Refractory materials are essential for lining high-temperature equipment like furnaces and kilns. They must withstand intense heat and resist damage. There are many types of refractories, but one unique form is plastic refractory. What exactly is plastic refractory and what makes it different from other refractory materials?
Plastic refractory has a clay-like consistency that allows it to be molded or shaped by hand without needing forms or molds. It has high plasticity and retains its shape after setting. The clay-like property comes from the addition of binders to the refractory aggregate. Common binders used are sodium silicate or fireclay.
The plasticity makes plastic refractory ideal for:
- Patching or filling gaps in existing refractory linings. The material can be pressed into cracks and holes and smoothed by hand.
- Creating custom shapes. Plastic refractory can be hand-molded into unique contours, corners, or designs.
- Lining hard to reach areas. The malleable material can be forced into tight spaces that would be difficult to line with solid bricks.
- Quick repairs. The ability to shape it by hand allows for fast patch jobs without setting forms or molds.
Plastic refractory sets by drying out. The installation surface needs to be dampened first so the material can adhere as it dries. Small amounts can be mixed and used as needed. It air-dries within 24 hours and requires a curing heat treatment.
Once fully cured, plastic refractory has low porosity and resists temperatures up to 3000°F. It provides the same insulating and heat-resistant properties as standard refractory bricks or castables. The key difference is the initial plasticity that makes it customizable and ideal for small repairs or linings.
The clay-like yet sturdy nature of plastic refractory makes it a versatile refractory material useful in many heat processing applications. Its moldability and ease of use help keep equipment safely lined and efficiently operating.