Every year, factories and industrial facilities lose millions of dollars due to unexpected failure of refractory bricks. The cause is often the same: relying on brand labels instead of objective quality data. Let's look at how to properly evaluate refractory materials to avoid downtime and reduce replacement costs.
Many consumers rely on well-known brands, believing them to be a guarantee of quality. However, experience shows otherwise: 43% of premature failures of fireproof structures involved so-called "prestige" brands. The reason is simple: manufacturers often invest more in marketing than in improving the physical and mechanical properties of their products.
Your kiln or clinker chamber operates at temperatures above 1500°C, comes into contact with aggressive slags, and experiences significant mechanical stress. In such conditions, what matters most are not advertising slogans, but specific performance indicators: plasticity temperature under load, tensile strength at high temperatures, and slag resistance.
According to a 2022 study by the International Refractory Association, facilities that implemented a refractory testing system based on ISO standards reduced downtime losses by 37% and increased furnace life by 28%.
Magnesia-aluminum spinel (MgAl₂O₄) bricks are considered among the most reliable for high-temperature processes. However, even among them, there are significant differences in quality. Let's look at the key characteristics worth checking:
This parameter determines the temperature at which the refractory material begins to deform under a constant load (usually 0.2 MPa). For magnesia-alumina spinel bricks, this parameter should be at least 1600°C. At values below 1550°C, the material quickly loses its shape in the furnace's working zone.
This test is conducted at temperatures corresponding to operating conditions (usually 1400-1600°C). The best magnesium-aluminum spinel samples demonstrate a strength of at least 12 MPa at 1500°C and at least 8 MPa at 1600°C. Low values (below 6 MPa at 1600°C) indicate poor spinel synthesis.
Slags generated during the production process can actively interact with refractory materials, causing their dissolution and destruction. By immersing a sample in slag at operating temperature for 50 hours, the depth of slag penetration and the degree of structural change in the material are assessed. High-quality bricks should have a slag resistance index of at least 85% (on a scale from 0 to 100%).
To properly evaluate the quality of the firebrick offered to you, compare the obtained test results with the reference values in the table below:
| Parameter | Minimum acceptable value | Recommended value | Test method |
|---|---|---|---|
| Plasticity temperature under load (PUT) | 1550°C | ≥1600°C | ISO 1893 |
| Bending strength at 1500°C | 8 MPa | ≥12 MPa | ISO 5013 |
| Resistance to slag attack | 65% | ≥85% | ISO 8890 |
| Density | 3.0 g/cm³ | ≥3.2 g/cm³ | ISO 5017 |
Implementing a refractory rating system doesn't require significant investment but significantly reduces furnace operating costs. Here are the steps to take:
Identify the critical parameters for your process. For example, slag resistance is important for cement plants, while plasticity temperature under load is important for metallurgy. Ensure that the specifications include test methods (ISO standards or national equivalents).
Each batch of refractory bricks must be accompanied by a certificate containing test results for all declared parameters. Ensure that the tests were performed by accredited laboratories. Avoid suppliers who refuse to provide detailed certificates.
Key suppliers are advised to commission additional sample testing from independent laboratories. This is especially important when changing suppliers or introducing a new product brand. The average cost of comprehensive testing per sample is approximately $300-500, but this is an investment that pays for itself by reducing losses from premature failure.
Create a database of the operating results of different brands of refractory bricks. Record their service life, operating conditions, and reasons for replacement. This will help you identify patterns and select the most suitable materials for specific areas of your furnaces.
We specialize in the production of refractory materials for the most demanding industries. Our magnesia-aluminum spinel bricks undergo comprehensive testing across all key parameters, certified by international laboratories.
For example, our MA-70 brand bricks exhibit the following characteristics:
These indicators allow our customers to increase the service life of furnace linings by 25-40% compared to the use of standard refractory materials.
Get a free consultation with a specialist on selecting refractory materials for your process. Our engineers will help determine the optimal brick parameters and develop a specification that will reduce your operating costs.
Get advice on the selection of magnesium-aluminum spinel bricks
Don't leave the fate of your industrial furnaces to the whims of brand names. Use data to make informed decisions and reduce operating costs. Your business deserves reliable refractory materials that meet the real-world requirements of your process.
