Different classification of monolithic refractories

Monolithic refractory is a kind of refractory material which has no certain shapes. In other words, they are castable and can be given any size or shape according to manufacturers’ wish. The demand for monolithic castable refractories has increased continuously over the past twenty years. The most special feature of monolithic castable refractory is that it can be molded into any shape. Therefore, monolithic refractory cement is often used for repairing or building furnaces, incinerators and so on. Moreover, monolithic refractories can be divided into several types according to their compositions. Further information about classification of monolithic refractories will be introduced in the following text.

-        What are monolithic refractories?

-        Classification of monolithic refractories

What are monolithic refractories?

Monolithic refractories, including castable refractories, plastic refractories and ramming materials, show superior characteristics compared to traditional refractory materials. These refractories can be molded or given any shape as required. Monolithic castable refractories are commonly seen in daily lives, such as mortars, plastic blocks, fettling mixture and ramming materials. Monolithic refractory cement has multiple applications. It can be used for building new kilns as well as maintaining old ones. Some high strength monolithic refractories have 2 to 3 times greater strength than previously available casting materials and are able to maintain their strength at moderate temperatures. Monolithic castable refractories are often used in places where materials are required to have good stability and high corrosion resistance such as linings of induction furnaces.

Classification of monolithic refractories

There are a number of monolithic refractories, making it comparatively difficult to classify them. Three main criteria, including physical state, setting method and installation method, are frequently adopted in the classification of monolithic castable refractories.

When classifying by physical state, monolithic refractories can be divided into powdered state, mud state and paste state. If people use setting method as the criterion, there are hydraulic setting, air setting, chemical setting and ceramic setting (also known as heat setting). When based on installation method, we have four kinds of monolithic refractories: trawling and pouring, ramming, gunning and vibrating.

One of the most common monolithic refractory products is monolithic castable refractory. It belongs to powdered state refractory, hydraulic setting refractory and trawling & pouring or vibrating refractory. Thus, monolithic castable refractories have hydraulic compositions and are aggregated with bonding materials. They can be further split into seven kinds, including conventional castable, low cement castable, ultra-low cement castable, no cement castable, light weight castable, self-flow castable and insulating castable.

Another popular monolithic refractory is ramming mass which is counted in the powdered state type, chemical or ceramic setting type and ramming installation type. Ramming mass is a type of ready-mix refractory material with monolithic structure, which means it is often blended with water. There are two kinds of ramming materials: dry ramming mass and wet ramming mass.

Some other examples of monolithic refractories include plastic refractory (can be classified into mud state refractory and air setting or chemical setting refractory), gunning compound (included in gunning installation type) and so on.