Thermal decomposition mechanism of ammonium phosphotungstate hydrate in air atmosphere
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS, cilt.31, ss.14-20, 2012 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 31
- Basım Tarihi: 2012
- Doi Numarası: 10.1016/j.ijrmhm.2011.08.007
- Dergi Adı: INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.14-20
- Anahtar Kelimeler: Ammonium phosphotungstate hydrate, Thermal decomposition, Tungsten oxide, Thermal analysis, TUNGSTEN BLUE OXIDE, BRONZE
- İstanbul Üniversitesi-Cerrahpaşa Adresli: Hayır
Özet
Production of W from scheelite mineral (CaWO4) by hydrometallurgical processes has grown up in the last decade. CaWO4 dissolves in HCl solutions containing H3PO4 as chelating agent and forms phosphotungstic acid (H-3(PW12O40), PhTA). Ammonium phoshpotungstate hydrate ((NH4)(3)[PW12O40NH2O, APhT) can be precipitated by addition of NH4Cl to solutions containing PhTA and WO3 can be produced by the thermal decomposition of APhT. W powder can be obtained by H-2 reduction of WO3.