What are Refractories?
Historically, bricks and shapes account for the majority of the refractory production but there are also monolithic (unformed) refractories.
Refractories come in all shapes and sizes. They can be small in size and complex in design or huge precast blocks that weigh tonnes.
Used on numerous applications, refractories are subjected to intense temperatures, chemical attack and mechanical stresses in today’s manufacturing processes in many industries such as steel, foundry, cement, aluminium, power, incineration, petrochemical, environmental and energy. 70% of all refractories are used in the steel industry.
Refractories are used to insulate processing equipment, minimise the loss of heat, line hot surfaces and prevent the deterioration of structures.
Refractories are produced from synthetic and natural materials or a combination of minerals such as zirconia, alumina, bauxite and dolomite, amongst others.
Use of Steel Fibres in Refractories
Steel fibres play an important role in the prevention of potential fractures and catastrophic failure of the refractories.
Their function is to reinforce refractories. This improvement of the flexural strength and increased ductility of the refractory pieces contributes to the longevity of the refractories used in applications subjected to mechanical shock, very high temperatures and/or thermal cycling and exposed to aggressive atmospheres.
The sizes of fibres used depends on the application and the most common dimensions are between 0.2-0.7mm in diameter and 12-35mm in length.
The addition rate varies depending on the application and the size of fibres used but is commonly set at around 4% by volume as a higher quantity can cause mixing difficulties. However, there are some applications that call for a high addition rate of up to 25% and many of our customers do so in their high-quality mixes especially on applications featuring high mechanical shock.