Method and device for removing carbon dioxide in phosphate ore by calcining CO-containing industrial tail gas
阅读说明：本技术 利用含co工业尾气煅烧去除磷矿石中二氧化碳的方法及其装置 (Method and device for removing carbon dioxide in phosphate ore by calcining CO-containing industrial tail gas ) 是由 郜华萍 严建华 黄群星 王六生 丁蕾蕾 孟详东 万欣 郜烨 黄信达 于 2019-10-17 设计创作，主要内容包括：本发明公开了一种利用含CO工业尾气煅烧去除磷矿石中二氧化碳的方法及其装置,该方法是将经过净化处理的CO工业尾气和空气通入煅烧窑体系统内,空气过剩系数为1.1～2.5,中低品位磷矿石先在煅烧窑体系统内预热至300～600℃,然后在600～900℃下进行煅烧,去除磷矿石中二氧化碳,提高P<Sub>2</Sub>O<Sub>5</Sub>含量,煅烧中产生的烟气进行余热回收,回收的热量用于煅烧,回收热量后的烟气净化排放；本发明方法以废治废,降低磷矿石中碳酸盐含量,获得高品级磷精矿,提高CO工业尾气利用率,实现了资源挖潜与品质提升；能源节约与循环经济；环境保护与污染减排的目标。(The invention discloses a method and a device for removing carbon dioxide in phosphate ore by calcining CO-containing industrial tail gas, wherein the method comprises the steps of introducing purified CO industrial tail gas and air into a calcining kiln system, wherein the excess air coefficient is 1.1-2.5, preheating medium and low-grade phosphate ore to 300-600 ℃ in the calcining kiln system, calcining at 600-900 ℃, removing carbon dioxide in the phosphate ore, and improving P 2 O 5 Content, the flue gas generated in the calcination is subjected to waste heat recovery, the recovered heat is used for calcination, and the flue gas after the heat recovery is purified and discharged; the method disclosed by the invention treats waste by waste, reduces the carbonate content in the phosphorus ore, obtains high-grade phosphorus concentrate, improves the utilization rate of CO industrial tail gas, and realizes resource potential excavation and quality improvement; energy conservation and circular economy; environmental protection and pollution emission reduction.)
1. A method for removing carbon dioxide in phosphate ore by calcining industrial tail gas containing CO is characterized by comprising the following steps: introducing purified CO industrial tail gas and air into a calcining kiln system, wherein the air surplus coefficient is 1.1-2.5, preheating medium and low grade phosphate ore to 300-600 ℃ in the calcining kiln system, calcining at 600-900 ℃, removing carbon dioxide in the phosphate ore, and improving P2O5Content, the flue gas produced in the calcination is subjected to waste heat recovery, the recovered heat is used for calcination, and the flue gas after the heat recovery is purified and discharged.
2. The method for removing carbon dioxide from phosphate ore by calcining CO-containing industrial tail gas as claimed in claim 1, wherein the method comprises the following steps: the industrial tail gas containing CO is blast furnace gas, converter gas, yellow phosphorus tail gas or calcium carbide furnace tail gas.
3. The method for removing carbon dioxide from phosphate ore by calcining CO-containing industrial tail gas as claimed in claim 1, wherein the method comprises the following steps: h in CO industrial tail gas after purification treatment2S content<50mg/Nm3，PH3Content (wt.)<10mg/Nm3，AsH3Content (wt.)<10mg/Nm3HF content<20mg/Nm3。
4. The device for removing the carbon dioxide in the phosphate ore by calcining the CO-containing industrial tail gas is characterized by comprising the following steps of: the system comprises a CO industrial tail gas purification and conveying system (1), a calcining kiln system (2), a feeding system (3), a flue gas waste heat utilization system (4), a flue gas treatment system (5) and a combustion air system (6); the feeding system (3) is communicated with the calcining kiln system (2), and the CO industrial tail gas purifying and conveying system (1) is communicated with the calcining kiln system (2); the combustion-supporting air system (6) is communicated with the calcining kiln system (2), and the other end of the calcining kiln system (2) is connected with the combustion-supporting air system (6); the calcining kiln system (2) is connected with the flue gas waste heat utilization system (4), and the other end of the flue gas waste heat utilization system (4) is connected with the calcining kiln system (2); the calcining kiln system (2), the flue gas waste heat utilization system (4) and the combustion air system (6) are respectively connected with the flue gas treatment system (5).
5. The apparatus of claim 4, wherein: the CO industrial tail gas purification and conveying system (1) comprises
The tail gas purification device comprises a tail gas purification device (1-1), a CO industrial tail gas storage tank (1-2), a safety water seal (1-3), an induced draft fan I (1-4), a check valve (1-5) and a CO alarm (1-6), wherein the tail gas purification device (1-1) is connected with the safety water seal (1-3) through the CO industrial tail gas storage tank (1-2), the safety water seal (1-3) is connected with the induced draft fan I (1-4), the induced draft fan I (1-4) is connected with a calcining kiln system (2) through a pipeline, and the check valve (1-5) and the CO alarm (1-6) are sequentially arranged on the pipeline.
6. The apparatus of claim 5, wherein: the calcining kiln system (2) comprises a hollow kiln body (2-1), a storage bin (2-2), an upper combustion beam (2-3), a lower combustion beam (2-4), an upper air suction beam (2-5), a lower air suction beam (2-6), a kiln lower cooling fan (2-7), a discharge bin (2-8), a rack (2-9) and a material level meter (2-10), wherein the kiln body (2-1) is fixed on the rack (2-9), the storage bin (2-2) is arranged on a feed inlet at the top end of the shell (2-1), an upper air suction beam (2-5), an upper combustion beam (2-3), a lower combustion beam (2-4) and a lower air suction beam (2-6) are sequentially arranged in the kiln body (2-1) from top to bottom, a cavity between the upper air suction beam (2-5) and the upper combustion beam (2-3) is a preheating cavity (2-11), a cavity between the upper combustion beam (2-3) and the lower combustion beam (2-4) is an upper calcining combustion chamber (2-12), a cavity between the lower combustion beam (2-4) and the lower air absorption beam (2-6) is a lower calcining combustion chamber (2-13), a cavity below the lower air absorption beam (2-6) is a discharge chamber (2-14), a discharge bin (2-8) is arranged at a discharge port at the bottom of the kiln body (2-1), a level gauge (2-10) is arranged on one side of the upper part of the kiln body (2-1), the feeding system (3) is connected with the storage bin (2-2), an outlet of a cooling fan (2-7) below the kiln is communicated into the discharge chamber (2-14), the upper air absorption beam (2-5) is respectively communicated with the flue gas waste heat utilization system (4) and the combustion-supporting air system (6), the lower air suction beams (2-6) are communicated with a flue gas treatment system (5).
7. The apparatus of claim 6, wherein: the upper combustion beam (2-3) comprises a beam body (2-3-1), combustion air burners (2-3-3), a CO industrial tail gas burner (2-3-4), a heat transfer oil inlet pipe (2-3-5), a heat transfer oil outlet pipe (2-3-6), a cluster fuel pipe (2-3-7), a combustion air pipe (2-3-8) and a spray gun igniter (2-3-9), wherein the beam body (2-3-1) is a hollow box body with an interlayer (2-3-2) on the outer side, the combustion air burners (2-3-3) and the CO industrial tail gas burners (2-3-4) are respectively arranged on the beam body (2-3-1), and 1 CO industrial tail gas burner is matched with 2 combustion air burners (2-3-3) to form a nozzle group, the front side and the rear side of the beam body are arranged in parallel by a plurality of nozzle groups; one ends of the plurality of cluster fuel pipes (2-3-7) are communicated with a draught fan I (1-4) of the CO industrial tail gas purification and delivery system, and the other ends of the plurality of cluster fuel pipes penetrate through the hollow beam body (2-3-1) and are communicated with the plurality of CO industrial tail gas burners (2-3-4); one end of more than 1 combustion-supporting air pipe (2-3-8) is connected with a combustion-supporting air system (6), and the other end is communicated to the beam body and communicated with a combustion-supporting air burner (2-3-3); the heat conducting oil inlet pipe (2-3-5) and the heat conducting oil outlet pipe (2-3-6) are respectively arranged at two ends of the beam body (2-3-1) and are communicated with the interlayer (2-3-2), and more than one spray gun igniter (2-3-9) is arranged on the beam body and is positioned beside the nozzle group; the structure of the lower combustion beam (2-4) is the same as that of the upper combustion beam (2-3), and the difference is that a plurality of nozzle groups are arranged on the lower end surface of the beam body.
8. The apparatus of claim 7, wherein: the flue gas waste heat utilization system (4) comprises an induced draft fan II (4-1), a flue gas economizer (4-2), a steam generator (4-3), a heat-conducting oil tank (4-4), an expansion tank (4-5) and a filter (4-6), wherein an upper air suction beam (2-5) is communicated with an air inlet of the flue gas economizer (4-2) through the induced draft fan II (4-1), a water outlet of the flue gas economizer (4-2) is communicated with the heat-conducting oil tank (4-4) through the steam generator (4-3), the heat-conducting oil tank (4-4) is respectively communicated with a heat-conducting oil inlet pipe on an interlayer of an upper combustion beam and a heat-conducting oil inlet pipe on an interlayer of a lower combustion beam through the expansion tank (4-5), a heat-conducting oil outlet pipe on the interlayer of the upper combustion beam and a heat-conducting oil outlet pipe on an interlayer of the lower combustion beam are connected with And the gas outlet of the flue gas economizer (4-2) is communicated with the flue gas treatment system (5), and the flue gas economizer (4-2) is provided with a water inlet.
9. The apparatus of claim 7, wherein: the combustion-supporting air system (6) comprises an air heat exchanger (6-1) and a combustion-supporting fan (6-2), the combustion-supporting fan (6-2) is respectively communicated with a combustion-supporting air pipe (2-3-8) on the upper combustion beam (2-3) and a combustion-supporting air pipe on the lower combustion beam (2-4) through the air heat exchanger (6-1), and an outlet of the upper air suction beam (2-5) is communicated with the air heat exchanger (6-1).
10. The apparatus of claim 9, wherein: the flue gas treatment system (5) comprises an induced draft fan III (5-1) and a dust remover (5-2), wherein the lower air suction beam (2-6) is connected with the dust remover (5-1) through the induced draft fan III (5-2), an air outlet of the flue gas economizer (4-2) is connected with the dust remover (5-1), and an air heat exchanger (6-1) is connected with the dust remover (5-1).
Technical Field
The invention relates to a method for utilizing a CO-containing materialThe industrial tail gas calcining process and apparatus for eliminating carbon dioxide from phosphate rock includes utilizing industrial tail gas containing CO as fuel, treating waste with waste, calcining middle and low grade phosphate rock with low value fuel to eliminate carbon dioxide and raise P content of phosphate rock2O5A method and apparatus for upgrading.
Background
Phosphorite is a general term of utilized phosphate minerals and is an important chemical mineral raw material; it can be used to prepare phosphate fertilizer, yellow phosphorus, phosphoric acid, phosphide and other phosphates, and can be used in medicine, food, match, dye, sugar, ceramics and national defence industries. The industrial use of phosphate rock has been known for over a hundred years. With P2O5>The annual total yield of the world phosphate rock is up to (l.26-1.35) hundred million tons based on 30% of commercial phosphate rock. The total scale, the yield and the export of yellow phosphorus production in China are all the first in the world, and about 80 percent of yellow phosphorus in the world is exported by China. China has proved that phosphorite resources are distributed in 27 province autonomous regions, phosphorite enrichment regions are Hubei, Hunan, Sichuan, Guizhou and Yunnan, 135 hundred million tons of 5 province phosphorite resources (ore amount) are found out and account for 76.7 percent of the whole country, and the 5 province phosphorite resources (P province phosphorite resource amount) is calculated according to the average ore grade of the ore in the ore region2O5Amount) 28.66 hundred million tons, accounting for 90.4% of the country. To possess the reserve of phosphorite resource according to P2O5The quantity is arranged, the phosphorite ranks in Yunnan province are nationwide first, the ore quantity is 40.2 hundred million tons, P2O5The amount was 8.94 million tons. The proven large phosphorite is concentrated in six ore areas of Kunyang, Haikou, Jinning, Anning, Huaning, Jianchuan and Chengjiang, most ore bodies are buried shallowly, and the phosphorite is positioned beside the plateau lake. High grade phosphate ore (w (P) over 60 years of mining and processing2O5）≥ 28%、w（SiO2) Not less than 30 percent) and the high-grade and non-renewable phosphate ore become the bottleneck restricting the sustainable development of the phosphorus chemical industry. By the end of 2018, the yield of the rich ore (mainly weathered rich ore) detected in Yunnan is about 0.42 hundred million tons, and the middle-low grade phosphorite resource is nearly 10 hundred million tons and cannot be utilized.
At present, the instituteThe reported methods for utilizing low-grade phosphate ore need to add a large amount of sulfuric acid or mineralizer and the like, and the methods can be used for treating P in the phosphate ore2O5The lifting rate is very low, and a large amount of secondary pollutants are generated at the same time, so that the pollution to water sources and soil is caused. Yellow phosphorus production enterprises are built around plateau lakes due to the geographical positions of yellow phosphorus ores, and only can improve the quality of the phosphorus pentoxide of middle-low-grade phosphate ores by utilizing a dry method according to the protection requirements of the environment and the plateau lakes.
Disclosure of Invention
Carbon dioxide in the phosphate ore is stored in carbonate impurities, the content of the carbon dioxide is increased, the content of phosphorus pentoxide in the phosphate ore is low, the power consumption in the production of yellow phosphorus is increased, and simultaneously, slag, phosphorus iron and phosphorus mud are increased, so that the phosphorus yield is reduced; the lower the carbon dioxide in the phosphate ore is, the higher the phosphorus pentoxide content is, the better the phosphate ore grade is, and the higher the phosphorus recovery rate is. Research and actual production show that: in the process of producing yellow phosphorus by an electric furnace method, the carbonate in the phosphate ore can cause the temperature in the furnace to be reduced, and CO released after pyrolysis2Reacting with phosphorus vapor sublimated from the reaction zone to form phosphorus suboxide (P)3O4，P2O3Etc.). P in phosphorus ore2O5The content is reduced by 1 percent, and the phosphorus yield is reduced by more than 0.5 percent; CO in phosphorus ore2The content is increased by 1 percent, the yellow phosphorus increases the power consumption by 200 KW.H/t, and 29Kg of coke (SI basic unit) is consumed more.
Aiming at the problems, the invention provides a method for removing carbon dioxide in phosphate ore by calcining CO-containing industrial tail gas, which comprises the steps of introducing purified CO industrial tail gas and air into a calcining kiln system, wherein the air surplus coefficient is 1.1-2.5, preheating medium and low-grade phosphate ore to 300-600 ℃ in the calcining kiln system, calcining at 600-900 ℃, removing carbon dioxide in the phosphate ore, and improving P2O5Content, the flue gas produced in the calcination is subjected to waste heat recovery, the recovered heat is used for calcination, and the flue gas after the heat recovery is purified and discharged.
The invention adopts CO-containing industrial tail gas as fuel to calcine phosphate ore, treats waste with waste, removes carbon dioxide in carbonate, and uses roastingDigestion method, P in middle-low grade phosphate ore2O5The content is increased from 12% -20% to 25% -32%; the content of carbon dioxide in the carbonate is reduced to below 6% from 10% -20%.
The industrial tail gas containing CO is blast furnace gas, converter gas, yellow phosphorus tail gas or calcium carbide furnace tail gas.
The blast furnace gas is combustible gas containing CO generated in the blast furnace ironmaking production process. 1300-1600 Nm blast furnace gas as by-product for producing 1 ton of iron3H, heat value of 3.34X 103～4.18×103And (5) carrying out KJ/Nm cultivation. Blast furnace gas total composition (V/V): CO: 20-40%; CO 22：14～20%；H2：1～2%；O2：0.5%；CH4：0.3～0.8%；N2: 50-60%; heat value: 3200 to 4000KJ/Nm3，SO2：100～200 mg/Nm3And (3) dust: 80-200 mg/Nm3。
The converter gas is combustible gas produced after top-blown oxygen reacts with carbon in molten iron in the process of steelmaking by a top-blown converter. Producing 1 ton steel with by-product converter gas 75-100Nm3A heat value of 6.27 to 8.37 x 103And (5) carrying out KJ/Nm cultivation. Converter gas total composition (V/V): CO: 45-60 percent; CO 22：14～20%；H2：1～2%；O2：0.6%～0.8%；CH4：0.3～0.8%；N2: 25-35%; heat value: 6800 to 7330KJ/Nm3，SO2：60～80 mg/Nm3And (3) dust: 130 to 180 mg/Nm3。
The calcium carbide furnace gas is the byproduct tail gas in the production of calcium carbide by the closed calcium carbide furnace. 1 ton of calcium carbide is produced, and 2400-2800 Nm of calcium carbide furnace gas is produced as a byproduct3And/h, the calorific value is 9627-10883 KJ/Nm. The total components (V/V) of the furnace gas of the closed calcium carbide furnace are as follows: 80% -85% of CO; h22.7%；CO22.4%；
The yellow phosphorus tail gas is a byproduct in the process of producing yellow phosphorus by an electric furnace method. 3000-4500 Nm of 1 ton yellow phosphorus byproduct tail gas3The heat value is 9964-11136 KJ/Nm3. Total components (V/V) of yellow phosphorus tail gas: CO 85-92%, Phosphorus (PH)3500~900mg/ Nm3，P4300~700 mg/ Nm3) Sulfur (H)2S 800～3000mg/Nm3）、As（1～2mg/Nm3）、F（400～500mg/Nm3) And impurities and a small amount of water.
The purification of CO industrial tail gas adopts the method and the device in the patent ZL200910094045.9 yellow phosphorus tail gas purification method and the device thereof to remove pollutants such as phosphorus, sulfur, fluorine, dust and the like in the tail gas; the purified CO industrial tail gas meets the requirement of a phosphorite calcining device on fuel, namely H in the CO industrial tail gas2S content<50mg/Nm3，PH3Content (wt.)<10mg/Nm3，AsH3Content (wt.)<10mg/Nm3HF content<20mg/Nm3。
The invention also aims to provide a device for completing the method, which comprises a CO industrial tail gas purification and conveying system, a calcining kiln system, a feeding system, a flue gas waste heat utilization system, a flue gas treatment system and a combustion air system; the feeding system is communicated with the calcining kiln system, and the CO industrial tail gas purifying and conveying system is communicated with the calcining kiln system; the combustion-supporting air system is communicated with the calcining kiln system, and the other end of the calcining kiln system is connected with the combustion-supporting air system; the calcining kiln system is connected with the flue gas waste heat utilization system, and the other end of the flue gas waste heat utilization system is connected with the calcining kiln system; the calcining kiln system, the flue gas waste heat utilization system and the combustion air system are respectively connected with the flue gas treatment system.
CO industry tail gas purification and conveying system includes tail gas cleanup unit, CO industry tail gas holder, safe water seal, draught fan I, check valve, CO alarm, and tail gas cleanup unit passes through CO industry tail gas holder and is connected with safe water seal, and safe water seal is connected with draught fan I, and draught fan I passes through the pipeline and is connected with calcining kiln systemic system, has set gradually check valve, CO alarm on the pipeline.
The calcining kiln system comprises a hollow kiln body, a storage bin, an upper combustion beam, a lower combustion beam, an upper air suction beam, a lower air suction beam, a kiln lower cooling fan, a discharge bin, a rack and a material level meter, wherein the kiln body is fixed on the rack, the storage bin is arranged on a feed inlet at the top end of the shell, the kiln body is internally provided with the upper air suction beam, the upper combustion beam, the lower combustion beam and the lower air suction beam from top to bottom in sequence, a cavity between the upper air suction beam and the upper combustion beam is a preheating cavity, a cavity between the upper combustion beam and the lower combustion beam is an upper calcining combustion chamber, a cavity between the lower combustion beam and the lower air suction beam is a lower calcining combustion chamber, a cavity below the lower air suction beam is a discharge chamber, the discharge bin is arranged at the discharge outlet at the bottom of the kiln body, the material level meter is arranged on one side of the upper part of the kiln body, the feed system is connected with the storage bin, an outlet of the kiln lower cooling fan is, The combustion-supporting air system is communicated, and the lower air suction beam is communicated with the flue gas treatment system.
The upper combustion beam comprises a beam body, combustion-supporting air burners, CO industrial tail gas burners, a heat conduction oil inlet pipe, a heat conduction oil outlet pipe, a cluster fuel pipe, a combustion-supporting air pipe and a spray gun igniter, wherein the beam body is a hollow box body with an interlayer on the outer side; one end of each cluster fuel pipe is communicated with a draught fan I of the CO industrial tail gas purification and conveying system, and the other end of each cluster fuel pipe penetrates through the hollow beam body to be communicated with the CO industrial tail gas burners; one end of more than 1 combustion-supporting air pipe is connected with a combustion-supporting air system, and the other end of the combustion-supporting air pipe is communicated to the beam body and communicated with a combustion-supporting air burner; the heat conducting oil inlet pipe and the heat conducting oil outlet pipe are respectively arranged at two ends of the beam body and communicated with the interlayer, and more than one spray gun igniter is arranged on the beam body and positioned beside the nozzle group; the lower combustion beam structure is the same as the upper combustion beam structure, and is different in that a plurality of nozzle groups are arranged on the lower end face of the beam body.
The flue gas waste heat utilization system comprises an induced draft fan II, a flue gas economizer, a steam generator, a heat conduction oil tank, an expansion tank, a filter, the upper air suction beam is communicated with an air inlet of the flue gas economizer through the induced draft fan II, a water outlet of the flue gas economizer is communicated with the heat conduction oil tank through the steam generator, the heat conduction oil tank is communicated with a heat conduction oil inlet pipe on an interlayer of an upper combustion beam through the expansion tank respectively, the heat conduction oil inlet pipe on an interlayer of a lower combustion beam is communicated, a heat conduction oil outlet pipe on an interlayer of the upper combustion beam, the heat conduction oil outlet pipe on the interlayer of the lower combustion beam is communicated with the steam generator through the filter, a gas outlet of the flue gas economizer is communicated.
The combustion-supporting air system comprises an air heat exchanger and a combustion-supporting fan, the combustion-supporting fan is respectively communicated with a combustion-supporting air pipe on the upper combustion beam and a combustion-supporting air pipe on the lower combustion beam through the air heat exchanger, and an outlet of the upper air suction beam is communicated with the air heat exchanger.
The flue gas treatment system comprises a dust remover and an induced draft fan III, wherein the lower air suction beam is connected with the dust remover through the induced draft fan III, an air outlet of the flue gas economizer is connected with the dust remover, and the air heat exchanger is connected with the dust remover. The emission concentration of the treated smoke dust and fluoride is in the secondary standard of the emission standard GB9078-1996 of the industrial kiln atmospheric pollutants; the emission concentration of the nitrogen oxides is subjected to the secondary standard of the industrial kiln atmospheric pollutant emission standard-GB 9078-1996; the concentration of smoke dust is less than or equal to 200mg/m3Nitrogen oxide is less than or equal to 400mg/m3Fluoride is less than or equal to 6mg/m3。
The feed system is a conventional feed device commercially available for adding phosphate ore to the calcining kiln system.
When the device is used, the medium and low grade phosphate ore (P) is obtained2O5(wt%) 8% -25%) is fed into a storage bin of the calcining kiln system through a feeding system, and after the temperature of the calcining kiln system reaches 600-900 ℃, phosphate ore enters the calcining kiln system; meanwhile, the CO industrial tail gas is purified by a tail gas purification device and then stored in a CO industrial tail gas storage tank, the purified CO industrial tail gas is introduced into an upper combustion beam and a lower combustion beam of the calcining kiln system from the CO industrial tail gas storage tank through a cluster fuel pipe by two draught fans I and is sprayed out by a CO industrial tail gas burner, and air is introduced into a combustion-supporting air system according to the air surplus coefficient of 1.1-2.5, wherein the combustion-supporting air burner is matched with the CO industrial tail gas burner; the CO industrial tail gas burner and the combustion air burner are requiredThe combustion heat value of the burner is set to be 60-160, and the sectional area of each burner is controlled to be less than or equal to 0.1m2After the CO industrial tail gas fuel gas is ignited by a spray gun igniter, the flame is in laminar flow and radial shape to calcine phosphate ore, V-shaped space combustion is formed on the material surface under the upper combustion beam and the lower combustion beam, the temperature of a calcining kiln system is 600-900 ℃, the temperature of a preheating cavity is 300-600 ℃, the height of the material is 12 m-16 m, the temperature of an upper calcining combustion chamber and a lower calcining combustion chamber is 600-900 ℃, the height of the material is 7-12 m, the temperature of a discharging chamber is 60-200 ℃, the height of the material is 1.5 m-7 m, and the continuous stable combustion is carried out for 1-8 hours;
the flue gas waste heat utilization system is started, the temperature of heat conducting oil is controlled to be 120-170 ℃, the pressure is 0.2-2.5 MPa, the flow is 200-550 m/h, the heat conducting oil is introduced into the jackets of the upper combustion beam and the lower combustion beam, the heat conducting oil is used as a heat exchange medium, the heat conducting coefficient is high, the corrosion is avoided, the heat stability and the oxidation resistance are good, the combustion beam can be effectively cooled, the overhigh temperature is avoided, and the safe operation of the calcining kiln system is guaranteed. And the heat conduction oil is conveyed to the expansion tank from the heat conduction oil tank and then is conveyed to the upper combustion beam and the lower combustion beam of the calcining kiln body system through the circulating pump, and the heat conduction oil return oil enters the steam generator for heat exchange cooling after being filtered by the filter, is repeatedly circulated and is not discharged outside. The steam generator utilizes the temperature difference between the heat conducting oil and the water to cause the heat of the high-temperature heat conducting oil to be transferred to the water, and the water is heated into steam, so that the purpose of cooling the heat conducting oil is achieved.
The temperature of flue gas generated by calcination is 200-400 ℃, a draught fan II is used for pumping out a kiln body through an upper suction beam, the flue gas waste heat is used for heating feed water, the feed water firstly passes through a flue gas economizer, the inner pipe of the flue gas economizer is communicated with the flue gas generated by calcining the kiln body system, the outer pipe of the flue gas economizer is communicated with cold water, the working principle is that the temperature difference between the high-temperature flue gas cold water is used for carrying out heat exchange, the heat in the high-temperature flue gas is transferred to the cold water, and the purposes of heating; the heated high-temperature hot water enters the outer pipe of the steam generator, and the inner pipe is communicated with high-temperature heat conductionThe temperature of the oil (the temperature is 180-200 ℃) is controlled to be stable within the range of 120-170 ℃ for recycling through heat exchange. The generated steam is provided for users to utilize. The water entering the flue gas economizer and the steam generator is softened tap water; the smoke from the upper combustion beam of the calcining kiln system also supplies heat to an air heat exchanger of a combustion air system to heat combustion air, and the principle of the air heat exchanger is that the heat exchange is carried out by utilizing the temperature difference between high-temperature smoke and the combustion air, and the heat in the high-temperature smoke is transferred to the combustion air to achieve the purpose of preheating the combustion air; and the smoke of the lower suction beam is pumped out by the draught fan III to a dust remover for treatment, enters the existing yellow phosphorus tail gas purification system after passing through the dust remover, and is discharged after reaching the standard. The emission concentration of the smoke dust and the fluoride executes the secondary standards of table 2 and table 4 in the emission standard of the industrial kiln air pollutants-GB 9078-1996; the emission concentration of nitrogen oxides is subjected to the secondary standard in Table 2 of the emission standard of atmospheric pollutants for industrial kilns-GB 9078-1996; the concentration of smoke dust is less than or equal to 200mg/m3Nitrogen oxide is less than or equal to 400mg/m3Fluoride is less than or equal to 6mg/m3；
The calcined material is set to be continuously discharged, and the discharge amount of the material is controlled to be 30 t/h-50 t/h; cooling air is adjusted and controlled by a kiln cooling fan (with the pressure of 8-20 Kpa), enters a discharging chamber through a furnace kiln bottom cooling air pipe, cools phosphate ore to the temperature of less than 80 ℃, discharges to obtain a finished product with the content of carbonate in the phosphate ore of less than or equal to 5 percent, and tests show that the content of carbonate in the modified medium-low grade phosphate ore is less than 5 percent, and the content of CO in the modified medium-low grade phosphate ore is less than or equal to 5 percent2The removal rate of the phosphorus ore is more than 80 percent, and simultaneously, the P in the phosphorus ore is increased2O5And (4) content.
The invention has the advantages and technical effects that:
according to the invention, the CO industrial tail gas is used for calcining the medium-grade and low-grade phosphate ores, the waste is treated by the waste, the carbonate content in the phosphate ores is reduced, high-grade phosphate concentrate is obtained, the utilization rate of the CO industrial tail gas is improved, and the resource potential excavation and quality improvement are realized; energy conservation and circular economy; environmental protection and pollution emission reduction.
Drawings
FIG. 1 is a schematic view of the apparatus of the present invention;
FIG. 2 is a schematic structural diagram of a CO industrial tail gas purification and delivery system;
FIG. 3 is a schematic structural view of a calcining kiln system;
FIG. 4 is a schematic structural view of an upper combustion beam and a lower combustion beam;
in the figure: 1-CO industrial tail gas purification and delivery system; 1-1 is a tail gas purification device; 1-2 is a CO industrial tail gas storage tank; 1-3 is a safe water seal; 1-4 is a draught fan I; 1-5 is a check valve; 1-6 is a CO alarm;
2-calcining the kiln system; 2-1 is a kiln body; 2-2 is a storage bin; 2-3 is an upper combustion beam; 2-4 is a lower combustion beam; 2-5 is an upper air suction beam; 2-6 is a lower air suction beam; 2-7 is a cooling fan under the kiln; 2-8 are discharge bins; 2-9 is a frame; 2-10 is a charge level indicator; 2-11 are preheating cavities; 2-12 is an upper calcining combustion chamber; 2-13 is a lower calcining combustion chamber; 2-14 is a discharge chamber;
2-3-1 is a beam body; 2-3-2 is an interlayer; 2-3-3 is a combustion air burner; 2-3-4 is a CO industrial tail gas burner; 2-3-5 are heat conducting oil inlet pipes; 2-3-6 are heat conducting oil outlet pipes; 2-3-7 is a cluster fuel pipe; 2-3-8 is a combustion air pipe; 2-3-9 is a spray gun igniter;
3-a feed system;
4-a flue gas waste heat utilization system; 4-1 is a draught fan II; 4-2 is a flue gas economizer; 4-3 is a steam generator; 4-4 is a heat-conducting oil tank; 4-5 is an expansion tank; 4-6 is a filter;
5-a flue gas treatment system; 5-1 is a draught fan III; 5-2 is a dust remover;
6-combustion air system; 6-1 is an air heat exchanger; and 6-2 is a combustion-supporting fan.
Detailed Description
The present invention is further illustrated by the following examples, but the scope of the invention is not limited to the above-described examples.
As shown in fig. 1 to 4, the apparatus used in this embodiment includes a CO industrial tail gas purification and conveying
the CO industrial tail gas purification and conveying
the calcining kiln system 2 comprises a hollow kiln body 2-1, a storage bin 2-2, an upper combustion beam 2-3, a lower combustion beam 2-4, an upper air suction beam 2-5, a lower air suction beam 2-6, a kiln lower cooling fan 2-7, a discharge bin 2-8, a rack 2-9 and a level indicator 2-10, wherein the kiln body 2-1 is welded on the rack 2-9, the storage bin 2-2 is arranged on a feed inlet at the top end of the shell 2-1, the kiln body 2-1 is internally provided with the upper air suction beam 2-5, the upper combustion beam 2-3, the lower combustion beam 2-4 and the lower air suction beam 2-6 from top to bottom in sequence, a cavity between the upper air suction beam 2-5 and the upper combustion beam 2-3 is a preheating cavity 2-11, a cavity between the upper combustion beam 2-3 and the lower combustion beam 2-4 is an upper calcining combustion chamber 2-12, a cavity between the lower combustion beam 2-4 and the lower gas absorption beam 2-6 is a lower calcining combustion chamber 2-13, a cavity below the lower gas absorption beam 2-6 is a discharge chamber 2-14, the upper combustion beam 2-3 comprises a beam body 2-3-1, combustion air burners 2-3-3, CO industrial tail gas burners 2-3-4, a heat transfer oil inlet pipe 2-3-5, a heat transfer oil outlet pipe 2-3-6, a fuel pipe bundle 2-3-7, a combustion air pipe 2-3-8 and a spray gun igniter 2-3-9, the beam body 2-3-1 is a hollow box body with an interlayer 2-3-2 on the outer side, the combustion air burners 2-3-3 and the CO industrial tail gas burners 2-3-4 are respectively arranged on the beam body 2-3-1, 1 CO industrial tail gas burner is matched with 2 combustion air burners 2-3-3 to form a nozzle group, and 80 nozzle groups are arranged on the front side and the rear side of the beam body in parallel; one ends of 80 cluster fuel pipes 2-3-7 are communicated with a draught fan I1-4 of the CO industrial tail gas purification and delivery system, and the other ends of the cluster fuel pipes penetrate through a hollow beam body 2-3-1 and are communicated with 80 CO industrial tail gas burners 2-3-4; one end of each of 2 combustion-supporting air pipes 2-3-8 is connected with a combustion-supporting air system 6, and the other end is communicated to the inside of the beam body and communicated with a combustion-supporting air burner 2-3-3; the heat conducting oil inlet pipe 2-3-5 and the heat conducting oil outlet pipe 2-3-6 are respectively arranged at two ends of the beam body 2-3-1 and are communicated with the interlayer 2-3-2, and more than one spray gun igniter 2-3-9 is arranged on the beam body and is positioned beside the nozzle group; the structure of the lower combustion beam 2-4 is the same as that of the upper combustion beam 2-3, and the difference is that a plurality of nozzle groups are arranged on the lower end surface of the beam body; a discharge bin 2-8 is arranged at a discharge port at the bottom of the kiln body 2-1, a level indicator 2-10 is arranged on one side of the upper part of the kiln body 2-1, a feeding system 3 is connected with the storage bin 2-2, an outlet of a cooling fan 2-7 under the kiln is communicated to the inside of the discharge bin 2-14, an upper air suction beam 2-5 is respectively communicated with a flue gas waste heat utilization system 4 and a combustion air system 6, and a lower air suction beam 2-6 is communicated with a flue gas treatment system 5.
The flue gas waste