Tungsten and Molybdenum Separation – Hyamine Extraction Method

Tungsten and molybdenum are similar elements, they both belong to VIB clan of element periodic table, have similar property. Tungsten and molybdenum separation has always been a difficult issue in tungsten ore metallurgy, and a key process during beneficiation. There are several methods include extraction method, precipitation method and ion exchange method to realize the separation. Here we introduce hyamine extraction method.

Hyamine is a strong complexting agent, it has different complexting ability for tungsten and molybdenum. Using this difference can realize tungsten and molybdenum separation. In recent years, experts in China use hyamine agent as extraction agent, ammonium hydrogen carbonate as stripping agent, sodium hydroxide as regenerating agent, did a lot of research of extracting tungsten directly from tungsten concentrate alkali decomposing solution, obtain a lot of scientific results.

Hyamine extraction method is the sulfuration process of sodium tungstate solution containing molybdenum or ammonium tungstate solution, transform MoO₄^2- into MoS₄^2-, then add MoS₄^2- into organic phase to realize separation of tungsten and molybdenum. Use NaClO to oxidize MoS₄^2- into MoO₄^2- and stripping to realize separation of tungsten and molybdenum.

Common used extraction solvent includes TBP, TRPO, DAMP and so on. Stripping agent includes NaOH, Na₂CO₃, NaHCO₃. Use Hyamine extraction method has the best molybdenum removing effect, also abduct H2S emission during molybdenum trioxide precipitation. But it also has shortcomings. Usage of oxidation agent will oxidize extraction agent results in short service life of extraction agent. It causes its rise in cost, the management difficult and condition is strictly required. Lowering its cost is the main study point for experts.

• < Prev
• Next >