Fluorspar


Fluorspar– fluoride subclass mineral, CaF2. Sometimes Ca is substituted in a small amount by Y (yttrium-fluorite) or rare-earth elements such as (TR), Sr, Mn, Na, U.

It crystallizes in isometrical system, forming so-called fluorite structure (see crystal structure). The crystals have the shape of a cube, octahedron and others; units are compact, coarse, grainy and earthy. Hardness - 4; density - 3.2 g / cc.

Such an impurities as TR, U may color fluorspar in purple, green, yellow and other colors. Pure colorless fluorite is rare (valuable optical materials) Polygenic mineral is used as a flux in metallurgy, raw material for hydrofluoric acid and its salts. Mono crystals (mainly synthetic) are used in optics.

Determination of fluorspar grades


  Metallurgical

In the determination of fluorspar types and grades the numbers indicate the main component content in per cent – calcium fluoride: the letters represent:

  • F (first) – fluorite (concentrate);
  • G, K – gravity, lump (concentrates), correspondingly;
  • M – small (concentrate);
  • Letters after the numbers (A and B) – low and high silicon dioxide content, correspondingly.

  Acid and ceramic

Depending on the main component content and impurities fluorspar is classified in the following grades: FF-97A, FF-97B, FF-95A, FF-95B, FF-92B, FF-90. In the grade determination the letters mean:

  • F (first) – fluorite (concentrate);
  • F (second) –flotation;
  • A and B – low and high silicon dioxide content, correspondingly
  • Numbers –the main component content of calcium fluoride in per cent.

  For welding consumables and cored wire:

  • FKS – fluorite, lump, welding;
  • FGS – fluorite, gravity, welding;
  • FFS –fluorite, flotation, welding.

In the concentrate grade determination, number represents the minimum content of the main component–calcium fluoride in per cent, and the letters A and B – low and high phosphorus content correspondingly.

Fluorspar chemical composition


  Metallurgical

Chemical standard of lump and gravity concentrates in terms of dry substance

Grade

 

Calcium fluoride mass fraction,%,  not less

 

Impurity mass fraction, %, not more

Silicon dioxide

Sulphur

 

Phosphorus

 

FK-95А

FK-95B

FK-92

FG-92

FK-85

FG-85

FK-75

FG-75

FGM-75

FK-65

FG-65

FG-55

95,0

95,0

92,0

92,0

85,0

85,0

75,0

75,0

75,0

65,0

65,0

55,0

2,0

2,5

5,0

5,0

10,0

10,0

20,0

20,0

20,0

30,0

-

-

0,15

0,15

0,20

0,20

0,30

0,30

0,30

0,30

0,30

0,30

0,30

0,30

0,1

0,1

0,2

0,2

0,3

0,3

0,3

0,3

0,3

0,3

0,3

0,3



Moisture content fraction of lump concentrates should not exceed 7%, gravity once –no more than 15%.

 

  Acid and ceramic

Chemical composition of concentrates in terms of dry substance

Grade

 

Calcium fluoride mass fraction,%,  not less

 

Impurity mass fraction, %, not more

Silicon dioxide

Calcium carbonate

Sulphur

FF-97А

FF-97Б

FF-95А

FF-95Б

FF-92А

FF-92Б

FF-90

97,0

97,0

95,0

95,0

92,0

92,0

90,0

0,8

1,0

2,0

3,0

2,5

3,0

3,5

1,0

1,0

1,5

2,0

2,5

3,0

4,5

0,1

0,1

0,2

0,2

0,2

0,2

0,2



Moisture content fraction in the flotation concentrate should not exceed 1%.

 

  For welding materials and cored wire

Fluorite concentrate Chemical composition must the following requirements

 

 

Grade

 

 

Calcium fluoride mass fraction,%,  not less

 

Impurity mass fraction, %, not more

 

Silica

 

Calcium carbonate

 

Sulphur

 

Phosphorus

 

FFS-97А

FFS-97Б

FFS-95А

FKS-95Б

FFS-95

FKS-92

FGS-92

FFS-92

FKS-85

FGS-85

FKS-75

FGS-75

97

97

95

95

95

92

92

92

85

85

75

75

2,0

2,0

2,5

2,5

3,0

5,0

5,0

3,0

-

-

-

-

1,0

1,0

2,0

2,0

2,0

2,0

2,0

3,0

5,0

5,0

-

-

0,05

0,05

0,07

0,07

0,10

0,10

0,10

0,15

0,20

0,20

0,30

0,30

0,015

0,03

0,015

0,02

0,03

0,04

0,04

0,06

0,15

0,15

0,20

0,20



In the flotation of fluorite concentrate all grades moisture content should not exceed 1%.