REFINING VESSEL FOR HIGH TEMPERATURE MELT WITH GAS BLOWING NOZZLE

• Main Authors: FUJIYOSHI RYOMA, IIDA ATSUHISA, HOSOHARA SEIJI, TORIGOE ATSUSHI
• Format: Patent
• Language: English; Japanese
• Published: 29.10.2020
• Subjects: CHEMISTRY; METALLURGY; METALLURGY OF IRON; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS

To provide a refining vessel having a highly durable gas blowing nozzle.SOLUTION: In the refining vessel for a high temperature melt, a refractory for a gas blowing nozzle constituting a gas blowing nozzle comprises a central part refractory a where a metal fine tube is embedded and an outer peripheral part refractory b at an outside thereof; the central part refractory a has a radius of R+r (r=10 to 150 mm) with respect to a radius R of a central region where the metal fine tube is arranged; the central part refractory a is composed of a MgO-C base brick having a C content of 40 to 80 mass% and containing 3 to 8 mass% of metal Al and metal Si of 0.30 to 1.0 time as large as the metal Al in terms of a mass ratio, and the outer peripheral part refractory b is composed of a MgO-C base brick having a C content of 10 to 25 mass%; the outer peripheral part refractory b has predetermined abrasion resistance and erosion resistance because of an ordinary C content; the central part refractory a has a high C content and therefore can inhibit cracks due to thermal shock from being caused, and it is cooled by gas flowing through the metal fine tube due to a high heat conductivity, whereby a coagulation film (protection film) of slag and metal is formed on an operation face side, and this coagulation film inhibits wear by abrasion and erosion.SELECTED DRAWING: Figure 1 【課題】ガス吹込みノズルが高い耐用性を有する精錬容器を提供する。【解決手段】ガス吹込みノズルを構成するガス吹込みノズル用耐火物が、金属細管が埋設された中心部耐火物ａとその外側の外周部耐火物ｂとからなり、中心部耐火物ａは、金属細管が配置された中心領域の半径Ｒに対してＲ＋ｒ（ｒ＝１０〜１５０ｍｍ）の半径を有し、中心部耐火物ａはＣ含有量が４０〜８０質量％であって、金属Ａｌを３〜８質量％、金属Ｓｉを質量比で金属Ａｌの０．３０〜１．０倍含有するＭｇＯ−Ｃ質れんがで構成され、外周部耐火物ｂはＣ含有量が１０〜２５質量％のＭｇＯ−Ｃ質れんがで構成される。外周部耐火物ｂは、通常のＣ含有量であるため所定の耐摩耗性、耐溶損性を有する。中心部耐火物ａは、Ｃ含有量が高いため熱衝撃による亀裂の発生を抑制できるとともに、高熱伝導率であるために金属細管を流れるガスより冷却されることで稼働面側にスラグや金属の凝固膜（保護膜）が形成され、この凝固膜により摩耗や溶損による損耗が抑制される。【選択図】図１