Aluminum is currently the most used metal in the world except steel. Among non-ferrous metals, aluminum is the former in terms of reserves, production and dosage. In 1997, the world's aluminum production and use reached 22 million tons and 23 million tons respectively. Since China's reform and opening up, the aluminum industry has developed rapidly, and its output has soared from 445,000 tons in 1983 to 2.43 million tons in 1998. Aluminum is used in a wide range of applications. Civil, military, construction, transportation, transportation, electronic telecommunications, household appliances, electricity, machinery... The aluminum alloys in all walks of life are almost ubiquitous. As the output and usage increase, the amount of scrap aluminum products is also increasing. Moreover, many aluminum products are used at one time, and the time from the manufacture of the product to the loss of use of the product is relatively short. Therefore, these waste materials have become a source of pollution. How to use the regeneration problem is very urgent.
Recycled aluminum is increasingly prominent in the production of aluminum in major developed countries. The ratio of primary aluminum to recycled aluminum in developed countries is close to or exceeds 1:1. For this reason, the recycling of waste aluminum has become a very important work of all countries in the world and has become an important industry.
However, the recovery and regeneration of aluminum alloy is a very complicated technical work. The wide range of use of various aluminum products, the dispersion of use, how to recycle and classify, and the recycling process are very complicated and huge projects. Secondly, there are hundreds of alloys with different alloy compositions and different properties in the world. Many of the alloys are mutually exclusive and incompatible with each other. How to make the waste Al regenerating component meet the ideal alloy requirements and performance in the easiest way, the lowest cost and the most effective process. The recycling technology with the quality can reach or close to the original material level is the pursuit goal of the world. .
At present, developed countries have formed a complete collection, management and sorting system for waste aluminum, adapting to the expanding market demand. Developed countries are constantly introducing new technological innovations in production, such as low-cost continuous smelting and treatment processes to make low grades. The process of upgrading aluminum scrap, etc., has been able to manufacture a large number of recycled aluminum ingots for casting, die casting, rolling and master alloys with scrap aluminum. The largest ingot weight is 13.5 tons, of which remelting secondary alloy ingots (RSI) For the manufacture of thin sheets for cans, the quality of the sheets has reduced the weight of each can to only about 14 grams, and some recycled aluminum is also used to make frames for computer floppy drives.
However, the degree of conception and understanding of waste aluminum in China has not been deepened to the level of developed countries such as the United States and Japan. The largest and most reclaimed aluminum enterprise in Asia is Shanghai Xinge Nonferrous Metal Co., Ltd. located in the suburbs of Shanghai. Although the company has two sets of 50 tons of smelting static furnace, a group of 40 tons of fuel smelting static furnace; a 12-ton oil rotary kiln, these 50-ton furnaces are not only China's largest regenerative aluminum smelting furnace, but also The largest regenerative aluminum melting furnace in Asia. However, at some level of loop measures and process technology, even if the level of Xinge Company is at the leading position in China, it still belongs to the level of foreign countries in the 1980s. As for some enterprises with small scale, low output and weak environmental protection measures, Most of them, technical transformation and environmental protection facilities can be said to be difficult to implement.
The cost of aluminum from ore to metal, to finished products is extremely high and energy consumption is huge. It takes one hour to produce only one ton of metal aluminum in one process. Recycling and reuse of waste metal aluminum can greatly reduce energy consumption and auxiliary materials consumption, saving resources and costs. Therefore, the recycling and reuse of waste aluminum is of great significance in terms of saving resources on the earth, saving energy and cost, shortening the production process cycle, and protecting the environment and improving the human ecological environment.