In the quest for new sources of rare and trace metals, researchers have turned their attention to diopside, a mineral that shows promising potential for scandium extraction. A recent study led by Alexandra D. Zaitseva, published in the journal “Известия Томского политехнического университета: Инжиниринг георесурсов” (Tomsk Polytechnic University Journal: Engineering of Georesources), presents a comprehensive, energy-efficient technology for processing diopside to produce scandium concentrate and a range of inorganic products.
Scandium, a rare earth metal, is highly sought after for its applications in high-performance materials, particularly in the energy sector. It is used to strengthen aluminum alloys for aerospace components and to enhance the performance of solid oxide fuel cells. However, the scarcity and difficulty of extracting scandium have limited its widespread use. This new research could change that.
The study focuses on developing a resource-saving technology for diopside processing. “We aimed to create a technology that not only extracts scandium efficiently but also produces a variety of valuable inorganic products, ensuring the economic feasibility of the production process,” Zaitseva explained.
The researchers employed atomic emission spectroscopy with magnetic plasma to analyze the composition of acidic solutions. They successfully obtained samples of impregnates based on macroporous activated carbons impregnated with a mixture of D2EDPA (oxyethylidene diphosphonic acid) and TBP (tributyl phosphate). These samples demonstrated a high capacity for scandium compounds, significantly increasing industrial safety by eliminating the need for liquid extraction.
One of the innovative aspects of this research is the use of two new re-extractants based on a mixture of ammonium salts or oxyethylidene diphosphonic acid. These re-extractants improve the environmental and economic performance of the re-extraction process. “The use of these innovative re-extractants allows us to enhance the efficiency and sustainability of scandium extraction,” Zaitseva noted.
The technology proposed by the researchers includes the co-precipitation of scandium compounds using calcium/magnesium oxides. The calcined scandium-containing concentrate contains between 0.8% and 1.4% scandium. The mother liquors from the opening process can be neutralized using magnesium-containing waste to produce magnesium sulfate, a valuable material for various industries, including construction and agriculture. The residues from neutralization can be partially returned to the diopside opening stage or used as raw materials for producing complex titanium-containing coagulants.
The comprehensive technology developed by Zaitseva and her team minimizes the generation of wastewater and solid waste, making it a sustainable and environmentally friendly solution. This research has significant implications for the energy sector, as it could lead to a more reliable and cost-effective supply of scandium, enabling the development of advanced materials and technologies.
As the demand for rare earth metals continues to grow, innovations like this one will be crucial in meeting the needs of various industries. The work published in “Tomsk Polytechnic University Journal: Engineering of Georesources” represents a significant step forward in the field of mineral processing and could shape the future of scandium extraction and utilization.