Fused Ceramic Sand and Sintered Ceramsite 2

Analysis from the perspective of gas generation of reclaimed sand

The holes on the surface of ceramsite are filled with resin residues, which cannot be completely removed by mechanical regeneration, and these residual resins will increase the gas generation of molding sand (burning impairment).


Comparison of refractoriness of sintered ceramsite and fused ceramic sand


Fire resistance is also called resistance to fusion. A performance index that represents the resistance of an object to high temperature without melting. Its level is determined by the chemical composition, dispersion, proportion of liquid phase and liquid viscosity of the material.

The meaning of refractoriness is different from that of melting point. The melting point is the temperature at which the liquid and solid phases of crystals are in equilibrium. Refractoriness is the temperature at which the multiphase reaches a certain degree of softening. For the vast majority of ordinary refractories, they are heterogeneous materials without a certain melting point. It is a gradual process from the beginning of liquid phase to complete melting. In a wide range of high temperature, solid and liquid phases coexist. Sintering temperature refers to the temperature at which the refractory or ceramic green body reaches the minimum porosity, maximum shrinkage, the densest product, the best performance or becomes a solid aggregate state through sintering. In the practical application of foundry, foundry workers are more concerned about the sinterability of sand.


The refractoriness of chromite sand is 1830 . In fact, when producing thick and large castings or thick and large heat-saving sand cores, it is still difficult to remove the sand after the chromite sand is glazed. The reason is that the sintering temperature of chromite sand is about 1550 , which shows that the burning point temperature of refractory materials is more important than the refractoriness index of refractory materials.


The sintering point temperature of Fused ceramic sand is about 1780 , and the sintering point of sintered ceramsite with aluminum oxide less than 65% begins to soften and sinter at about 1550 .


If steel castings and stainless steel parts are produced, fused ceramic sand and sintered ceramsite with a large al3o2 content of 72% are recommended, otherwise sand sticking and other defects will be caused due to low burning point temperature.

According to the analysis of the difficulty of industrial production of sintered ceramsite, the selection of sintered ceramsite with Al2O3 content greater than 65% is a major test for sintering equipment and sintering cost. The quality of fused ceramic sand is better. The surface of fused ceramic sand pellets is smoother, rounder, denser, stronger chilling, higher sintering point and higher fire resistance. The new national standard defines the artificial sand produced by electrofusion method as electrofusion ceramic sand.