Treatment method of waste gas in the process of recycled aluminum smelting

Aluminum melting furnace dust collector, iron furnace dust collector, copper melting furnace bag dust collector, zinc melting furnace high temperature dust collector. The high-temperature pulse bag filter with an exhaust air volume of 50,000m3 h designed and produced by our company for an aluminum plant in Shandong collects all the high-temperature flue gas (temperature 250) generated during the combustion process and the flue gas discharged from the furnace door cover, which ensures the operating environment of workers, meets the emission standards stipulated by the state, and brings huge economic benefits to the production enterprises. The particle pollutants collected by the dust collector are mainly metal oxides and non-metal oxides produced in the smelting process, as well as a large amount of carbon ash and so on.

After dust removal and desulfurization: soot concentration: 30mg m3, SO2 concentration:

200mg/m3。

<> iron-making furnace dust collector, copper melting furnace bag dust collector, zinc melting furnace high temperature dust collector features:

1.High temperature: inlet temperature up to +350 ;

2.The dust is fine Most of the dust is soot-like, with a particle diameter of 5um;

Design features of melting dust removal and dust removal system:

1.The workshop adopts semi-open dust collection;

2.The front primary cyclone + multi-pipe cooling system reduces the temperature to +150;

3.Fine dust is removed through a pulsed baghouse system; Clean air is discharged from the outlet of the induced draft fan to the outside;

4.The blanking system all adopts rotary star discharger + screw conveyor, which not only ensures air tightness but also can remove dust in time and stop the machine;

5.The dust removal filter bag is made of high-temperature resistant material (pps), which can withstand +200 instantaneous temperature and +180 long-lasting temperature;

6.The main engine is made of high-temperature resistant steel plate, and the filter bag filter room is equipped with a temperature alarm system + automatic cold air pneumatic valve;

This kind of dust collector is widely used in: the collection and filtration of high-temperature flue gas dust such as molten aluminum, ironmaking, molten copper, molten zinc, drying furnace, etc.

In the smelting process of recycled aluminum, the exhaust gas mainly includes carbon dioxide, oxygen, nitrogen, sulfur dioxide, hydrogen, fluorine, etc. In order to prevent these exhaust gases from polluting the environment, they need to be treated and treated. The following are some commonly used methods for treating exhaust gas in the process of recycled aluminum smelting:

Desulfurization: In the process of recycled aluminum smelting, the exhaust gas may contain harmful gases such as sulfur dioxide, which can be treated by desulfurization technologies such as wet lime-gypsum method.

Defluorination: During the smelting process of recycled aluminum, the exhaust gas may contain fluorine gas, which can be treated by defluorination technologies such as wet or dry hydrofluoric acid method.

Dust removal: In the process of recycled aluminum smelting, the exhaust gas may contain a large amount of particles, which can be treated by dust removal equipment such as electrostatic precipitators and bag filters.

Heat: In the process of recycled aluminum smelting, the exhaust gas contains a large amount of heat energy, which can be heated by waste heat boilers, heat exchangers and other equipment to improve energy efficiency.

Tail gas treatment: In the process of recycled aluminum smelting, the tail gas contains some organic substances, which can be treated by biodegradation, activated carbon adsorption and other methods.

It should be noted that the exhaust gas in the process of treating recycled aluminum smelting should be selected and combined according to the specific situation to meet environmental protection requirements and ensure the operation efficiency and stability of the treatment equipment.

Sell scrap and go to the scrap house, I'll come to your problem].

Most of the scrap aluminum at home and abroad is remelted and cast into recycled aluminum ingots, or a small part of the scrap aluminum is directly restructured and utilized. In the society, aluminum scrap should be carefully pretreated according to the ** aluminum scrap classification standards before smelting, including sorting, packing, drying, purification and dust removal. China's scrap aluminum ** is generally manually sorted.

Other methods can also be used when the amount of aluminum scrap processed is large, such as mechanized sorting, magnetic separation, heavy media separation and cold treatment of aluminum scrap. There are special sorting tables or sorting lines abroad for continuous processing, with large sorting volume and high work efficiency. The main function of magnetic separation is to remove the ferromagnetic substances in the scrap aluminum, and the electromagnet or permanent magnet is used as the iron suction device or magnetic wheel, the iron suction device is suspended above the sorting belt, and the magnetic wheel is placed on the transmission roller of the sorting conveyor belt.

The British Comagnetic Wald separator is when the scrap aluminum material is sent into the sorting machine, there is a steel plate of about 800 and 800mm on the separator on the machine, there is a copper pipe with cooling water in the upper groove, the steel plate produces a magnetic field after the copper tube is energized, and the aluminum sheet is cut by the magnetic field line to generate an induced current and generate another magnetic field, and the interaction of the two magnetic fields pushes the aluminum sheet to a certain direction, so that the aluminum can be separated from the scrap non-metallic object.

The density of aluminum alloys with different compositions is also different, and heavy media separation can be used. Generally, the density of aluminum-magnesium alloy and aluminum-magnesium-silicon alloy is smaller than that of aluminum-zinc alloy, aluminum-copper alloy and aluminum-silicon alloy. The former Soviet Union used this method to process aluminum scrap, with a productivity of up to 10t HO aluminum can maintain its original properties and plasticity at low temperatures, while other metals and non-metals show greater brittleness at low temperatures, such as low carbon steel, zinc, plastics and rubber.

Belgium has a liquid nitrogen low-temperature treatment aluminum scrap production line with a processing capacity of 15,000t a, and the economic benefits are considerable. Crushed aluminum scrap is easy to handle and transport, and generally scrap aluminum materials, waste castings, slag, wires and cans must be crushed. Crushing equipment includes shears, crushers and flame cutting.

The purpose of baling is to compress loose aluminum scrap into bales of a certain size and density, which are easy to transport and melt. In particular, scraps, scraps, aluminum foil, cut waste cables and wires, cans, etc. should be packed.

Aluminum scrap is dried before smelting to remove moisture, lubricants, oil, etc. Generally, rotary drying furnaces and box drying furnaces can be used. In the modern drying production line, there are exhaust gas combustion chambers and dust collectors to purify the exhaust gas and waste water.

For a large quantity, a single and stable chemical composition of scrap aluminum scrap by classification and centralized treatment, which can improve production efficiency, reduce costs and improve economic benefits. For example, France, Japan, the United States, the United Kingdom, Germany, etc., all adopt the classification and centralized treatment of waste cables, wires, waste cans, waste aluminum slag and slag, and the effect is better.

Scrap aluminum parts are melted and reused, poured into molds and cast into mechanical parts, and the master's technology is really good.

The intention of the pre-disposal of scrap miscellaneous aluminum is to remove other metals and impurities mixed in the scrap miscellaneous aluminum, the second is to classify the waste miscellaneous aluminum according to its composition, so that the alloy components between it can be used to the greatest extent, and the third is to dispose of the oil, oxides and coatings on the surface of the scrap miscellaneous aluminum. The result of the end of pre-treatment is to dispose of the scrap aluminum into a charge that fits the furnace conditions, and the fourth is to make the aluminum (including alumina) in the aluminum-containing waste guess get the most economical and reasonable use.

The domestic scrap miscellaneous aluminum pre-treatment technology is still very simple and backward, even in large-scale recycled aluminum plants, there is no more advanced technology for the pre-disposal of scrap miscellaneous aluminum. As far as the method of recycling, recycling, use and disposal of a single type of scrap aluminum, the waste miscellaneous aluminum with a single type or no other impurities at all is usually not disposed of in a messy manner, but is only classified according to the type and composition of the scrap and is piled up independently. A single kind of scrap aluminum only needs to check and test a component when using, you can know the composition of the batch, it is a high-quality recycled aluminum material, usually can be smelted in the furnace without any pre-treatment, when smelting a certain kind of aluminum alloy, you can choose to use the corresponding composition and type of scrap aluminum directly to participate in the reverberatory furnace smelting, and can be easily smelted into the aluminum alloy of the corresponding trademark.

Some scrap aluminum with high copper and zinc content can also be used as a central alloy for adjusting the composition in the aluminum alloy smelting process. In the enterprise that chooses a small reverberatory furnace or crucible furnace, it is necessary to crush the large volume of scrap aluminum (shearing or other methods) into a material that meets the furnace standard. It is worth mentioning that some single types of aluminum scrap will mechanically contain a small number of non-aluminum metals, such as scrap steel such as screws on scrap aluminum doors and windows, although the content is very small, but it will seriously affect the quality of the alloy, so it must be separated before smelting.

Using the principle that various objects with the same volume are thrown with the same force and fall at different landing points, various waste non-ferrous metals with different densities in scrap miscellaneous aluminum can be separated. When the same force is used to shoot objects of different densities and basically the same volume in a straight line, the various objects move in the parabolic direction and fall to different points when they land. The simplest experiment can be carried out on the horizontal conveyor belt, when the mixed waste material runs with the conveyor belt at high speed on the conveyor belt, when the operation reaches the end, the scrap miscellaneous aluminum is thrown along the straight line, and due to the different gravity of various wastes, they land at different points, so as to achieve the purpose of waste miscellaneous aluminum sorting.

This method separates aluminum, copper, lead and other wastes evenly. The equipment manufactured according to this principle has been adopted abroad and is in the research stage in China.

Scrap aluminum smelting refers to the re-smelting and processing of scrap aluminum products, which can not only save a lot of resource consumption, but also reduce the social accumulation of renewable non-ferrous metals. In addition, the development of renewable aluminum resources and the implementation of circular economy for waste aluminum can not only save money, save energy, improve resource utilization, protect the ecological environment and other economic benefits for the country, enterprises or individuals, but also reduce many social problems. All in all, the recycling of aluminum metal can accelerate the realization of comprehensive, coordinated and sustainable development of China's aluminum metal industry.

Scrap aluminum smelting equipment is the general name of recycled aluminum smelting and melting equipment, and its form and structure play an important role in the production capacity, cost, product quality and environmental protection of recycled aluminum alloy. Its types mainly include aluminum melting furnaces, melting furnaces, holding furnaces, annealing furnaces, crucible furnaces, etc.

1. Aluminum melting furnace and smelting furnace.

The aluminium melting furnace is one of the main products produced and developed by Henan Dongpu Thermal Energy Technology, which is mainly used for the preparation and melting of aluminum and its alloys to obtain higher precision aluminum and aluminum products. The aluminum melting furnace of Dongpu Thermal Energy Technology Co., Ltd. is the representative of Henan aluminum melting furnace, which has a reasonable and beautiful design, good rigidity and air tightness; The targeted design of refractory materials for different parts and different working conditions in different parts of the furnace is carried out, and mechanical slag scraping is adopted, which greatly reduces the human labor intensity. Dongpu Thermal Energy's smelting furnace is also equipped with a complete furnace chamber and flue gas dust removal system at the furnace door, which enables enterprises to achieve the purpose of high efficiency, energy saving, clean and environmental protection, thereby greatly reducing energy consumption.

China is a large country in aluminum production, but compared with its wide grip and his cautious developed countries, the core structure of the entire industry is unreasonable, and the scale of the recycled aluminum industry is backward. The development of recycled aluminum industry can solve the crisis of China's aluminum industry, in line with the development trend of the aluminum industry in the world today, and in line with the needs of China's sustainable development and scientific development concept related policies, so the structure of China's aluminum industry urgently needs to increase the proportion of the development of the recycled aluminum industry.

Scrap aluminum is smelted into an alloy containing a certain composition in a counter-flow two-chamber reverberatory furnace, an open smelting chamber reverberatory furnace or other forms of furnace, and the key to its technology is to add flux (KCL: NaCl=1:1, plus cryolite 10% or fluorite to absorb the alumina film that hinders the aggregation of aluminum droplets, and strengthen stirring to promote the aggregation of aluminum droplets.

Aluminum alloys are commonly aerated (containing Cl215%, the rest is inert gas) refining or vacuum refining (residual pressure 3 mm Hg) to remove Al2O3 slag and dissolved hydrogen. If necessary, cryolite can be added to remove magnesium (containing Mg< and silicon to remove iron (containing Fe "Ascend, add magnesium to dissolve aluminum, and then use the melting method to remove iron, silicon (containing Fe<, Si<. Generally, scrap aluminum can be melted and refined into malleable aluminum alloys, cast aluminum alloys and deoxidizers for steelmaking and ferroalloys.

In addition, leaching and dry processes (crushing, screening and magnetic separation) are used to extract small aluminum particles from scum and slag.