Scandium was originally extracted from scandium yttrium stone. At present, it is mainly comprehensively recovered from the by-products of processing titanium, aluminum, tungsten, tin, uranium, rare earth and other minerals. See Table 3 [19] for the annual production scale of these minerals, the scandium content in them and the amount of scandium mined along with them. It can be seen that the amount of scandium mined every year is very large, but most of it has not been recovered. Therefore, the key to scandium industrial production is to explore effective separation methods and establish a reasonable recovery process. Its rationality depends on the scandium content in raw materials, the production scale of main metals, and the enrichment degree of scandium in intermediate products and waste materials. When recovering scandium in the production process, the distribution of scandium in the main products is very important. When enriching scandium from production wastes (waste liquid, waste residue, sludge, etc.), a reasonable process should be established without destroying the main process.
The degree of development of scandium resources is closely related to the progress of industrial utilization. The international market has different demands for varieties, specifications and quantities of scandium in different periods. The market capacity is limited, and the price fluctuation is completely dominated by the market. In 1983, the United States suddenly purchased a large amount of scandium accumulated in the past in the international market, which increased the price of 99.9% scandium oxide by 2.5 times. In the 1990s, the United States and Japan stored scandium as a strategic material related to the development of high-tech applications, resulting in a surge in the price of scandium in the world market. However, since the former Soviet Union sold a large number of its past inventories, domestic overproduction and the sharp decline of market capacity, the world scandium market was oversupplied, and the price fell rapidly. Today, the price of scandium has dropped by 60-70% over the past decade.
