The grinding balls for mining is used as a combustion aid. When used, a suitable sintering aid reduces the sintering temperature, improves the microstructure of the ceramic, improves the mechanical properties, and further improves the wear resistance of the ceramic ball. The quality of the sintering aid includes quantity, phase composition, chemical composition and fineness. The sintering aid is generally formulated using a SiO2-CaO-MgO ternary system. The use of a combustion aid that emits gas at a high temperature and undergoes a phase change should be avoided as much as possible to avoid new defects, which affect the densification and yield of the product and reduce the competitiveness of the product.
Grinding ball for mining molding
Grinding balls are used in mining. In the process of operation, the isostatic pressing technology is mainly used to overcome the defects of other forming methods such as hollow, delamination, low density and uneven density. The particle size, shape and additives of the raw materials all affect isostatic pressing. The molding pressure and the holding time affect the density of the green body, the sintering shrinkage rate, and the sintering temperature. Therefore, it is necessary to use a suitable raw material and a scientific molding process to ensure that the green body has good sintering characteristics.
Excessive sintering temperature and excessive holding time of the grinding ball for mining promote the growth of the aluminum oxide crystal, and the liquid phase increases, so that not only the strength is lowered, but also the wear resistance is weakened. Of course, the temperature is too low, the sintered density is lowered, and the wear resistance of the ceramic ball is lowered. If the sintering temperature is not suitable, even if the content of aluminum oxide is high, the wear resistance is not necessarily good, and the key depends on the phase composition and microstructure of the ceramic ball.