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Why do refractory bricks have color differences?
When refractory bricks are fired, if the operation method is improper, it is very likely to cause uneven color. In addition to this reason, there is actually another possibility for the color difference, that is, during the construction, the temperature or operation method is not in place, so the color difference problem occurs. Next, let's analyze the reasons for the color difference.
1. The bricks are not stacked properly when loading the kiln car, and the sparse and uneven flames cannot evenly heat all the bricks, so that the bricks are heated unevenly during preheating. The moisture of the refractory bricks is not completely removed before entering the firing zone, causing some refractory bricks to have different colors, some dark and some light.
2. The refractory brick processing temperature is not well controlled. Since most of the current tunnel kilns use gas generator gas as fuel, the firing temperature fluctuates too much due to reasons such as coal quality, gas furnace operation, and different fired products, resulting in high temperatures in some parking spaces and low temperatures in others.
3. The exhaust fan has too much pulling force, so that when the flame cannot reach the top of the kiln, it is pulled out of the high-temperature zone in the horizontal direction, causing the temperature difference between the top and the bottom to be too large. The temperature difference of the fired refractory bricks can reach 50 degrees, so that sometimes the lower products are adhered and deformed to produce waste, while the upper part still does not reach the sintering temperature.
When the refractory bricks have color difference, we must find out the cause in time so that we can avoid it in time when we process it next time.
