Technical Paper
www.ireng.org
FAST CHANGING REFRACTORIES WORLD
Christoph Wöhrmeyer, Phil Edwards, Christopher Parr Kerneos S.A., Paris-La Defense, Puteaux, France
The recent global economic difficulties have resulted in overcapacities in many industries and the refractory industry isn’t an exception. In an uncertain environment driven by the slowing Chinese economy and the low crude oil price many industries have slowed down their investments. However, difficult times trigger also new ideas that lead in innovation- friendly companies to renewed product portfolios with materials and services that have a better performance/cost ratio, are more user and environmental friendly, more predictable in their performance and offer more value for the customer. This article gives examples of raw material innovations that target improvements at different steps in the value chain of castables, from the raw materials dry-mix, castable installation, dry-out, to the ultimate performance in service. Efforts to make castable rheology and setting more predictable have resulted in new types of binders and deflocculants and active compounds that achieve a higher robustness against variable parameter in the system. Other developments target the replacement of high-pH shotcrete gelling agents by more health and safety friendly systems. Developments also look at a better compromise between permeability, strength, and the water removal temperature of calcium aluminate bonded dense castables to allow an easier and safer water release. New castable microstructures have been achieved with innovative bond systems that improve the service life of alumina-spinel and alumina magnesia castables. The main driving force behind all these innovations is the never ending request of the steel industry to reduce specific refractory costs and to improve safety and equipment reliability.
Keywords: Refractory raw material, Refractory Binder, Calcium Aluminates, Castable Deflocculation.
Introduction
With steel production being the biggest consumer of refractory materials, the refractory industry has gone through a few difficult years as steel production in most western countries was slowing. China, the globally biggest steel producer representing close to 50% of the global steel production, has seen 3 years without growth in steel production, after a more than a decade long strong increase [1]
. Low crude oil prices have
slowed down the activities in the oil exploring and transforming industry which resulted in lower demand of steel pipes [2]
. In contrast to this slowing
trend in major steel producing nations, India’s steel production has shown a steady growth over the last 10 years (Figure 1). Nevertheless, the global steel production capacity utilisation has dropped since the middle of 2014 to very low levels (Figure 2) which has put steel prices under strong pressure and forced the refractory manufacturer once again to work on cost rather than on performance optimisation. However, with the traditionally used
refractory raw materials further saving potentials are limited and when moving to lower quality raw materials typically also performance drops so that overall there is no significant benefit for the refractory costs per ton of produced steel. Total cost might even be higher as maintenance costs might increase.
RAW MATERIAL INNOVATIONS – A KEY SUCCESS FACTOR IN A
Figure 1: Annual crude steel production [1]
Figure 2: Steel production capacity utilization [3]
Therefore the development of new refractory raw materials especially for refractory castables have been in the focus in recent years which resulted in significant innovations driven by the never ending quest of the steel industry for reduced costs per ton of produced steel. Different factors have allowed to make significant progress, the search for solutions with increased performance/cost-ratio but also the quest to make refractory castables more reliable and robust during the installation and commissioning process.
14 ENGINEER THE REFRACTORIES
January 2018 Issue
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