Improvement in the steel-pouring ladle lining life in open-hearth production of ZAO metallurgical plant Petrostal’

Abstract

Basic principles are considered for the development of refractory linings for steel-pouring ladles operating under severe conditions using a furnace-ladle unit. Joint action of personnel of the metallurgical enterprise and refractory supplier makes it possible to determine the local area of lining wear and to adopt timely measures for improving life. The effect of the main factors governing wear is determined. The order of selecting the required standard sizes and quality indices for objects taking account of the type of metal smelted is determined.Keywords: refractory lining, slag belt, local wear.As a result of technical progress in the field of refractory production the possibility has developed not only of improving metal quality, but also reducing expenditure connected with steel-pouring ladle lining operation, in particular those operating under conditions of furnace-ladle installations and metal evacuation.Refractory consumption for lining ladles in metallurgical enterprises with a complete cycle is about one quarter of all refractory consumption (in absolute value and cost) [1]. The overall expenditure for traditional ladle refractories in the cots of Russian metal was previously 1.5 -2.0%, and therefore a insufficient attention has been devoted used to saving refractories. A long life for a lining has a marked effect the non-metallic inclusion content in metal.Currently the expenditure on acquiring contemporary refractories is 4 -7% of metal cost. An increase in metal cost may be balanced by a reduction in specific refractory consumption due to the use of modern methods for lining operation and new standard sizes for refractory objects.For effective operation of carbon-containing refractories it is necessary to have a high-temperature unit for warming up refractories. A lining warm-up unit may be horizontal or vertical. Expenditure in installing a high-temperature unit is repaid in 6 -8 months. Each uint is equipped with a heat-protective cover in order to avoid heat loss during pouring.The carbon-containing composition refractories used in contemporary linings do not exhibit high heat resistance and during operation they should not be cooled to lower than 800°C. With presence in some cycles of cooling below 800°C there may be some reduction in lining life.The life of refractory linings used in furnace-ladle devices is determined by a group of factors, each of which should be considered in lining operation. These are factors connected with refractory properties, lining construction, and pouring technology.In the presence of high quality refractories it is not always possible to achieve maximum lining life. Even insignificant changes in metal smelting technology and pouring may lead to a reduction in refractory life. EFFECT OF REFRACTORY QUALITY ON LINING LIFE Refractories usedIn contemporary linings there is mainly use of carbon-containing refractories based on periclase-carbon or aluminopericlase-carbon composition. Some Russian enterprises manufacture these refractories based on imported Chinese raw ma...