The Basic Oxygen Furnace (BOF), also known as the converter, is the primary steelmaking vessel in integrated steel mills, converting molten iron from the blast furnace into steel through oxygen blowing. Operating under extreme conditions—temperatures exceeding 1700°C, intense thermal shock during oxygen lancing, severe chemical corrosion from basic slags, and continuous mechanical abrasion from scrap charging and molten steel flow—the converter demands refractory materials that deliver exceptional durability, reliability, and ease of maintenance. As a leading refractory supplier serving over 4,000 industrial furnaces worldwide, JHR Refractory provides comprehensive converter refractory solutions engineered to extend campaign life, maximize steel production, and reduce maintenance costs.
1. Zone‑Specific Magnesia‑Carbon Brick Lining Solutions
Each zone of the converter lining faces distinct wear mechanisms. The slag line and trunnion areas endure intense chemical attack from corrosive basic slags and thermal cycling. The barrel (body) section withstands continuous abrasion from steel flow and mechanical impact. The bottom and tap hole areas are subjected to severe thermal shock and erosion. Our magnesia‑carbon brick series are manufactured from high‑purity, high‑density fused magnesia or large‑crystal fused magnesia and high‑purity graphite as primary raw materials, with special antioxidants and phenolic resin binders, produced through high‑pressure molding. These products feature high strength, high refractoriness, and strong resistance to slag erosion and thermal shock. Available in multiple carbon content grades (from 10% to 18%) to match different service zones, these bricks deliver bulk density of 2.92–3.0 gcm³ and cold crushing strength of 30–40 MPa. This zone‑specific approach ensures balanced wear and extended campaign life.
2. Advanced Gunning and Repair Materials
Extending converter campaign life requires not only high‑quality initial linings but also effective maintenance and repair solutions. Our converter gunning mix series is manufactured from high MgO or MgO‑CaO based materials with specially formulated binders and additives, featuring high adhesion strength, low rebound rate, easy sintering, and good resistance to erosion and corrosion. Available in JH‑MG86 and JH‑MG82 grades with MgO content of 86% and 82% respectively, these mixes are ideal for hot repair of the converter working face, tap hole side, tap hole, and bottom areas. Our converter repair mixes, developed using fused magnesia as the main raw material with optimized gradation and binders, offer good fluidity, high carbonization strength, and long service life. Available in JH‑ZXB‑C (carbon bonded) and JH‑ZXB‑W (water‑based, environmentally friendly) grades with MgO content of 72% and 85% respectively, these materials deliver cold crushing strength of 6 MPa at 1500℃.
3. Durable Taphole and Tapping System Solutions
The tap hole is the critical interface between the converter and the ladle, where consistent and reliable tapping is essential for stable steelmaking operations. Our tap hole blocks are manufactured from magnesia and carbon as the main components and baked under high temperatures, featuring good thermal conductivity, high resistance to slag erosion, molten slag penetration, and thermal shock. For taphole maintenance, our gunning mixes enable quick and effective hot repairs during the intervals between heats. Additionally, our tap hole filler sand ensures high self‑opening rates, safe operation, and no contamination of molten steel. Featuring SiO₂≥30%, MgO≥50%, C≤5%, and grain size ≤6 mm, this material is essential for achieving reliable automatic pouring and stable converter operation.
4. Bottom Purging and Functional Refractories
For converters equipped with bottom blowing systems, purging plugs and bottom tuyeres are essential for enhancing bath agitation and improving steel quality. Our purging plug systems are manufactured from high‑purity chrome corundum or corundum‑spinel materials, featuring good safety, high blowing rates, long service life, and high air permeability. Each plug is individually tested for gas flow rate before shipment, ensuring consistent and reliable performance throughout the converter campaign.
5. Sustainable and Intelligent Refractory Solutions
As the steelmaking industry places increasing emphasis on environmental responsibility and operational efficiency, JHR Refractory continues to innovate in energy‑saving, environmentally friendly, and long‑life refractory materials. Our commitment to green technology innovation has been recognized through our selection as a green technology innovation demonstration enterprise. Our intelligent manufacturing capabilities—including fully automated production lines for magnesia‑carbon bricks, monolithic refractories, and functional ceramics—ensure consistent product quality and reliable supply. Backed by ISO9001, ISO14001, and OHSAS18001 certifications, we deliver cost‑effective, environmentally responsible solutions that help customers maximize steel production, reduce maintenance downtime, and achieve sustainable growth.
6.Conclusion
From the slag line and barrel to the bottom and tap hole, from magnesia‑carbon bricks and gunning mixes to repair materials and tap hole filler sand, JHR Refractory provides comprehensive, zone‑specific refractory solutions for Basic Oxygen Furnace systems. With proven performance in major steel mills worldwide and a commitment to technological innovation, we deliver refractory solutions that help our customers achieve longer campaign life, higher steel quality, and lower operating costs.
