CN110902717A - Method for reducing content of nitrogen oxides in tail gas generated by calcining titanium dioxide in rotary kiln - Google Patents
Method for reducing content of nitrogen oxides in tail gas generated by calcining titanium dioxide in rotary kiln Download PDFInfo
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- CN110902717A CN110902717A CN201911233924.5A CN201911233924A CN110902717A CN 110902717 A CN110902717 A CN 110902717A CN 201911233924 A CN201911233924 A CN 201911233924A CN 110902717 A CN110902717 A CN 110902717A
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- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G23/00—Compounds of titanium
- C01G23/04—Oxides; Hydroxides
- C01G23/047—Titanium dioxide
- C01G23/08—Drying; Calcining ; After treatment of titanium oxide
Abstract
The invention discloses a method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln, belonging to the field of chemical industry. The invention provides a method for reducing titanium dioxide tail gas nitrogen oxides calcined in a rotary kiln, which comprises the steps of conveying metatitanic acid to the rotary kiln for calcination, adjusting primary air quantity to enable a combustion medium and primary air to be fully combusted, adjusting secondary air quantity to control combustion temperature and conveying heat, enabling metatitanic acid to be converted into rutile type titanium dioxide through dehydration, desulfurization and crystal form conversion, wherein the flow ratio of the secondary air to the primary air is controlled to be 1.3: 1-2.1: 1. The invention can realize the temperature control of the combustion chamber, reduce the content of nitrogen oxide after combustion, effectively solve the problem of scattered leakage of the kiln tail gas and improve the field environment.
Description
Technical Field
The invention belongs to the field of chemical industry, and particularly relates to a method for reducing content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln.
Background
The calcination in a rotary kiln is an important link in the production process of titanium dioxide by a sulfuric acid method, and the aim is to press metatitanic acid① the burning generates heat after mixing air and burning medium in the rotary kiln, the heat is transmitted to the rotary kiln to be burnt by secondary air, the temperature of the combustion chamber is controlled to be high, the nitrogen oxide generated after air burning is increased sharply, the nitrogen oxide of the tail gas reaches 240mg/Nm3The requirements of environmental protection emission cannot be met, ② has larger newly added investment and higher running cost to influence the production cost if being treated by a subsequent kiln tail denitration device, ③ has larger primary air volume to reduce the temperature of the combustion chamber by only increasing the primary air volume, thereby leading a large amount of heat to be taken away from tail gas, reducing the heat utilization efficiency, increasing the consumption of combustion media, and leading the unit consumption of per ton of titanium white natural gas to be more than or equal to 220m3And ④, after the primary air volume is large, because the air speed is high, the zone division of the crystal form conversion and particle growth areas is difficult in the calcining process, the product quality is influenced, and meanwhile, the kiln tail negative pressure control difficulty is high, the phenomenon of tail gas leakage is caused, and the field environment is influenced.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a method for reducing the content of nitrogen oxides in tail gas generated by titanium dioxide calcination in a rotary kiln, wherein metatitanic acid is conveyed to the rotary kiln for calcination, primary air quantity is adjusted to enable a combustion medium and primary air to be fully combusted, secondary air quantity is adjusted to control combustion temperature and convey heat, and metatitanic acid is converted into rutile titanium dioxide through dehydration, desulfurization and crystal form conversion, wherein the flow ratio of the secondary air to the primary air is controlled to be 1.3: 1-2.1: 1.
Wherein the ratio of the primary air volume to the flow of the combustion medium is controlled to be 9: 1-15: 1.
Wherein the combustion temperature is controlled to be 1100-1350 ℃; preferably 1150 to 1250 ℃.
Wherein the amount of metatitanic acid fed is TiO2The amount is 4-7 t/h; the preferable feeding amount is 6-6.5 t/h.
Wherein the primary air volume is 10000-20000 m3H, secondary air volume of 10000-40000 m3/h。
Preferably, the primary air volume is 12000-15000 m3The secondary air volume is preferably 20000-30000 m3/h。
Wherein, the frequency of the primary fan is 20-50 Hz, and the frequency of the secondary fan is 10-50 Hz.
Preferably, the frequency of the primary air fan is preferably 36-42 Hz, and the frequency of the secondary air fan is preferably 15-25 Hz.
Wherein, the combustion medium is natural gas or coal gas; preferably natural gas.
The method also comprises the steps of controlling the frequency of the kiln tail air cooler, keeping the negative pressure of the rotary kiln, and conveying residual tail gas after combustion to a tail gas device for treatment through the kiln tail air cooler.
Wherein the frequency of the air cooler is 10-30 Hz, and the negative pressure of the kiln tail is-120 to-20 pa.
The frequency of the air cooler is preferably 20-25 Hz, and the negative pressure of the kiln tail is preferably-70 to-40 pa.
Wherein the solid content of the metatitanic acid is 55-65%.
The invention has the beneficial effects that:
the invention makes the burning medium fully burn by controlling the primary air quantity, and realizes the control of the temperature of the burning chamber by adjusting the secondary air quantity to convey heat, thereby being more beneficial to the partition of the calcining area of the rotary kiln and reducing the content of nitrogen oxide after burning; the invention does not need to be treated by a rotary kiln tail gas denitration device, the content of the tail gas nitrogen oxide is controllable, the fuel gas consumption is reduced, and the content of the tail gas nitrogen oxide can be stably controlled to be less than or equal to 240mg/Nm3The consumption of per ton of titanium dioxide natural gas is less than or equal to 220m3T; the invention controls the negative pressure through the air cooler at the tail of the kiln, effectively solves the problem of the dispersion and leakage of the tail gas at the tail of the kiln and improves the field environment.
Detailed Description
The method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in the rotary kiln can be specifically carried out according to the following steps:
a. pressing metatitanic acid to a filter cake with certain solid content in front of a kiln, and feeding the filter cake into a rotary kiln for calcination;
b. controlling the frequency of a primary fan, and mixing and burning a combustion medium and primary air in a combustion chamber of the rotary kiln through a burner;
c. controlling the frequency of a secondary fan, ensuring the temperature of the combustion chamber, and conveying heat generated by combustion in the combustion chamber to the cylinder of the rotary kiln through secondary air;
d. controlling the rotation speed of the rotary kiln to ensure that metatitanic acid is converted into rutile type titanium dioxide in a rotary kiln cylinder body through dehydration, desulfurization and crystal form conversion;
e. controlling the frequency of a kiln tail air cooler, keeping the negative pressure of the rotary kiln, and conveying the residual tail gas after combustion to a tail gas device for treatment through the kiln tail air cooler;
f. and the titanium dioxide qualified by calcination falls into the cooling kiln through a kiln head flap valve and is conveyed to the post-process.
In order to better realize the invention, the rotating speed of the rotary kiln in the step d is controlled to be 3-8 min/rotation, and the preferred rotating speed is 4-6 min/rotation.
The frequency and the air volume are two related process parameters, the air volume is mainly controlled through the fan frequency, the air volume is influenced by the fan frequency, and the purpose of controlling the fan frequency in a certain range is to better control the air volume.
The invention provides a method for solving the problem of tail gas nitrogen oxide in titanium dioxide calcination in a rotary kiln by air volume proportion for the first time, and the method is mainly characterized in that the air volume of primary air and secondary air is controlled, the type of the rotary kiln is not limited, and the method can be adopted by properly and conventionally adjusting various types of rotary kilns used for titanium dioxide calcination in a sulfuric acid method.
The invention is further illustrated and described below by means of examples and performance examples.
Example 1
The metatitanic acid is pressed by a plate frame to have the solid content of 57 percent and is conveyed to a rotary kiln by a screwThe tail feed port has the feed speed of 6.0t/h, natural gas and primary air are mixed and combusted in the combustion chamber, the flow of secondary air is adjusted to convey heat into the rotary kiln, the heat is reversely exchanged with metatitanic acid, the flow of the natural gas is 1200m3H, primary fan frequency 35Hz, air quantity 12000m3The frequency of the secondary fan is 22Hz, and the air quantity is 24800m3The temperature of the combustion chamber is 1248 ℃, the frequency of the kiln tail air cooler is 20HZThe negative pressure at the tail of the kiln is-54 pa, and the unit consumption of per ton of titanium dioxide natural gas is 200m at the moment3T, the nitrogen oxide NOx in the tail gas of the rotary kiln is 204mg/Nm3And no gas scattering and leakage phenomenon exists at the kiln tail.
Example 2
The solid content of metatitanic acid is 57% after the metatitanic acid is squeezed by a plate frame, the metatitanic acid is conveyed to a kiln tail feed inlet of a rotary kiln through a screw, the feed speed is 6.0t/h, natural gas and primary air are mixed and combusted in a combustion chamber, the flow of secondary air is adjusted to convey heat into the rotary kiln, the heat is reversely exchanged with metatitanic acid, the flow of the natural gas is 1260m3H, primary fan frequency 42Hz, air quantity 15000m3H, secondary fan frequency is 16Hz, air quantity is 20000m3The temperature of the combustion chamber is 1225 ℃, the frequency of a kiln tail air cooler is 20Hz, the negative pressure of the kiln tail is-42 pa, and the unit consumption of per ton of titanium dioxide natural gas is 210m at the moment3T, the nitrogen oxide NOx in the tail gas of the rotary kiln is 186mg/Nm3And no gas scattering and leakage phenomenon exists at the kiln tail.
Example 3
The solid content of metatitanic acid is 59 percent after the metatitanic acid is squeezed by a plate frame, the metatitanic acid is conveyed to a kiln tail feed inlet of a rotary kiln through a screw, the feed speed is 6.5t/h, natural gas and primary air are mixed and combusted in a combustion chamber, the flow of secondary air is adjusted to convey heat into the rotary kiln, the heat is reversely exchanged with metatitanic acid, the flow of the natural gas is 1290m3H, primary fan frequency of 36Hz, air quantity of 12000m3The frequency of the secondary fan is 22Hz, and the air quantity is 24800m3The temperature of the combustion chamber is 1252 ℃, the frequency of the air cooler at the tail of the kiln is 20Hz, the negative pressure at the tail of the kiln is-52 pa, and the unit consumption of per ton of the titanium dioxide natural gas is 198.5m3T, the nitrogen oxide NOx in the tail gas of the rotary kiln is 206mg/Nm3And no gas scattering and leakage phenomenon exists at the kiln tail.
Example 4
The solid content of metatitanic acid is 59 percent after the metatitanic acid is squeezed by a plate frame, the metatitanic acid is conveyed to a kiln tail feed inlet of a rotary kiln through a screw, the feeding speed is 6.5t/h, natural gas and primary air are mixed and combusted in a combustion chamber, the flow of secondary air is adjusted to convey heat into the rotary kiln, the heat is reversely exchanged with metatitanic acid, the flow of the natural gas is 1320m3H, primary fan frequency 42Hz, air quantity 15000m3H, secondary fan frequency is 16Hz, air quantity is 20000m3The temperature of the combustion chamber is 1236 ℃, the frequency of the air cooler at the tail of the kiln is 20Hz, the negative pressure at the tail of the kiln is-58 pa, and the unit consumption of titanium dioxide natural gas per ton is 203m at the moment3The NOx content in the tail gas of the rotary kiln is 196mg/Nm3And no gas scattering and leakage phenomenon exists at the kiln tail.
The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.
It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.
In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.
Claims (10)
1. The method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln is characterized by comprising the following steps of: the method comprises the steps of conveying metatitanic acid to a rotary kiln for calcination, adjusting primary air quantity to enable a combustion medium to be fully combusted with primary air, adjusting secondary air quantity to control combustion temperature and convey heat, enabling metatitanic acid to be converted into rutile type titanium white through dehydration, desulfurization and crystal form conversion, wherein the flow ratio of the secondary air to the primary air is controlled to be 1.3: 1-2.1: 1.
2. The method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln according to claim 1, which is characterized in that: the ratio of the primary air quantity to the flow quantity of the combustion medium is controlled to be 9: 1-15: 1.
3. The method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln according to claim 1, which is characterized in that: the combustion temperature is controlled to be 1100-1350 ℃; preferably 1150 to 1250 ℃.
4. The method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln according to claim 1, which is characterized in that: the feeding amount of the metatitanic acid is TiO2The amount is 4-7 t/h; the preferable feeding amount is 6-6.5 t/h.
5. The method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln according to claim 1 or 4, which is characterized in that: the primary air volume is 10000-20000 m3H, secondary air volume of 10000-40000 m3H; preferably, the primary air volume is 12000-15000 m3Per hour, the secondary air volume is 20000-30000 m3/h。
6. The method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln according to any one of claims 1, 4 or 5, is characterized in that: the frequency of the primary air fan is 20-50 Hz, and the frequency of the secondary air fan is 10-50 Hz; preferably, the frequency of the primary fan is 36-42 Hz, and the frequency of the secondary fan is 15-25 Hz.
7. The method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln according to claim 1, which is characterized in that: the combustion medium is natural gas or coal gas; preferably natural gas.
8. The method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln according to claim 1, which is characterized in that: the method also comprises the steps of controlling the frequency of a kiln tail air cooler, keeping the negative pressure of the rotary kiln, and conveying residual tail gas after combustion to a tail gas device for treatment through the kiln tail air cooler.
9. The method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln as claimed in claim 8, wherein the method comprises the following steps: the frequency of the air cooler is 10-30 Hz, and the negative pressure of the kiln tail is-120 to-20 pa; preferably, the frequency of the air cooler is 20-25 Hz, and the negative pressure of the kiln tail is-70 to-40 pa.
10. The method for reducing the content of nitrogen oxides in tail gas generated by calcining titanium dioxide in a rotary kiln according to claim 1, which is characterized in that: the solid content of the metatitanic acid is TiO2Calculated as 55 to 65 percent.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111704373A (en) * | 2020-05-19 | 2020-09-25 | 新兴铸管股份有限公司 | Method for reducing concentration of NOx in tail gas of lime rotary kiln |
| CN112665404A (en) * | 2020-12-18 | 2021-04-16 | 包头钢铁（集团）有限责任公司 | Method for reducing emission of nitric oxide in rotary kiln waste gas |
| CN115583808A (en) * | 2022-09-08 | 2023-01-10 | 首钢京唐钢铁联合有限责任公司 | Environment-friendly data regulation and control method and device for sleeve kiln |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106969351A (en) * | 2017-05-08 | 2017-07-21 | 中国华能集团清洁能源技术研究院有限公司 | It is a kind of to reduce the flue gas recirculation method and system of CFBB NOx emission |
| US20180094561A1 (en) * | 2016-10-05 | 2018-04-05 | National Kaohsiung University Of Applied Sciences | Ferrite as three-way catalyst for treatment of exhaust gas from vehicle engine |
| CN108302947A (en) * | 2018-01-29 | 2018-07-20 | 武汉东晟捷能科技有限公司 | A kind of titanium dioxide calcining comprehensive utilization system for tail-gas and exhaust gas treating method |
| CN108613194A (en) * | 2018-05-10 | 2018-10-02 | 哈尔滨工业大学 | A kind of method and device for villages and small towns consumer waste incineration |
| CN208229626U (en) * | 2018-01-29 | 2018-12-14 | 武汉东晟捷能科技有限公司 | A kind of titanium dioxide calcining comprehensive utilization system for tail-gas |
-
2019
- 2019-12-05 CN CN201911233924.5A patent/CN110902717B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20180094561A1 (en) * | 2016-10-05 | 2018-04-05 | National Kaohsiung University Of Applied Sciences | Ferrite as three-way catalyst for treatment of exhaust gas from vehicle engine |
| CN106969351A (en) * | 2017-05-08 | 2017-07-21 | 中国华能集团清洁能源技术研究院有限公司 | It is a kind of to reduce the flue gas recirculation method and system of CFBB NOx emission |
| CN108302947A (en) * | 2018-01-29 | 2018-07-20 | 武汉东晟捷能科技有限公司 | A kind of titanium dioxide calcining comprehensive utilization system for tail-gas and exhaust gas treating method |
| CN208229626U (en) * | 2018-01-29 | 2018-12-14 | 武汉东晟捷能科技有限公司 | A kind of titanium dioxide calcining comprehensive utilization system for tail-gas |
| CN108613194A (en) * | 2018-05-10 | 2018-10-02 | 哈尔滨工业大学 | A kind of method and device for villages and small towns consumer waste incineration |
Non-Patent Citations (3)
| Title |
|---|
| RICHARD A. DAVIS: "Nitric Oxide Formation in an Iron Oxide Pellet Rotary Kiln Furnace", 《JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION》 * |
| 李永华: "褐煤及其混煤燃烧NOx生成的试验研究", 《中国电机工程学报》 * |
| 郑步清: "钛白粉厂煅烧窑改造", 《四川冶金》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111704373A (en) * | 2020-05-19 | 2020-09-25 | 新兴铸管股份有限公司 | Method for reducing concentration of NOx in tail gas of lime rotary kiln |
| CN112665404A (en) * | 2020-12-18 | 2021-04-16 | 包头钢铁（集团）有限责任公司 | Method for reducing emission of nitric oxide in rotary kiln waste gas |
| CN115583808A (en) * | 2022-09-08 | 2023-01-10 | 首钢京唐钢铁联合有限责任公司 | Environment-friendly data regulation and control method and device for sleeve kiln |
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