Abstract
This chapter discusses the methods of determination of molybdenum and tungsten in silicate rocks. There is small number of reagents that are suggested for the spectrophotometric determination of molybdenum and tungsten and of these, only thiocyanate and dithiol are widely used for the analysis of silicate rocks. Both molybdenum and tungsten react with alkali thiocyanate to give intense yellow-to-orange colors. The reactions occur in acid solution in the presence of strong reducing agents such as stannous chloride. Earlier procedures for molybdenum and tungsten in silicate rocks were based upon the decomposition of the sample by fusion with alkali carbonate, followed by an aqueous extraction of the melt. However, the erratic recoveries of molybdenum and tungsten are because of the failure to recover these two elements quantitatively in the alkaline filtrate. For this reason, an acid decomposition procedure based upon evaporation with hydrofluoric acid is now preferred. The chapter discusses the spectrophotometric determination of tungsten and molybdenum in silicate rocks. It also illustrates the determination of molybdenum in silicate rocks by atomic absorption spectroscopy (AAS).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
