuge II are sequentially connected with a mother liquor tank respectively, the centrifuge II is connected with an ammonia centrifuge, an ammonia pump, an ammonia separator, a separator and a distillation tank are sequentially connected with a distillation tank.

2. The method for removing SO from flue gas by manganese ore pulp according to claim 1 ₂ And a method for recycling the same, which is characterized in that the outlet temperature in the step (6) is 80-95 ℃.

3. The method for removing SO from flue gas by manganese ore pulp according to claim 1 ₂ The method for recycling the waste water is characterized in that a honeycomb sloping plate filler is arranged in the clarification and sedimentation tank.

4. The method for removing SO from flue gas by manganese ore pulp according to claim 1 ₂ The method for recycling the desulfurization slurry is characterized in that stirring paddles are arranged in the slurry mixing tank, the desulfurization slurry storage tank, the purification tank, the neutralization tank and the carbonization tank.

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