Method for co-processing blast furnace cloth bag ash and sintering machine head ash and purifying CO

Abstract

The invention relates to a method for co-processing blast furnace cloth bag ash and sintering machine head ash and purifying CO. The method comprises the following steps: 1) respectively washing the sintering machine head ash and the sintering machine head ash with water to obtain sintering ash washing water, a sintering ash washing filter cake, blast furnace ash washing water and a blast furnace ash washing filter cake, and combining the sintering ash washing water and the blast furnace ash washing water to obtain a mixed solution; 2) performing heavy metal removal and precipitation on the mixed solution, and performing solid-liquid separation to obtain heavy metal sludge and a high-salt solution; (3) adjusting the high-salt solution to be alkaline, and evaporating and separating salt to obtain dirty condensed water, potassium salt, sodium salt and dilute ammonia water; (4) blast furnace ash washing filter cakes are pelletized, obtained green pellets are preheated, dried and then subjected to heat treatment, and high-temperature flue gas and kiln slag are obtained; ammonia water is sprayed into the high-temperature flue gas for primary denitration, the high-temperature flue gas after primary denitration is cooled and then sequentially subjected to decarburization, secondary denitration and dust removal, and secondary zinc oxide and medium-temperature flue gas are obtained. Ammonia water circulation is utilized while the sintering machine head ash and the blast furnace cloth bag ash are treated, and deep co-treatment of the sintering machine head ash and the blast furnace cloth bag ash is achieved.

Description

Technical Field

[0001] The invention relates to a coordinated disposal method, in particular to a method for coordinated disposal of blast furnace bag ash and sintering machine head ash and CO purification, belonging to the technical field of metallurgical solid waste treatment. Background Art

[0002] With the continuous advancement of the "industry-city integration" development model, the steel industry has gradually evolved towards a coordinated model of "zero wastewater discharge, ultra-low waste gas discharge, and no solid waste leaving the house". At present, the solid waste generated by the steel industry is mainly iron-containing, and most of it has been recycled within the steel plant through high-temperature furnaces such as sintering, blast furnaces, and rotary kilns. However, there are still some high-salt solid wastes (such as sintering third and fourth electric field ash, blast furnace bag dust removal ash), which contain more alkali and chlorine metals. If they are directly returned to high-temperature furnaces such as sintering, blast furnaces, and rotary kilns, it will cause equipment corrosion and cause adverse conditions such as kiln agglomeration.

[0003] At present, water washing is often used to remove alkali and chlorine metals from blast furnace bag ash and sintering machine head ash. After water washing and leaching, the high-salt solid waste is dehydrated, and the sintering ash is returned to the sintering, and the blast furnace bag ash is further processed through a rotary kiln. In the process of water washing and leaching high-salt solid waste, the high-salt leaching wastewater generated is evaporated and salted after pretreatment.

[0004] In the prior art, only how to recycle the crystallized salt is generally considered. Chinese patent CN103435073A "Method for producing potassium chloride using blast furnace gas ash from steel enterprises" reports the use of tap water to leach blast furnace gas ash, which greatly reduces the potassium and chlorine in the blast furnace gas ash, and the leaching solution is used to prepare potassium chloride and sodium chloride. For the tail gas generated by the rotary kiln to dispose of blast furnace bag ash, an additional flue gas purification system is used for disposal. Chinese patent CN 108295652 A "Integrated process and system for utilizing waste heat from flue gas desulfurization and denitrification of carbon rotary kiln" reports the use of direct reduction denitrification and selective catalytic reduction denitrification within a suitable temperature range to achieve flue gas purification. For the utilization of flue gas waste heat, Chinese patent CN 208516990 U "Multi-stage high-efficiency evaporator for heating wastewater with high-temperature flue gas" reports the use of a multi-stage high-efficiency evaporator for heating wastewater with high-temperature flue gas to achieve direct utilization of high-temperature flue gas.

[0005] In general, the current treatment methods for blast furnace bag ash and sintering machine head ash are relatively independent, without sufficient consideration of the coordinated treatment of water-gas-heat, resulting in high overall operating costs and repeated investment in equipment, as well as failure to consider the treatment of rotary kiln exhaust CO, causing serious environmental damage. Summary of the invention

[0006] In view of the existing problems in the prior art, such as the independent treatment of blast furnace bag ash and sintering machine head ash, the high operating cost, and the failure to consider the treatment of CO, the present invention washes the blast furnace bag ash and sintering machine head ash separately, and uses the recovered ammonia water to remove nitrogen oxides in the high-temperature flue gas according to the pollutant content in the high-temperature flue gas after the blast furnace ash water-washed filter cake is roasted, and the heat released during the catalytic oxidation of CO into CO2 is used to further remove nitrogen oxides in the flue gas, and the emission standards can be met without additional flue gas treatment. In addition, the resources in the blast furnace bag ash and sintering machine head ash are also recovered, realizing true coordinated treatment.

[0007] According to an embodiment of the present invention, a method for co-disposal of blast furnace bag ash and sintering machine head ash and CO purification is provided.

[0008] A method for co-disposal of blast furnace bag ash and sintering machine head ash and CO purification, the method comprising the following steps:

[0009] 1) washing the sintering machine head ash with water to obtain sintering ash washing water and sintering ash water washing filter cake; washing the blast furnace bag ash with water to obtain blast furnace ash washing water and blast furnace ash water washing filter cake, and combining the sintering ash washing water and the blast furnace ash washing water to obtain a mixed solution;

[0010] 2) adding a de-heaving agent and a de-hardening agent to the mixed solution obtained in step 1) to react, and after the reaction is completed, performing solid-liquid separation to obtain heavy metal sludge and a high-salt solution;

[0011] 3) first adjusting the high salt solution obtained in step 2) to be alkaline, and then subjecting the alkaline high salt solution to evaporation and salt separation treatment to obtain polluted condensed water, potassium salt, sodium salt and dilute ammonia water;

[0012] 4) First, the blast furnace ash water-washed filter cake is mixed with coal powder and auxiliary materials and pelletized. The obtained green pellets are preheated and dried and then sent to a rotary kiln for heat treatment to obtain high-temperature flue gas and kiln slag; then, ammonia water is sprayed into the high-temperature flue gas for a primary denitrification treatment, and then the high-temperature flue gas after the primary denitrification treatment is cooled and then decarbonized, secondary denitrified and dust removed in sequence to obtain secondary zinc oxide and medium-temperature flue gas.

[0013] Preferably, the method further comprises: 5) introducing the diluted ammonia water obtained in step 3) as a reactant into the high-temperature flue gas in step 4) to participate in a denitrification treatment.

[0014] Preferably, the method further comprises: 6) introducing the medium-temperature flue gas obtained in step 4) into the evaporation and salt separation treatment in step 3) as a heat source.

[0015] Preferably, the sintering machine head ash water washing in step 1) is a multi-stage water washing, preferably a three-stage countercurrent water washing; preferably, the sintering ash water-to-ash ratio is 1.5 to 5:1, preferably 2 to 4:1.

[0016] Preferably, the de-heaving agent in step 2) is sodium sulfide or a heavy capture agent, and the added amount is 0.3 to 3 g / L, preferably 0.5 to 2 g / L.

[0017] Preferably, the de-hardening agent in step 2) is sodium carbonate, and the added amount is 0.3-3.5 g / L, preferably 0.5-3 g / L.

[0018] Preferably, the reaction time for removing weight and hardness is 0.5 to 2 hours, preferably 0.8 to 1.5 hours.

[0019] Preferably, the blast furnace bag ash washing in step 2) is a multi-stage washing, preferably a three-stage countercurrent washing; preferably, the water-to-ash ratio of the blast furnace bag ash is 0.5 to 3:1, preferably 1 to 2:1.

[0020] Preferably, the three-stage countercurrent water washing is specifically as follows: the sintering machine head ash or blast furnace bag ash solids are sequentially subjected to primary, secondary and tertiary water washings, wherein the water source for the primary water washing is the filtrate from the secondary water washing, the water source for the secondary water washing is the filtrate from the tertiary water washing, the water source for the tertiary water washing is industrial water and / or sewage condensate, and the filtrate from the primary water washing is discharged from the system.

[0021] Preferably, the alkalinity in step 3) has a pH value between 10 and 13, preferably a pH value between 11 and 12; preferably, the alkaline substance is sodium hydroxide and / or potassium hydroxide.

[0022] Preferably, the evaporation and salt separation in step 3) is temperature-variable evaporation and salt separation, preferably, the evaporation is countercurrent multi-effect salt separation, the high-salt solution passes through a triple-effect reactor, a second-effect reactor and a first-effect reactor in sequence, and the liquid flow direction is opposite to the steam flow direction, and the condensed water at the steam outlet of the triple-effect reactor is collected separately to obtain dilute ammonia water; preferably, the temperature in the triple-effect reactor is controlled at 20 to 60°C (preferably 30 to 50°C), the vacuum degree is -150 to -50 kPa (preferably -100 to -70 kPa), the temperature of the second-effect evaporation is controlled at 40 to 90°C (preferably 50 to 80°C), the vacuum degree is -100 to -30 kPa (preferably -70 to -40 kPa), the temperature of the first-effect evaporation is controlled at 70 to 105°C (preferably 80 to 100°C), and the vacuum degree is -50 to -10 kPa (preferably -40 to -15 kPa).

[0023] Preferably, the step 3) further comprises: 31) the evaporation and salt separation process also obtains low-temperature flue gas discharged for drying the blast furnace bag ash after pelletizing in step 4).

[0024] Preferably, the single-effect reactor evaporation described in step 3) adopts a flue gas heat exchange evaporator; the flue gas heat exchange evaporator includes a main body, the interior of the main body is divided into an observation and maintenance chamber and an evaporation chamber from top to bottom, and a partition is provided between the observation and maintenance chamber and the evaporation chamber; the observation and maintenance chamber is provided with a steam outlet at the top, and an observation port and a maintenance entrance at the side; a steam channel is opened in the middle of the partition; a high-salt solution inlet is provided on one side of the bottom of the evaporation chamber, a high-temperature flue gas inlet and a low-temperature flue gas outlet are provided on the side of the evaporation chamber, and a flue gas duct and a drain pipe are provided inside the evaporation chamber, wherein the two ends of the flue gas duct are respectively connected to the high-temperature flue gas inlet and the low-temperature flue gas outlet, the upper end of the drain pipe is arranged in the evaporation chamber, and the lower end of the drain pipe extends downward from the outside of the main body and a high-salt solution outlet is provided at the end.

[0025] Preferably, the flue gas duct is bent in the evaporation chamber.

[0026] Preferably, the upper end of the liquid drain pipe is arranged in the upper middle area of ​​the evaporation chamber and below the steam channel.

[0027] Preferably, a drainage branch pipe is provided at the bottom of the evaporation chamber; the upper end of the drainage branch pipe is arranged in the evaporation chamber, and the lower end extends downwardly out of the main body; preferably, the end of the drainage branch pipe is connected to the drainage pipe, and a valve is provided in the drainage branch pipe.

[0028] Preferably, a condensate discharge pipe is further provided at the bottom of the evaporation chamber, the upper end of the condensate discharge pipe is connected to the flue gas duct, and the lower end of the pipe extends downwardly out of the main body.

[0029] Preferably, a horizontal baffle and / or a vertical baffle is further provided inside the evaporation chamber; preferably, a plurality of horizontal baffles and / or vertical baffles are staggered inside the evaporation chamber.

[0030] Preferably, a pressure detection port is provided on the side of the observation and inspection chamber and / or the evaporation chamber.

[0031] Preferably, the decarbonization, secondary denitration and dust removal treatment described in step 4) is specifically as follows: decarbonization, secondary denitration and dust removal are performed on the cooled high-temperature flue gas using a decarbonization, denitration and dust removal integrated filter cartridge, wherein the decarbonization, denitration and dust removal integrated filter cartridge comprises a catalytic layer, a filter layer and a support layer, all of which are air-permeable, and the catalytic layer, the filter layer and the support layer are arranged from the inside to the outside of the decarbonization, denitration and dust removal integrated filter cartridge, and the catalytic layer contains a CO oxidation catalyst and an SCR catalyst;

[0032] Preferably, the CO oxidation catalyst and the SCR catalyst are Pt catalyst and CoMn catalyst, and the filter layer is a mesh; the total content of the catalyst in the filter cartridge is 20-30% of the weight of the filter cartridge, wherein the mass ratio of the Pt catalyst to the CoMn catalyst is 1:0.5-2.5, preferably 1:0.6-2.

[0033] Preferably, the carrier of the Pt catalyst is TiO2, wherein the content of Pt is 0.3-2wt%, preferably 0.5-1.5wt%.

[0034] Preferably, the Co content of the CoMn catalyst is 50-70wt%, preferably 55-65wt%, and the Mn content is 10-20wt%, preferably 15-20wt%;

[0035] Preferably, the integrated decarbonization, denitrification and dust removal filter cartridge comprises a plurality of alternately arranged catalytic layers, filtration layers and support layers.

[0036] Preferably, the high temperature flue gas temperature in step 4) is 830-1000°C (preferably 850-950°C), and the injection amount of ammonia water is 70-150 mg / m 3 The injection method is atomization injection.

[0037] Preferably, the step 4) of cooling the high-temperature flue gas after the primary denitration treatment comprises: recovering the waste heat from the high-temperature flue gas through a waste heat boiler; preferably, adjusting the circulating water volume of the waste heat boiler to control the flue gas temperature entering the filter cartridge to be 370-450°C (preferably 400-430°C) and the air velocity to be 1000-10000h -1 .

[0038] Preferably, the pelletizing in step 4) is to pelletize the blast furnace ash washed filter cake using a disc pelletizer to obtain spherical particles of 3 to 8 mm (preferably 4 to 6 mm).

[0039] Preferably, the calcination temperature in step 4) is 1000-1400° C. (preferably 1100-1300° C.), and the calcination time is 1-2 hours.

[0040] Preferably, the auxiliary materials in step 4) include a binder and miscellaneous auxiliary materials.

[0041] Preferably, the step 1) is specifically as follows: the sintering machine head ash is subjected to three-stage countercurrent water washing at a water-ash ratio of 1.5 to 5:1 (preferably 2 to 4:1), and the blast furnace bag ash is subjected to three-stage countercurrent water washing at a water-ash ratio of 0.5 to 3:1 (preferably 1 to 2:1), and the washing liquids of the two are mixed after filtering respectively to obtain a sintering ash washed filter cake, a blast furnace ash washed filter cake and a mixed solution.

[0042] Preferably, the step 2) is specifically as follows: adding a de-weighting agent and a de-hardening agent to the mixed solution obtained in step 1), wherein the amount of the de-weighting agent added is 0.3 to 3 g / L (preferably 0.5 to 2 g / L), and the amount of the de-hardening agent added is 0.3 to 3.5 g / L (preferably 0.5 to 3 g / L), reacting for 0.5 to 2 h (preferably 0.8 to 1.5 h) and then filtering to obtain heavy metal sludge and a high salt solution.

[0043] Preferably, the step 3) is specifically as follows: adjusting the pH of the high-salt solution obtained in step 2) to 10-13 (preferably 11-12) with sodium hydroxide, and then subjecting the high-salt solution after the pH adjustment to multi-stage temperature-variable evaporation to obtain contaminated condensed water, potassium salt, sodium salt and dilute ammonia water.

[0044] Preferably, the step 4) is specifically as follows: the blast furnace ash water-washed filter cake obtained in step 1) is sent to a disc granulator for pelletizing to obtain blast furnace ash pellets of 3 to 8 mm (preferably 4 to 6 mm), the blast furnace ash pellets are sent to a rotary kiln and roasted at a temperature of 1000 to 1400° C. (preferably 1100 to 1300° C.) for 1 to 2 hours, and high-temperature flue gas and kiln slag are obtained after the roasting is completed. Dilute ammonia water is sprayed into the high-temperature flue gas at a ratio of 1:1, and then the high-temperature flue gas is passed through a waste heat boiler, cooled to 370 to 460° C. (preferably 400 to 430° C.), and then passed into a filter cartridge for decarbonization, denitrification and dust removal, and the air velocity is 1000 to 10000 h -1 , obtaining zinc oxide and medium-temperature flue gas.

[0045] Preferably, the step 5) is specifically as follows: 1% to 10% of the dilute ammonia water obtained in step 3) is introduced into the high-temperature flue gas in step 4) as a reactant.

[0046] Preferably, the step 6) is specifically: the low-temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and the low-temperature flue gas discharged from the evaporation and salt separation step is used to dry the blast furnace ash pellets in step 4).

[0047] In the present invention, sintering machine head ash (i.e. sintering dust removal ash) and blast furnace bag ash (i.e. blast furnace dry process ash) are washed with water respectively, and after washing, the washing liquids of the two are mixed to obtain a mixed solution, a blast furnace ash washed filter cake and a sintering ash washed filter cake, and then a weight removal agent and a hardness removal agent are added to the mixed solution to remove heavy metals in the mixed solution, and the remaining high-salt solution is subjected to a salt separation step by evaporation to obtain potassium salt, sodium salt, dilute ammonia water and dirty condensed water. The washed filter cake of blast furnace ash is sent to the rotary kiln for roasting after balling to obtain high-temperature flue gas and kiln slag. Dilute ammonia water (preferably the dilute ammonia water collected during the evaporation and salt separation process) is added to the high-temperature flue gas. The ammonia water is mixed with the high-temperature flue gas, and the SNCR reaction occurs at 830-1000°C to reduce the content of nitrogen oxides in the flue gas. The high-temperature flue gas is then cooled and passed into the decarbonization, denitration and dust removal process. The CO in the flue gas passes through the catalyst layer in the filter cartridge and becomes CO2 and releases heat. The dust in the flue gas is physically intercepted and separated by the filter layer. At the same time, the low concentration of ammonia and nitrogen oxides in the flue gas will undergo SCR reaction on the surface of the CoMn catalyst to further remove the residual nitrogen oxides. Through the above method, the present invention realizes the true coordinated disposal of sintering machine head ash and blast furnace bag ash. While disposing of sintering machine head ash and blast furnace bag ash, the recycling of ammonia water and the efficient removal of pollutants in the flue gas are realized, and the efficient recovery of resources is completed.

[0048] In the present invention, the washing liquid of the sintering machine head ash and the blast furnace bag ash contains a certain concentration of ammonia nitrogen (3000-7000 mg / L). The solution after preliminary purification (i.e., the high salt solution obtained after removing the weight and hardness and separating the solid and liquid) adopts an alkaline substance to adjust the pH of the solution to 11-12, and then undergoes countercurrent multi-effect salt separation. The evaporation temperature of the three-effect reactor is controlled to 20-60°C and the vacuum degree is controlled to -150--50 kPa, so that the ammonia nitrogen in the wastewater is forced to be separated from the brine, and the condensed water at the steam outlet of the three-effect reactor is collected separately, so as to obtain high-concentration dilute ammonia water.

[0049] In the present invention, it is found that the high temperature flue gas discharged from the rotary kiln contains about 70-150 ppm of NO x , 5 to 10 ppm of SO2. By comparing the emission standards, it can be seen that the high-temperature flue gas only needs to be denitrated. Therefore, the present invention controls the flue gas temperature discharged from the rotary kiln to 830 to 1000°C, and sprays the recovered ammonia water into the high-temperature flue gas. The flue gas undergoes an SNCR reaction under this temperature condition to remove nitrogen oxides in the flue gas, thereby realizing the internal circulation of ammonia water, avoiding the subsequent addition of a denitrification device, and reducing investment. Preferably, the present invention uses the low-temperature flue gas discharged from the evaporation and salt separation process to pre-dry and preheat the material, increase the temperature of the material entering the rotary kiln, thereby reducing the reaction heat loss and reducing fuel consumption.

[0050] In the present invention, the flue gas discharged from the rotary kiln also contains a large amount of CO, and its concentration reaches 1.5-3%. At the same time, the flue gas also contains a large amount of secondary zinc oxide dust. If the flue gas passes through the decarbonization device and the denitration device successively, the flue gas temperature may change, resulting in it not being within the optimal temperature range of decarbonization and denitration. In order to achieve synchronous decarbonization, denitration and dust removal, the present invention prepares a decarbonization, denitration and dust removal integrated filter cartridge comprising a catalytic layer, a filter layer and a support layer. The catalytic layer is mainly a Pt catalyst and a CoMn catalyst, which is used to catalytically oxidize CO to CO2. The filter layer is composed of a filter screen, which is used to remove solid impurities in the flue gas. After the high-temperature flue gas enters the filter cartridge, the CO in the flue gas passes through the Pt / TiO2 and CoMn catalyst layers, and a catalytic oxidation reaction occurs, turning it into CO2 and releasing heat. The dust in the flue gas is physically intercepted and removed by the filter layer, and the low-concentration ammonia and nitrogen oxides remaining in the flue gas will undergo an SCR reaction on the surface of the CoMn catalyst, and the nitrogen oxides are further removed. Preferably, the filter cartridge contains multiple layers of catalytic layers, filter layers and support layers, the filter layers remove particulate matter in the flue gas, and the support layers serve as a skeleton. The integrated filter cartridge for decarbonization, denitration and dust removal is used to enhance the catalytic effect of the catalyst and the dust removal effect of the filter layer, achieve the basic removal of nitrogen oxides, CO and dust, make the flue gas meet the emission standards and facilitate subsequent recycling.

[0051] In the present invention, with respect to the contents of CO, ammonia and nitrogen oxides in high-temperature flue gas, after a large number of experiments, the dosage of Pt catalyst and CoMn catalyst and the contents of Pt, Co and Mn are determined as follows: the mass ratio of Pt catalyst and CoMn catalyst is limited to the range of 1:0.5 to 2.5 (for example, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2.0, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5) to ensure the purification efficiency of CO, ammonia and nitrogen. The platinum content in the Pt catalyst is set to 0.3-2wt% (e.g., 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1.0wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2.0wt%), and the Co content in the CoMn catalyst is set to 50-70wt% (e.g., 50wt%, 51wt%, 52wt%, 53wt%, 54wt%). The catalyst is preferably selected from the group consisting of 54wt%, 55wt%, 56wt%, 57wt%, 58wt%, 59wt%, 60wt%, 61wt%, 62wt%, 63wt%, 64wt%, 65wt%, 66wt%, 67wt%, 68wt%, 69wt%, 70wt%), the Mn content is set to 10-20wt% (e.g., 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%), and the total amount of catalyst is 20-30% of the weight of the filter cartridge. Under the above conditions, the catalyst has the best comprehensive catalytic effect on CO, nitrogen oxides and ammonia. In addition, the catalyst needs to be placed in the filter cartridge, otherwise a large amount of dust carried in the flue gas will not be removed by the filter layer of the filter cartridge and will adhere to the surface of the catalyst, affecting the catalytic effect.

[0052] In the present invention, during the decarbonization, denitration and dust removal process of the filter cartridge, the heat released during the CO oxidation process will cause the flue gas to significantly increase in temperature (according to theoretical calculations, it can be increased by about 135 to 270°C), and too high a temperature will cause the catalyst layer to agglomerate and the secondary volatilization of ZnO, affecting the recovery rate of ZnO and the dust removal effect. At the same time, too high a temperature will also affect the efficiency of the SCR reaction of the residual nitrogen oxides in the flue gas. Therefore, the present invention achieves temperature control by adjusting and controlling the circulating water volume of the waste heat boiler, so that the temperature in the filter cartridge is 370 to 450°C, ensuring the effect of decarbonization, denitration and dust removal and the recovery rate of secondary zinc oxide.

[0053] In the present invention, the flue gas temperature after decarbonization, denitrification and dust removal is about 450°C. Taking a steel enterprise with an annual crude steel output of about 5 million tons as an example, the flue gas volume after CO purification is about 100,000 m 3 / h, the supporting blast furnace bag ash and sintering machine head ash washing scale is about 30,000 tons / year, and the heat required for evaporation mainly comes from the indirect heating of flue gas. The heat loss is considered to be 20-30%. Through heat balance calculation, the flue gas temperature is reduced by 70-90°C to achieve complete evaporation of wastewater, that is, after evaporation, the flue gas temperature can still be maintained at 310-360°C. Based on the process characteristics of evaporation and salt separation, the present invention uses the medium-temperature flue gas discharged from the decarbonization, denitration and dust removal integrated filter cartridge as a heat source to pass into the evaporation and salt separation step to improve the utilization rate of energy. Preferably, the flue gas (310-360°C) after the evaporation and salt separation process is returned and used to dry the blast furnace bag ash before entering the rotary kiln after pelletizing. The moisture content of the green pellets is generally 10-12%. According to the supporting disposal scale, the amount of green pellets produced is about 200,000 tons / year. The hot flue gas is in countercurrent contact with the green pellets. Considering the heat loss of 10-15%, through heat balance calculation, the flue gas temperature can be reduced to about 100°C to achieve complete drying of the green pellets, and the temperature of the dried green pellets can reach 250-300°C, realizing the full utilization of the waste heat of the flue gas.

[0054] In the present invention, an evaporator is used to evaporate and separate the high-salt solution, and a flue gas duct is arranged in the evaporator. The heat of the medium-temperature flue gas is used to heat the high-salt solution in the form of indirect heat exchange. Preferably, the flue gas duct is bent in the evaporation chamber to increase the heat exchange area between the medium-temperature flue gas and the high-salt solution and improve the heat exchange efficiency. In addition, a horizontal baffle and a vertical baffle are arranged in the evaporator. When the high-salt solution flows in the evaporator, its flow path is extended to increase the heat exchange time.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] 1. The present invention provides a method for coordinated disposal of blast furnace bag ash and sintering machine head ash and CO purification. Ammonia water circulation is used while disposing of sintering machine head ash and blast furnace bag ash, thereby achieving deep coordinated disposal of sintering machine head ash and blast furnace bag ash, and achieving full coordination of "solid-liquid-gas-heat", obtaining substances such as zinc, potassium, and sodium salts, and completing resource recovery.

[0057] 2. The present invention provides a method for coordinated disposal of blast furnace bag ash and sintering machine head ash and CO purification, which utilizes refluxed ammonia water and an integrated filter cartridge for decarbonization, denitrification and dust removal to remove pollutants in high-temperature flue gas in two steps, thereby completing the deep purification of nitrogen oxides and CO in the flue gas and achieving basic removal of pollutants. The temperature in the filter cartridge is controlled by a waste heat boiler to maintain the temperature in the filter cartridge within an optimal range.

[0058] 3. The method of coordinated disposal of blast furnace bag ash and sintering machine head ash and CO purification provided by the present invention fully utilizes the heat of flue gas discharged from the rotary kiln, realizes low-cost denitrification and evaporation and salt separation, and reduces operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure markings: A: main body; 1: observation and maintenance room; 11: steam outlet; 12: observation port; 13: maintenance entrance; 2: evaporation chamber; 21: high salt solution inlet; 22: high temperature flue gas inlet; 23: low temperature flue gas outlet; 24: drain pipe; 25: high salt solution outlet; 26: drain branch pipe; 261: valve; 27: condensate discharge pipe; 28: horizontal baffle; 29: vertical baffle; 3: partition; 31: steam channel; 4: pressure detection port; B: decarbonization, denitrification and dust removal integrated filter cartridge; B1: catalytic layer; B2: support layer; B3: filter layer.

[0060] Figure 1 The present invention provides a flow chart of a method for coordinated disposal of blast furnace bag ash and sintering machine head ash and CO purification.

[0061] Figure 2 A schematic structural diagram of a flue gas heat exchange evaporator used in a method for coordinated disposal of blast furnace bag ash and sintering machine head ash and CO purification provided by the present invention.

[0062] Figure 3 A top view of a flue gas heat exchange evaporator used in a method for coordinated disposal of blast furnace bag ash and sintering machine head ash and CO purification provided by the present invention.

[0063] Figure 4 A schematic structural diagram of an integrated filter cartridge for decarbonization, denitrification and dust removal used in a method for coordinated disposal of blast furnace bag ash and sintering machine head ash and CO purification provided by the present invention. DETAILED DESCRIPTION

[0064] The technical solution of the present invention is illustrated below by way of example, and the scope of protection requested by the present invention includes but is not limited to the following embodiments.

[0065] According to an embodiment of the present invention, a method for co-disposal of blast furnace bag ash and sintering machine head ash and CO purification is provided.

[0066] A method for co-disposal of blast furnace bag ash and sintering machine head ash and CO purification, the method comprising the following steps:

[0067] 1) washing the sintering machine head ash with water to obtain sintering ash washing water and sintering ash water washing filter cake; washing the blast furnace bag ash with water to obtain blast furnace ash washing water and blast furnace ash water washing filter cake, and combining the sintering ash washing water and the blast furnace ash washing water to obtain a mixed solution;

[0068] 2) adding a de-heaving agent and a de-hardening agent to the mixed solution obtained in step 1) to react, and after the reaction is completed, performing solid-liquid separation to obtain heavy metal sludge and a high-salt solution;

[0069] 3) first adjusting the high salt solution obtained in step 2) to be alkaline, and then subjecting the alkaline high salt solution to evaporation and salt separation treatment to obtain polluted condensed water, potassium salt, sodium salt and dilute ammonia water;

[0070] 4) First, the blast furnace ash water-washed filter cake is mixed with coal powder and auxiliary materials and pelletized. The obtained green pellets are preheated and dried and then sent to a rotary kiln for heat treatment to obtain high-temperature flue gas and kiln slag; then, ammonia water is sprayed into the high-temperature flue gas for a primary denitrification treatment, and then the high-temperature flue gas after the primary denitrification treatment is cooled and then decarbonized, secondary denitrified and dust removed in sequence to obtain secondary zinc oxide and medium-temperature flue gas.

[0071] Preferably, the method further comprises: 5) introducing the diluted ammonia water obtained in step 3) as a reactant into the high-temperature flue gas in step 4) to participate in a denitrification treatment.

[0072] Preferably, the method further comprises: 6) introducing the medium-temperature flue gas obtained in step 4) into the evaporation and salt separation treatment in step 3) as a heat source.

[0073] Preferably, the sintering machine head ash water washing in step 1) is a multi-stage water washing, preferably a three-stage countercurrent water washing; preferably, the sintering ash water-to-ash ratio is 1.5 to 5:1, preferably 2 to 4:1.

[0074] Preferably, the de-heaving agent in step 2) is sodium sulfide or a heavy capture agent, and the added amount is 0.3 to 3 g / L, preferably 0.5 to 2 g / L.

[0075] Preferably, the de-hardening agent in step 2) is sodium carbonate, and the added amount is 0.3-3.5 g / L, preferably 0.5-3 g / L.

[0076] Preferably, the reaction time for removing weight and hardness is 0.5 to 2 hours, preferably 0.8 to 1.5 hours.

[0077] Preferably, the blast furnace bag ash washing in step 2) is a multi-stage washing, preferably a three-stage countercurrent washing; preferably, the water-to-ash ratio of the blast furnace bag ash is 0.5 to 3:1, preferably 1 to 2:1.

[0078] Preferably, the three-stage countercurrent water washing is specifically as follows: the sintering machine head ash or blast furnace bag ash solids are sequentially subjected to primary, secondary and tertiary water washings, wherein the water source for the primary water washing is the filtrate from the secondary water washing, the water source for the secondary water washing is the filtrate from the tertiary water washing, the water source for the tertiary water washing is industrial water and / or sewage condensate, and the filtrate from the primary water washing is discharged from the system.

[0079] Preferably, the alkalinity in step 3) has a pH value between 10 and 13, preferably a pH value between 11 and 12; preferably, the alkaline substance is sodium hydroxide and / or potassium hydroxide.

[0080] Preferably, the evaporation and salt separation in step 3) is temperature-variable evaporation and salt separation, preferably, the evaporation is countercurrent multi-effect salt separation, the high-salt solution passes through a triple-effect reactor, a second-effect reactor and a first-effect reactor in sequence, and the liquid flow direction is opposite to the steam flow direction, and the condensed water at the steam outlet of the triple-effect reactor is collected separately to obtain dilute ammonia water; preferably, the temperature in the triple-effect reactor is controlled at 20 to 60°C (preferably 30 to 50°C), the vacuum degree is -150 to -50 kPa (preferably -100 to -70 kPa), the temperature of the second-effect evaporation is controlled at 40 to 90°C (preferably 50 to 80°C), the vacuum degree is -100 to -30 kPa (preferably -70 to -40 kPa), the temperature of the first-effect evaporation is controlled at 70 to 105°C (preferably 80 to 100°C), and the vacuum degree is -50 to -10 kPa (preferably -40 to -15 kPa).

[0081] Preferably, the step 3) further comprises: 31) the evaporation and salt separation process also obtains low-temperature flue gas discharged for drying the blast furnace bag ash after pelletizing in step 4).

[0082] Preferably, the single-effect reactor evaporation described in step 3) adopts a flue gas heat exchange evaporator. The flue gas heat exchange evaporator includes a main body A, the interior of the main body A is divided into an observation and maintenance chamber 1 and an evaporation chamber 2 from top to bottom, and a partition 3 is provided between the observation and maintenance chamber 1 and the evaporation chamber 2. The upper part of the observation and maintenance chamber 1 is provided with a steam outlet 11, and the side is provided with an observation port 12 and a maintenance entrance 13. A steam channel 31 is opened in the middle of the partition 3. A high-salt solution inlet 21 is provided on one side of the bottom of the evaporation chamber 2, and a high-temperature flue gas inlet 22 and a low-temperature flue gas outlet 23 are provided on the side of the evaporation chamber 2. A flue gas duct and a drain pipe 24 are provided inside the evaporation chamber 2, wherein the two ends of the flue gas duct are respectively connected to the high-temperature flue gas inlet 22 and the low-temperature flue gas outlet 23, and the upper end of the drain pipe 24 is arranged in the evaporation chamber 2, and the lower end of the drain pipe 24 extends downward from the outside of the main body A and a high-salt solution outlet 25 is provided at the end.

[0083] Preferably, the flue gas duct is bent in the evaporation chamber 2 .

[0084] Preferably, the upper end of the drain pipe 24 is disposed in the upper middle area of ​​the evaporation chamber 2 and below the steam channel 31 .

[0085] Preferably, a drainage branch pipe 26 is provided at the bottom of the evaporation chamber 2. The upper end of the drainage branch pipe 26 is arranged in the evaporation chamber 2, and the lower end extends downwardly out of the main body A. Preferably, the end of the drainage branch pipe 26 is connected to the drainage pipe 24, and a valve 261 is provided in the drainage branch pipe 26.

[0086] Preferably, a condensate discharge pipe 27 is further provided at the bottom of the evaporation chamber 2 , the upper end of the condensate discharge pipe 27 is connected to the flue gas duct, and the lower end extends downward out of the main body A.

[0087] Preferably, a horizontal baffle 28 and / or a vertical baffle 29 are further provided inside the evaporation chamber 2. Preferably, a plurality of horizontal baffles 28 and / or vertical baffles 29 are staggeredly arranged inside the evaporation chamber 2.

[0088] Preferably, a pressure detection port 4 is provided on the side of the observation and inspection chamber 1 and / or the evaporation chamber 2 .

[0089] Preferably, the decarbonization, secondary denitration and dust removal treatment described in step 4) is specifically as follows: decarbonization, secondary denitration and dust removal are performed on the cooled high-temperature flue gas using a decarbonization, denitration and dust removal integrated filter cartridge, wherein the decarbonization, denitration and dust removal integrated filter cartridge comprises a catalytic layer, a filter layer and a support layer, all of which are air-permeable, and the catalytic layer, the filter layer and the support layer are arranged from the inside to the outside of the decarbonization, denitration and dust removal integrated filter cartridge, and the catalytic layer contains a CO oxidation catalyst and an SCR catalyst;

[0090] Preferably, the CO oxidation catalyst and the SCR catalyst are Pt catalyst and CoMn catalyst, and the filter layer is a mesh; the total content of the catalyst in the filter cartridge is 20-30% of the weight of the filter cartridge, wherein the mass ratio of the Pt catalyst to the CoMn catalyst is 1:0.5-2.5, preferably 1:0.6-2;.

[0091] Preferably, the carrier of the Pt catalyst is TiO2, wherein the content of Pt is 0.3-2wt%, preferably 0.5-1.5wt%.

[0092] Preferably, the Co content of the CoMn catalyst is 50-70wt%, preferably 55-65wt%, and the Mn content is 10-20wt%, preferably 15-20wt%;

[0093] Preferably, the integrated decarbonization, denitrification and dust removal filter cartridge comprises a plurality of alternately arranged catalytic layers, filtration layers and support layers.

[0094] Preferably, the high temperature flue gas temperature in step 4) is 830-1000°C (preferably 850-950°C), and the injection amount of ammonia water is 70-150 mg / m 3 The injection method is atomization injection.

[0095] Preferably, the step 4) of cooling the high-temperature flue gas after the primary denitration treatment comprises: recovering the waste heat from the high-temperature flue gas through a waste heat boiler; preferably, adjusting the circulating water volume of the waste heat boiler to control the flue gas temperature entering the filter cartridge to be 370-450°C (preferably 400-430°C) and the air velocity to be 1000-10000h -1 .

[0096] Preferably, the pelletizing in step 4) is to pelletize the blast furnace ash washed filter cake using a disc pelletizer to obtain spherical particles of 3 to 8 mm (preferably 4 to 6 mm).

[0097] Preferably, the calcination temperature in step 4) is 1000-1400° C. (preferably 1100-1300° C.), and the calcination time is 1-2 hours.

[0098] Preferably, the auxiliary materials in step 4) include a binder and miscellaneous auxiliary materials.

[0099] Preferably, the step 1) is specifically as follows: the sintering machine head ash is subjected to three-stage countercurrent water washing at a water-ash ratio of 1.5 to 5:1 (preferably 2 to 4:1), and the blast furnace bag ash is subjected to three-stage countercurrent water washing at a water-ash ratio of 0.5 to 3:1 (preferably 1 to 2:1), and the washing liquids of the two are mixed after filtering respectively to obtain a sintering ash washed filter cake, a blast furnace ash washed filter cake and a mixed solution.

[0100] Preferably, the step 2) is specifically as follows: adding a de-weighting agent and a de-hardening agent to the mixed solution obtained in step 1), wherein the amount of the de-weighting agent added is 0.3 to 3 g / L (preferably 0.5 to 2 g / L), and the amount of the de-hardening agent added is 0.3 to 3.5 g / L (preferably 0.5 to 3 g / L), reacting for 0.5 to 2 h (preferably 0.8 to 1.5 h) and then filtering to obtain heavy metal sludge and a high salt solution.

[0101] Preferably, the step 3) is specifically as follows: adjusting the pH of the high-salt solution obtained in step 2) to 10-13 (preferably 11-12) with sodium hydroxide, and then subjecting the high-salt solution after the pH adjustment to multi-stage temperature-variable evaporation to obtain contaminated condensed water, potassium salt, sodium salt and dilute ammonia water.

[0102] Preferably, the step 4) is specifically as follows: the blast furnace ash water-washed filter cake obtained in step 1) is sent to a disc granulator for pelletizing to obtain blast furnace ash pellets of 3 to 8 mm (preferably 4 to 6 mm), the blast furnace ash pellets are sent to a rotary kiln and roasted at a temperature of 1000 to 1400° C. (preferably 1100 to 1300° C.) for 1 to 2 hours, and high-temperature flue gas and kiln slag are obtained after the roasting is completed. Dilute ammonia water is sprayed into the high-temperature flue gas at a ratio of 1:1, and then the high-temperature flue gas is passed through a waste heat boiler, cooled to 370 to 460° C. (preferably 400 to 430° C.), and then passed into a filter cartridge for decarbonization, denitrification and dust removal, and the air velocity is 1000 to 10000 h -1 , obtaining zinc oxide and medium-temperature flue gas.

[0103] Preferably, the step 5) is specifically as follows: 1% to 10% of the dilute ammonia water obtained in step 3) is introduced into the high-temperature flue gas in step 4) as a reactant.

[0104] Preferably, the step 6) is specifically: the low-temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and the low-temperature flue gas discharged from the evaporation and salt separation step is used to dry the blast furnace ash pellets in step 4).

[0105] Example 1

[0106] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0107] 1) The sintering machine head ash is washed with three-stage countercurrent water at a water-ash ratio of 3:1 and filtered to obtain 3.75m 3 / h sinter ash washing liquid and 20.25t / d sinter ash washing filter cake, at the same time, blast furnace bag ash is washed with three-stage countercurrent water at a water-ash ratio of 1:1 and filtered to obtain 3.5m 3 / h blast furnace ash water washing liquid and 96.6t / d blast furnace ash water washing filter cake (water content 21%), the sintering ash water washing liquid and blast furnace ash water washing liquid are mixed to obtain 7.25m 3 / h mixed solution;

[0108] 2) Add 7.25m obtained in step 1) 3 / h mixed solution, add 7.25kg / h sodium sulfide and 13.05kg / h sodium carbonate, and filter after reaction to obtain 0.73t / d heavy metal sludge and 7.1m 3 / h high salt solution;

[0109] 3) Adjust the 7.1m obtained in step 2) with NaOH 3 / h high salt solution to 11, and then the pH adjusted high salt solution is passed into a multi-stage temperature variable evaporation device for evaporation and salt separation, wherein the high salt solution passes through a triple effect reactor, a second effect reactor and a first effect reactor in sequence, the temperature in the triple effect reactor is 40°C, the vacuum degree is -90kPa, the temperature in the second effect reactor is 65°C, the vacuum degree is -65kPa, the temperature in the first effect reactor is 85°C, the vacuum degree is -25kPa, the condensed water in the triple effect reactor is collected separately, and 18g / L of 2.41m 3 / h of dilute ammonia water. At the same time, 7.84t / d of sodium chloride with a purity of 83% and 16.99t / d of potassium chloride with a purity of 89% were obtained by evaporation and separation of salt.

[0110] 4) The 96.6 t / d blast furnace ash water-washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.45 t / d kiln slag and 15350 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 60%, and the content of Mn is 18%. Finally, 5.4t / d of zinc oxide and 15350m 3 / h medium temperature flue gas;

[0111] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0112] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and the evaporation and salt separation step discharges 15350m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0113] Example 2

[0114] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0115] Repeat steps 1)-3) of Example 1;

[0116] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.5 t / d of kiln slag and 15356 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 55%, and the content of Mn is 18%. Finally, 5.2t / d of zinc oxide and 15356m 3 / h medium temperature flue gas;

[0117] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0118] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15356 m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0119] Example 3

[0120] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0121] Repeat steps 1)-3) of Example 1;

[0122] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator for pelletization to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.43 t / d of kiln slag and 15348 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 65%, and the content of Mn is 18%. Finally, 5.3t / d of zinc oxide and 15348m 3 / h medium temperature flue gas;

[0123] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0124] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15348 m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0125] Example 4

[0126] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0127] Repeat steps 1)-3) of Example 1;

[0128] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator for pelletization to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.45 t / d of kiln slag and 15352 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 50%, and the content of Mn is 18%. Finally, 5.1t / d of zinc oxide and 15352m 3 / h medium temperature flue gas;

[0129] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0130] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15352 m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0131] Example 5

[0132] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0133] Repeat steps 1)-3) of Example 1;

[0134] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.48 t / d of kiln slag and 15361 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 70wt%, and the content of Mn is 18wt%. Finally, 5.3t / d of zinc oxide and 15361m 3 / h medium temperature flue gas;

[0135] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0136] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15361m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0137] Example 6

[0138] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0139] Repeat steps 1)-3) of Example 1;

[0140] 4) The washed filter cake of blast furnace ash obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.41 t / d of kiln slag and 15343 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 15wt%. Finally, 5.2t / d of zinc oxide and 15343m 3 / h medium temperature flue gas;

[0141] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0142] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15343 m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0143] Example 7

[0144] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0145] Repeat steps 1)-3) of Example 1;

[0146] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator for pelletization to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200°C for 1.5 h. After the roasting is completed, 72.42 t / d of kiln slag and 15356 m3 / h of kiln tail flue gas are obtained, and 0.8 m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 20wt%. Finally, 5.3t / d of zinc oxide and 15356m 3 / h medium temperature flue gas;

[0147] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0148] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15356 m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0149] Example 8

[0150] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0151] Repeat steps 1)-3) of Example 1;

[0152] 4) The washed filter cake of blast furnace ash obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.37 t / d of kiln slag and 15345 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 10wt%. Finally, 5.1t / d of zinc oxide and 15345m 3 / h medium temperature flue gas;

[0153] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0154] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15345m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0155] Example 9

[0156] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0157] Repeat steps 1)-3) of Example 1;

[0158] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.41 t / d of kiln slag and 15344 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 0.5wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 18wt%. Finally, 5.2t / d of zinc oxide and 15344m 3 / h medium temperature flue gas;

[0159] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0160] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15344m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0161] Example 10

[0162] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0163] Repeat steps 1)-3) of Example 1;

[0164] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.40 t / d of kiln slag and 15346 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 1.5wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 18wt%. Finally, 5.4t / d of zinc oxide and 15346m 3 / h medium temperature flue gas;

[0165] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0166] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15346 m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0167] Embodiment 11

[0168] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0169] Repeat steps 1)-3) of Example 1;

[0170] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.42 t / d of kiln slag and 15351 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 0.3wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 18wt%. Finally, 5.1t / d of zinc oxide and 15351m 3 / h medium temperature flue gas;

[0171] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0172] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15351m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0173] Example 12

[0174] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0175] Repeat steps 1)-3) of Example 1;

[0176] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.46 t / d of kiln slag and 15355 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 2wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 18wt%. Finally, 5.4t / d of zinc oxide and 15355m 3 / h medium temperature flue gas;

[0177] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0178] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15355m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0179] Embodiment 13

[0180] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0181] Repeat steps 1)-3) of Example 1;

[0182] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.39 t / d of kiln slag and 15342 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 16% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 9% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 18wt%. Finally, 5.2t / d of zinc oxide and 15342m 3 / h medium temperature flue gas;

[0183] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0184] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15342 m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0185] Embodiment 14

[0186] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0187] Repeat steps 1)-3) of Example 1;

[0188] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.40 t / d of kiln slag and 15350 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 8% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 17% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 18wt%. Finally, 5.4t / d of zinc oxide and 15350m 3 / h medium temperature flue gas;

[0189] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0190] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and the evaporation and salt separation step discharges 15350m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0191] Embodiment 15

[0192] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0193] Repeat steps 1)-3) of Example 1;

[0194] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.48 t / d of kiln slag and 15356 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 17% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 8% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 18wt%. Finally, 5.1t / d of zinc oxide and 15356m 3 / h medium temperature flue gas;

[0195] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0196] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15356 m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0197] Example 16

[0198] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0199] Repeat steps 1)-3) of Example 1;

[0200] 4) The washed filter cake of blast furnace ash obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.43 t / d of kiln slag and 15337 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 7% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 18% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 18wt%. Finally, 5.2t / d of zinc oxide and 15337m 3 / h medium temperature flue gas;

[0201] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0202] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15337m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0203] Embodiment 17

[0204] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0205] Repeat steps 1)-3) of Example 1;

[0206] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.49 t / d of kiln slag and 15359 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 9% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 11% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 18wt%. Finally, 5.2t / d of zinc oxide and 15359m 3 / h medium temperature flue gas;

[0207] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0208] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15359 m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0209] Embodiment 18

[0210] The existing 30t / d sintering machine head ash (containing 25% chlorine) and 84t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0211] Repeat steps 1)-3) of Example 1;

[0212] 4) The blast furnace ash washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 72.41 t / d of kiln slag and 15338 m 3 / h kiln tail flue gas, spray 0.8m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and pass it into the integrated filter cartridge for decarbonization, denitrification and dust removal. The air velocity is 5000h -1 The mass of the Pt catalyst in the filter cartridge is 13% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 17% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 18wt%. Finally, 5.4t / d of zinc oxide and 15338m 3 / h medium temperature flue gas;

[0213] 5) Spraying the diluted ammonia water collected in step 3) as a reactant into the high-temperature flue gas described in step 4);

[0214] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and 15338 m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0215] Embodiment 19

[0216] The existing 26t / d sintering machine head ash (containing 25% chlorine) and 87t / d blast furnace bag ash (containing 5% chlorine) are treated as follows:

[0217] 1) The sintering machine head ash was washed with three-stage countercurrent water at a water-ash ratio of 2.5:1 and filtered to obtain 3.29m 3 / h sinter ash washing liquid and 17.51t / d sinter ash washing filter cake, at the same time, blast furnace bag ash is washed with three-stage countercurrent water at a water-ash ratio of 1.5:1 and filtered to obtain 4.3m 3 / h blast furnace ash water washing liquid and 93.8t / d blast furnace ash water washing filter cake, the sintering ash water washing liquid and blast furnace ash water washing liquid are mixed to obtain 7.59m 3 / h mixed solution;

[0218] 2) Add 7.59m obtained in step 1) 3 / h mixed solution, add 7.59kg / h sodium sulfide and 13.66kg / h sodium carbonate, and filter after reaction to obtain 0.76t / d heavy metal sludge and 7.39m 3 / h high salt solution;

[0219] 3) Adjust the 7.39 m obtained in step 2) with NaOH 3 / h high salt solution to 11, and then the pH adjusted high salt solution is passed into a multi-stage temperature variable evaporation device for evaporation and salt separation, wherein the high salt solution passes through a triple effect reactor, a second effect reactor and a first effect reactor in sequence, the temperature in the triple effect reactor is 35°C, the vacuum degree is -80kPa, the temperature in the second effect reactor is 70°C, the vacuum degree is -55kPa, the temperature in the first effect reactor is 90°C, the vacuum degree is -20kPa, the condensed water in the triple effect reactor is collected separately, and 18g / L of 2.54m 3 / h of dilute ammonia water. At the same time, evaporation of salts yielded 8.22t / d of sodium chloride with a purity of 85% and 17.82t / d of potassium chloride with a purity of 91%.

[0220] 4) The 93.8 t / d blast furnace ash water-washed filter cake obtained in step 1) is sent to a disc granulator to obtain 5 mm blast furnace ash pellets, and the blast furnace ash pellets are sent to a rotary kiln for roasting at 1200° C. for 1.5 h. After the roasting is completed, 70.58 t / d of kiln slag and 14800 m 3 / h kiln tail flue gas, spray 0.76m 3 / h dilute ammonia water, and then pass the high-temperature flue gas into the waste heat boiler, cool it to 410℃ and then pass it into the filter cartridge, with an air velocity of 5000h -1 The mass of the Pt catalyst in the filter cartridge is 11% of the weight of the filter cartridge, and the Pt loading is about 1.0wt%; the mass of the CoMn catalyst is 14% of the weight of the filter cartridge, the content of Co is 60wt%, and the content of Mn is 18wt%. 5.2t / d of zinc oxide and 14800m 3 / h medium temperature flue gas;

[0221] 5) The dilute ammonia water collected in step 3) is used as a reactant, wherein 0.76m 3 / h sprayed into the high-temperature flue gas described in step 4);

[0222] 6) The medium temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and the evaporation and salt separation step discharges 14800m 3 / h low-temperature flue gas, and the low-temperature flue gas is used to dry the blast furnace ash pellets in step 4).

[0223] Comparative Example 1

[0224] Example 1 was repeated except that the Co content in the CoMn catalyst was 45 wt %.

[0225] Comparative Example 2

[0226] Example 1 was repeated except that the Co content in the CoMn catalyst was 75 wt %.

[0227] Comparative Example 3

[0228] Example 1 was repeated except that the Mn content in the CoMn catalyst was 5 wt %.

[0229] Comparative Example 4

[0230] Example 1 was repeated except that the Mn content in the CoMn catalyst was 25 wt %.

[0231] Comparative Example 5

[0232] Example 1 was repeated except that the content of Pt in the Pt catalyst was 0.2 wt %.

[0233] Comparative Example 6

[0234] Example 1 was repeated except that the Pt content in the Pt catalyst was 2.5 wt %.

[0235] Comparative Example 7

[0236] Example 1 was repeated, except that the mass ratio of the Pt catalyst to the CoMn catalyst was 1:0.4.

[0237] Comparative Example 8

[0238] Example 1 was repeated, except that the mass ratio of the Pt catalyst to the CoMn catalyst was 1:3.

[0239] Comparative Example 9

[0240] Example 1 was repeated except that the total catalyst content was 15% by weight of the filter cartridge.

[0241] Comparative Example 10

[0242] Example 1 was repeated except that the total catalyst content was 35% by weight of the filter cartridge.

[0243] Comparative Example 11

[0244] Example 1 was repeated except that the filter cartridge did not contain a Pt catalyst.

[0245] Comparative Example 12

[0246] Example 1 was repeated except that the filter cartridge did not contain the CoMn catalyst.

[0247] Comparative Example 13

[0248] Example 1 was repeated except that the filter cartridge did not contain the Pt catalyst and the CoMn catalyst.

[0249] Comparative Example 14

[0250] Example 1 is repeated, except that the filter cartridge is not included. The Pt catalyst and the CoMn catalyst are placed in a rectangular container with a smoke inlet on one side and a smoke outlet on the other side. High-temperature smoke is introduced from the smoke inlet and discharged from the smoke outlet after purification to obtain medium-temperature smoke.

[0251] Among them, some process conditions of Examples 1 to 19 and Comparative Examples 1 to 14 are shown in Table 1.

[0252] Detection of CO and NO in the medium-temperature flue gas obtained in Examples 1 to 19 and Comparative Examples 1 to 14 x and NH3 concentrations, the results are shown in Table 2.

[0253] Table 1

[0254]

[0255]

[0256] Table 2

[0257]

[0258]

[0259]

[0260] According to the above experiments, the present invention uses Pt / TiO2 catalyst and CoMn catalyst to catalyze CO and nitrogen oxides in high-temperature flue gas and filter dust in the flue gas at the same time, which has a good catalytic effect, and determines the optimal dosage range and the optimal content range of Pt, Co, and Mn in the catalyst. It is concluded that the catalytic and filtering effects are best when the mass ratio of Pt catalyst and CoMn catalyst is 1:0.5-2.5, the platinum content in the Pt catalyst is 0.3-2wt%, the Co content in the CoMn catalyst is 50-70wt%, and the Mn content is 10-20wt%. The total amount of catalyst is 20-30% of the weight of the filter cartridge.

Claims

1. A method for coordinated disposal of blast furnace bag ash and sintering machine head ash and CO purification, characterized in that: The method comprises the following steps: 1) washing the sintering machine head ash with water to obtain sintering ash washing water and sintering ash water washing filter cake; washing the blast furnace bag ash with water to obtain blast furnace ash washing water and blast furnace ash water washing filter cake, and combining the sintering ash washing water and the blast furnace ash washing water to obtain a mixed solution; 2) adding a de-heaving agent and a de-hardening agent to the mixed solution obtained in step 1) to react, and after the reaction is completed, performing solid-liquid separation to obtain heavy metal sludge and a high-salt solution; 3) first adjusting the high salt solution obtained in step 2) to be alkaline, and then subjecting the alkaline high salt solution to evaporation and salt separation treatment to obtain polluted condensed water, potassium salt, sodium salt and dilute ammonia water; 4) First, the blast furnace ash water-washed filter cake is mixed with coal powder and auxiliary materials and pelletized. The obtained green pellets are preheated and dried and then sent to a rotary kiln for heat treatment to obtain high-temperature flue gas and kiln slag; then, ammonia water is sprayed into the high-temperature flue gas for a primary denitrification treatment, and then the high-temperature flue gas after the primary denitrification treatment is cooled and then decarbonized, secondary denitrified and dust removed in sequence to obtain secondary zinc oxide and medium-temperature flue gas.

2. The method according to claim 1, characterized in that: The method further comprises: 5) introducing the diluted ammonia water obtained in step 3) as a reactant into the high-temperature flue gas in step 4) to participate in a denitration treatment; and / or The method further comprises: 6) introducing the medium-temperature flue gas obtained in step 4) into the evaporation and salt separation treatment in step 3) as a heat source.

3. The method according to claim 2, characterized in that: The sintering machine head ash water washing in step 1) is a multi-stage water washing, preferably a three-stage countercurrent water washing; preferably, the sintering ash water-to-ash ratio is 1.5-5:1, preferably 2-4:

1.

4. The method according to claim 2 or 3, characterized in that: Step 2) the de-heaving agent is sodium sulfide or a heavy capture agent, and the amount added is 0.3 to 3 g / L, preferably 0.5 to 2 g / L; and / or Step 2) the hardness removal agent is sodium carbonate, the addition amount is 0.3-3.5 g / L, preferably 0.5-3 g / L; Preferably, the reaction time for removing weight and hardness is 0.5 to 2 hours, preferably 0.8 to 1.5 hours; Preferably, the blast furnace bag ash washing in step 2) is a multi-stage washing, preferably a three-stage countercurrent washing; preferably, the blast furnace bag ash water-to-ash ratio is 0.5 to 3:1, preferably 1 to 2:1; Preferably, the three-stage countercurrent water washing is specifically as follows: the sintering machine head ash or blast furnace bag ash solids are sequentially subjected to primary, secondary and tertiary water washings, wherein the water source for the primary water washing is the filtrate from the secondary water washing, the water source for the secondary water washing is the filtrate from the tertiary water washing, the water source for the tertiary water washing is industrial water and / or sewage condensate, and the filtrate from the primary water washing is discharged from the system.

5. The method according to any one of claims 2 to 4, characterized in that: Step 3) The alkalinity is a pH value between 10 and 13, preferably a pH value between 11 and 12; preferably, the alkaline substance is sodium hydroxide and / or potassium hydroxide; Preferably, the evaporation and salt separation in step 3) is temperature-variable evaporation and salt separation, preferably, the evaporation is countercurrent multi-effect salt separation, the high-salt solution passes through a triple-effect reactor, a second-effect reactor and a first-effect reactor in sequence, and the liquid flow direction is opposite to the steam flow direction, and the condensed water at the steam outlet of the triple-effect reactor is collected separately to obtain dilute ammonia water; preferably, the temperature in the triple-effect reactor is controlled to be 20-60°C (preferably 30-50°C), the vacuum degree is -150-50kPa (preferably -100-70kPa), the temperature of the second-effect evaporation is controlled to be 40-90°C (preferably 50-80°C), the vacuum degree is -100-30kPa (preferably -70-40kPa), the temperature of the first-effect evaporation is controlled to be 70-105°C (preferably 80-100°C), and the vacuum degree is -50-10kPa (preferably -40-15kPa); Preferably, the step 3) further comprises: 31) the evaporation and salt separation process also obtains low-temperature flue gas discharged for drying the blast furnace bag ash after pelletizing in step 4).

6. The method according to any one of claims 2 to 5, characterized in that: The single-effect reactor evaporation described in step 3) adopts a flue gas heat exchange evaporator; the flue gas heat exchange evaporator comprises a main body (A), the interior of the main body (A) is divided into an observation and maintenance chamber (1) and an evaporation chamber (2) from top to bottom, and a partition (3) is provided between the observation and maintenance chamber (1) and the evaporation chamber (2); the observation and maintenance chamber (1) is provided with a steam outlet (11) at the top, and an observation port (12) and a maintenance entrance (13) at the side; a steam channel (31) is opened in the middle of the partition (3); the evaporation chamber (2 ) is provided with a high-salt solution inlet (21) on one side of the bottom, a high-temperature smoke inlet (22) and a low-temperature smoke outlet (23) are provided on the side of the evaporation chamber (2), a smoke duct and a liquid discharge pipe (24) are provided inside the evaporation chamber (2), wherein the two ends of the smoke duct are respectively connected to the high-temperature smoke inlet (22) and the low-temperature smoke outlet (23), the upper end of the liquid discharge pipe (24) is arranged inside the evaporation chamber (2), and the lower end of the liquid discharge pipe (24) extends downwardly out of the main body (A) and is provided with a high-salt solution outlet (25) at the end; Preferably, the flue gas duct is bent in the evaporation chamber (2); and / or The upper end of the liquid discharge pipe (24) is arranged in the upper middle area of ​​the evaporation chamber (2) and is located below the steam channel (31).

7. The method according to claim 6, characterized in that: A drainage branch pipe (26) is provided at the bottom of the evaporation chamber (2); the upper end of the drainage branch pipe (26) is arranged in the evaporation chamber (2), and the lower end extends downwardly out of the main body (A); preferably, the end of the drainage branch pipe (26) is connected to the drainage pipe (24), and a valve (261) is provided in the drainage branch pipe (26); and / or A condensate discharge pipe (27) is also provided at the bottom of the evaporation chamber (2), the upper end of the condensate discharge pipe (27) is connected to the flue gas duct, and the lower end of the condensate discharge pipe (27) extends downwardly out of the main body (A); and / or The evaporation chamber (2) is further provided with a horizontal baffle (28) and / or a vertical baffle (29); preferably, a plurality of horizontal baffles (28) and / or vertical baffles (29) are staggeredly arranged inside the evaporation chamber (2); Preferably, a pressure detection port (4) is provided on the side of the observation and inspection chamber (1) and / or the evaporation chamber (2).

8. The method according to any one of claims 2 to 7, characterized in that: The decarbonization, secondary denitration and dust removal treatment described in step 4) is specifically as follows: decarbonization, secondary denitration and dust removal are performed on the cooled high-temperature flue gas using a decarbonization, denitration and dust removal integrated filter cartridge, wherein the decarbonization, denitration and dust removal integrated filter cartridge comprises a catalytic layer, a filter layer and a support layer, all of which are air-permeable, and the catalytic layer, the filter layer and the support layer are arranged from the inside to the outside of the decarbonization, denitration and dust removal integrated filter cartridge, and the catalytic layer contains a CO oxidation catalyst and an SCR catalyst; Preferably, the CO oxidation catalyst and the SCR catalyst are Pt catalyst and CoMn catalyst, and the filter layer is a mesh; the total content of the catalyst in the filter cartridge is 20-30% of the weight of the filter cartridge, wherein the mass ratio of the Pt catalyst to the CoMn catalyst is 1:0.5-2.5, preferably 1:0.6-2; Preferably, the carrier of the Pt catalyst is TiO2, wherein the content of Pt is 0.3-2wt%, preferably 0.5-1.5wt%; and / or The CoMn catalyst has a Co content of 50-70wt%, preferably 55-65wt%, and a Mn content of 10-20wt%, preferably 15-20wt%; Preferably, the integrated decarbonization, denitrification and dust removal filter cartridge comprises a plurality of alternately arranged catalytic layers, filtration layers and support layers.

9. The method according to any one of claims 2 to 8, characterized in that: The high temperature flue gas temperature in step 4) is 830-1000°C (preferably 850-950°C), and the injection amount of ammonia water is 70-150 mg / m 3 , the injection method is atomization injection; and / or The step 4) of cooling the high-temperature flue gas after the primary denitrification treatment is as follows: the high-temperature flue gas is passed through a waste heat boiler for waste heat recovery; preferably, the circulating water volume of the waste heat boiler is adjusted to control the flue gas temperature entering the filter cartridge to be 370-450°C (preferably 400-430°C) and the air velocity to be 1000-10000h -1 ; and / or The pelletizing in step 4) is to pelletize the blast furnace ash water-washed filter cake using a disc pelletizer to obtain spherical particles of 3 to 8 mm (preferably 4 to 6 mm); and / or Step 4) the calcination temperature is 1000-1400° C. (preferably 1100-1300° C.) and the calcination time is 1-2 h; and / or The auxiliary materials described in step 4) include binders and miscellaneous auxiliary materials.

10. The method according to any one of claims 2 to 9, characterized in that: The step 1) specifically comprises: performing three-stage countercurrent water washing on the sintering machine head ash at a water-ash ratio of 1.5 to 5:1 (preferably 2 to 4:1), and performing three-stage countercurrent water washing on the blast furnace bag ash at a water-ash ratio of 0.5 to 3:1 (preferably 1 to 2:1), filtering the washing liquids of the two respectively, and mixing the washing liquids to obtain a sintering ash washing filter cake, a blast furnace ash washing filter cake and a mixed solution; and / or The step 2) is specifically as follows: adding a de-weighting agent and a de-hardening agent to the mixed solution obtained in step 1), wherein the amount of the de-weighting agent added is 0.3 to 3 g / L (preferably 0.5 to 2 g / L), and the amount of the de-hardening agent added is 0.3 to 3.5 g / L (preferably 0.5 to 3 g / L), reacting for 0.5 to 2 h (preferably 0.8 to 1.5 h) and then filtering to obtain heavy metal sludge and a high salt solution; and / or The step 3) specifically comprises: adjusting the pH of the high-salt solution obtained in step 2) to 10-13 (preferably 11-12) with sodium hydroxide, and then subjecting the high-salt solution after the pH adjustment to multi-stage temperature-variable evaporation to obtain polluted condensed water, potassium salt, sodium salt and dilute ammonia water; and / or The step 4) is specifically as follows: the blast furnace ash water-washed filter cake obtained in step 1) is sent to a disc granulator for pelletizing to obtain 3-8 mm (preferably 4-6 mm) blast furnace ash pellets, the blast furnace ash pellets are sent to a rotary kiln for roasting at a temperature of 1000-1400° C. (preferably 1100-1300° C.) for 1-2 h, and high-temperature flue gas and kiln slag are obtained after the roasting is completed. Dilute ammonia water is sprayed into the high-temperature flue gas at a ratio of 1:1, and then the high-temperature flue gas is passed through a waste heat boiler, cooled to 370-460° C. (preferably 400-430° C.), and then passed into a filter cartridge for decarbonization, denitrification and dust removal, with an air velocity of 1000-10000 h -1 , obtaining zinc oxide and medium-temperature flue gas; and / or The step 5) specifically comprises: introducing 1% to 10% of the dilute aqueous ammonia obtained in step 3) as a reactant into the high-temperature flue gas in step 4); and / or The step 6) is specifically as follows: the low-temperature flue gas obtained in step 4) is introduced into the evaporation and salt separation step in step 3) as a heat source, and the low-temperature flue gas discharged from the evaporation and salt separation step is used to dry the blast furnace ash pellets in step 4).

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