In the refractory industry, ensuring the quality and performance of refractory materials is of utmost importance. This is especially true for refractory bricks, which play a crucial role in various high-temperature applications. When these bricks arrive at your facility, it is essential to conduct thorough tests to verify their quality and ensure they meet the required standards. This article will discuss the importance of testing refractory firebricks upon arrival and the standards that should be followed.
Refractory brick inspection items: five items: main chemical component content, compressive strength, flexural strength, linear change rate after burning, and volume density.
sampling rules
Refractory firebrick specifications and dimensions, appearance, cross-section inspection and theoretical performance inspection samples are randomly sampled: appearance quality is limited to ten tons per batch, and physical and chemical performance is limited to sixty tons per batch. Take 20 pieces for appearance, size, and unit weight inspection, and take 6 pieces for physical and chemical performance inspection. The number of samples for each type of fire brick shall not be less than 3 pieces.
Refractories often inspect appearance
1. Size error:
Why is the error of the big head and small head allowed to be 1mm, the length error allowed to be 2mm, and the height error allowed to be 1%. Because the error of the big and small heads of 1mm can be adjusted with mortar, and the length error of 2mm can be adjusted by the expansion cardboard and mortar on the side of the brick. The height is allowed to be 1%, which is a form of expression. Commonly used refractory bricks have three different heights: 200mm, 220mm, and 250mm. The error limit of bricks of different heights is different, but it cannot exceed 2-2.5mm. Under normal circumstances, we should control it within 1-1.5mm. This error can also be adjusted by fire clay.
2. Flatness: controlled at 0.5mm.
Explanation: Use a feeler gauge to detect the flatness of the large surface of the brick. The commonly used feeler gauge specifications are 0.1, 0.2, 0.25, 0.3, 0.4, and 0.5. The maximum flatness value of refractory bricks cannot exceed 0.5mm. In operation, it is best to control it within 0.2-0.3mm. If the brick can pass the 0.5mm feeler gauge, it means that the flatness of the brick is not good. You should open more boxes and measure more pieces (this is because the brick is easy to crush when sealing if it exceeds the standard value of 0.5mm; after the brick is produced in the kiln, the large surfaces of the brick are squeezed against each other due to the rotation of the kiln, which is also easy to break). If this is still the case, you should contact the supplier, and the owner, the construction party, and the supplier will jointly determine the corresponding construction and masonry plan. And the supplier promises the quality of this batch of bricks.
3. Weight:
The theoretical unit weight of refractory bricks can be calculated or provided by the manufacturer. We compare the actual weight of the brick with the theoretical weight to estimate the density of the fire brick.
Explanation: The weight deviation of the brick is preferably ±0.5. If it is too heavy, it means that the size of the refractory fire brick may be too large or damp; if it is too light, it means that the porosity is large, the texture is loose, and the standard density is not reached.
