Topic: How to Dezincify and Reuse Dedusting Ash in Steel Plant? - Dezincification Bunder
In the process of steel making,there will be a large amount of dedusting dust, and a considerable part of the steel plant reuse it as raw material for the sintering system. However, due to the large amount of K, Zn and other elements in the dedusting ash, it will severely damage the corresponding equipment. Cold-pressed briquettes by dezincification binder enable zinc recovery in multiple processes
Process Flow for Extracting Secondary Zinc Oxide from Dedusting Ash
Wet process and dry process are commonly used. The dry process accounts for more than 80% of the current domestic production of sub-zinc oxide.
Rotary Kiln Fuming Method
Zinc-containing dedusting ash is used as the main material, coke powder is used as the combustion raw material, and dezincification binder is added in a certain proportion. After mixing and forming, it is transported to the kiln for high-temperature calcination, and the furnace material is continuously turned and rolled.
When the temperature in the kiln is about 1000, a series of chemical reactions will occur under the action of high temperature. At this time, Zn will combine with air and transform into ZnO. The zinc in the raw material exists in the flue gas after the oxidation-reduction reaction, but it will gradually transform into a solid state as the temperature cools, and then be trapped in the filter bag.
Open Hearth Process Flow
Add anthracite coal powder, dezincification binder, lime to the dedusting ash→stirring→drying→combustion in the furnace, oxidation-reduction reaction occurs→zinc vapor is generated→oxidation separation in the oxidation chamber→cooling→mixed flue gas separation in the dust collection chamber→ Low-grade zinc oxide products and slags.
The whole process of the production process is under negative pressure, no waste water is discharged, and the waste gas is discharged up to the standard. The dedusting ash is oxidized and reduced to produce low-grade zinc oxide products, and the dedusting ash of zinc oxide recovered after refining is used in the blast furnace, which can greatly reduce zinc damage and avoid nodules on the upper part of the furnace body and the riser.
The slag obtained by refining and recovering zinc oxide in an open hearth furnace is similar to sintered ore, denser, and the proportion of Fe content is higher than that of dust removal ash, which is between 30% and 50%. Harmful impurities are reduced, and it can be used as a low-grade ore for blast furnaces.
Rotary Hearth Furnace Process
The dust is mixed with reducing agent (coal powder), dezincification binder, etc. to make briquettes, and the green briquettes with a certain strength are dried by a dryer, and the moisture content of the green briquettes is reduced to below 3%. Then, the dried raw briquettes are evenly arranged in the rotary hearth furnace through the vibrating distributor, and the temperature in the rotary hearth furnace is controlled at 1100-1300°, and the briquettes undergo direct reduction reaction in the furnace.
More than 70% of the iron oxides are reduced to metallic iron and remain in the metallized briquettes. At the same time, the zinc, lead, potassium and sodium in the briquettes are reduced or volatilized and enter the flue gas system of the rotary hearth furnace. Separation of zinc, potassium and sodium, so as to realize the recycling of iron, separation of zinc and potassium and sodium.
JIANJIE GROUP is a leading binder manufacturer and supplier located in Chengdu, China, which is a technological enterprise integrating R&D, production, sales and related service. Devoted to manufacturing binder products for more than fifteen years, we have professional production equipment and processes, a strong technical team and a scientific management system.
Welcome to visit our official website for more company information and product detail.
E-mail: info@jianjiebinder.com
Web: jianjiebinder.com
article source: https://www.jianjiebinder.com/news/how-to-dezincify-and-reuse-dedusting-ash-in-steel-plant-dezincification-bunder/
Media Contact
Company Name: Sichuan Jianjie Composite Materials Co., Ltd.
Email:Send Email
Country: China
Website: https://www.jianjiebinder.com/
