Factors affecting Lining Life of a Basic Oxygen Converter Sep20

Factors affecting Lining Life of a Basic Oxygen Converter...

Factors affecting Lining Life of a Basic Oxygen Converter The life, reliability and costs of lining in a basic oxygen converter are vital for the smooth operations of the steel melting shop utilizing basic oxygen process for steel production.  Higher lining life results into improved availability of the converter which in turn improves its productivity. Three important factors for achieving higher lining life of the basic oxygen converter (Fig 1) are (i) qualities of refractories and their laying pattern in the converter, (ii) operating practices followed, and (iii) monitoring of the lining wear and practices for the maintenance of the refractory lining. Development of improved refractory materials in combination with improved process control and better maintenance during campaigns make it possible to increase the lining life of the basic oxygen converter. Fig 1 Factors affecting lining life of the basic oxygen converter These days without exception, basic oxygen converters are lined with magnesia – carbon (MgO-C) refractories because of their superior properties than other types of converter lining materials. However zoned refractory lining practices are followed by using MgO-C refractories of different qualities in different areas of the converter. The causes of wear of refractories in the basic oxygen converter are either due to chemical reasons or due to the physical reasons. Chemical causes for the wear of the converter lining are mainly due to gaseous materials (oxidizing gases, reducing gases, and water vapour), liquid materials (slag. hot metal, and liquid steel melt), and solid materials (fluxes, and carbon disintegration).  Physical causes for the wear of the converter lining are excessive temperatures (poor dissipation, and hot spots), static mechanical stresses (spalling, and expansion), and dynamic mechanical stresses (abrasion, impact, and vibrations). The key wear mechanisms of the refractory lining of basic oxygen converter can...

Refractory lining of a Basic Oxygen Furnace Mar28

Refractory lining of a Basic Oxygen Furnace...

Refractory lining of a Basic Oxygen Furnace The purpose of a refractory lining in a basic oxygen furnace is to provide maximum furnace availability during operation of the converter in order to meet production requirements and to ensure lowest possible specific refractory consumption. For this it is essential To optimize lining design To optimize lining maintenance practices To have good technological discipline during converter operation Typical refractory lining is shown in the converter cross section in Fig 1.               Fig 1 Refractory lining of a converter with removable bottom (Cross section) Lining design Wear of refractory lining is due to either the individual or the combined effect of the following agents. i)             Corrosion due to chemical attack of slag ii)            Temperature iii)          Oxidizing atmosphere iv)           Impact and Abrasion v)            Mechanical damage during deskulling Due to varying action of these agents there are many wear areas in the converter Theoretically the refractory lining of a converter is to be designed by the refractory type and different thicknesses so that no material is wasted at the end of the converter campaign. These   mean all the zones (Fig 2) of the converter lining is worn out to the stopping thickness at the same time. But in practice this does not happen and the refractories in some zones are worn out faster than the refractories in other zones. A balanced lining design is always aimed to improve lining life at the optimum refractory cost. A balanced lining is the lining where different qualities and thicknesses of refractories are used in different zone of the converter after careful study of the wear pattern of the refractories in the converter. This type of lining is also called zonal lining since in such type of...