CEE Jul-Sep-2012

Figure 4 : Bosh loadings Figure 5: 'Hoogovens' bosh design These loadings depend on the raw materials and blast furnace operations. The loadings should preferably be quantified. Otherwise, it is recommended to qualify the loadings and investigate the (historical) performance and track records of other bosh designs. The loadings depend on the temperature level and may occur within a limited temperature range or above a certain threshold level. A simple rule states that the loadings converge to zero at lower temperature levels. Vice versa, loadings are increased when temperature levels are increased. Stable and moderate process temperatures at the interface between the burden and gas and lining will thus minimize lining corrosion and degradation. Some critical threshold temperatures for lining corrosion mechanisms are summarized in Table 3. Table 3: Critical threshold temperature levels for Chemical Attack/Corrosion CO Disintegration 480-850 900-1560 Alkali-and Zinc Attack 800-950 1470-1740 Oxidation by 02 > 400 >750 Oxidation by C02 and > 700 >1300 H20 Performance monitoring Advanced instrumentation permits continuous and accurate process and equipment control. We have also attended many postmortem analyses and provided FMEA consulting and engineering services. 'Hoogovens' bosh, belly and stack design have proven to be robust and stable and permits multi– campaign low-cost hot metal production. We have also noticed that many 'myths' have been developed around copper stave cooler designs and specific operational pre-cautions are often required to prevent premature failures. These observations are supported by extensive lab analysis and multi-physics models. Our models also indicate that copper stave cooler designs are more sensitive to dynamic process conditions and providing ultra-efficient copper stave cooling systems could de-stabilize operations. In this respect, it can be said that the dense plate cooler design de-couples the process from the limitations of equipment. This then provides a sound equipment basis from which the long-term improvement in process stability and fuel rate can be realized. Concluding summary • Advanced bosh, belly and stack designs combine (lower) bosh plate coolers and upper stack cast iron stave coolers; • Bosh plate coolers are required to decouple process and equipment- a robust bosh permits operators to achieve high productivity, low coke, high fuel injection and oxygen rates; • The 'Hoogovens' lining design has proven (multi-campaign) lifetime > 20 years at high productivity and high fuel injection rates contributing to low-cost hot metal producti on. Courtesy: IRMA Journal, Vol ><XXXIV, Dec. 2011, Pp103-107. 'TODAY'S LEADERSHIP CHALLENGE WITH FOCUS ON TECHNOLOGY, COST AND EXTERNAL ENVIRONMENT by Naveen Kumar Sharma, J.K. Lakshmi Cement Ltd. Consequent to the current economic and political turbulence, Leaders - both new and matured -find themselves at a very critical juncture in their efforts to compete and succeed due to increased pressure not only from technology and cost but also from the external environment. All three challenges are interlinked I interdependent. 14