WO2008052465A1

WO2008052465A1 - A sintered flue gas wet desulfurizing and dedusting process

Info

Publication number: WO2008052465A1
Application number: PCT/CN2007/070951
Authority: WO
Inventors: Xiaolin Shen; Hongzhi Shi; Guomin Shi; Daoqing Liu; Yu Lin; Lei Shi; Ruyi Wang
Original assignee: Baoshan Iron & Steel Co., Ltd.
Priority date: 2006-10-25
Filing date: 2007-10-25
Publication date: 2008-05-08
Also published as: KR101140748B1; CN100534587C; KR20090112628A; BRPI0718179A2; CN101168118A; BRPI0718179B1

Abstract

A sintered flue gas wet desulfurizing and dedusting process comprises: defluorinating the compressed flue gas by alkali and cooling to under 80°C, introducing the flue gas in a tower for desulfurizing and absorbing(9), rotating into a slurry pool(14) by cyclones in jet pipes of the tower, breaking the flue gas in the slurry and mixing the gas with the slurry to complete the desulfurizing and dedusting process, demisting the flue gas and reheating by exhaust steam, and discharging the purified flue gas from a chimney(1).

Description

Sintering flue gas wet desulfurization and dust removal process

The invention relates to a sintering flue gas desulfurization and dust removal process, in particular to a wet desulfurization and dust removal process for steel metallurgy sintering flue gas. Background technique

At present, the sintering flue gas has become a major iron and steel smelting so ₂ emission sources, and domestic research on sintering flue gas desulphurization technology basically blank, which has become a bottleneck restricting the development of China's iron and steel industry.

To solve the problem of sintering flue gas emissions so _2, the existing countermeasures are mainly two.

First, low-sulfur fuel is used or a desulfurizing agent is added to the sintering raw material to reduce the emission of so _{2. For} example, Chinese patent CN1285415A performs desulfurization in combustion by adding an ammonia-containing compound to the sintering raw material. Due to the uneven distribution of the additive layer and the uneven temperature and concentration field in the combustion zone, the desulfurization efficiency of the method is not high.

The second is to desulfurize the sintering flue gas. The flue gas desulfurization technology includes dry and wet methods. The dry process includes a circulating fluidized bed method, a rotary spray method, an activated carbon adsorption method, an electron beam irradiation method, and the like. The desulfurization efficiency corresponding to the circulating fluidized bed method and the rotary spray method is not high, generally 70~85 %; and the by-product after purification is unstable and difficult to use calcium sulfite, such as long-term stacking will cause a large site. Occupied, and will cause secondary pollution. The activated carbon adsorption method has application performance in Japanese steel companies. For example, the No. 3 sintering machine of the Nagoya Iron and Steel Plant has set up a sintering flue gas desulfurization and denitration device using activated carbon adsorption. Although the method can achieve a desulfurization rate of 95% and a denitration rate of 40%, the activated carbon is expensive, the purification system and the absorbent regeneration system are complicated, and the investment and operation cost are extremely high. Japanese Patent JP52051846 discloses an electron beam irradiation process which can achieve a desulfurization and denitration rate of more than 80%, but which consumes a high amount of energy and has a risk of radiation leakage. The above several sintering flue gas dry desulfurization processes have no obvious effect on the removal of fine dust in the flue gas, and do not have corresponding measures for recovering the metal in the sintering flue gas.

Compared with the dry process, the sintering flue gas wet desulfurization process is more widely used. Japan's Kitakyushu Steel Works sprayed magnesium hydroxide solution into the sintering flue gas to convert S0 ₂ to magnesium sulfate, which was then separated from the sintering process by a scrubber. Japanese Keihin sintered iron flue gas desulfurization using the ammonia-ammonium sulfate method, this method is useless coke oven gas and ammonia sintering reaction S0 ₂ in the flue gas recovered ammonium sulfate. First, the S0 ₂ solution is absorbed by ammonium sulfite solution (concentration: 3%) to form ammonium hydrogen sulfite, and the absorption liquid is sent to the coking plant to absorb NH ₃ in the coke oven gas to form ammonium sulfite, which is then sent back to the sintering. Factory to cycle Reciprocal use. Limestone-gypsum method is used in the sinter plants in Chiba, Mizushima, Kashima, and Kobe in Japan. This type of process equipment was built in the 1970s. It adopts the most traditional limestone-gypsum process in the early stage. The level of process equipment is relatively backward, and the cost and operation cost are relatively high. Experts in the industry have always believed that foreign technology is complicated and economical, and it is not desirable to operate in China.

Key equipment for wet desulfurization The absorption towers are in different forms, and the desulfurization efficiency, system cost, operating cost, and system operation stability are also different. At present, the limestone-gypsum absorption tower, which is relatively mature and widely used in the world, is a spray tower. This type of tower has been widely used in thermal power units of 300,000 kilowatts or more at home and abroad. However, unlike the flue gas of coal-fired boilers, the sintering flue gas has the following characteristics:

(1) The concentration of S0 _{2 in the} sintering flue gas is relatively low (generally 300~1000mg/Nm ³ ), and the lower limit is even lower than that of the flue gas after the wet desulfurization of the coal-fired boiler; The concentration of S0 ₂ fluctuates greatly. These characteristics determine the desulfurization technology for sintering flue gas desulfurization with high efficiency and low investment. The gas-liquid mass transfer efficiency of the spray tower is generally high. To remove such a low concentration of S0 ₂ , it is necessary to ensure that the spray slurry is sufficiently covered in the cross section of the absorption tower, and even the coverage between the spray layer and the layer exceeds 200%. Therefore, the corresponding liquid-gas ratio (W/G) is large (generally W/G is 12 to 20), the power consumption is large, and the economy is poor.

(2) Compared with the flue gas of coal-fired boilers, the particle size of dust particles in the sintering flue gas is small, and the fraction of sub-micron dust is high. The traditional spray tower has low dust removal efficiency in this particle size range. .

(3) The temperature of the sintering flue gas from the electrostatic precipitator is relatively low (85~150 °C), which makes the regenerative gas heat exchanger (GGH) at the front of the spray tower unable to remove the purified flue gas. Heat again to above 80 °C. Moreover, the composition of the sintering flue gas is complicated, which will worsen the working condition of the GGH which is more likely to be blocked, thereby reducing the availability of the system.

(4) The composition of the sintering flue gas is complex. Depending on the sinter ore, the sulphur gas per cubic meter contains tens or even hundreds of milligrams of HF gas. In addition, the content of HC1 gas and heavy metals in the sintering flue gas is high, and the dust adsorption and adsorption are strong. These characteristics of the sintering flue gas put forward higher requirements for anti-corrosion and anti-scaling performance of the absorption tower and the whole desulfurization system, and wastewater treatment.

Therefore, considering the particularity of the sintering flue gas, the wet desulfurization process and the spray tower, which are widely used in desulfurization of power plants, are completely copied to the flue gas desulfurization, which is not necessarily feasible and uneconomical. Summary of the invention

The technical problem to be solved by the invention is to provide a wet flue gas desulfurization and dedusting process for sintering flue gas, which has high efficiency of sintering flue gas desulfurization and dust removal, low energy consumption, low operation cost, small volume, low cost, reliable operation, etc. Features to ease the impact of sintering flue gas so ₂ emissions on the ecological environment and human health, and to reduce the economic losses and environmental pressures businesses. The process is suitable for different sintering flue gas volumes, and can adapt to a wide range of sintering flue gas temperature and smoke composition changes.

The steps of the technical solution of the present invention to solve the above technical problem include:

1) After the sintering flue gas from the precipitator is boosted by the booster fan, it is first cooled and defluorinated, that is, the HF, HC1 gas and large particle soot in the flue gas are basically removed by the alkali solution, and the temperature of the flue is lowered. Up to 80 °C;

2) the flue gas enters the desulfurization absorption tower, and the S0 ₂ in the flue gas reacts with the alkali liquid in the absorption tower;

3) The purified flue gas enters the mist eliminator to remove droplets from the flue gas, and is then reheated and discharged from the chimney.

Different from coal-fired boiler flue gas, tens or even hundreds of milligrams of HF gas per cubic meter of sintering flue gas varies depending on the sinter. The HF gas is extremely corrosive, and the hydrofluoric acid formed after being dissolved in water will cause serious corrosion to the internal components of the absorption tower and the anticorrosive material, and is particularly destructive to the FRP material, thereby reducing the reliability of the operation of the desulfurization system. In order to ensure the safe operation of the absorption tower, reduce the grade of anti-corrosion materials in the tower and provide the best reaction conditions for subsequent desulfurization, the flue gas is cooled and defluorinated before entering the absorption tower. During this process, the flue gas reacts with the fresh alkali solution from the lye tank to substantially remove the HF gas therein; at the same time, the evaporation of the lye and the process water reduce the temperature of the flue gas to below 80 ° C for subsequent desulfurization. Provide the best reaction conditions. If the absorption tower is working above 8CTC for a long time, no matter what anti-corrosion materials, there will be problems of fatigue aging and reduced service life. Therefore, the intake air temperature of the absorption tower is lowered to below 80 ° C, which is beneficial to the long-term use of the absorption tower material, and ensures the thermal safety of the absorption tower. Since the HC1 gas in the flue gas also has an extremely high solubility, most of the HC1 is removed during cooling defluorination, and large particles of soot are removed.

The flue gas after cooling and defluorination enters the high-efficiency desulfurization absorption tower unique to the process, and the S0 ₂ therein is substantially removed by reacting with the alkali liquid in the absorption tower. Since the concentration of S0 ₂ in the sintering flue gas is low, as in the case of the conventional spray tower, high power consumption is required to achieve higher desulfurization efficiency. Therefore, this process uses a specially designed desulfurization absorber. The absorption tower does not adopt the traditional slurry circulation cycle and the upper spray method, but allows the flue gas after cooling fluorine to be uniformly transferred from the middle of the absorption tower into a plurality of vent pipes arranged in a certain manner in the tower, the vent tube The lower vent is immersed under the surface of the absorbent slurry. After the flue gas passes through the swirling device in the jet tube, it generates a strong rotation, and then rushes from the vent hole into the absorption tower slurry tank. The bubbles are mutually opposed, rotated, sheared and broken after being flushed out, in the slurry. Be further Breaking, enhanced gas-liquid contact effect, in this process can achieve more than 95% desulfurization efficiency and more than 99% of dust removal efficiency. The lower part of the absorption tower slurry tank is a stirring mechanism and an oxidizing device. The purpose of the agitation mechanism is to prevent precipitation of gypsum at the bottom of the slurry tank; the function of the oxidation mechanism is to further oxidize the by-products of the reaction into usable gypsum crystals. When the concentration of the gypsum slurry at the bottom of the absorption tower slurry tank reaches a set value, the gypsum slurry is discharged from the bottom of the tower and enters a subsequent gypsum dewatering system.

The purified flue gas enters the demister, and the flue gas after defogging achieves a good droplet separation effect. The flue gas after the de-fog is reheated and discharged from the chimney.

As an improvement of the present invention, the gypsum slurry produced after desulfurization is subjected to two-stage dehydration, and the water content is reduced to less than 10%, and the two-stage dehydration is respectively performed by a screw discharge sedimentation centrifuge or a hydrocyclone separator and a vacuum belt conveyor. . .

As an improvement of the present invention, the sintering flue gas is cooled and defluorinated, and is carried out in a cooling defluorinator. This will better ensure that the temperature of the smoke is rapidly reduced to below 80 ° C, while substantially removing the HF gas from the flue gas.

As a further improvement of the invention, the temperature of the flue gas in step 1) is cooled by the evaporation of the lye and the process water in the cooled defluorinator.

As another improvement of the present invention, the waste water generated in the cooling defluorinator is directly discharged into the wastewater treatment system. The waste water generated in the cooling defluoridation unit contains F_, Cl_, heavy metal-containing soot and a small amount of calcium sulphite, and the amount of waste water is not large, so it is directly discharged into the wastewater treatment system, and no longer enters the subsequent desulfurization tower. Thereby, the chloride ion and heavy metal enrichment effects of the desulfurization system are greatly alleviated, the chlorine corrosion problem of the subsequent equipment is alleviated, and the grade of desulfurization by-product gypsum is improved.

As another improvement of the present invention, the waste water discharged from the cooling defluoridation device separates the heavy metal in the waste water by a process such as sedimentation and pH adjustment, and the dried heavy metal sludge is recovered by magnetic separation to recover the iron therein. The iron then returns to the sintering head to participate in the ore blending. Thereby increasing the resource utilization rate of the sintering system.

As another improvement of the present invention, in the desulfurization absorption tower of the step 2), the flue gas after cooling and defluorination is passed through the action of the swirling device in the gas injection tube in the absorption tower, and is rapidly swirled into the slurry pool, and the flue gas is The slurry is broken and thoroughly mixed with it, and the gas and liquid complete the desulfurization and dust removal process during the high-efficiency contact process. The high-efficiency desulfurization absorber in step 2) has no slurry circulation pump, so the operating cost is low. Moreover, the gas flow rate in the absorption tower is high, so the tower body structure is relatively compact and the floor space is small. Moreover, there is no moving parts and no nozzle inside the desulfurization absorption tower, thereby greatly reducing the clogging and fouling tendency of the absorption tower, and the system has high operational reliability and reduced maintenance. As a further improvement of the present invention, the reheating process of the flue gas after the demisting by the step 3) is carried out by using the sintering waste heat vapor of the system. The waste heat vapor generated during the cooling and sinter of the ring cooler is introduced into the steam flue gas reheater, so that the flue gas temperature is heated to 80 ° C and then discharged from the chimney. This method of using the residual heat of steam to replace the conventional regenerative gas heat exchanger (GGH) eliminates the expensive GGH and avoids the occurrence of clogging, thereby improving the stability of the system operation and reducing the investment. cost.

As the above alkali solution, can be used as long as the basic substance the reaction of S0 ₂ is configured to solution or slurry. Commonly used desulfurized alkaline materials are calcium-based absorbents such as limestone and slaked lime, which have a good price advantage. Other basic compounds such as sodium, magnesium and ammonium may also be used.

The gypsum in this patent refers to any sulfate formed after the above-mentioned alkaline substance is desulfurized.

Since the present invention adopts the above technical solution, it has the following advantages and positive effects compared with the prior art:

1 can adapt the amount of sintering gas, flue gas temperature and flue gas so ₂ concentration in a wide range of requirements, more than 95% desulfurization efficiency, collection efficiency of 99%, in particular for submicron dust good Remove the effect.

2. Separate a defluorination unit in front of the absorption tower to remove most of the HF gas while lowering the temperature of the smoke below 80 °C. On the basis of providing optimal reaction conditions for subsequent desulfurization, the measure ensures the thermal safety of the absorption tower, effectively reduces the corrosion problem in the tower, and improves the reliability of the operation of the desulfurization system.

3. Simultaneously remove most of the HC1 gas and large particles of soot in the cooling defluorinator, reduce the chloride ion and heavy metal enrichment effect of the desulfurization system, alleviate the chlorine corrosion problem of the subsequent equipment, and improve the desulfurization by-product gypsum. grade.

4. Treat a small amount of wastewater generated by the cooling defluoridation unit to reduce the amount of wastewater treatment. At the same time, the heavy metals in the wastewater, especially iron, are recovered and sent to the nose to participate in the ore blending, which improves the resource utilization rate of the sintering system.

5. Compared with the traditional spray tower, the absorption tower inside the process has no moving parts and no nozzle inside, which reduces the possibility of scale formation, high reliability of equipment operation and greatly reduced maintenance.

6. Compared with the traditional spray tower, the absorption tower used in this process has no slurry circulation pump, so the operation cost is low. Moreover, the gas flow rate in the absorption tower is high, so the tower body structure is relatively compact and the floor space is small.

7. The absorption tower used in this process, the flue gas is rushed into the slurry pool at high speed, and the gas-liquid contact effect is good. Desulfurization and dust removal efficiency is high.

8. In view of the characteristics of sintering flue gas, the use of sintering waste heat steam to reheat the traditional regenerative gas gas heater, eliminating the expensive GGH and avoiding the occurrence of blockage, improving the stability of the system operation and reducing The investment cost. BRIEF abstract

Figure 1 is a schematic view of the process flow of the present invention.

2 is a schematic diagram of a process system of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

As can be seen from Fig. 1 to Fig. 2, the sintering flue gas to be treated from the electrostatic precipitator 6 is first pressurized by the turbocharger 7, and then enters the cooling defluoridation unit 8 located at the front of the desulfurization absorption tower 9 for defluorination cooling. At this stage, the flue gas is reacted with the fresh alkali solution sprayed from the limestone slurry tank 14 into the cooling defluoridation unit 8 and washed by the process water sprayed from the process water tank 13, so that the HF gas in the sintering flue gas can be substantially removed. At the same time, the temperature of the flue gas is reduced to below 80 ° C, which provides the best reaction conditions for subsequent desulfurization and ensures the thermal safety of the absorption tower. Since the HC1 gas in the flue gas also has an extremely high solubility, most of the HC1 is removed while cooling the defluorination, while removing large particles of soot.

Among them, the wastewater generated by the cooling defluoridation unit 8 is directly discharged into the wastewater treatment system 15 . The waste water generated in the cooling defluoridation unit 8 contains F_, Cl_, heavy metal-containing soot and a small amount of calcium sulfite, and the amount of waste water is not large, so it is directly discharged into the wastewater treatment system, and no longer enters the subsequent desulfurization tower. Thereby, the chloride ion and heavy metal enrichment effects of the desulfurization system are greatly reduced, the chlorine corrosion problem of the subsequent equipment is alleviated, and the grade of desulfurization by-product gypsum is improved.

The waste water discharged from the cooling defluoridation unit 8 is separated from the heavy metal in the wastewater by a process such as sedimentation and pH adjustment in the wastewater treatment system 15, and the dried heavy metal sludge is magnetically selected by the magnetic separator 16 to recover the iron therein. The recovered iron is returned to the head of the sintering machine 4 to participate in the ore blending. Thereby increasing the resource utilization of the sintering system. The remaining heavy metals may be further utilized or sent out as appropriate.

The flue gas cooled from the cooling defluoridation device 8 uniformly enters a plurality of vent pipes arranged in a certain regular pattern in the desulfurization absorption tower 9, and the flue gas rotates downwardly in the tube by the action of the swirling device in the lance tube. It is sprayed into the lye along the tangential direction of the vent hole in the lower part of the lance. Due to the special arrangement of the vent tube, the jetted bubbles produce severe effects such as hedging, shearing, swirling, and crushing in the slurry. Thereby, a gas-liquid two-phase turbulent zone with high mixing and strong interference is generated, which greatly improves the gas-liquid mass transfer effect. , So ₂ in the flue gas is dissolved in the liquid phase in the process of chemical absorption reaction, after removing the dust remaining in the flue gas are in contact with the liquid. The bubbles in the turbulent zone continue to flicker up until they rupture on the top of the slurry, completing the entire flue gas scrubbing process. The calcium sulfite formed after the reaction is further oxidized into calcium sulfate in the absorption tower slurry storage tank by the air blasted by the oxidation fan 12, and crystallized to form gypsum. The agitator 5 at the bottom of the column is always running to prevent the gypsum slurry from settling. In addition to the commonly used carbon steel lining glass flakes or rubber lining materials, the desulfurization absorption tower of the present invention may also adopt integral FRP (when the amount of flue gas is small) or carbon steel lining FRP (when the amount of flue gas is large) ) to manufacture. FRP material has superior anti-corrosion and anti-fouling performance, and low cost; the defluorination cooling section 8 provides a reliable guarantee for the thermal safety and anti-corrosion safety of the FRP absorption tower.

The flue gas after desulfurization exits the desulfurization absorption tower 9 and enters the mist eliminator 10 for gas-liquid separation. The flue gas from the mist eliminator 10 needs to be heated to 80 ° C in the steam flue gas reheater 3 before being discharged into the chimney 1 by the induced draft fan 2 . The steam flue gas reheater uses a ring cooler to cool the waste heat vapor generated during the sintering process as a reheat heat source.

The gypsum slurry generated by the reaction of the flue gas in the desulfurization absorption tower 9 and the alkali solution enters the gypsum dehydration system 1 1 and is dehydrated by two stages. The two-stage dewatering is performed by a screw discharge sedimentation centrifuge or a hydrocyclone separator and a vacuum belt conveyor, respectively. Since the concentration of S0 _{2 in the} sintering flue gas is low, the gypsum output is not high. In order to reduce the load of the gypsum treatment system and facilitate dehydration, a method of intermittent ointment is adopted. That is, the density of the gypsum slurry is regularly monitored by a densitometer. When the requirements for the ointment are met, the gypsum slurry is taken out from the bottom of the absorption tower by a gypsum removal pump, pumped to the gypsum slurry tank, and then sent to the screw discharge by the gypsum dewatering pump. The centrifuge (or hydrocyclone) performs the first-stage dewatering, and the gypsum thickened by the first-stage dewatering is further dehydrated to a moisture content of about 10% by a vacuum belt conveyor.

The wet flue gas desulfurization and dust removal process of the sintering flue gas is controlled by a DCS distributed control system.

Test apparatus for a sintering hot flue gas desulfurization: test from a sintering plant flue gas discharge flue gas temperature of 150 ° C, flow rate of 90000m ³ / h, converted into dry standard 57800 (N. d. m ³ ) /h. The concentration of S0 _{2 in the} flue gas is 300~800 mg/Nm ³ , the concentration of HF is 50~90 mg/Nm ³ , the concentration of HC1 is 80~150 mg/Nm ³ , and the dust concentration is 50~120 mg/Nm ³ . Tobacco temperature was lowered to 80 ° C is cooled after the defluorination; when the original flue is 15CTC, cooling off the injected limestone slurry in an amount of fluorine is 120~250 kg / h, the amount of cooling water is nicotinamide 2 t / h ₀ Cooling The gas enters the absorption tower for reaction, the diameter of the tower is 4 m, the height of the slurry surface is 3.5 m, and the number of the jet tubes is 28, and the swirling device is located in the middle of the jet tube. The absorbent is 15%wt limestone slurry, the amount of slurry is 250~500kg/h, stone The limestone consumption is 37.6~75.2kg/ho. The amount of 20%wt gypsum discharged is 0.3~0.6 m ³ /h. The amount of oxidizing air was 3 m ³ /min, and the oxidizing air head was 49 kPa. The flue gas temperature after desulfurization is 50 ° C, and the water droplet carrying capacity in the flue gas after two-stage demisting is less than 75 mg/Nm ³ ; the flue gas temperature rises to 80-90 ° C after reheating.

The desulfurization efficiency of the above desulfurization system is over 95%, the defluorination and dechlorination efficiency is over 95%, and the dust removal efficiency is 99%. The amount of discharged gypsum slurry is 0.3~0.6 m ³ /h, and the water content after dewatering by the horizontal screw discharge sedimentation centrifuge is 50%~60%, and the moisture content of the gypsum after dehydration by the vacuum belt machine is less than 10%. The resulting gypsum crystal particles have a particle size of 46 to 100 μm.

Claims

Rights request

A sintering flue gas wet desulfurization and dust removal process, comprising the steps of:

The wet flue gas desulfurization and dedusting process according to claim 1, wherein the cooling and defluorination process in the step 1) is carried out in a cooling defluorinator.

3. The sintering flue gas wet desulfurization and dust removal process according to claim 2, wherein: step 1) the temperature of the flue gas is cooled by evaporation of the lye and cooling of the process water in the defluorinator.

The wet flue gas desulfurization and dedusting process according to claim 3, characterized in that: the small amount of waste water generated in the cooling defluorinator is directly discharged into the wastewater treatment system.

The wet flue gas desulfurization and dedusting process according to claim 4, wherein the waste water discharged from the cooling defluoridation device separates heavy metals in the waste water by a process such as sedimentation and pH adjustment, and is dried. The heavy metal sludge is recovered by magnetic separation, and the recovered iron is returned to the sintering head to participate in the ore blending.

The wet flue gas desulfurization and dedusting process according to claim 1, wherein in the desulfurization absorption tower of step 2), the flue gas after desulfurization is cooled and passed through a swirling device in the jet tube of the absorption tower. Function, high-speed spin into the slurry pool, the flue gas is broken and fully mixed in the slurry, and the gas-liquid completes the desulfurization and dust removal process in the process of high-efficiency contact.

The wet flue gas desulfurization and dedusting process for sintering flue gas according to claim 6, wherein the gypsum slurry produced in the step 2) is dehydrated by two stages, and the water content is reduced to less than 10%.

The wet flue gas desulfurization and dedusting process for sintering flue gas according to claim 7, wherein the two-stage dewatering of the gypsum slurry is performed by a screw discharge sedimentation centrifuge or a hydrocyclone separator and a vacuum belt conveyor, respectively.

9. The sintering flue gas wet desulfurization and dust removal process according to claim 1, wherein: (3) reheating of the flue gas is carried out by using sintering waste heat vapor.

10. The sintering flue gas wet desulfurization and dust removal process according to claim 1, wherein: the alkali liquid in steps 1) and 2) comprises one of limestone, slaked lime, sodium, magnesium and ammonium. An aqueous solution or slurry in which a plurality of basic compounds are configured.