CN-122006454-A - Waste gas recovery system and recovery method in ammonium metavanadate drying and calcining process

CN122006454ACN 122006454 ACN122006454 ACN 122006454ACN-122006454-A

Abstract

The invention relates to the technical field of industrial waste gas treatment and discloses a waste gas recovery system in the ammonium metavanadate drying and calcining process, which comprises a first spray tower, wherein an acid absorption liquid is stored at the bottom of the first spray tower, a first mist removing layer, a first spray head and a first packing layer are sequentially arranged in the first spray tower from top to bottom, a waste gas pipe communicated with a waste gas source is arranged on the side wall of the first spray tower, the first spray head is communicated with the bottom of the first spray tower through a first pipeline to circularly spray the acid absorption liquid, clear water is stored at the bottom of the second spray tower, the rest of the clear water is the same as the first spray tower, an air outlet of the first spray tower is communicated with an air inlet of the second spray tower through a first air outlet pipe, and an air outlet of the second spray tower is communicated with a fan through a second air outlet pipe. The invention also provides a recovery method using the recovery system. The invention realizes dust recovery, ammonia absorption and cyclic utilization, improves vanadium yield, reduces production cost and solves environmental protection risks.

Inventors

WU FENG
PENG ZHEN
LI YUEPENG
Du Zuwu
WANG CHAO
YOU BENYIN
TANG WENJIANG
WEI SHAN
LI CAIXIA
SHU LI

Assignees

攀钢集团钒钛资源股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260402

Claims (10)

1. An exhaust gas recovery system in an ammonium metavanadate drying and calcining process, comprising: the acid absorption liquid is stored at the bottom of the first spray tower, a first mist removing layer, a first spray head and a first packing layer are sequentially arranged in the first spray tower from top to bottom, an exhaust pipe communicated with an exhaust gas source is arranged on the side wall of the first spray tower, and the first spray head is communicated with the bottom of the first spray tower through a first pipeline so as to circularly spray the acid absorption liquid; The second spray tower is internally provided with a second mist removing layer, a second spray head and a second packing layer from top to bottom in sequence, and the second spray head is communicated with the bottom of the second spray tower through a second pipeline so as to circularly spray the acidic absorption liquid; the lateral part of first spray column is provided with the intake pipe that extends to acid liquid soap direction, the air outlet of first spray column communicates with the air inlet of second spray column through first tuber pipe, the air outlet of second spray column communicates with the fan through the second tuber pipe.
2. The system for recycling waste gas in the drying and calcining process of ammonium metavanadate according to claim 1, wherein a first circulating pump is arranged on the first pipeline to circularly spray the acidic absorption liquid, and a second circulating pump is arranged on the second pipeline to circularly spray the clean water.
3. The system for recovering waste gas in the drying and calcining process of ammonium metavanadate according to claim 1, wherein the air outlet of the first spray tower is positioned at the top of the first spray tower, the air inlet of the second spray tower is arranged at the side part of the second spray tower, and the air outlet of the second spray tower is positioned at the top of the second spray tower.
4. The system for recovering waste gas in the drying and calcining process of ammonium metavanadate according to claim 1, wherein the first packing layer and the second packing layer are hollow sphere packing layers made of polypropylene.
5. The system for recovering exhaust gas in the drying and calcining process of ammonium metavanadate according to claim 1, wherein the first demisting layer and the second demisting layer are multilayer corrugated plates made of polypropylene.
6. A recovery method for recovering exhaust gas using the exhaust gas recovery system according to any one of claims 1 to 5, comprising: S1, introducing dust-containing and ammonia-containing waste gas generated in the drying, conveying and calcining processes of ammonium metavanadate into a first spray tower, carrying out first-stage purification by countercurrent contact of the waste gas and an acid absorption liquid sprayed circularly through a first packing layer, and allowing the waste gas after the first-stage purification to enter a second spray tower after passing through a first demisting layer; S2, the waste gas is in countercurrent contact with the clean water sprayed circularly through the second packing layer to carry out secondary purification, and the waste gas after the secondary purification is discharged after passing through the second demisting layer.
7. The recovery method according to claim 6, wherein the acidic absorption liquid is ammonium polyvanadate vanadium precipitation supernatant, and the pH value is 2.0-2.5.
8. The recycling method according to claim 6, further comprising: When the concentration of vanadium in the acid absorption liquid at the bottom of the first spray tower reaches a first threshold value, conveying the acid absorption liquid to a vanadium precipitation process of ammonium vanadate at most to recover vanadium; when the concentration of vanadium in the clear water at the bottom of the second spray tower reaches a second threshold value, the clear water is conveyed to a vanadium extraction leaching process to be used as leaching water for roasting clinker.
9. The recovery method of claim 8, wherein the first threshold is a vanadium concentration of 2g/L or more and the second threshold is a vanadium concentration of 0.2g/L or more.
10. The recycling method according to claim 6, wherein liquid levels at bottoms of the first spray tower and the second spray tower are controlled to be 1.5 m-1.8 m, filler thicknesses of the first filler layer and the second filler layer are 2.0m, and thicknesses of the first mist removing layer and the second mist removing layer are 1.0m.

Description

Waste gas recovery system and recovery method in ammonium metavanadate drying and calcining process Technical Field The invention relates to the technical field of industrial waste gas treatment, in particular to a waste gas recovery system and a waste gas recovery method in the drying and calcining processes of ammonium metavanadate. Background The technological process of the production line for producing high purity vanadium pentoxide in China comprises the steps of purifying vanadium-containing leaching solution obtained by sodium treatment of vanadium slag, removing silicon from aluminum sulfate, precipitating vanadium by Ammonium Polyvanadate (APV), dissolving APV, removing chromium and removing aluminum, precipitating vanadium by Ammonium Metavanadate (AMV) from the obtained filtrate, filtering, washing and drying the AMV, and calcining the AMV in a rotary kiln to obtain the high purity vanadium pentoxide. The AMV is a powdery light material (bulk specific gravity is about 1.04kg/cm 3), a microwave dryer is adopted for drying, a drying area is a negative pressure environment, a small amount of AMV enters a dust removing system along with water vapor, a dust producing point of the dried AMV is also connected into the dust removing system in the bucket lifting and conveying process, a negative pressure dynamic environment is arranged in a rotary kiln, and a small amount of AMV and the AMV which is not completely decomposed are pumped into the dust removing system. After being intercepted by a cloth bag dust remover, the existing dust removing system has the gas dust content of about 15mg/m 3 and meets the emission standard of less than or equal to 50mg/m 3, but vanadium is high-value metal, and the dust emission causes vanadium loss, so that the production cost is increased. Meanwhile, a small amount of ammonia is generated in the AMV drying process, the ammonia is generated by decomposition in the calcining process, and the direct discharge has the environmental protection risk. Accordingly, there is a need in the art for improved systems and methods for waste gas recovery during drying and calcination of ammonium metavanadate. Disclosure of Invention In view of the above, the embodiment of the invention aims to provide a waste gas recovery system and a recovery method in the drying and calcining processes of ammonium metavanadate, so that dust recovery, ammonia absorption and recycling are realized, the vanadium yield is improved, the production cost is reduced, and the environmental protection risk is solved. In view of the above object, an embodiment of the present invention provides an exhaust gas recovery system in an ammonium metavanadate drying and calcining process, comprising: the acid absorption liquid is stored at the bottom of the first spray tower, a first demisting layer, a first spray head and a first packing layer are sequentially arranged in the first spray tower from top to bottom, an exhaust pipe communicated with an exhaust gas source is arranged on the side wall of the first spray tower, and the first spray head is communicated with the bottom of the first spray tower through a first pipeline so as to circularly spray the acid absorption liquid; The second spray tower is internally provided with a second mist removing layer, a second spray head and a second packing layer from top to bottom in sequence, and the second spray head is communicated with the bottom of the second spray tower through a second pipeline so as to circularly spray the acidic absorption liquid; The lateral part of first spray column is provided with the intake pipe that extends to acid liquid soap direction, and the air outlet of first spray column communicates with the air inlet of second spray column through first tuber pipe, and the air outlet of second spray column communicates with the fan through second tuber pipe. In some embodiments, a first circulating pump is arranged on the first pipeline to circularly spray the acid absorption liquid; In some embodiments, the air outlet of the first spray tower is located at the top of the first spray tower, the air inlet of the second spray tower is located at the side of the second spray tower, and the air outlet of the second spray tower is located at the top of the second spray tower. In some embodiments, the first filler layer and the second filler layer are hollow sphere filler layers made of polypropylene. In some embodiments, the first and second mist eliminator layers are multilayer corrugated plates made of polypropylene. The invention also provides a recovery method adopting the waste gas recovery system, which comprises the following steps: S1, introducing dust-containing and ammonia-containing waste gas generated in the drying, conveying and calcining processes of ammonium metavanadate into a first spray tower, carrying out first-stage purification by countercurrent contact of the waste gas and an acid absorption liquid sprayed circularly through a fir