General methods of manufacture of refractories

General methods of manufacture of refractories

The manufacture of refractories involve the following steps.
1. Grinding
Raw materials crushed and ground to fine powder using crushers, pulveriser, ball mills.

2. Mixing
In order to alter the chemical properties of the refractories, two or more powdered raw materials are thoroughly mixed with a suitable binding material, which makes moulding easier.

3. Moulding
Moulding can be done either manually or mechanically by application of high pressure.
Hand-moulding produces refractories of low strength and low density. Mechanical-moulding produces refractories of high strength and high density

4. Drying
Drying is carried out slowly to the moisture from refractories.

5. Firing
It is done at a temperature as high as or higher than their use temperature . Firing is generally carried out in kilns.

The refractories are fired,
(i) to stabilize and strengthen their structures.
(ii) to remove water of hydration.
(iii) to facilitate development of stable mineral to form the finished products.