Bottom blocks

Bottom blocks are used for lining the bottoms of aluminium electrolytic cells 


 

Properties

Units of measurement

Typical values

Grade

 

PB3

PB7

PB10

PBG2

Graphite content

%

30

70

100

graphitized

Real density

g/cm3

2.00

2.06

2.15

2.22

Bulk density

g/cm3

1.58

1.64

1.61

1.70

Total porosity

%

21

21

 

 

Open porosity

%

16

17

20

18

Specific electrical resistance

µОhm•m

29

21

20

10

Heat conductivity

W/m•K

12

20

30

120

Compression strength

MPa

35

45

29

28

Flexural strength

MPa

11

15

10

12

Modulus of elasticity (Young's modulus) *

GPa

7

9

6

7

Rappoport's relative elongation in cryolite-alumina melt*

%

0.4

0.2

0.1

<0.2

Linear thermal expansion coefficient  (20-520) °C

10-6•K-1

2.2

3.0

3.4

2.6

Ash content

%

2.0

1.5

0.6

0.2

 

  

 

* - perpendicular to the direction of extrusion. The above values are average values  and they do not constitute a specification.

Bottom blocks are manufactured on the basis of electrically calcined anthracite.

 

 

 

 

Dimensions of bottom blocks

Maximum dimensions, mm

Standard tolerances, mm

Width

720

± 3

Height

490

± 3

Length

3850

± 5

Groove

rectangular

trapezoidal

cylindrical

 

 

 

 

 

 

The chief expert can be reached at hlopkov@ukrgrafit.com.ua.

 

 

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