Environmental pollution control of regenerated aluminum exhaust gas
Recycled aluminum (recycled aluminium) is composed of waste scrap aluminum and aluminum alloy scrap material or aluminum, by re melting and refining the Aluminum Alloy or aluminum metal, is an important source of metal aluminum. The regeneration aluminum mainly appears in the form of aluminum alloy. The recycled aluminum must be rigorously tested before use. National non-ferrous metals can be recycled aluminum testing, issued a corresponding test report.
I. sources of pollutants from recycled aluminum exhaust gases
China's scrap recycling mainly adopts the smelting waste gas, and is likely to affect the environment of the process is the main smelting process. In the process of melting, using fuels mainly coal, coke, heavy oil, diesel oil, coal gas, natural gas, fuel in the combustion after oxide gas produced gas containing large amounts of soot and sulfur, carbon, phosphorus and nitrogen (scrap); charge after heating, and the inclusion of oily waste itself fuel combustion, will produce large amounts of sulfur, carbon and nitrogen oxides; in the smelting process, in order to reduce the loss and improve the recovery rate of aluminium and ensure the quality Aluminum Alloy, to add a certain amount of covering agent, refining agent and degassing agent, these additives and various impurities in aluminum melt and the reaction that produces a large amount of gas and smoke, all kinds of metal oxides and non metal oxide containing waste gases and dust, and may also contain harmful substances, which may cause pollution to the environment.
The classification and composition of two aluminum, flue gas
1. aluminum industry waste classification
According to the regulations of the environmental protection department, the waste gas produced by the industrial department can be divided into two categories: particulate matter, exhaust gas and gaseous pollutants and exhaust gases. As the recycled aluminum industry raw materials in the production process is complex, and the existence of more than two kinds of waste gas, waste gas containing both particulate and gaseous pollutants containing waste gas, so in the governance of the exhaust gas at the same time, to consider the influence of dust in the waste gas and harmful gas to the environment caused by.
2. main components of flue gas
Because the sources of scrap industry of different raw materials, different varieties of waste and contaminated to different degrees, the fuel additive is different, the different components, the smelting technology is different, therefore, emissions of pollutants are also different, can be summed up the following:
(1) granular waste is mainly produced in the smelting process of metal oxide and metal oxides, such as Mg, Zn, Ca, Al, Fe, Na, Mg, K oxides and chlorides, as well as a large number of carbon particles of ash, the above form we often speak of dust.
(2) the main components of gaseous pollutants and exhaust gases. Recycled aluminum industry may exist below the gas exhaust pollutants, CO, CO2, NOX, SO2, HCl, HF, hydrocarbons and volatile metal oxides or volatile metals may also have chlorine and so on, of course not all components are harmful, but most of them will have a greater impact on the environment. Some may endanger the safety of the workers.