Appetite for new steel grades drives demand for high-performance refractories

By Liz Gyekye
Published: Wednesday, 30 September 2015

Quality demands offset volume contractions; HPA to benefit from new steel technologies.

New commercial opportunities for producers of high purity alumina (HPA) products are emerging due to the growth of secondary metallurgy performed in steel ladles, delegates at the 14th UNITECR in Vienna, were told.

Andreas Buhr, global technical director of refractories at German speciality alumina supplier Almatis said that the development of new high purity steel grades over the past few years is having a positive impact on refractory consumption.

Buhr outlined that further opportunities were being created by an increased appetite for low impurity steel from the automobile sector and that companies were becoming increasingly aware of energy losses and the cost savings made possible by better refractory lining concepts.

Notable examples of progression in steel technology are basic oxygen furnaces (BOF) replacing open hearth furnaces, the introduction of continuous casting and the growth of secondary metallurgy performed in steel ladles, according to Buhr.

Around 60-70% of the world’s refractories are used in steel making, while the rest are mostly consumed in the manufacturing of iron, cement, glass and non-ferrous metals.

Extended processing of liquid steel in secondary metallurgy requires continuous adjustment and improvement of refractory linings and can be considered among the most important drivers for refractory innovations, Buhr said.

This type of processing can only be performed with specific high-performance refractory linings, such as HPA refractories, which must be thermodynamically stable in contact with steel, in order to avoid re-oxidising the metal.

Buhr noted that refractories for steel ladle side walls must also be able to withstand slag attack by aggressive, metallurgical reactive slag – for example, calcium-aluminate slag (CaO/Al2O3).

As silica-containing high alumina refractories, such as andalusite or bauxite, show higher wear rates with aggressive, low-melting CaO/Al2O3 slag, there has been a trend towards HPA spinel refractories replacing andalusite and bauxite in ladle linings, Buhr said.

Despite flat steel industry demand, refractory producers can still benefit, Alteo’s director of marketing, Mike Rodgers, told IM on the sidelines of the conference: "The refractories industry is an old one and it has its ups and downs."

However, he said that there was still growth in developing countries such as South America, Vietnam and with the recent lifting of trade sanctions, Iran.

He added that further opportunities existed in Brazil and Japan with infrastructure development during the 2016 and 2020 Olympics.