Phosphate minerals

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.

Phosphate minerals 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
• hinsdalite PbAl₃(PO₄)(SO₄)(OH)₆
• 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
• struvite (NH₄)MgPO₄·6H₂O

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.

See also

• Parkerizing

References

• Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., John Wiley and Sons, New York ISBN 0-471-80580-7
• Webmineral - Strunz
• Webmineral - Dana
• - Australian Mineral Atlas