Nozzle Filling Compound — Automatic Free-Flow Opening for Ladle & Tundish
A free-flowing refractory sand that keeps the tundish nozzle open between casts and opens it automatically when casting starts.
FerrumX supplies silica-based and chromite-based filling sands in graded particle sizes — sealing the nozzle well, resisting sintering, and protecting the flow path at 1600–1900°C.
What it is
What Nozzle Filling Compound Is & Where It Is Used
Nozzle Filling Compound (NFC) is a free-flowing refractory sand placed in the nozzle well of ladle and tundish nozzles and in sliding-gate assemblies. During initial tapping it fills the nozzle and keeps the tundish nozzle open between casts; when casting starts, the hydrostatic pressure of the molten steel head pushes it out, opening the nozzle.
NFC is supplied in grades with different particle sizes and chemical makeups matched to nozzle diameter, steel holding time, and plant conditions. FerrumX supplies silica-based and chromite-based formulations.
Where it is used
Ladle bottom nozzles and well blocks
Fills the ladle bottom-nozzle well before tapping; opens automatically without oxygen lancing.
Tundish nozzles and sliding-gate plates
Placed at the tundish nozzle and sliding-gate port; keeps the tundish nozzle open between casts.
Automatic pouring and continuous casting lines
Enables automatic free-opening of the ladle, reducing the need for oxygen burning.
Steel flow control and high-temperature flow-path protection
Isolates molten steel from air and maintains structural integrity at 1600–1900°C.
Technical Specifications
Technical Specifications
The table below lists the compositional and physical data for FerrumX’s three stock NFC grades. Values are as measured per production batch.
| Product Type | Chemical Composition | Physical Properties | Particle Size | Refractoriness | Bulk Density | LOI |
|---|---|---|---|---|---|---|
| Silica-Based Filling Sand | Si₂₃: 95% ; Fe₂O₃: 0.32% | High refractoriness; suitable for steel flow-path sealing | 0.5–1.5 mm | 1700 °C | ~2.2 g/cm³ | — |
| Chromite-Based Filling Sand | Cr₂O₃: 13.8% ; SiO₂: 66.8% ; Al₂O₃: 4.08% ; Fe₂O₃: 7.83% ; MgO: 3.075% | Excellent thermal resistance; suitable for high-temperature steel flow | 0.15–1.5 mm | 1790 °C | ~2.3 g/cm³ | — |
| Silica-Chromite Filling Sand | Cr₂O₃: 28–33% ; SiO₂: 27% ; Fe₂O₃: 21% ; Al₂O₃: 12% ; MgO: 7% | Designed for ladle nozzle sealing; optimized flowability | 0–1 mm | 1800–1850 °C | 2.25 g/cm³ | <0.15% |
Material grades and particle sizes currently offered
FerrumX supplies silica-based and chromite-based grades, plus a silica-chromite blend for ladle nozzle sealing; industry-standard bases (olivine, high-alumina, zircon) are also supported.
Silica-Based Filling Sand
Si₂₃ 95%, Fe₂O₃ 0.32%; particle size 0.5–1.5 mm; refractoriness 1700 °C; bulk density ~2.2 g/cm³. Used for steel flow-path sealing.
Chromite-Based Filling Sand
Cr₂O₃ 13.8%, SiO₂ 66.8%, Al₂O₃ 4.08%, Fe₂O₃ 7.83%, MgO 3.075%; particle size 0.15–1.5 mm; refractoriness 1790 °C; bulk density ~2.3 g/cm³. For high-temperature steel flow.
Silica-Chromite Filling Sand
Cr₂O₃ 28–33%, SiO₂ 27%, Fe₂O₃ 21%, Al₂O₃ 12%, MgO 7%; particle size 0–1 mm; refractoriness 1800–1850 °C; bulk density 2.25 g/cm³; LOI <0.15%. Optimized flowability for ladle nozzle sealing.
Industry-standard base materials
Olivine/forsterite (Mg₂SiO₄), high-alumina, and zircon (ZrSiO₄) compounds; particle sizing commonly spans 0.1–1.5 mm depending on nozzle geometry.
Material & Manufacturing
Material & Manufacturing
FerrumX develops and produces NFC from high-refractory raw materials — silica and chromite ores — selected for heat resistance, erosion resistance, and chemical stability. Raw materials are crushed, screened, and graded to a controlled particle distribution. The uniform particle size and distribution give consistent free-flow and a predictable sintered layer against the hot steel.
Manufacturing controls cover raw-material selection, blending, screening, and packing. Each batch is tested for chemical composition, particle-size distribution, and flow properties. Third-party testing and certification are provided where required.
The material resists chemical reaction between molten steel and slag, reduces secondary oxidation, and helps maintain the surface quality of the cast product. Where conditions require it, particle size and chemistry are tailored to nozzle diameter, steel holding time, and on-site operating conditions.
Applications
Applications at Every Steel-Transfer Point
NFC is applied at each steel-transfer point where a nozzle must open reliably and stay free of blockage.
Ladle nozzle & well-block sealing
Fills the ladle bottom-nozzle well before tapping. It remains loose under the steel head and flows out when casting starts, opening the nozzle without oxygen lancing and preventing premature solidification at the well block.
Tundish nozzle & sliding gate
Placed at the tundish nozzle and sliding-gate port. It supports the stopper, prevents clogging, and keeps the tundish nozzle open between casts so the caster restarts cleanly.
Continuous casting & automatic pouring
Enables automatic free-opening of the ladle, reducing the need for oxygen burning. A steady stream improves casting reliability and lowers the risk of interruptions on the continuous-casting line. Per FerrumX data, NFC achieves an automatic free-flowing rate exceeding 95%.
Steel flow control & oxidation protection
By isolating molten steel from air at the nozzle, NFC reduces secondary oxidation and metal inclusions, improving the surface quality of cast billets and slabs.
High-temperature flow-path protection
Maintains structural integrity at 1600–1900°C without sintering, protecting the nozzle, well block, and slide-gate plate from erosion and steel penetration during tapping and holding.
Quality & Support
Quality, Certifications & Engineering Support
FerrumX operates quality and workplace-safety management systems aligned with ISO 9001 (quality management) and ISO 45001 (occupational health and safety). Every batch is tested for chemical composition, particle-size distribution, flow properties, and bulk density before delivery, and is assigned a traceable batch record.
Engineering support covers raw-material selection, formulation, on-site application guidance, and ongoing process optimisation. Standardised production processes and a documented quality-management system maintain consistent, repeatable product performance.
FAQ
Nozzle Filling Compound — Frequently Asked Questions
Yes. Formulations are adjusted for particle size and chemical composition to match ladle nozzle diameter, steel holding time, and plant conditions. FerrumX’s laboratory and testing team develop grades for specific steelmaking conditions.
Standard packing is 10 kg small bags. 25 kg bags, 1-tonne jumbo bags, and palletised packaging are supplied on request to suit handling and storage.
Yes. Support includes material-selection advice, usage guidance, on-site service, and performance optimisation for steelmaking applications.
Standard NFC grades are stocked for prompt delivery. Customised products typically ship in 7–15 days, depending on order volume and requirements.
Every batch is tested before delivery under a standardised production process and quality-management system. Certificates of Analysis and third-party testing are provided where required.
It fills the nozzle well as a loose, free-flowing sand. When casting begins, the molten-steel head pushes it out, so the nozzle opens automatically without oxygen lancing and without premature freezing of steel at the nozzle.
FerrumX supplies silica-based and chromite-based grades. Across the industry, nozzle filling sands are also produced from olivine/forsterite (Mg₂SiO₄), high-alumina, and zircon (ZrSiO₄) bases, selected for refractoriness and flow behaviour at the nozzle.
Gradation controls the sintered layer that forms against the hot steel. Too fine a size sinters and blocks the nozzle; too coarse allows steel penetration. A controlled distribution (for example 0.15–1.5 mm for the FerrumX chromite grade) forms a thin sintered skin over a free-flowing core, giving reliable automatic opening.
FerrumX reports an automatic free-flowing rate exceeding 95% with its NFC. Industry references for chromite and silica stuffing sands commonly cite ladle self-opening rates of 95–99%, depending on grade and practice.
Store in a dry, ventilated area with rainproof and moisture-proof protection. Moisture causes caking and reduces free-flow, lowering the automatic opening rate.
Get Started
Ready to Specify Your Nozzle Filling Compound?
To specify NFC for your ladle or tundish, provide your nozzle diameter, steel grade and holding time, and current filling practice. FerrumX’s engineering team returns a grade recommendation and quotation.
Related: Ladle Shroud · Tundish Nozzle · Stopper Rods · Tundish Well Block · Slide Gate Plate · Trough & Runners Refractory
