Device and method for harmlessly treating secondary aluminum ash

Abstract

A device for harmlessly treating secondary aluminum ash comprises a high-temperature reaction furnace, a cyclone separation tower, an electrode dust remover, a calcium carbonate absorption tower, a cloth bag type dust remover and a collection box, and is characterized in that the high-temperature reaction furnace is provided with a hot air return pipe and a smoke exhaust pipe, and the high-temperature reaction furnace is respectively connected with the hot air return pipe and the smoke exhaust pipe through pipelines; the hot air return pipe is communicated and connected with the smoke exhaust pipe; the cyclone separation tower is in pipeline connection with the high-temperature reaction furnace through a smoke exhaust pipe; an air draft connecting pipe is arranged between the cyclone separation tower and the electrode dust remover; the cyclone separation tower is connected with an electrode dust collector pipeline through an air draft connecting pipe; the electrode dust remover is connected with a calcium carbonate absorption tower pipeline through an air draft connecting pipe; the calcium carbonate absorption tower is in pipeline connection with the cloth bag type dust collector through an air draft connecting pipe; collection boxes are mounted below the cyclone separation tower, the electrode dust collector, the calcium carbonate absorption tower and the bag type dust collector; the device can effectively treat secondary aluminum ash and reduce environmental pollution.

Description

technical field [0001] The invention relates to the technical field of industrial hazardous waste treatment, in particular to a device and method for harmlessly treating secondary aluminum ash. Background technique [0002] Secondary aluminum ash: the waste after extracting metal aluminum from primary aluminum ash, the main components are alumina (30%~70%), aluminum nitride (5%~30%), metal aluminum (1%~10%) , salts (5% to 25%) and other components. Secondary aluminum ash contains toxic and harmful substances such as fluorine and nitrogen, which is the reason why aluminum ash is included in the "National List of Hazardous Wastes". [0003] In recent years, the development of my country's aluminum industry has made great progress. At the same time, the output of aluminum ash has increased year by year. According to statistics, the amount of secondary aluminum ash produced in my country every year is about 1 million tons. With the collection of environmental protection tax, e...

AI Technical Summary

Problems solved by technology

The quality of ash treatment has a great impact on the economic benefits of the recycled aluminum industry; the aluminum content in the aluminum ash just taken out of the furnace is 45% to 75%, because the amount of aluminum ash is 15% of the melting amount in the furnace Therefore, how to increase the recovery of aluminum from aluminum ash slag is an important issue in the secondary aluminum industry; the aluminum recovery rate in aluminum ash slag is closely related to the cost of secondary aluminum products. Taking a factory with a monthly smelting capacity of 3,000 tons as an example, aluminum The output of ash slag can reach 450t, and the aluminum content is 202.5-337.5t; if the recovery rate of aluminum is 45%, the recovered aluminum is 90-152t; if the recovery rate is 70%, the recovered aluminum can reach 142-236t, with a difference of 52-84t , this difference is equivalent to a gross profit rate of 2% to 3%. However, the higher the recovery rate, the more difficult it is to recover aluminum from aluminum ash, even if it can be recovered to 70%, the remaining residue is difficult to handle; More than 100% of the aluminum ash can be used as a deoxidizer for steelmaking. Therefore, most of the recycled aluminum companies now avoid excessive recovery from the aluminum ash, but sell the aluminum slag to the aluminum slag treatment plant or the steelmaking deoxidizer. factory

[0005] The composition of the secondary aluminum ash is very complex, and the metal aluminum (3-9wt.%) is tiny aluminum particles mixed in the ash residue after frying ash. It is difficult to use chemical methods or physical methods under the premise of considering the recovery cost. Methods to realize further recycling of resources

Among them, metal aluminum particles, AlN, Al 4 C 3 Substances such as fluorine and other substances are highly active, and will produce flammable and toxic gases when exposed to water or in humid air, which is highly environmentally harmful; fluorine-containing compounds and a small amount of heavy metals are leachable and toxic, causing serious pollution to water bodies and air; soluble salts are also It is easy to enter the river and cause environmental pollution; therefore, aluminum ash is difficult to dispose of through traditional landfill methods

Images