In this article we review the advances that have been made on the understanding of the high-pressure structural, vibrational, and electronic properties of wolframite-type oxides since the first works in the early 1990s. Mainly tungstates, which are the best known wolframites, but also tantalates and niobates, with an isomorphic ambient-pressure wolframite structure, have been included in this review. Apart from estimating the bulk moduli of all known wolframites; the cation-oxygen bond distances and their change with pressure have been correlated with their compressibility. The composition variations of all wolframites have been employed to understand their different structural phase transitions to post-wolframite structures as a response to high pressure. The number of Raman modes and band gap energy changes have been also analyzed in the basis of these compositional differences. The reviewed results are relevant for both fundamental science and for the development of wolframites as scintillating detectors. The possible next research venues of wolframites have also been evaluated.

Tungsten is a high-value resource with a wide range of applications. The end-products of tungsten industry are tungsten metal and alloys that are produced through many steps from high-grade concentrates. Pyrometallurgical extraction of tungsten from complex and low-grade ores has great potential to overcome the problems associated with the hydrometallurgical process. In this study, sodium carbonate and silica were used to extract tungsten from wolframite at high temperatures. Sodium tungstate can be obtained directly from the smelting reaction between 1100 and 1300 oC. The smelting slag is further water-leached to recover sodium tungstate in the solution. The effects of Na2CO3/Ore and SiO2/Ore ratios, temperature and reaction time on the recovery of tungstate and the purity of sodium tungstate were systematically studied, which provides a theoretical basis for the pyrometallurgical smelting process of tungsten extraction.