1. Phosphates, Vanadates, Arsenates, Tungstates, and Molybdates
GLY 4200
Lab 9 - Fall, 2016

2. Phosphates, Vanadates, and Arsenates
Groups are tetrahedral, with strong bonding with in the group
PO43-, VO43-, AsO43-
What is the charge on the cation?

3. Apatite Most important phosphate mineral Major ore of phosphorous
Ca5(PO4)3(F,Cl, OH)
Occurs in three varieties
Fluor
Chlor
Hydroxy

4. Phosphates and Radiation
Uranium occurs in many phosphate group minerals, making them radioactive
The mining of phosphate ores often releases radioactivity into the environment
Houses built on or around phosphate gangue material may be plagued by high radon concentrations as a result

5. Tungstates and Molybdates
Cations are quite large
W and Mo have nearly identical radii – why?
Anionic groups are distorted square planar rather than tetrahedral

6. Extensive Partial Solid Solution
Involves both cations and anionic groups
Cation substitution –
Wolframite series – complete solid solution
FeWO4, Ferberite
MnWO4, Huebnerite
Wulfenite – PbMoO4
Partial series to Powellite, CaMoO4

7. Anionic Substitution Partial solid solution CaWO4, Scheelite
CaMoO4, Powellite

8. Text Reference
See chapter 17 in the text for more information on phosphates, vanadates, arsenates, tungstates, and molybdates, pp and