Phosphate minerals

From Wikipedia, the free encyclopedia

Phosphate minerals are those minerals that contain the tetrahedrally coordinated phosphate (PO₄^3-) anion along with the freely substituting arsenate (AsO₄^3-) and vanadate (VO₄^3-). Chlorine (Cl^-), fluorine (F^-), and hydroxide (OH^-) anions also fit into the crystal structure.

The phosphate class of minerals is a large and diverse group, however, only a few species are relatively common.

Examples include:

triphylite Li(Fe,Mn)PO₄
monazite (Ce,La,Y,Th)PO₄
Apatite group Ca₅(PO₄)₃(F,Cl,OH)
- hydroxylapatite Ca₅(PO₄)₃OH
- fluorapatite Ca₅(PO₄)₃F
- chlorapatite Ca₅(PO₄)₃Cl
pyromorphite Pb₅(PO₄)₃Cl
vanadinite Pb₅(VO₄)₃Cl
erythrite Co₃(AsO₄)₂·8H₂O
amblygonite LiAlPO₄F
lazulite (Mg,Fe)Al₂(PO₄)₂(OH)₂
wavellite Al₃(PO₄)₂(OH)₃·5H₂O
turquoise CuAl₆(PO₄)₄(OH)₈·5H₂O
autunite Ca(UO₂)₂(PO₄)₂·10-12H₂O
carnotite K₂(UO₂)₂(VO₄)₂·3H₂O
phosphophyllite Zn₂(Fe,Mn)(PO₄)₂•4H₂O

[edit] Applications

Phosphate rock is a general term that refers to rock with high concentration of phosphate minerals, most commonly of the apatite group. It is the major resource mined to produce phosphate fertilisers for the agriculture sector. Phosphate is also used in animal feed supplements, food preservatives, anti-corrosion agents, cosmetics, fungicides, ceramics, water treatment and metallurgy.

The largest use of minerals mined for their phosphate content is the production of fertilizer.

Phosphate minerals are often used for control of rust and prevention of corrosion on ferrous materials applied with electrochemical conversion coatings.