Manufacturing Process
UHP (Ultra-High Power) graphite electrodes undergo an advanced production process to meet extreme operational demands:
Premium Raw Materials
Uses needle coke (low CTE, high purity) with sulfur <0.5% and ash <0.1%
Modified coal-tar pitch binder with controlled viscosity
Precision Particle Engineering
Multi-stage particle sizing (0.1-4mm) with 35-45% fine powder (<75μm)
Isostatic Pressing
150-200MPa pressure forms green bodies with density >1.80g/cm³
Multi-Stage Baking
Slow pyrolysis over 30-40 days (max 1300°C) with precise thermal profiling
Deep Impregnation
3-4 cycles using low-viscosity pitch to achieve final density >1.82g/cm³
Extended Graphitization
3200-3500°C treatment for 15-20 days using Acheson/Longitudinal furnaces
Precision Machining
Sub-millimeter tolerance threading (ISO/DIN standards) with laser-guided QC
Advanced Coating
Multi-layer anti-oxidation treatment (Al-Si + ceramic composites)
Product Characteristics
|
Property |
UHP Specification |
Advantage vs HP-Grade |
|
Resistivity (μΩ·m) |
3.5-5.0 |
30% lower |
|
Flexural Strength (MPa) |
≥16 |
25% higher |
|
CTE (×10⁻⁶/°C) |
0.8-1.2 |
40% improvement |
|
Current Density (A/cm²) |
35-45 |
50% increase |
|
Oxidation Loss (kg/ton) |
0.8-1.2 |
60% reduction |
Key Advantages:
Superior Thermal Stability: Withstands 1800°C intermittent operation
Extended Service Life: 500-800 heats in continuous EAF operation
Energy Efficiency: Reduces power consumption by 8-12% vs HP electrodes
Industry Applications
Advanced Steelmaking
200+ ton UHP-EAFs for specialty steels (tool steels, aerospace grades)
Thin-slab casting (CSP) lines with >1.5Mtpa capacity
High-Grade Ferroalloys
Production of ultra-low carbon ferrochrome (<0.05%C)
Silicon metal (99.9% purity) for solar/PV applications
Critical Non-Ferrous
Titanium sponge production (Kroll process reactors)
High-purity nickel superalloys
Emerging Technologies
Synthetic graphite for lithium-ion battery anodes
Nuclear graphite for Gen-IV reactors
Economic Considerations
|
Factor |
UHP Electrode |
HP Electrode |
|
Initial Cost |
$6000-8000/t |
$3500-4500/t |
|
Consumption |
1.2-1.8kg/t |
2.0-2.8kg/t |
|
ROI Period* |
8-12 months |
12-18 months |
*For 1Mtpa EAF with 80% utilization
Selection Criteria:
Mandatory for currents >80kA
Essential for >150 heats/week operations
ROI-positive when electrode costs <3.5% of melt shop OPEX
Future Trends
Nano-modified electrodes: Graphene-enhanced versions in development (resistivity <3μΩ·m)
IoT-enabled electrodes: Embedded sensors for real-time wear monitoring
Circular manufacturing: 90%+ recycling rate for spent UHP electrodes
UHP electrodes represent the pinnacle of graphite technology, enabling the most demanding metallurgical processes while driving sustainability through efficiency gains. Their adoption is projected to grow 8-10% annually through 2030, particularly in green steelmaking initiatives.
Products Parameters
|
Item |
Unit |
Diameter 550(556-562)Mm |
|||
|
UHP Graphite Electrode |
Nipple |
||||
|
Guaranteed |
Typical |
Guaranteed |
Typical |
||
|
Resistivity ≤ |
UΩ*M |
6.3 |
5.0-6.0 |
5.3 |
3.8-4.5 |
|
Flexural Strength≥ |
MPA |
10.5 |
11.0-13.0 |
20 |
20-25 |
|
Young's Modulus≤ |
GPA |
14 |
8-12 |
20 |
12-16 |
|
Bulk Density≥ |
G/CM3 |
1.66 |
1.68-1.73 |
1.75 |
1.76-1.82 |
|
CTE(100 ℃-600℃) ≤ |
10-6/℃ |
1.5 |
1.3-1.5 |
1.4 |
1.0-1.3 |
|
ASH ≤ |
% |
0.5 |
0.2-0.4 |
0.5 |
0.2-0.4 |
Note:We can provide lengths of 2000/2200/2400mm for UHP500 graphite electrodes. Of course, we can also customize the length according to customer requirements.
Recommended Current Load Of Electrode
|
Grade |
Inch |
Nominal Dia |
Allowable current |
Current density |
||
|
AC |
DC |
AC |
DC |
|||
|
UHP Graphite Electrode |
10 |
250 |
10000-13000 |
- |
14-18 |
- |
|
12 |
300 |
13500-20000 |
- |
14-18 |
- |
|
|
14 |
350 |
20000-32000 |
- |
20-32 |
- |
|
|
16 |
400 |
25000-41000 |
- |
20-32 |
- |
|
|
18 |
450 |
32000-49000 |
- |
20-30 |
- |
|
|
20 |
500 |
40000-60000 |
- |
20-30 |
- |
|
|
22 |
550 |
45000-68000 |
49000-78000 |
18-28 |
20-32 |
|
|
24 |
600 |
52000-81000 |
58000-93000 |
18-28 |
20-32 |
|
|
26 |
650 |
60000-85000 |
64000-100000 |
18-28 |
20-32 |
|
|
28 |
700 |
71000-100000 |
79000-120000 |
18-27 |
20-30 |
|
|
30 |
750 |
82000-123000 |
91000-135000 |
18-27 |
20-30 |
|

