The isothermal melting process (ITM-IsothermalMelting) developed by the United States Department of Energy (DOE) and Apogee Technology Inc. (Apogee Technology Inc.) is a milestone in the development of aluminum and aluminum alloy melting technology. Here, "Isothermal" means "constant temperaturation", which makes the temperature of the aluminum melt in the molten pool of the isothermal melting furnace uniform and almost at the same temperature.
The introduction of isothermal melting technology is a revolution in aluminum smelting and is of great significance in energy conservation and emission reduction. This technology has entered the commercialization stage. Of course, it needs a development process to get full promotion and application, and it will take some time. The isothermal melting technique is a general term for aluminum and aluminum alloy melting systems consisting of Apoge direct immersed electric heaters, partition walls and side channels (BSPP-Baffleandside pocket pentels), and we call them isothermal smelting furnaces. The world's first isothermal smelting furnace was successfully commissioned on November 3rd, 2003 at the Apogee Technology Company, and announced the success of this technology. The molten aluminum melt is homogenized and degassed and purified in the intermediate treatment zone. The aluminum melt pool actually acts as a stationary furnace.
· Great decline in investment; · Simple furnace structure, ie simple hardware; · The floor space of the smelting furnace is only equivalent to 1/5 of the area of ​​the conventional reflective smelting furnace; · No pollutants are emitted, and the melting shop is free of pollution and air Fresh; • Three-dimensional heating (Volu鄄metric heating) of the charge, ie no temperature gradient - no thermal layering (thermal stratification); • Uniform melt temperature, homogeneous composition; • Improved melt quality , The dissolved gas and solid inclusions are few; The thermal efficiency of the resistance heater is as high as 97%; The smelting potential loss of the metal such as aluminum can be reduced from 6% to less than 2%; The first step should be to smelt the aluminum, but the same Suitable for smelting copper, glass, steel, cast iron, platinum, etc., as well as other industrial sectors; · For the United States in 2004, if the smelting furnace of the aluminum industry was changed from a reverberatory furnace to an isothermal furnace, then due to the improvement of thermal efficiency, the entire industry It can save energy up to 18TBTU (1T=1012, 1BTU=1055J,); In addition, due to aluminum loss during smelting can be reduced by about 4 percentage points, it can save aluminum extraction energy 54.5TBTU (including the loss of electricity); Increased carbon emissions can be reduced by 0.6×106 TCE ( Writing for MTCE metric tons of carbon equivalent), since the melting drop burning, reduces carbon emissions 2.4 × 106TCE.
The application and promotion of isothermal smelting technology is of great significance to saving two sources (energy and resources) and reducing greenhouse gas emissions. The author roughly calculated that in 2006, China's aluminum processing industry and foundry industry had jointly melted the original aluminum ingots and process aluminum. Waste and recycled scrap aluminum is about 1600 kt. It is calculated based on smelting oil consumption of 80 kg/t aluminum and consumes about 128 kt of diesel. If melting in isothermal smelting furnace can save 50% of energy, 64 kt of diesel can be saved; 640 kt can be saved from reduction of aluminum's refining Aluminum, equivalent to one year's output of an ultra-large aluminum plant; greenhouse gas emissions can be reduced by 5.5 x 106 TCE (ton carbon equivalent).
Isothermal smelting technology has entered a preliminary commercialization and practical stage in the aluminum industry in the United States, and is undergoing further improvement and expansion. This technology involves more than 100 patents, the introduction of expensive, still do not know that people do not transfer. In the United States, this technology was successfully studied according to the development plan of the US Department of Energy, which was undertaken by Apoge Technologies and involved with Aleris and Argonne Naé„„tional Laboratory. In the current and commercial promotion of production, General Motors (GM) and Novelis (Newvelis) participated. It is suggested that relevant departments in China organize relevant companies, universities, and research institutes to develop this revolutionary technology with a holistic approach. This technology is applicable not only to the aluminum industry but also to all metallurgical sectors. The author believes that it is better to introduce an isothermal melting aluminum furnace and related technology to develop and research as soon as possible. Under our current state of technology, even if there is sufficient financial guarantee, it will take at least two or three years to produce an isothermal aluminum smelting furnace with commercial value. I hope this estimate by the author is too conservative. Therefore, the introduction of one Taiwan, even if it costs hundreds of millions, is also very cost-effective. However, even if it can be introduced, it is indispensable for independent research and development and digestion and absorption.
