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Bottom blocks intended for lining bottoms of aluminium electrolytic cells
| Technical characteristics | Units of measurements |
Typical values nn | ||||||||
| Grade | PB3 | PB5 | PB7 | PB10 | PBG2 | |||||
| Graphite contents | % | 30 | 50 | 70 | 100 |
graphi- tized |
||||
| Real density | g/sm3 | 2.00 | 2.02 | 2.06 | 2.15 | 2.22 | ||||
| Bulk density | g/sm3 | 1.58 | 1.60 | 1.64 | 1.61 | 1.70 | ||||
| Total porosity | % | 21 | 21 | 21 | ||||||
| Open porosity | % | 16 | 17 | 17 | 20 | 18 | ||||
| Specific electrical resistance | µОhm·m | 29 | 25 | 21 | 20 | 10 | ||||
| Heat conductivity | W/m·K | 12 | 17 | 20 | 30 | 120 | ||||
| Compression strength | MPа | 35 | 40 | 45 | 29 | 28 | ||||
| Flexural strength | MPа | 11 | 13 | 15 | 10 | 12 | ||||
| Modulus of elasticity (Young's)* | GPа | 7 | 8 | 9 | 6 | 7 | ||||
| Rappoport's relative elongation in cryolite-alumina melt* | % | 0.4 | 0.3 | 0.2 | 0.1 | 0.1 | ||||
| Temperature coefficient of linear expansion | 10-6•К-1 | 2.2 | 2.6 | 3.0 | 3.4 | 2.6 | ||||
| Ash content | % | 2.0 | 1.5 | 1.3 | 0.6 | 0.2 | ||||
* - perpendicular to the direction of extrusion. Indicated values are given as average values of properties and they do not constitute 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 | 470 | ± 3 |
| Length | 3850 | ± 5 |
| Groove | rectangular trapezoid cylindrical |
Chief expert in cathode products churilin@ ukrgrafit.com.ua.