Magnetite Production from Steel Wastes with Concentrated Solar Energy

In order to achieve a balanced development in the application of materials for structural or functional purposes, one of the priority objectives of future work is to achieve the goal of “zero waste” in the different production lines. As would be expected from what was agreed in the Kyoto Protocol and the meetings of Copenhagen 2009 and Cancun 2010, the production of clean energy will be strongly encouraged in the future, and indeed that is already the case now. Taking that into consideration, while the promotion of clean energy production is mainly directed toward electricity, solar thermal is quite interesting because of its direct application to metal mining and the chemical processes used in the sustainable development of materials. The combination of both objectives, “zero waste” and “clean energy,” may pose an interesting challenge in the development of primary iron and steel, as well as in other areas of metal production and even in the field of mining. The help of solar thermal energy, which can be concentrated to reach high temperatures, is a tool that could support both the direct production and the recycling of waste steel, in particular waste which is physically and chemically the worst for the environment. This would mean that the environment itself, solar energy, is in fact the key to environmental protection. The use of solar thermal energy is quite interesting because of its direct application to metallurgical and chemical processes. A fluidized bed furnace, heated by solar energy has been used to reduce mill scale. The search of the objectives, “zero waste” and “clean energy”, may pose an interesting challenge in the manufacturing of primary iron and steel, as well as in areas of other metal production and even in the recycling of wastes, minimizing CO2 emissions.