Refractoriness is an important indicator of the quality of refractory bricks. It is directly related to the chemical mineral composition of the raw material. If a variety of raw materials are used in the ingredients of refractory bricks, attention must be paid to the purity of the raw materials and their mutual influence. Generally, the refractory performance of clay clinker or barren clay (hard clay with small shrinkage), which accounts for the main amount in clay brick ingredients, determines the quality of sk34 refractory bricks. The clay (soft, clay) used as a combination is usually a raw material with large shrinkage and low refractoriness. If the amount is too large, the refractory performance of clinker or barren clay will be greatly reduced. When making silica bricks, quartz sand is originally a raw material with high refractoriness, but because a part of clay is added as a forming binder, and the refractoriness of such clay may be low, the refractoriness of the product must be lower than that of quartz sand itself. Therefore, it can be said that the chemical mineral composition of the ingredients determines the refractory performance of the sk34 refractory brick.
It must be pointed out that the refractoriness of sk34 refractory bricks can only be one of the important indicators to measure its quality. As for the use quality of refractory bricks, it should also be controlled in combination with the manufacturing process, that is, whether the appearance and internal structure of sk34 refractory bricks are dense. These are closely related to factors such as the particle coordination of the ingredients, the size of the molding pressure, and whether the adobe is cooked or overfired. If the refractoriness of the sk34 refractory brick ingredients is very high (even above 1700°C), but the adobe is not tightly packed and has not been sintered (loose), its service life must be very short, because this kind of sk34 refractory brick has large porosity and strength. Poor, easily corroded by harmful liquid or gas when in use. Therefore, when deciding whether the refractory fire brick is good or bad (especially the quality of use), it must be considered comprehensively. The refractoriness index is only the first basis for the participant data.
As mentioned above, to measure the refractoriness of the sample is to take the beech from the test piece, grind it to make a triangular pyramid with a specified shape, and then measure the natural melting temperature of the triangular pyramid in the electric furnace as the sample index of refractoriness. This situation is inconsistent with the actual use conditions of sk34 refractory bricks. Usually, after the refractory fire bricks are built into the wall, the lowermost bricks are subjected to both high temperature and considerable pressure (the bottom bricks are also eroded by the smelting metal solution), and this pressure or external impulse can also Reduce the refractoriness of refractory materials (the refractoriness under a certain pressure is called the load softening temperature). Therefore, the refractoriness does not indicate the temperature at which refractory fire bricks can be used. For the sake of safe operation, the service temperature of general refractory fire bricks is about 200-250 ℃ lower than its refractoriness index.
