RP Graphite Electrode
RP Graphite Electrode is mainly made of common Cacined Petroleum Coke, Graphitized in lower temperature. With its higher resistivity, larger CTE value and weaker thermal shock resistance ability, RP graphite electrode allows lower current density that pass through the furnace.
RP graphite electrode can carry current density lower than 17A/cm2 which is mostly used in regular power electric furnace for
- steelmaking
- silicon smelting
- yellow phosphorus smelting
- other smelting application
Industrial Specification of RP Graphite Electrode
Technical Specification of RP Graphite Electrode
| Item | Dia 150-225mm | Dia 250-300mm | Dia 350-450mm | Dia 500-800mm | ||||
| Electrode | Nipple | Electrode | Nipple | Electrode | Nipple | Electrode | Nipple | |
| Specific Resistance | ≤9-10.5µΩm | ≤8µΩm | ≤9-10.5µΩm | ≤8µΩm | ≤9-10.5µΩm | ≤8µΩm | ≤9-10.5µΩm | ≤8µΩm |
| Bending Strength | ≥10Mpa | ≥15Mpa | ≥8Mpa | ≥15Mpa | ≥7Mpa | ≥15Mpa | ≥6.5Mpa | ≥15Mpa |
| Elastic Modulus | ≤9.3Gpa | ≤14Gpa | ≤9.3Gpa | ≤14Gpa | ≤9.3Gpa | ≤14Gpa | ≤9.3Gpa | ≤14Gpa |
| Bulk density | ≥1.53g/cm³ | ≥1.7g/cm³ | ≥1.53g/cm³ | ≥1.7g/cm³ | ≥1.53g/cm³ | ≥1.7g/cm³ | ≥1.52g/cm³ | ≥1.7g/cm³ |
| CTE (100-600℃) | ≤2.9*10^-6/℃ | ≤2.7*10^-6/℃ | ≤2.9*10^-6/℃ | ≤2.7*10^-6/℃ | ≤2.9*10^-6/℃ | ≤2.7*10^-6/℃ | ≤2.9*10^-6/℃ | ≤2.7*10^-6/℃ |
| Ash | ≤0.3% | ≤0.3% | ≤0.3% | ≤0.3% | ≤0.3% | ≤0.3% | ≤0.3% | ≤0.3% |
RP Graphite Electrode Sizes & Tolerance
| Diameter (mm) | Length (mm) | ||||
| Nominal Diameter | Actual Diameter | Nominal Length (Options) | Tolerance | ||
| (inch) | (mm) | (max.) | (min.) | ||
| 3 | 75 | 78 | 73 | 1000/1200/1400/1600 | ±100 |
| 4 | 100 | 103 | 98 | 1000/1200/1400/1600 | |
| 6 | 150 | 154 | 149 | 1000/1200/1400/1600 | |
| 7 | 175 | 179 | 174 | 1200/1400/1600/1800 | |
| 8 | 200 | 205 | 200 | 1600 | |
| 9 | 225 | 230 | 225 | 1600 | |
| 10 | 250 | 256 | 251 | 1600/1800 | |
| 12 | 300 | 307 | 302 | 1600/1800 | |
| 14 | 350 | 357 | 352 | 1600/1800 | |
| 16 | 400 | 409 | 403 | 1600/1800/2000/2200 | |
| 18 | 450 | 460 | 454 | 1600/1800/2000/2200 | |
| 20 | 500 | 511 | 505 | 1800/2000/2200/2400 | |
| 22 | 550 | 562 | 556 | 1800/2000/2200/2400 | |
| 24 | 600 | 613 | 607 | 2000/2200/2400 | |
| 26 | 650 | 663 | 659 | 2000/2200/2400/2700 | |
| 28 | 700 | 714 | 710 | 2000/2200/2400/2700 | |
| 30 | 750 | 765 | 761 | 2000/2200/2400/2700 | |
| 32 | 800 | 816 | 812 | 2000/2200/2400/2700 | |
Suggested Current-Capacities of RP Electrodes
| Nominal Diameter | Suggested Current-Carrying Capacity (A) | Current Density(A/cm2) | |
| mm | inch | ||
| 150 | 6 | 3000-4500 | 16-25 |
| 200 | 8 | 5000-6900 | 15-21 |
| 250 | 10 | 7000-10000 | 14-20 |
| 300 | 12 | 10000-13000 | 14-18 |
| 350 | 14 | 13500-18000 | 14-18 |
| 400 | 16 | 18000-23500 | 14-18 |
| 450 | 18 | 22000-27000 | 13-17 |
| 500 | 20 | 25000-32000 | 13-16 |
| 550 | 22 | 28000-34000 | 12-14 |
| 600 | 24 | 30000-36000 | 11-13 |
| 650 | 26 | 32000-39000 | 10-12 |
| 700 | 28 | 34000-42000 | 9-11 |
Surface Quality
| Item Defect Dimension | Nominal Diameter of Graphite Electrode | |
| 300–400mm | 450–600mm | |
| Diameter (mm) | 20–40 (< 20 mm should be negligible) |
30–50 (< 30 mm should be negligible) |
| Depth (mm) | 5–10 (< 5 mm should be negligible) |
10–15 (< 10 mm should be negligible) |
| Remarks: 1. There should be less than two defects or holes on the electrode surface, the max size of which is mentioned in the above chart. 2. There should be no transverse crack on the electrode surface. For the longitudinal crack, the length should be less than 5% of the electrode circumference and the width in between 0.3-1.0mm. 3. The width of black area on electrode surface should be less than 1/10 of electrode circumference and the length less than 1/3 of electrode. |
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