Recent Patents in Reuse of Metal Mining Tailings and Emerging Potential in Nanotechnology Applications

Background: Reuse of waste materials present in the technosphere, such as the metal mining tailings is becoming a more economical and energy-efficient method for obtaining the raw materials than the classical mining. Number of patents are presenting methods for tailings recycling, often in construction industry and metallurgy. At the same time, world market for metallic nanomaterials is rapidly increasing with numerous new applications and these two subjects should be connected. Methods: Paper presents the hypothesis that fine sludge from the metal mining tailings could be dominant source of the raw material for the nanotechnology. The idea is based on the fact that most of the usual publications present methodologies for synthesis of nanomaterials only from high-quality chemicals which is often expensive and unsustainable. Proposition here says, that it would be more economical to use the tailings as one of the technospheric wastes, directly by extracting the metal ions, selectively precipitating their cations and subsequently using them in nanotechnologies. Arguments are given by cross-comparison of the literature and patents on iron, bauxite, lead/zinc, copper, tailings and also the extraction of rare earth elements from tailing resources. Results: Metal mining tailings are shown to be an emerging subject in various research papers and patents together with other secondary raw materials. Conclusions: Use of the metal mining tailings as the resources in nanotechnology, is a large energysaving potential. Taking advantage of this readily available technospheric waste which contains mostly micrometer particles, should contribute also to the zero-metal waste goals.