Environmental footprint and green development of aluminum industry in China
The production of primary aluminum is usually made by bauxite mining, alumina preparation, electrolytic aluminum and aluminum ingot casting in 3 stages. Because of its wide range of applications, raw aluminium has been determined to be of great output. With the development of our country's economy, the production of primary aluminum has increased from 2003 tons to 22 million 60 thousand tons in 2013. 5 million 550 thousand. Although compared with 10 years ago, China's primary aluminum production energy consumption dropped by about 16%, greenhouse gas emissions dropped by about 21%, and achieved remarkable results in environmental protection. But in order to meet the needs of its rapid development, there are always some things contrary to the concept of green development.
Aluminum production is energy intensive industries, aluminum industry power consumption accounted for more than 5% of the country's electricity consumption. At the same time, aluminum production process will produce a large number of air pollutants (such as fluoride, sulfur dioxide, nitrogen oxides and polycyclic aromatic hydrocarbons (PAH), etc.), seriously damage the environment and human health in the vicinity. Professor Hong Jinglan College of environmental science and engineering Shandong University report "the study on the environmental footprint in recycled aluminum electrolytic aluminum production in China put forward the primary aluminum production more than alumina and aluminum recycling of the environmental burden. The original aluminium production will produce 15800 kg of greenhouse gas carbon dioxide, which is equivalent to 21 times the production of alumina and recycled aluminum together.
Shandong last year, the Liaocheng Municipal Environmental Protection Bureau found Chiping Xinfa Huayuan Aluminum Co. Ltd. 1-3 furnace carbon dioxide emissions average concentration were 607 mg/m3, 475 mg/m3, 401mg/m3 501, mg/m3, 326 mg/m3, 554 mg/m3; in April 26, 2016, the 4-5 two oxidation furnace sulfur emissions average concentration is 245mg/m3, sulfur dioxide 200mg/m3 more than the provisions of the "Shandong Province thermal power plant air pollutant emission standards". Environmental Protection Agency has let the enterprise to make a fine of 1 million yuan decision. Guangxi Xinfa aluminum in 2015 because of environmental violations illegal discharge of waste water by the Ministry of environmental protection of punishment. On the blue map, enter the name of several large aluminum enterprises in Shandong, it is not difficult to see from the regulatory records of their violations of pollution emissions in the past.
Red mud as the main solid waste of aluminum production, in 2016 alone, Shandong, Shanxi and Henan provinces have accumulated 6.1 tons of red mud piled up three. A large number of red mud eventually become landfill, causing serious environmental impact and burden. The comprehensive utilization of red mud becomes an urgent problem to be solved in the aluminum smelting industry. Red mud is the polluting waste residue discharged from the alumina industry when extracting alumina. It produces 1 tons of alumina on average, and produces 1 - 2 tons of red mud. The red mud contains alkali chemicals, such as fluoride, sodium and aluminum, the pH value of diluted 10 times is 11.25-11.50 (the original soil is more than 12), high pH value determines the red mud on the biological and metal, siliceous materials have a strong corrosive. High alkalinity sewage seeps into the ground or enters the surface water, and makes the water body pH value rise. At the same time, because the pH value often affects the toxicity of the compound in the water, it will cause more serious water pollution. Generally speaking, the alkali content is 30-400 mg/L, which is suitable for the public water source, and the alkalinity of the red mud is as high as 26348mg/L. The red mud with high alkalinity is added into the water body, and the pollution is self-evident.
As the world's largest producer of alumina, China has produced tens of millions of tons of red mud every year. In 2014, the eastern hope Sanmenxia Aluminum Co., Ltd. several kilometers of red mud pool, because of no relevant coverage measures, affecting the nearby villages, resulting in the relocation of the entire village. The company's red mud bank suffered an unexpected landslide in 2016, killing 2 people. The best way to deal with red mud is to carry out comprehensive utilization, such as using red mud to produce building materials, soil amendments, and recycling metals
The recycled aluminum not only has 100% characteristics of the original aluminum, but also saves 95% of the energy produced by the original aluminum. Data show that the total output of recycled aluminum has been as high as 99.43% in Japan, 89.53% in Italy, 62.35 in the United States and 60.74% in Germany, compared with 19.24% in china. According to projections, in our country the output of recycled aluminum increased by 10% every year, it can reduce the pollution source 11.2%.
Aluminum production enterprises take the road of green development, and the utilization of recycled aluminum is one of the inevitable choices. China's aluminum output has been ranked first in the world for 16 consecutive years since 2001, with a total production of 2.3 tons during the period. There is no doubt that the growth rate of scrap, Chinese always way ahead. China is a major producer and consumer of aluminum products, and scrap aluminum resources are increasing at an annual rate of more than 20%. With a large number of aluminum scrap products coming period, huge waste resources for recycling of waste materials, provides a solid foundation for the rapid development of aluminum recycling in china. In addition, when approved the construction of aluminum production enterprises, should consider more factors such as innovation, clean energy such as hydropower, biomass power generation to replace traditional power; technology and application of advanced technology to reduce waste emissions; we should add traffic logistics status, change our aluminum production at present, enterprise capacity, energy consumption, low energy efficiency, metal loss, serious environmental pollution problems hinder the development of green.