CEE Jul-Sep-2012

to changes, whereas the present generation with their energy and dreams want to be convinced and to do things their way. Were we any different? Do I need to recall what happened in the sixties and seventies of the last century? The problem is not trying to understand young people, because it is clear what they want! The battle is for us to present them with the refractory area in a way that they can be attracted! For example, why not thinking and showing the challenges of refractory energy saving issues from an integrated point of view? High emissivity paints, slag foaming , advanced foaming spray insulating, novel ceramic burner designs made by 3 D printing , et, can be part of a holistic view of refractory subjects that will help the environment, the society and make us feel useful! How about the courses that are taught? Are we concerned with the importance of the transversality of the knowledge? Philosophy, nanotechnology, sciences of nature, anthropology, etc, they must all be part of the package for the global professional. How could we understand and teach ethics in a broad sense, if our cosmos is limited to a nut shell? We have arguments and history to change the old and current "Dirty-Messy-Polluting" image of the refractory area for a "Clean-Green-Challenging" one. The problem is that we are expecting the young generation to see the importance of refractory on their own, whereas the other professionals are marketing their area better. By the way, if you are not convinced by the statements above and still think that the present generation is unique and complicated, a quotation by Roger Allen , a contemporary American writer, can explain this issue better: "In case you're worried about what's going to become of the younger generation, It's going to grow up and start worrying about younger generation". Courtesy: IRMA Journal, Vol. XXXXV, March 2012, Pp 17-18. 21 5 r CENTURY LINING DESIGN FOR BLAST FURNACES by R J van Laar and V van Straaten, Danieli Corus Abstract Blast furnaces are cooled by stave and/or plate coolers to protect the furnace shell. Choi ces for either system are usually based on objectives related to working volume or durability. In modern blast furnace iron making operations, process stability and hence a plant's performance is greatly influenced by the furnace's internal profile. The purpose of this article is to present a process-based comparison of lining systems. Based on the documented knowledge of the blast furnace iron making process from zone to zone, field observations (i.e. post mortem and interim findings at shut down furnaces) are analyzed to compare successes and failures of lining and cooling systems. Several findings were analyzed, which provided insight into how and why designs have been successful or have failed under various circumstances (i.e. productivity, raw materials. etc.) Critical factors for maximized process stability and campaign length from hearth to throat are presented . Keywords Blast Furnace, Bosh and Stack, Refractory, Cooling, Lining, Campaign Life Introduction 21 st Century blast furnace design requirements should focus on low cost hot metal production . This requires the right balance between capital expenses (CAPEX) and operational expenses (OPEX). Low– cost hot metal production can be achieved by: • Low coke rate <300 kg/THM); • High fuel injection rate (PCI > 200 kg/THM); • High oxygen rate (>30%); • High productivity (>3.0THM/m 3 WV/d); • Stable operation and high availability (>95%). The blast furnace must also be able to cope with various raw material compositions of sinter, pellets and lump ore and achieve a 20 year campaign life. It is of paramount importance that the profile of the bosh, belly and stack is maintained during the entire campaign as any degradation will immediately have a negative influence on low-cost hot metal production requirements. Hence, bosh , belly and stack designs must be robust and strong. Process conditions The blast furnace is a high-temperature, pressurized counter-current reactor. Abrasive raw materials are descending and gradually softening due to (s) melting whilst high temperature gases are ascending through the burden but also along the lining. The tuyere levels flame temperature is > 2000°C and the blast furnace operational pressure is 2 - 4 Bar (g). This can result in high thermal loadings to the lining. The blast furnace process is semi-continuous since charging and tapping are batch operations and hot blast and fuel injection are continuous . This combination results in dynamic process conditions. Average process conditions are well understood and reported in industry. Designers, however, must also have a good understanding of the dynamic process conditions' fluctuations since these impose significantly higher thermal and mechanical loadings II