With the vigorous development of China's aluminum industry, the discharge volume of solid waste waste tank lining produced in the electrolytic aluminum production process is also increasing year by year. Energy conservation, consumption reduction, and pollutant reduction and emission reduction are the main subjects of current scientific development. The hazards of the environment and the realization of the harmony between the aluminum industry and the environment are issues that the aluminum industry must face together. The waste chute lining contains about 35% of carbonaceous materials, 30% of refractory materials, and also contains about 30% of fluoride that directly affects the environment and a small amount of highly toxic substance cyanide. According to the calculation of waste lining of 30 kilograms of primary aluminum discharged per ton of produced aluminum, over the years, China's waste tank lining has accumulated more than 2 million tons of external effluent, and the number of 300,000 tons per year is increasing. China's aluminum plants mostly use open-pit or direct soil landfill, not only polluting the atmosphere, soluble fluoride, cyanide will flow into the river with the rain, infiltrating the underground contaminated soil and water sources, causing damage to the surrounding ecological environment, human health and animal and plant growth. Great harm.
The harmless treatment technology of electrolytic aluminum waste tank lining is the key common technology in the aluminum industry. The United States Environmental Protection Agency issued a decree in 1992 prohibiting the storage and burying of aluminum electrolytic waste tank linings. Subsequently, the world's major aluminum companies have successively developed the harmless treatment technology for waste tank linings with the characteristics of the company, and have formed 10,000 tons. Industrial-scale processing plants of a large scale perform harmless treatment and comprehensive utilization of solid waste discharged from electrolytic aluminum production. All major aluminum companies use the harmless treatment technology of waste tank lining as their core technology and build a large number of patented technical barriers. China also issued corresponding environmental discharge standards for the storage and discharge of solid wastes for aluminum electrolysis. However, the practice of the aluminum industry is mainly based on burying, and research on the harmless treatment of spent tank linings started late. Existing wet The technologies such as waste disposal tank lining and direct use of waste cathode carbon block are not perfect, and they have encountered great difficulties in the implementation of scale. There is equipment corrosion, the product is difficult to separate after treatment, waste can not meet the standard discharge, can not deal with all the waste tank Lining materials and other issues.
As the flagship of aluminum industry, China Aluminum Corporation shoulders the heavy responsibility of scientifically developing the aluminum industry in China. As the only large-scale scientific research institution in China's aluminum-magnesium industry, China Aluminium Zhengzhou Research Institute adopts independent and innovative technologies to achieve scientific development. The concept of development follows the development philosophy of “a harmonious development, scientific development, graceful society, and the benefit of mankind†of Aluminum Corporation of China. It supports the sound and rapid development of China’s aluminum industry with technology and “creates a world-class enterprise, builds a century-old store, and builds harmony. Chinalco's Strategic Objectives.
In July 2002, President of China Aluminum Research Institute Zhengzhou Research Institute Li Wangxing visited Alcoa, and learned that only a few transnational corporations such as Alcoa had mastered the harmless treatment technology of waste chute lining. After returning home, he organized research and development personnel to tackle the problem of harmless treatment of waste chute lining. He said: “We must dare to compete with Alcoa, Alcoa can do it, and Chinalco can do it. Alcoa waste tank lining is not available. Harmonic treatment technology has benefited the United States. We need to develop a better harmless treatment technology for waste tank lining to benefit China." In 2003, Chinalco initiated the research and development of harmless treatment of waste aluminum sluice lining, and established the first domestic 3,000 ton/year waste tank lining harmless treatment industrial test line in the national large aluminum electrolytic industrial test base. After two years of hard work, it overcomes many technical difficulties and finally succeeded in developing the Chalco-SPL technology with the independent intellectual property rights of China Aluminum and can apply for industrial promotion and application, and applied for 5 invention patents. Industrial tests showed that the solidification rate of fluorides in hazardous substances reached 98.66%, and the cyanide decomposition rate reached 99.68%. The obtained final solid slag had better dispersion performance. The average content of soluble fluorine was 39.7 mg/l, and the average content of cyanide was 0.053 mg/l. The indicators are better than the national environmental protection standards.
The technology has passed the appraisal of the China Nonferrous Metals Industry Association. Experts believe that Chalé„„co-SPL technology is a domestic initiative, fully owning independent intellectual property rights, adopting unique formula technology and additive technology, advanced technology, reliable technology and low processing cost. With strong industrial applicability, it can deal with waste tank lining materials of different electrolytic plants and different compositions, and the treated waste can be used for paving roads and producing cement, and the waste tank lining with Chinese characteristics and waste treatment is harmless. Handle key technologies. The various technical and economic indicators are equivalent to those of Alcoa, indicating that Chinalco has reached the international advanced level in the harmless treatment technology of the aluminum tank slot lining. After being popularized and applied, the country will avoid burying 300,000 tons of waste lining in the country each year, technically eliminating pollution to the atmosphere, soil, and water quality, and has broad application prospects, and significant environmental and social benefits. The continuous, healthy and harmonious development of the aluminum industry is of great significance.
The successful development of harmless waste lining technology has aroused the attention of the country. On December 20th, 2006, the expert group headed by Teng Jing, the deputy secretary-general of the China Environmental Protection Industry Association, inspected and reviewed the technology after the research institute unanimously held that the successful research and development of the harmless treatment technology of the aluminum tank slot lining is to achieve cleanliness. The model of production and development of circular economy is the typical representative of Chinalco's independent innovation to implement the scientific concept of development and promote harmony between the aluminum industry and nature. The National Environmental Protection Association will strongly recommend this technical achievement to industrialize it as soon as possible to completely solve the electrolytic aluminum. Industrial waste tank lining pollution to soil and water quality. The “Harmless Treatment Technology for Aluminium Reduction Cell Slot Lining†has been recognized as a national key environmental protection practical technology by the National Environmental Protection Industry Association.
The successful research and development of this technology has a strong response in the aluminum industry at home and abroad. At the TMS annual meeting held in the United States in 2007 and in the Asia-Pacific six-nation aluminum industry pollution reduction and emission reduction forum held in Beijing, many national environmental protection agencies including Quebec Provincial Environmental Protection Agency, Alcoa, Alcan, etc. The company has developed a keen interest in the harmless treatment technology of the waste tank lining independently developed by Chinalco. In China, the industrial sector, environmental protection agencies, and electrolytic aluminum enterprises have also attracted great attention and attention. Many provincial and municipal environmental protection units and electrolytic aluminum plants have visited the Zhengzhou Research Institute to investigate and promote the application of this technology. The National Development and Reform Commission has listed this technology. Into a major industrial technology plan. Chinalco has decided to intensify efforts to promote the industrialization of this technology, and took the lead in applying this technology to Chinalco Guangxi Branch to do a good job in the promotion of the national aluminum electrolysis industry.