Casting & Covering Powders
Covering fluxes protect the steel surface at every stage from the ladle to the continuous-casting mould. Each grade is designed for a particular steel grade, section and casting speed, so we recommend grades from a short questionnaire about your process.
Why use covering fluxes
Grades and technical data
Mould powders
Mould powder melts on the meniscus in the continuous-casting mould. It lubricates between the solid shell and the copper mould wall, controls heat transfer, insulates the meniscus and absorbs inclusions. Supplied as powder or granules.
Physical properties
| Grade | Form | Basicity CaO/SiO₂ | Softening °C | Melting °C | Flow °C | η 1200 °C | η 1300 °C | η 1400 °C | Bulk density g/cm³ |
|---|---|---|---|---|---|---|---|---|---|
| 100 LC&MC 1020 | Powder | 0.70 | 1115 | 1130 | 1155 | 50.7 | 19.7 | 8.6 | 0.70 |
| KT-02-010 | Granule | 0.65 | 1080 | 1100 | 1120 | 52.3 | 20.2 | 8.8 | 0.85 |
| KT-04-020 | Granule | 0.75 | 1048 | 1075 | 1200 | 1.35 | 0.50 | 0.27 | 0.70 |
| KT-05-020 | Granule | 0.80 | 1050 | 1115 | 1140 | — | 2.37 | — | 0.80 |
| PRT/SLB AT 74M | Powder | 0.80 | 1050 | 1115 | 1140 | — | 2.37 | — | 0.80 |
| KT-08-020 | Granule | 0.88 | 1150 | 1225 | 1260 | 19.3 | 8.0 | 3.7 | 0.70 |
| KT-10-025 | Powder | 0.63 | 1010 | 1060 | 1085 | 9.0 | 4.4 | 2.4 | 0.84 |
| KT-11-010 | Granule | 0.88 | 1120 | 1130 | 1140 | 4.0 | 2.1 | 1.3 | 0.88 |
| 250-AC-11 | Powder | 0.85 | 1120 | 1130 | 1140 | 4.0 | 2.1 | 1.3 | 0.70 |
| KT-12-005 | Powder | 1.01 | 1020 | 1050 | 1090 | 1.4 | 0.8 | 0.5 | 0.62 |
| KT-15-010 | Powder | 0.79 | 1040 | 1090 | 1120 | — | 1.8 | — | 0.65 |
| KT-18-015 R | Powder | 0.98 | 1135 | 1140 | 1145 | 10.6 | 4.9 | 2.5 | 0.82 |
| KT-19-025 | Powder | 0.69 | 950 | 1090 | 1100 | — | 4.2 | — | 0.70 |
| SLB-28-1 | Powder | 1.15 | 1100 | 1120 | 1140 | 3.6 | 1.8 | 1.0 | 0.70 |
| PRT/SLB 0912/22-LS 01 | Powder | 1.15 | 1175 | 1175 | 1190 | 0.40 | 0.20 | 0.12 | 0.85 |
η: viscosity in dPa·s at the stated temperature. Temperatures ± 30 °C · particle size < 500 µm (max 1 mm). “—” means the value is not published on the data sheet.
Chemical composition (mass %)
| Grade | SiO₂ | CaO | MgO | Al₂O₃ | Fe₂O₃ | MnO₂ | F | Na₂O | K₂O | Li₂O | BaO | Cfree | CO₂ | LOI | Moisture H₂O |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 100 LC&MC 1020 | 29–31.5 | 20–23 | < 3 | 5–8 | < 3 | < 3 | 3–5.7 | 3–6 | < 3 | — | — | 13–16 | 5–7 | 18–21 | — |
| KT-02-010 | 36.9–40.9 | 24–28 | < 3 | 8.1–11.1 | < 3 | < 3 | 4.0–6.0 | 5.9–7.9 | < 3 | — | — | 1.0–5.0 | 3.2–4.2 | 9.4 | < 0.5 |
| KT-04-020 | 29.6–33.6 | 22.3–26.3 | 0.9–3.9 | 3.3–6.3 | < 3 | < 2 | 3.7–5.7 | 7.2–9.2 | < 2 | — | — | 12.6–16.1 | 6.8–7.8 | 24.3 | < 0.5 |
| KT-05-020 | 27.7–30.7 | 22.0–25.0 | 3.8–6.8 | 0.2–2.1 | 0.5–2.6 | 6.5–9.7 | 0.9–3.3 | 4.5–6.7 | < 1 | — | — | 14.5–17.5 | 4.5–7.7 | 23.3–25.3 | < 0.5 |
| PRT/SLB AT 74M | 27.7–30.7 | 22.0–25.0 | 3.8–6.8 | 0.2–2.1 | 0.5–2.6 | 6.5–9.7 | 0.9–3.3 | 4.5–6.7 | < 1 | — | — | 14.5–17.5 | 4.5–7.7 | 23.3–25.3 | < 0.5 |
| KT-08-020 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| KT-10-025 | 29.6–33.6 | 17.9–21.9 | 1.0–3.0 | 3.2–6.2 | < 2.0 | < 2.0 | 4.0–6.0 | 9.7–11.7 | < 1.0 | — | — | 18.3–22.3 | 5.6–6.6 | — | < 0.5 |
| KT-11-010 | 32.0–35.0 | 29.0–32.0 | 2.5–4.5 | 3.0–5.0 | 1.3–2.3 | < 0.5 | — | — | — | 0.0 | — | — | — | — | — |
| 250-AC-11 | 33.0–36.0 | 29.0–32.0 | 2.0–4.0 | 3.3–5.3 | 1.2–2.2 | < 0.5 | — | — | — | 0.0 | — | — | — | — | — |
| KT-12-005 | 29.2–33.2 | 29.5–33.5 | 1.5–3.0 | 3.0–5.0 | < 1.0 | < 0.5 | 6.6–8.6 | 9.8–11.8 | < 0.5 | 0.2–0.6 | — | 3.8–5.3 | 7.0–9.0 | — | < 0.5 |
| KT-15-010 | 33.4–37.5 | 26.1–30.1 | < 2.0 | 1.8–4.8 | < 1.0 | < 2.0 | 6.9–8.9 | 8.2–10.2 | < 2.0 | < 2.0 | < 0.1 | 5.8–9.8 | 5.5–7.5 | — | < 0.5 |
| KT-18-015 R | 27.0–30.0 | 25.5–29.0 | 1.2–4.2 | 6.6–9.6 | < 2.0 | 2.2–5.2 | 1.8–3.8 | 3.7–5.7 | < 1.0 | — | — | 14.0–18.0 | 2.3–4.3 | — | < 0.5 |
| KT-19-025 | 29.0–31.0 | 19.5–22.0 | 0.5–1.5 | 5.0–7.0 | 1.0–2.0 | < 1.0 | 4.5–6.0 | 7.5–9.0 | < 1.0 | — | — | 20.0–23.0 | 5.0–7.0 | — | < 0.5 |
| SLB-28-1 | 22.6–26.6 | 27.8–31.8 | < 3.0 | 6.0–9.0 | < 3.0 | 3.8–6.8 | 3.0–5.0 | 6.1–8.1 | < 2.0 | — | — | 2.2–6.2 | 10.9–11.9 | 18.0–20.0 | < 0.5 |
| PRT/SLB 0912/22-LS 01 | 31.5–34.5 | 36.5–39.5 | 0.5–1.5 | 6.0–8.0 | < 1.0 | < 1.0 | 6.0–9.0 | 2.5–4.5 | < 1.0 | — | — | 2.5–4.5 | 3.5–5.5 | — | < 0.5 |
Empty cells (—) mean the component is not specified for that grade.
Tundish covering
Insulating cover for the steel in the tundish: reduces heat loss, prevents re-oxidation and absorbs inclusions. BZ-MG 01 is magnesia (MgO) based.
Physical properties
| Grade | Melting °C | Particle size | Bulk density g/cm³ |
|---|---|---|---|
| TC-02-020 MX | 1220 | < 200 µm | 0.75 |
| TC-02-020-A MX | 1225 | < 200 µm (max 1 mm) | 0.85 |
| TC-02-020-AF3 MX | 1215 | < 200 µm (max 1 mm) | 0.85 |
| BZ-MG 01 | > 1500 | < 63 µm: 95–100 % | — |
Chemical composition (mass %)
| Grade | SiO₂ | CaO | MgO | Al₂O₃ | Fe₂O₃ | AlF₃ | Na₂O+K₂O | Cfree | CO₂ | LOI | Moisture H₂O |
|---|---|---|---|---|---|---|---|---|---|---|---|
| TC-02-020 MX | 39–43 | < 1.5 | < 1 | 15–22 | < 4.5 | — | < 8 | 18–23 | — | 20–30 | < 0.5 |
| TC-02-020-A MX | 38–46 | < 3 | < 2 | 12–20 | < 5 | — | < 9 | 19.6–21.6 | — | 20–30 | < 0.5 |
| TC-02-020-AF3 MX | 38–46 | < 3 | < 2 | 12–20 | < 5 | < 4 | < 9 | 19.6–21.6 | — | — | < 0.8 |
| BZ-MG 01 | < 5 | 0.5–2.5 | 70–76 | < 1.5 | < 1.5 | — | 0.5–2.0 | 14.5–16.5 | 1–4 | — | < 1 |
Empty cells (—) mean the component is not specified for that grade.
Ladle covering
Covering compound for the steel surface in the ladle, for thermal insulation and protection between tapping and casting.
Physical properties
| Grade | Melting °C | Particle size | Bulk density g/cm³ |
|---|---|---|---|
| PT-01-005 MX | 1300 | D90 200 µm (< 500 µm) | 0.55 |
Chemical composition (mass %)
| Grade | SiO₂ | CaO | MgO | Al₂O₃ | Fe₂O₃ | Na₂O+K₂O | Cfree | LOI | Moisture H₂O |
|---|---|---|---|---|---|---|---|---|---|
| PT-01-005 MX | 52–58 | 1.5–5.5 | 2–6 | 20–25 | 6.5–9.5 | 2–5 | < 2 | < 3 | < 0.5 |
Empty cells (—) mean the component is not specified for that grade.
Ladle nozzle sand
Chromite filler sand for the ladle nozzle: keeps steel from penetrating and freezing in the well block so the slide gate opens freely at the start of casting. Three grades by Cr₂O₃ content.
Chemical composition (mass %)
| Grade | Cr₂O₃ | SiO₂ | CaO | MgO | Al₂O₃ | Fe₂O₃ | C | Moisture H₂O |
|---|---|---|---|---|---|---|---|---|
| PNK 6500 | 33.6–36.6 | 34.1–37.1 | < 0.5 | 6.2–9.2 | 9.7–12.7 | 6.8–9.8 | < 0.5 | < 0.2 |
| PNK 7000 | 36.0–39.0 | 29.3–32.3 | < 0.5 | 6.8–9.8 | 10.5–13.5 | 7.5–10.5 | < 0.5 | < 0.2 |
| PNK 7500 | 39.0–42.0 | 24.4–27.4 | < 0.5 | 7.4–10.4 | 11.4–14.4 | 8.1–11.1 | < 0.5 | < 0.2 |
Empty cells (—) mean the component is not specified for that grade.
Synthetic slag
CaO-SiO₂ synthetic slag with basicity 0.9 for fast slag formation in the ladle.
Physical properties
| Grade | Melting °C | Particle size | Bulk density g/cm³ | Basicity CaO/SiO₂ |
|---|---|---|---|---|
| SC-04-MX | — | D90 1600 µm | 0.90 | 0.9 ± 0.02 |
Chemical composition (mass %)
| Grade | SiO₂ | CaO | MgO | Al₂O₃ | FeO | LOI |
|---|---|---|---|---|---|---|
| SC-04-MX | 48.5 ± 3 | 43.5 ± 3 | 0.5–1.5 | 0.5–1.3 | 0.1–0.4 | < 0.1 |
Empty cells (—) mean the component is not specified for that grade.
Further grades available (data on request): KT-01-010 KT-03-010 KT-03-010 R KT-06-004 KT-07-005 KT-09-020 PT-01-005-1 PT-01-010 PT-02-015 MX PT-03-015 GRN TC-01-020 TC-03-00-B MX TC-03-015 MX TC-K2-01 MX
Mould powder selection questionnaire
The right mould powder depends on your process. Send us these details and we will propose a grade with its data sheet for a plant trial.
Send process details- Steel grade and carbon range (low C, peritectic, high C…)
- Caster type and section size (billet, bloom, slab)
- Casting speed (m/min)
- Tundish superheat (°C)
- Current powder and consumption (kg/t)
- Current issues: surface cracks, breakouts, inclusions
- Preferred form (powder or granule) and packing