CN-122012941-A - Rotary kiln steelmaking dust mud dezincification process

Abstract

The invention discloses a rotary kiln steelmaking dust and mud dezincification process, and belongs to the technical field of metallurgical solid waste resource utilization. According to the invention, fe 2 O 3 in the dust and mud is primarily reduced into Fe 3 O 4 and a small amount of FeO through coke powder, and then H 2 is generated by lignite pyrolysis to replace part of C reduction, so that the efficient reduction and separation of zinc and iron in the dust and mud by carbon-hydrogen recombination in the rotary kiln are realized. According to the invention, through excessive addition of lignite, iron oxide in the raw materials can fully react, meanwhile, oxygen is isolated by controlling the state of the kiln head, kiln slag is recycled after being cooled, the reformation of FeO is avoided, the phenomenon of ring formation of the rotary kiln is relieved, and the continuous working time of the rotary kiln is prolonged.

Inventors

• Pan Yingshuai
• ZHANG QINGMING

Assignees

• 本溪东风湖钢铁资源利用有限公司

Dates

Publication Date

20260512

Application Date

20260106

Claims (6)

1. 1. The rotary kiln steelmaking dust and sludge dezincification process is characterized by comprising the following steps of: S1, adding water into dust and mud, coke powder and a binder, uniformly mixing to prepare raw materials, feeding the raw materials into a rotary kiln from a kiln tail, feeding lignite into a calcining zone of the rotary kiln from a kiln head, wherein the mass ratio of the dust and mud to the coke powder to the binder to the lignite is 100:5-6:4-5:15-20; S2, heating the raw materials to 850-900 ℃ in a drying preheating zone; s3, heating the raw materials to 1000-1300 ℃ in a calcining zone for 10-30min to obtain Zn steam and kiln slag; S4, recovering Zn steam in the calcining zone; s5, sealing the kiln head when the kiln slag enters the recovery belt; s6, cooling the recovery belt for 40-60min, wherein the temperature of the recovery belt after cooling is less than or equal to 120 ℃; s7, opening the kiln head, and taking out the kiln slag.
2. 2. The rotary kiln steelmaking dust and mud dezincification process according to claim 1, wherein a blower is arranged at the kiln head of the rotary kiln, an induced draft fan is arranged at the kiln tail of the rotary kiln, and the lignite is sprayed to the calcining zone through a spray gun.
3. 3. The rotary kiln steelmaking dust and sludge dezincification process as claimed in claim 1, wherein the kiln tail temperature is 450-500 ℃.
4. 4. The rotary kiln steelmaking dust and sludge dezincification process according to claim 1, wherein the raw materials are pellets with the diameter of 25-50mm manufactured by adopting a disc pelletizing method.
5. 5. The rotary kiln steelmaking dust and sludge dezincification process according to claim 1, wherein the Zn steam is recovered by a flue gas recovery system, the Zn steam is cooled to Zn powder, and the Zn powder is collected after being cooled to 180-200 ℃.
6. 6. A rotary kiln steelmaking dust and sludge dezincification process as claimed in claim 1 wherein said recovery zone is cooled by a circulating cooling water pipe.

Description

Rotary kiln steelmaking dust mud dezincification process Technical Field The invention belongs to the technical field of metallurgical solid waste resource utilization, and particularly relates to a rotary kiln steelmaking dust and mud dezincification process. Background With the continuous rising of steel yield, the production of dust and mud containing iron and zinc is increased year by year. The prior art is difficult to efficiently recycle and utilize the iron-containing and zinc-containing dust mud, which not only causes resource waste and irrecoverable damage to the environment. If the method can pertinently recycle metals in the iron-containing and zinc-containing dust mud, considerable economic benefits are brought to enterprises. Therefore, a need exists for a rational technological process for effectively treating such iron and zinc-containing sludge. At present, although quite mature technologies exist at home and abroad to extract zinc in the dust mud containing iron and zinc, the synchronous recovery of iron in the dust mud is still challenging. At present, certain domestic iron and steel enterprises face the treatment difficulty of a large amount of iron and zinc-containing dust and sludge, and the dust and sludge is characterized by low zinc content and rich iron and carbon resources. And after comprehensive consideration, deciding to recycle the waste water by adopting a rotary kiln. The rotary kiln process belongs to pyrometallurgy, and the aim of simultaneously recovering iron and zinc can be fulfilled by heating at a certain temperature. However, during the operation of rotary kilns, problems of ring formation are generally accompanied, and in particular, as the temperature increases, the likelihood of ring formation increases accordingly. Therefore, how to provide a process capable of reducing iron and zinc in iron-and zinc-containing dust and sludge and relieving ring formation of a rotary kiln is a problem to be solved. Disclosure of Invention In view of the above, the invention aims to provide a rotary kiln steelmaking dust and mud dezincification process, which utilizes lignite pyrolysis to generate H 2 to replace part of C reduction, realizes high-efficiency reduction and separation of zinc and iron in dust and mud by carbon-hydrogen composite in a rotary kiln, isolates oxygen by controlling kiln head state, recovers kiln slag after cooling, avoids FeO formation, relieves rotary kiln looping phenomenon, and further prolongs continuous working time of the rotary kiln. In order to achieve the above object, the present invention provides the following technical solutions: The rotary kiln steelmaking dust and sludge dezincification process comprises the following steps: S1, adding water into dust and mud, coke powder and a binder, uniformly mixing to prepare raw materials, feeding the raw materials into a rotary kiln from a kiln tail, feeding lignite into a calcining zone of the rotary kiln from a kiln head, wherein the mass ratio of the dust and mud to the coke powder to the binder to the lignite is 100:5-6:4-5:15-20; S2, heating the raw materials to 850-900 ℃ in a drying preheating zone; s3, heating the raw materials to 1000-1300 ℃ in a calcining zone for 10-30min to obtain Zn steam and kiln slag; S4, recovering Zn steam in the calcining zone; s5, sealing the kiln head when the kiln slag enters the recovery belt; s6, cooling the recovery belt for 40-60min, wherein the temperature of the recovery belt after cooling is less than or equal to 120 ℃; s7, opening the kiln head, and taking out the kiln slag. Based on the technical scheme, further, the kiln head of the rotary kiln is provided with a blower, the kiln tail of the rotary kiln is provided with a draught fan, and lignite is sprayed to the calcining zone through a spray gun. Based on the technical scheme, further, the kiln tail temperature is 450-500 ℃. Based on the technical scheme, the raw materials are pellets with the diameter of 25-50mm, which are manufactured by adopting a disc pelletizing method. Based on the technical scheme, further, zn steam is recovered through a flue gas recovery system, the Zn steam is cooled to Zn powder, and the Zn powder is collected after being cooled to 180-200 ℃. Based on the technical scheme, further, the recycling belt is cooled through the circulating cooling water pipe. Compared with the prior art, the invention has the following beneficial effects: 1. According to the invention, fe 2O3 in the dust and mud is primarily reduced into Fe 3O4 and a small amount of FeO through coke powder, and then H 2 is generated by lignite pyrolysis to replace part of C reduction, so that the efficient reduction and separation of zinc and iron in the dust and mud by carbon-hydrogen recombination in the rotary kiln are realized. 2. According to the invention, through excessive addition of lignite, iron oxide in the raw materials can fully react, meanwhile, oxygen is isolated by controlling the state of the kiln