As the market further accelerates the industrialization process, the international market of refractory materials ushered in a golden period of industrial development, the current state of the refractory brick market is basically in the stage of oversupply. But how customers can purchase high-quality refractory material is important. Nowadays, there are hundreds of refractory qualities on the market, but the quality of the material varies, how can users buy a good product worthy of the name? The user can let the manufacturer provide certain samples before placing the refractory bricks, the customer can determine the merits of the product according to the following items.
1. The detection of physical and chemical functions of refractory materials
1.1 The testing items of refractory bricks: six items such as the content of the main chemical composition, bulk density, porosity, compressive strength at room temperature, thermal shock stability, and load hardening temperature.
1.2 Testing items of refractory castables: the content of main chemical composition, compressive strength, flexural strength, post-fired line change rate, bulk density five items.
2. Refractory bricks often appearance testing
2.1 Why the error of large head and small head is allowed 1mm, the length error is allowed 2mm, and the height error is allowed 1%.
Because the large and small head error of 1mm can be adjusted with mortar, the length error of 2mm can be adjusted after the brick front expansion cardboard and mortar. The height allows 1%, which is a way of expression.
There are three different heights of refractory bricks used in the kiln: 200mm, 220mm, and 250mm. the error limit of different height bricks is different, but can not exceed 2–2.5mm, in general, we should control in 1–1.5mm. this error can also be regulated by fireclay.
2.2 flatness: control in 0.5mm. because with the plug ruler to detect the flatness of the large surface of the brick, commonly used plug ruler specifications are 0.1, 0.2, 0.25, 0.3, 0.4, 0.5 six kinds.
The refractory brick flatness of the large value can not exceed 0.5mm. in operation, we are good to control in 0.2–0.3mm is appropriate. If can go through the 0.5mm plugging, it means that the brick flatness is not good, so should open a few more boxes, and more measurements of a few pieces (this is because beyond the standard value of 0.5mm, in the sealing, brick is easy to crush.
Brick in the kiln after consumption due to the kiln rotation, brick large surface extrusion each other, also easy to crack) assume or so, should contact the supplier, by the owner, our, suppliers together to determine the corresponding construction masonry program. And the supplier promises the quality of the use of this batch of bricks.
2.3 Weight: The actual unit weight of refractory bricks can be calculated or provided by the manufacturer.
We compare the theoretical weight of the brick with the practical weight and estimate the density of the refractory brick. Because the weight of the brick tendency ± 0.5 is appropriate.
If the focus on the refractory brick size can be on the large, or moisture. The lighter side indicates that the porosity is large, the texture is loose, and the standard density is not reached. About beyond the range of the brick, supplier did not explain and commitment, can not use.
2.4 Side loss, corner loss, cracks, pits, melt stains, bulging.
Because these defects are refractory bricks in the manufacturing, firing, packaging, and transportation process in the onset of damage and defects, the above phenomena only need to be within the range of values on the table, if the brick can be used.
Generally speaking, sampling 6 bricks should not have these situations, such as finding one to two, should open a box again, and this phenomenon should contact the supplier, seeking information.
3. Refractory brick sampling rules
Refractory brick specifications and size, appearance, cross-sectional inspection, and physical and chemical properties test samples, using random sampling method: appearance quality per batch to ten tons as the limit, physical and chemical properties per batch to sixty tons as the limit to suspend sampling.
Appearance, size, single weight test to take 20 pieces, physical and chemical function test to take 6 pieces. Each type of refractory brick sampling quantity shall not be less than 3 pieces.
