What Is High Alumina Balls

High alumina balls are grinding media with an alumina content of over 90%, belonging to the category of alumina balls, which are divided into series such as 90, 92, 95, 99, etc. according to the alumina content. Its characteristics include high strength, high hardness, wear resistance, high temperature resistance, and corrosion resistance. It is mainly used in the fine processing of hard materials in industries such as ceramics, glass, and chemical engineering.
The main domestic production areas are located in Shandong and Foshan, Guangdong, with representative brands including Sinoma High tech, Kunpeng, Foshan Wangao, etc. During the production process, the fineness of the powder and the firing process directly affect the specific gravity and wear resistance, and excessive sintering may reduce the actual wear resistance. In the ceramic industry application, adding high alumina balls can shorten the grinding time by 15% -30%, and save about two years of recoverable cost increment through electricity bills. The use of high alumina balls in industries such as quartz can improve the quality of silicon micro powder, but dry grinding environments can easily cause cracking and require pre polishing to screen qualified products.
The specific gravity of high alumina balls is usually above 3.60 (92% content), with a Mohs hardness of level 9, and is formed using rolling or isostatic pressing processes [2]. Its low wear characteristics have gradually replaced traditional grinding media in fields such as refractory materials, coatings, and electronic packaging.
Product Features
High alumina balls are widely used in the precision and deep processing of thick and hard materials in various types of ceramics, glazes, glass, chemical and other factories due to their excellent characteristics such as high strength, high hardness, high wear resistance, high specific gravity, small size, high temperature resistance, corrosion resistance, and no pollution.
Taking a high alumina ball with a content of 92% as an example, its specific gravity (density) should be above 3.60, the alumina content should be above 91.5%, and the iron content should be low. Under the same raw materials, formula, and firing temperature, the finer the powder after grinding, the higher the specific gravity and wear resistance. The specific gravity of high alumina balls is mainly affected by the powder and firing process. Factors such as undercooking, coarse powder, and the addition of impurities can lead to insufficient specific gravity of the ball stones. Low specific gravity spherulites are not wear-resistant and prone to cracking, but high specific gravity does not necessarily mean that spherulites are wear-resistant, as excessively sintered spherulites can also achieve higher specific gravity.
The most important quality indicator of a ball stone is its wear resistance. Some testing institutions can also conduct wear tests, and these test reports can show the quality of the ball stone. However, the data is for reference only because the environmental conditions for laboratory testing and production are very different. Firstly, the testing is done by water grinding, while many manufacturers use dry grinding; Secondly, many times during testing, no other raw materials are added, only friction between the stones, and various raw materials need to be added in the actual production process. In the actual use process, to detect the wear of the ball stones, it is necessary to make more records. After the initial mixing ratio, by recording the number of added ball stones and combining with the production volume, the wear of the ball stones in production can be calculated, so as to compare the cost of high aluminum balls with other grinding balls, and also compare the quality of ball stones among various manufacturers. Factors that affect the wear of ball stones include not only the hardness and fineness of the feed, but also the grinding method (such as the difference between dry and wet grinding), the speed of the ball mill, whether the proportion of ball stones is reasonable, and the viscosity of the feed.
The main production areas of ordinary high aluminum balls in China are Shandong and Foshan, Guangdong. Brands in Shandong include Zhongcai, Kunpeng, Dongci, etc. Foshan has Wangao and Tegaote, among which Zhongcai has the largest scale and output. The quality of its microbeads has been recognized by domestic and foreign peers and customers, while Wangao's product quality is the most stable.
Scope of application
Mainly in ceramic factories, using pebbles (natural stones) and 10% high alumina balls (diameter 35MM) to grind thin mud can shorten the grinding time by 15% compared to using only pebbles; By using medium aluminum balls and 30% high aluminum balls (diameter 35MM) to grind the slurry, the grinding time can be reduced by about 30% compared to using only medium aluminum balls. Calculated solely based on the saved electricity costs, the cost of using high aluminum balls can be "saved" in about 2 years. According to reports from individual manufacturers, ball mills use high alumina balls and high alumina lining bricks instead of medium alumina grinding ceramic raw materials. The loss of ball stones is less than one-third of that of medium alumina balls, and the grinding time is reduced by 20%. The product quality is more stable, and high alumina products have a longer service life without the need for frequent replacement of ball liners, resulting in higher overall cost-effectiveness. Grinding raw materials with high alumina balls can not only save electricity costs and increase production, but also improve mechanical efficiency and provide great protection for mechanical equipment.
In addition to the ceramic industry, industries such as quartz and chemical are also gradually trying and using high alumina balls for production. The quartz factory is mainly used for producing silicon micro powder. Practice has shown that using high alumina balls instead of quartz balls for grinding in the production of 325 mesh silicon micro powder can significantly improve yield and product quality, such as whiteness and uniformity. Moreover, due to the slower loss rate compared to quartz balls, the labor and time costs of adding spherulites are saved. The main problem encountered when using high alumina balls is that due to their high hardness and brittleness, dry grinding can easily cause the stones to crack and the surface of the stones to be bumpy, resulting in very high wear. Therefore, only the method of polishing the stones before leaving the factory can be used to pick out the stones with high cracking or wear, in order to minimize customer losses.